<?xml version="1.0" encoding="us-ascii" standalone="yes"?>
<!--XBRL Document Created with XBRLMaster-->
<!--Version: 2.3.08-->
<!--Based on XBRL 2.1-->
<!--Date of creation: 05/13/2024-->
<!--Software architectural design and coding: A'c Dharmapremananda Avt.-->
<!--Copyright (c) 2024 I-NET Business Solutions, Inc. All Rights Reserved.-->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" roleURI="http://www.xbrl.org/2009/role/negatedLabel" />
  <link:roleRef xlink:type="simple" roleURI="http://www.xbrl.org/2009/role/negatedPeriodEndLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodEndLabel" />
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel" roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel" />
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel" roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel" />
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedNetLabel" roleURI="http://www.xbrl.org/2009/role/negatedNetLabel" />
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel" roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel" />
  <link:roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" roleURI="http://www.xbrl.org/2009/role/netLabel" />
  <link:labelLink xlink:type="extended" xlink:role="http://www.xbrl.org/2003/role/link">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CoverAbstract" xlink:to="dei_CoverAbstract_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CoverAbstract_lbl" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityRegistrantName_lbl" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCentralIndexKey_lbl" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType" xlink:label="dei_DocumentType" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentType_lbl" xml:lang="en-US">Document Type</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US">Amendment Flag</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US">Current Fiscal Year End Date</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntitySmallBusiness_lbl" xml:lang="en-US">Entity Small Business</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityShellCompany_lbl" xml:lang="en-US">Entity Shell Company</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xml:lang="en-US">Entity Emerging Growth Company</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCurrentReportingStatus_lbl" xml:lang="en-US">Entity Current Reporting Status</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentPeriodEndDate_lbl" xml:lang="en-US">Document Period End Date</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFilerCategory_lbl" xml:lang="en-US">Entity Filer Category</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xml:lang="en-US">Document Fiscal Period Focus</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentFiscalYearFocus_lbl" xml:lang="en-US">Document Fiscal Year Focus</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US">Entity Common Stock Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityFileNumber_lbl" xml:lang="en-US">Entity File Number</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xml:lang="en-US">Entity Incorporation State Country Code</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xml:lang="en-US">Entity Tax Identification Number</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressAddressLine1_lbl" xml:lang="en-US">Entity Address Address Line 1</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressCityOrTown_lbl" xml:lang="en-US">Entity Address City Or Town</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressStateOrProvince_lbl" xml:lang="en-US">Entity Address State Or Province</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityAddressPostalZipCode_lbl" xml:lang="en-US">Entity Address Postal Zip Code</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CityAreaCode_lbl" xml:lang="en-US">City Area Code</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LocalPhoneNumber_lbl" xml:lang="en-US">Local Phone Number</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12bTitle" xlink:to="dei_Security12bTitle_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_Security12bTitle_lbl" xml:lang="en-US">Security 12b Title</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US">Trading Symbol</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityExchangeName" xlink:to="dei_SecurityExchangeName_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_SecurityExchangeName_lbl" xml:lang="en-US">Security Exchange Name</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentQuarterlyReport" xlink:to="dei_DocumentQuarterlyReport_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentQuarterlyReport_lbl" xml:lang="en-US">Document Quarterly Report</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentTransitionReport" xlink:to="dei_DocumentTransitionReport_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_DocumentTransitionReport_lbl" xml:lang="en-US">Document Transition Report</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityInteractiveDataCurrent" xlink:to="dei_EntityInteractiveDataCurrent_lbl" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xml:lang="en-US">Entity Interactive Data Current</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl_2e4391" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl_2e4391" xml:lang="en-US">Consolidated Balance Sheets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl_e8edef" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl_e8edef" xml:lang="en-US">Statement [Table]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl_f8c644" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl_f8c644" xml:lang="en-US">Statement [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis_lbl_330a58" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementClassOfStockAxis_lbl_330a58" xml:lang="en-US">Statement Class Of Stock Axis</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesAConvertiblePreferredStocksMember" xlink:label="ptn_SeriesAConvertiblePreferredStocksMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesAConvertiblePreferredStocksMember" xlink:to="ptn_SeriesAConvertiblePreferredStocksMember_lbl_a2d932" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesAConvertiblePreferredStocksMember_lbl_a2d932" xml:lang="en-US">Series A Convertible Preferred Stocks [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_0765c2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_0765c2" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="us-gaap_MarketableSecuritiesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesCurrent" xlink:to="us-gaap_MarketableSecuritiesCurrent_lbl_b2c2d6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesCurrent_lbl_b2c2d6" xml:lang="en-US">Marketable securities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl_6779e8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl_6779e8" xml:lang="en-US">Accounts receivable</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl_6a4e2b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNet_lbl_6a4e2b" xml:lang="en-US">Inventories</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl_c44574" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl_c44574" xml:lang="en-US">Prepaid expenses and other current assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl_5b36c0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl_5b36c0" xml:lang="en-US">Total current assets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl_7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_lbl_7" xml:lang="en-US">[Assets, Current]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl_22f922" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl_22f922" xml:lang="en-US">Property and equipment, net</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl_58c0e0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl_58c0e0" xml:lang="en-US">Right-of-use assets - operating leases</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl_7806be" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl_7806be" xml:lang="en-US">Other assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl_510a7b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl_510a7b" xml:lang="en-US">Total assets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl_11" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl_11" xml:lang="en-US">[Assets]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl_d52d5f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableCurrent_lbl_d52d5f" xml:lang="en-US">Accounts payable</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl_0a9b67" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl_0a9b67" xml:lang="en-US">Accrued expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_lbl_8fa5e1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl_8fa5e1" xml:lang="en-US">Short-term operating lease liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityCurrent" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent_lbl_f6a1df" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl_f6a1df" xml:lang="en-US">Short-term finance lease liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl_5381e3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl_5381e3" xml:lang="en-US">Other current liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl_877418" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl_877418" xml:lang="en-US">Total current liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl_17" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_lbl_17" xml:lang="en-US">[Liabilities, Current]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl_c3d022" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl_c3d022" xml:lang="en-US">Long-term operating lease liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl_41f9c5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl_41f9c5" xml:lang="en-US">Long-term finance lease liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLongTermDebt" xlink:label="us-gaap_OtherLongTermDebt" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLongTermDebt" xlink:to="us-gaap_OtherLongTermDebt_lbl_0f25c4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLongTermDebt_lbl_0f25c4" xml:lang="en-US">Other long-term liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl_fe6bf7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl_fe6bf7" xml:lang="en-US">Warrant liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl_cc6c26" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl_cc6c26" xml:lang="en-US">Total liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl_22" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl_22" xml:lang="en-US">[Liabilities]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl_50cfea" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl_50cfea" xml:lang="en-US">Commitments and contingencies (Note 13)</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ContingentlyRedeemableWarrants" xlink:label="ptn_ContingentlyRedeemableWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ContingentlyRedeemableWarrants" xlink:to="ptn_ContingentlyRedeemableWarrants_lbl_60f576" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ContingentlyRedeemableWarrants_lbl_60f576" xml:lang="en-US">Contingently redeemable warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl_f98a96" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl_f98a96" xml:lang="en-US">Stockholders' deficiency:</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PreferredStockAbstract" xlink:label="ptn_PreferredStockAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PreferredStockAbstract" xlink:to="ptn_PreferredStockAbstract_lbl_686578" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PreferredStockAbstract_lbl_686578" xml:lang="en-US">Preferred stock of $0.01 par value - authorized 10,000,000 shares: shares issued and outstanding designated as follows:</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl_15e017" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValue_lbl_15e017" xml:lang="en-US">Series A Convertible: authorized 4,030 shares as of March 31, 2024: issued and outstanding 4,030 shares as of March 31, 2024 and June 30, 2023</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl_935536" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl_935536" xml:lang="en-US">Common stock of $0.01 par value - authorized 300,000,000 shares issued and outstanding 16,136,640 shares as of March 31, 2024 and 11,656,714 shares as of June 30, 2023</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital_lbl_3bd794" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapital_lbl_3bd794" xml:lang="en-US">Additional paid-in capital</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl_b6ea64" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl_b6ea64" xml:lang="en-US">Accumulated deficit</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl_486dc4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl_486dc4" xml:lang="en-US">Total stockholders' equity (deficiency)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl_31" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl_31" xml:lang="en-US">[Stockholders' Equity Attributable to Parent]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl_302eae" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl_302eae" xml:lang="en-US">Total liabilities and stockholders' equity (deficiency)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl_32" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl_32" xml:lang="en-US">[Liabilities and Equity]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_lbl_ce2b81" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl_ce2b81" xml:lang="en-US">Preferred stock, par value</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl_024b8b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl_024b8b" xml:lang="en-US">Preferred stock, shares authorized</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl_53613b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl_53613b" xml:lang="en-US">Common stock, par value</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl_8e2ee3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl_8e2ee3" xml:lang="en-US">Common stock, shares authorized</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl_dd0462" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl_dd0462" xml:lang="en-US">Common stock, shares issued</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl_2ae7d7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl_2ae7d7" xml:lang="en-US">Common stock, shares outstanding</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl_a3a957" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesIssued_lbl_a3a957" xml:lang="en-US">Preferred stock, shares issued</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl_e17ecb" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl_e17ecb" xml:lang="en-US">Preferred stock, shares outstanding</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl_016d1e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl_016d1e" xml:lang="en-US">Consolidated Statements of Operations (unaudited)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesAbstract" xlink:label="us-gaap_RevenuesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuesAbstract" xlink:to="us-gaap_RevenuesAbstract_lbl_705791" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenuesAbstract_lbl_705791" xml:lang="en-US">REVENUES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl_6c8eeb" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Revenues_lbl_6c8eeb" xml:lang="en-US">Product revenue, net</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl_800ff5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpensesAbstract_lbl_800ff5" xml:lang="en-US">OPERATING EXPENSES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfRevenue" xlink:label="us-gaap_CostOfRevenue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfRevenue" xlink:to="us-gaap_CostOfRevenue_lbl_5cff38" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostOfRevenue_lbl_5cff38" xml:lang="en-US">Cost of products sold</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense_lbl_28f547" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl_28f547" xml:lang="en-US">Research and development</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense_lbl_e63cd4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl_e63cd4" xml:lang="en-US">Selling, general and administrative</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="us-gaap_GainLossOnSaleOfBusiness" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfBusiness" xlink:to="us-gaap_GainLossOnSaleOfBusiness_lbl_d48fb7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl_d48fb7" xml:lang="en-US">Gain on sale of Vyleesi</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_GainLossOnPurchaseCommitment" xlink:label="ptn_GainLossOnPurchaseCommitment" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_GainLossOnPurchaseCommitment" xlink:to="ptn_GainLossOnPurchaseCommitment_lbl_6b2601" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_GainLossOnPurchaseCommitment_lbl_6b2601" xml:lang="en-US">Gain on purchase commitment</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl_43cafe" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingExpenses_lbl_43cafe" xml:lang="en-US">Total operating expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl_10" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpenses_lbl_10" xml:lang="en-US">[Operating Expenses]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl_6a33a0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl_6a33a0" xml:lang="en-US">Loss from operations</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl_11" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl_11" xml:lang="en-US">[Operating Income (Loss)]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_OtherNonoperatingIncomeExpenseAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpenseAbstract_lbl_772c49" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpenseAbstract_lbl_772c49" xml:lang="en-US">OTHER INCOME (EXPENSE)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentIncomeNet" xlink:label="us-gaap_InvestmentIncomeNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentIncomeNet" xlink:to="us-gaap_InvestmentIncomeNet_lbl_2aa156" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentIncomeNet_lbl_2aa156" xml:lang="en-US">Investment income</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_lbl_736cb7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossUnrealized_lbl_736cb7" xml:lang="en-US">Foreign currency gain (loss)</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl_6ecad4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InterestExpense_lbl_6ecad4" xml:lang="en-US">Interest expense</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl_15" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_lbl_15" xml:lang="en-US">[Interest Expense]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherExpenses" xlink:to="us-gaap_OtherExpenses_lbl_73709e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_OtherExpenses_lbl_73709e" xml:lang="en-US">Offering expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherExpenses" xlink:label="us-gaap_OtherExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherExpenses" xlink:to="us-gaap_OtherExpenses_lbl_16" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherExpenses_lbl_16" xml:lang="en-US">[Other Expenses]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeGainLossOnDerivativeNet" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeGainLossOnDerivativeNet" xlink:to="us-gaap_DerivativeGainLossOnDerivativeNet_lbl_85d41e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet_lbl_85d41e" xml:lang="en-US">Change in fair value of warrant liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl_398e9e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl_398e9e" xml:lang="en-US">Total other income (expense), net</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl_18" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl_18" xml:lang="en-US">[Other Nonoperating Income (Expense)]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromSubsidiariesBeforeTax" xlink:label="us-gaap_IncomeLossFromSubsidiariesBeforeTax" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromSubsidiariesBeforeTax" xlink:to="us-gaap_IncomeLossFromSubsidiariesBeforeTax_lbl_b5271c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromSubsidiariesBeforeTax_lbl_b5271c" xml:lang="en-US">Loss before income taxes</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl_990576" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl_990576" xml:lang="en-US">Income tax benefit</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl_20" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl_20" xml:lang="en-US">[Income Tax Expense (Benefit)]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl_f160ee" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl_f160ee" xml:lang="en-US">NET LOSS</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl_21" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_lbl_21" xml:lang="en-US">[Net Income (Loss) Attributable to Parent]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EarningPerShareBasicAndDiluted" xlink:label="ptn_EarningPerShareBasicAndDiluted" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EarningPerShareBasicAndDiluted" xlink:to="ptn_EarningPerShareBasicAndDiluted_lbl_90dfed" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EarningPerShareBasicAndDiluted_lbl_90dfed" xml:lang="en-US">Basic and diluted net loss per common share</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WeightedAverageNumberOfCommonSharesOutstandingUsedInComputingBasicAndDiluted" xlink:label="ptn_WeightedAverageNumberOfCommonSharesOutstandingUsedInComputingBasicAndDiluted" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WeightedAverageNumberOfCommonSharesOutstandingUsedInComputingBasicAndDiluted" xlink:to="ptn_WeightedAverageNumberOfCommonSharesOutstandingUsedInComputingBasicAndDiluted_lbl_70b568" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WeightedAverageNumberOfCommonSharesOutstandingUsedInComputingBasicAndDiluted_lbl_70b568" xml:lang="en-US">Weighted average number of common shares outstanding used in computing basic and diluted net loss per common share</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementOfStockholdersEquityAbstract_lbl_1c5d40" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl_1c5d40" xml:lang="en-US">Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders (Deficiency) Equity (unaudited)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl_2b9ab8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl_2b9ab8" xml:lang="en-US">Statement Equity Components [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesAConvertiblePreferredStockMember" xlink:label="ptn_SeriesAConvertiblePreferredStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesAConvertiblePreferredStockMember" xlink:to="ptn_SeriesAConvertiblePreferredStockMember_lbl_a7975d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesAConvertiblePreferredStockMember_lbl_a7975d" xml:lang="en-US">Series A Convertible Preferred Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl_78aa17" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl_78aa17" xml:lang="en-US">Common Stock</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ContigentlyRdeemableWarrantMember" xlink:label="ptn_ContigentlyRdeemableWarrantMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ContigentlyRdeemableWarrantMember" xlink:to="ptn_ContigentlyRdeemableWarrantMember_lbl_652c1c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ContigentlyRdeemableWarrantMember_lbl_652c1c" xml:lang="en-US">Contigently Rdeemable Warrant Member</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl_f20ed7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl_f20ed7" xml:lang="en-US">Additional Paid-In Capital</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl_7ee959" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsMember_lbl_7ee959" xml:lang="en-US">Retained Earnings (Accumulated Deficit)</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RedeemableConvertiblePreferredStockSeriesBMember" xlink:label="ptn_RedeemableConvertiblePreferredStockSeriesBMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RedeemableConvertiblePreferredStockSeriesBMember" xlink:to="ptn_RedeemableConvertiblePreferredStockSeriesBMember_lbl_758746" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RedeemableConvertiblePreferredStockSeriesBMember_lbl_758746" xml:lang="en-US">Series B Redeemable Convertible Preferred Stock Series B Member</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RedeemableConvertiblePreferredStockSeriesCMember" xlink:label="ptn_RedeemableConvertiblePreferredStockSeriesCMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RedeemableConvertiblePreferredStockSeriesCMember" xlink:to="ptn_RedeemableConvertiblePreferredStockSeriesCMember_lbl_829ffa" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RedeemableConvertiblePreferredStockSeriesCMember_lbl_829ffa" xml:lang="en-US">Series C Redeemable Convertible Preferred Stock Member</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EscrowProceedsMember" xlink:label="ptn_EscrowProceedsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EscrowProceedsMember" xlink:to="ptn_EscrowProceedsMember_lbl_351387" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EscrowProceedsMember_lbl_351387" xml:lang="en-US">Escrow Proceeds</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssued" xlink:to="us-gaap_SharesIssued_lbl_b58e30" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharesIssued_lbl_b58e30" xml:lang="en-US">Balance, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssued" xlink:to="us-gaap_SharesIssued_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssued_lbl_2" xml:lang="en-US">[Shares, Issued]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl_ea4527" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_lbl_ea4527" xml:lang="en-US">Balance, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CumulativeEffectOfAccountingChange" xlink:label="ptn_CumulativeEffectOfAccountingChange" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CumulativeEffectOfAccountingChange" xlink:to="ptn_CumulativeEffectOfAccountingChange_lbl_ab997e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CumulativeEffectOfAccountingChange_lbl_ab997e" xml:lang="en-US">Cumulative effect of accounting change</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_StockBasedCompensationShares" xlink:label="ptn_StockBasedCompensationShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_StockBasedCompensationShares" xlink:to="ptn_StockBasedCompensationShares_lbl_d9641b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_StockBasedCompensationShares_lbl_d9641b" xml:lang="en-US">Stock-based compensation, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_StockBasedCompensationAmount" xlink:label="ptn_StockBasedCompensationAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_StockBasedCompensationAmount" xlink:to="ptn_StockBasedCompensationAmount_lbl_9cb329" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_StockBasedCompensationAmount_lbl_9cb329" xml:lang="en-US">Stock-based compensation, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WithholdingTaxesRelatedToRestrictedStockUnitsShares" xlink:label="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsShares" xlink:to="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsShares_lbl_1d0532" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsShares_lbl_1d0532" xml:lang="en-US">Withholding taxes related to restricted stock units, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WithholdingTaxesRelatedToRestrictedStockUnitsAmount" xlink:label="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsAmount" xlink:to="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsAmount_lbl_43975d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WithholdingTaxesRelatedToRestrictedStockUnitsAmount_lbl_43975d" xml:lang="en-US">Withholding taxes related to restricted stock units, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockShares" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockShares" xlink:to="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockShares_lbl_747eba" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockShares_lbl_747eba" xml:lang="en-US">Redemption of convertible series B &amp; series C preferred stock, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockAmount" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockAmount" xlink:to="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockAmount_lbl_91fa7c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStockAmount_lbl_91fa7c" xml:lang="en-US">Redemption of convertible series B &amp; series C preferred stock, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleOfCommonStockAndWarrantsNetOfCostsShares" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCostsShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleOfCommonStockAndWarrantsNetOfCostsShares" xlink:to="ptn_SaleOfCommonStockAndWarrantsNetOfCostsShares_lbl_fe5536" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCostsShares_lbl_fe5536" xml:lang="en-US">Sale of common stock and warrants, net of costs, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleOfCommonStockAndWarrantsNetOfCostsAmount" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCostsAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleOfCommonStockAndWarrantsNetOfCostsAmount" xlink:to="ptn_SaleOfCommonStockAndWarrantsNetOfCostsAmount_lbl_afe0e2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCostsAmount_lbl_afe0e2" xml:lang="en-US">Sale of common stock and warrants, net of costs, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConversionOfLiabilityClassifiedWarrants" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilityClassifiedWarrants" xlink:to="ptn_ConversionOfLiabilityClassifiedWarrants_lbl_3c549f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrants_lbl_3c549f" xml:lang="en-US">Conversion of liability classified warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WarrantExcercisesShares" xlink:label="ptn_WarrantExcercisesShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WarrantExcercisesShares" xlink:to="ptn_WarrantExcercisesShares_lbl_e4ce49" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WarrantExcercisesShares_lbl_e4ce49" xml:lang="en-US">Warrant excercises, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WarrantExcercisesAmount" xlink:label="ptn_WarrantExcercisesAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WarrantExcercisesAmount" xlink:to="ptn_WarrantExcercisesAmount_lbl_4e7178" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WarrantExcercisesAmount_lbl_4e7178" xml:lang="en-US">Warrant excercises, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ReverseStockSplitFractionalSharesShares" xlink:label="ptn_ReverseStockSplitFractionalSharesShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ReverseStockSplitFractionalSharesShares" xlink:to="ptn_ReverseStockSplitFractionalSharesShares_lbl_d1062e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ReverseStockSplitFractionalSharesShares_lbl_d1062e" xml:lang="en-US">Reverse stock split fractional shares, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ReverseStockSplitFractionalSharesAmount" xlink:label="ptn_ReverseStockSplitFractionalSharesAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ReverseStockSplitFractionalSharesAmount" xlink:to="ptn_ReverseStockSplitFractionalSharesAmount_lbl_342e7c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ReverseStockSplitFractionalSharesAmount_lbl_342e7c" xml:lang="en-US">Reverse stock split fractional shares, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ReclassificationOfContingentlyRedeemableWarrants" xlink:label="ptn_ReclassificationOfContingentlyRedeemableWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ReclassificationOfContingentlyRedeemableWarrants" xlink:to="ptn_ReclassificationOfContingentlyRedeemableWarrants_lbl_07356f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ReclassificationOfContingentlyRedeemableWarrants_lbl_07356f" xml:lang="en-US">Reclassification of contingently redeemable warrants</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl_916a90" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl_916a90" xml:lang="en-US">Net loss</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStock" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStock" xlink:to="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStock_lbl_879785" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RedemptionOfConvertibleSeriesBSeriesCPreferredStock_lbl_879785" xml:lang="en-US">Redemption of convertible series B &amp; series C preferred stock</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WarrantExercisesShares" xlink:label="ptn_WarrantExercisesShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WarrantExercisesShares" xlink:to="ptn_WarrantExercisesShares_lbl_446bc0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WarrantExercisesShares_lbl_446bc0" xml:lang="en-US">Warrant exercises, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WarrantExercisesAmount" xlink:label="ptn_WarrantExercisesAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WarrantExercisesAmount" xlink:to="ptn_WarrantExercisesAmount_lbl_7b8cae" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WarrantExercisesAmount_lbl_7b8cae" xml:lang="en-US">Warrant exercises, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleOfCommonStockAndWarrantsNetOfCosts" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCosts" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleOfCommonStockAndWarrantsNetOfCosts" xlink:to="ptn_SaleOfCommonStockAndWarrantsNetOfCosts_lbl_8c23ee" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleOfCommonStockAndWarrantsNetOfCosts_lbl_8c23ee" xml:lang="en-US">Sale of common stock and warrants, net of costs</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleOfCommonStockNetOfCostsShares" xlink:label="ptn_SaleOfCommonStockNetOfCostsShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleOfCommonStockNetOfCostsShares" xlink:to="ptn_SaleOfCommonStockNetOfCostsShares_lbl_775e6b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleOfCommonStockNetOfCostsShares_lbl_775e6b" xml:lang="en-US">Sale of common stock, net of costs, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleOfCommonStockNetOfCostsAmount" xlink:label="ptn_SaleOfCommonStockNetOfCostsAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleOfCommonStockNetOfCostsAmount" xlink:to="ptn_SaleOfCommonStockNetOfCostsAmount_lbl_01e74e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleOfCommonStockNetOfCostsAmount_lbl_01e74e" xml:lang="en-US">Sale of common stock, net of costs, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseShares" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseShares" xlink:to="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseShares_lbl_7f0180" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseShares_lbl_7f0180" xml:lang="en-US">Conversion of liability classified warrants upon warrant exercise, shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseAmount" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseAmount" xlink:to="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseAmount_lbl_681ab9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExerciseAmount_lbl_681ab9" xml:lang="en-US">Conversion of liability classified warrants upon warrant exercise, amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssued" xlink:to="us-gaap_SharesIssued_lbl_5bbbb8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_SharesIssued_lbl_5bbbb8" xml:lang="en-US">Balance, shares</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl_83ac72" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_lbl_83ac72" xml:lang="en-US">Balance, amount</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl_bd01e1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl_bd01e1" xml:lang="en-US">Consolidated Statements of Cash Flows (unaudited)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl_28cfa6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl_28cfa6" xml:lang="en-US">CASH FLOWS FROM OPERATING ACTIVITIES:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl_e7ce3f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl_e7ce3f" xml:lang="en-US">Net loss</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AdjustmentsToReconcileNetLossToNetCashNewAbstract" xlink:label="ptn_AdjustmentsToReconcileNetLossToNetCashNewAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AdjustmentsToReconcileNetLossToNetCashNewAbstract" xlink:to="ptn_AdjustmentsToReconcileNetLossToNetCashNewAbstract_lbl_95b7ea" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AdjustmentsToReconcileNetLossToNetCashNewAbstract_lbl_95b7ea" xml:lang="en-US">Adjustments to reconcile net loss to net cash</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization_lbl_a570de" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationAndAmortization_lbl_a570de" xml:lang="en-US">Depreciation and amortization</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:label="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense" xlink:to="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_lbl_de4c67" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_lbl_de4c67" xml:lang="en-US">Decrease in right-of-use asset</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UnrealizedForeignCurrencyTransactionGain" xlink:label="ptn_UnrealizedForeignCurrencyTransactionGain" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UnrealizedForeignCurrencyTransactionGain" xlink:to="ptn_UnrealizedForeignCurrencyTransactionGain_lbl_11750b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UnrealizedForeignCurrencyTransactionGain_lbl_11750b" xml:lang="en-US">Unrealized foreign currency transaction gain</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl_8e95dd" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_lbl_8e95dd" xml:lang="en-US">Stock-based compensation</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ChangeInFairValueOfLiabilityClassifiedWarrants" xlink:label="ptn_ChangeInFairValueOfLiabilityClassifiedWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ChangeInFairValueOfLiabilityClassifiedWarrants" xlink:to="ptn_ChangeInFairValueOfLiabilityClassifiedWarrants_lbl_7705d4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ChangeInFairValueOfLiabilityClassifiedWarrants_lbl_7705d4" xml:lang="en-US">Change in fair value of liability classified warrants</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfOtherAssets" xlink:to="us-gaap_GainLossOnSaleOfOtherAssets_lbl_2096d1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_GainLossOnSaleOfOtherAssets_lbl_2096d1" xml:lang="en-US">Gain on sale of Vyleesi</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnSaleOfOtherAssets" xlink:label="us-gaap_GainLossOnSaleOfOtherAssets" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfOtherAssets" xlink:to="us-gaap_GainLossOnSaleOfOtherAssets_lbl_10" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSaleOfOtherAssets_lbl_10" xml:lang="en-US">[Gain (Loss) on Disposition of Other Assets]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_GainLossOnPurchaseCommitment" xlink:to="ptn_GainLossOnPurchaseCommitment_lbl_761c0d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_GainLossOnPurchaseCommitment_lbl_761c0d" xml:lang="en-US">Gain on purchase commitment</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl_7a12bd" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl_7a12bd" xml:lang="en-US">Changes in operating assets and liabilities:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl_bb3beb" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl_bb3beb" xml:lang="en-US">Accounts receivable</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl_13" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl_13" xml:lang="en-US">[Increase (Decrease) in Accounts Receivable]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl_061d0f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl_061d0f" xml:lang="en-US">Prepaid expenses and other assets</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInventories" xlink:to="us-gaap_IncreaseDecreaseInInventories_lbl_cfdfe7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl_cfdfe7" xml:lang="en-US">Inventories</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="us-gaap_IncreaseDecreaseInInventories" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInInventories" xlink:to="us-gaap_IncreaseDecreaseInInventories_lbl_15" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInInventories_lbl_15" xml:lang="en-US">[Increase (Decrease) in Inventories]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_lbl_12ac99" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl_12ac99" xml:lang="en-US">Accounts payable</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_lbl_16" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl_16" xml:lang="en-US">[Increase (Decrease) in Accounts Payable]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl_886ffd" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl_886ffd" xml:lang="en-US">Accrued expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl_17" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl_17" xml:lang="en-US">[Increase (Decrease) in Accrued Liabilities]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl_d84833" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl_d84833" xml:lang="en-US">Operating lease liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:to="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_lbl_812b5c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_lbl_812b5c" xml:lang="en-US">Other liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl_8911e5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl_8911e5" xml:lang="en-US">Net cash used in operating activities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl_20" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl_20" xml:lang="en-US">[Net Cash Provided by (Used in) Operating Activities]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl_60750f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl_60750f" xml:lang="en-US">CASH FLOWS FROM INVESTING ACTIVITIES:</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl_6673d0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl_6673d0" xml:lang="en-US">Maturity of marketable securities</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ProceedsFromSaleOfBusiness" xlink:label="ptn_ProceedsFromSaleOfBusiness" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ProceedsFromSaleOfBusiness" xlink:to="ptn_ProceedsFromSaleOfBusiness_lbl_76d981" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ProceedsFromSaleOfBusiness_lbl_76d981" xml:lang="en-US">Proceeds from sale of Vyleesi</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl_9f3fab" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl_9f3fab" xml:lang="en-US">Purchases of property and equipment</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl_24" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl_24" xml:lang="en-US">[Payments to Acquire Property, Plant, and Equipment]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl_db1c0c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl_db1c0c" xml:lang="en-US">Net cash provided by (used in) investing activities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl_25" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl_25" xml:lang="en-US">[Net Cash Provided by (Used in) Investing Activities]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl_228845" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl_228845" xml:lang="en-US">CASH FLOWS FROM FINANCING ACTIVITIES:</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl_e27332" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl_e27332" xml:lang="en-US">stock units</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl_27" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl_27" xml:lang="en-US">[Payment, Tax Withholding, Share-Based Payment Arrangement]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl_49ac83" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl_49ac83" xml:lang="en-US">Proceeds from the sale of common stock and warrants,</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeasePrincipalPayments" xlink:to="us-gaap_FinanceLeasePrincipalPayments_lbl_2a416a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl_2a416a" xml:lang="en-US">Payment of finance lease obligations</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="us-gaap_FinanceLeasePrincipalPayments" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeasePrincipalPayments" xlink:to="us-gaap_FinanceLeasePrincipalPayments_lbl_29" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl_29" xml:lang="en-US">[Finance Lease, Principal Payments]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromWarrantExercises" xlink:label="us-gaap_ProceedsFromWarrantExercises" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromWarrantExercises" xlink:to="us-gaap_ProceedsFromWarrantExercises_lbl_92a9f2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromWarrantExercises_lbl_92a9f2" xml:lang="en-US">Proceeds from exercise of warrants</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl_6f0a39" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl_6f0a39" xml:lang="en-US">Net cash provided by financing activities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl_31" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl_31" xml:lang="en-US">[Net Cash Provided by (Used in) Financing Activities]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl_4dbbdf" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl_4dbbdf" xml:lang="en-US">NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl_32" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl_32" xml:lang="en-US">[Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_685a4c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_685a4c" xml:lang="en-US">CASH AND CASH EQUIVALENTS, beginning of period</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_e6744d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl_e6744d" xml:lang="en-US">CASH AND CASH EQUIVALENTS, end of period</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_lbl_2d610c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl_2d610c" xml:lang="en-US">SUPPLEMENTAL CASH FLOW INFORMATION:</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl_96135d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaidNet_lbl_96135d" xml:lang="en-US">Cash paid for interest</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilitiesClassifiedAsWarrants" xlink:to="ptn_ConversionOfLiabilitiesClassifiedAsWarrants_lbl_6b4a12" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_ConversionOfLiabilitiesClassifiedAsWarrants_lbl_6b4a12" xml:lang="en-US">Conversion of liability classified warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConversionOfLiabilitiesClassifiedAsWarrants" xlink:label="ptn_ConversionOfLiabilitiesClassifiedAsWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilitiesClassifiedAsWarrants" xlink:to="ptn_ConversionOfLiabilitiesClassifiedAsWarrants_lbl_37" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConversionOfLiabilitiesClassifiedAsWarrants_lbl_37" xml:lang="en-US">[Conversion of liability classified warrants]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExercise" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExercise" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExercise" xlink:to="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExercise_lbl_9b1668" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConversionOfLiabilityClassifiedWarrantsUponWarrantExercise_lbl_9b1668" xml:lang="en-US">Conversion of liability classified warrants upon warrant exercise</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OrganizationAbstract" xlink:label="ptn_OrganizationAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OrganizationAbstract" xlink:to="ptn_OrganizationAbstract_lbl_b68dfa" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OrganizationAbstract_lbl_b68dfa" xml:lang="en-US">ORGANIZATION</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl_b39c12" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl_b39c12" xml:lang="en-US">ORGANIZATION</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl_2" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_BasisOfPresentationAbstract" xlink:label="ptn_BasisOfPresentationAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_BasisOfPresentationAbstract" xlink:to="ptn_BasisOfPresentationAbstract_lbl_51a6f2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_BasisOfPresentationAbstract_lbl_51a6f2" xml:lang="en-US">BASIS OF PRESENTATION</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_BasisOfPresentationDisclosureTextBlock" xlink:to="ptn_BasisOfPresentationDisclosureTextBlock_lbl_44d3c5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_BasisOfPresentationDisclosureTextBlock_lbl_44d3c5" xml:lang="en-US">BASIS OF PRESENTATION</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_BasisOfPresentationDisclosureTextBlock" xlink:label="ptn_BasisOfPresentationDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_BasisOfPresentationDisclosureTextBlock" xlink:to="ptn_BasisOfPresentationDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_BasisOfPresentationDisclosureTextBlock_lbl_2" xml:lang="en-US">[BASIS OF PRESENTATION]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl_d56138" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl_d56138" xml:lang="en-US">SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl_5f53ac" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl_5f53ac" xml:lang="en-US">SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl_2" xml:lang="en-US">Significant Accounting Policies [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" xlink:label="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract_lbl_a97146" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract_lbl_a97146" xml:lang="en-US">New and recently Adopted Accounting Pronouncements</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_NewAccountingPronouncementsAndChangesInAccountingPrinciplesDisclosureTextBlock" xlink:label="ptn_NewAccountingPronouncementsAndChangesInAccountingPrinciplesDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_NewAccountingPronouncementsAndChangesInAccountingPrinciplesDisclosureTextBlock" xlink:to="ptn_NewAccountingPronouncementsAndChangesInAccountingPrinciplesDisclosureTextBlock_lbl_cc2e57" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_NewAccountingPronouncementsAndChangesInAccountingPrinciplesDisclosureTextBlock_lbl_cc2e57" xml:lang="en-US">New and recently adopted accounting pronouncements</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AssetPurchaseAgreementabstract" xlink:label="ptn_AssetPurchaseAgreementabstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AssetPurchaseAgreementabstract" xlink:to="ptn_AssetPurchaseAgreementabstract_lbl_13afe5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AssetPurchaseAgreementabstract_lbl_13afe5" xml:lang="en-US">ASSET PURCHASE AGREEMENT</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AssetPurchaseAgreementDisclosureTextBlock" xlink:to="ptn_AssetPurchaseAgreementDisclosureTextBlock_lbl_876ae5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_AssetPurchaseAgreementDisclosureTextBlock_lbl_876ae5" xml:lang="en-US">ASSET PURCHASE AGREEMENT</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AssetPurchaseAgreementDisclosureTextBlock" xlink:label="ptn_AssetPurchaseAgreementDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AssetPurchaseAgreementDisclosureTextBlock" xlink:to="ptn_AssetPurchaseAgreementDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AssetPurchaseAgreementDisclosureTextBlock_lbl_2" xml:lang="en-US">[ASSET PURCHASE AGREEMENT]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ManufacturingSupplyAgreementsForVyleesiabstract" xlink:label="ptn_ManufacturingSupplyAgreementsForVyleesiabstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ManufacturingSupplyAgreementsForVyleesiabstract" xlink:to="ptn_ManufacturingSupplyAgreementsForVyleesiabstract_lbl_192620" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ManufacturingSupplyAgreementsForVyleesiabstract_lbl_192620" xml:lang="en-US">MANUFACTURING SUPPLY AGREEMENTS FOR VYLEESI</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ManufacturingSupplyAgreementsTextBlock" xlink:to="ptn_ManufacturingSupplyAgreementsTextBlock_lbl_25299b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_ManufacturingSupplyAgreementsTextBlock_lbl_25299b" xml:lang="en-US">MANUFACTURING SUPPLY AGREEMENTS FOR VYLEESI</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ManufacturingSupplyAgreementsTextBlock" xlink:label="ptn_ManufacturingSupplyAgreementsTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ManufacturingSupplyAgreementsTextBlock" xlink:to="ptn_ManufacturingSupplyAgreementsTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ManufacturingSupplyAgreementsTextBlock_lbl_2" xml:lang="en-US">[MANUFACTURING SUPPLY AGREEMENTS FOR VYLEESI]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AgreementWithFosunAbstract" xlink:label="ptn_AgreementWithFosunAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithFosunAbstract" xlink:to="ptn_AgreementWithFosunAbstract_lbl_584d2b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AgreementWithFosunAbstract_lbl_584d2b" xml:lang="en-US">AGREEMENT WITH FOSUN</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithFosunTextBlock" xlink:to="ptn_AgreementWithFosunTextBlock_lbl_40cf6c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_AgreementWithFosunTextBlock_lbl_40cf6c" xml:lang="en-US">AGREEMENT WITH FOSUN</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AgreementWithFosunTextBlock" xlink:label="ptn_AgreementWithFosunTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithFosunTextBlock" xlink:to="ptn_AgreementWithFosunTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AgreementWithFosunTextBlock_lbl_2" xml:lang="en-US">[AGREEMENT WITH FOSUN]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AgreementWithKwangdongAbstract" xlink:label="ptn_AgreementWithKwangdongAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithKwangdongAbstract" xlink:to="ptn_AgreementWithKwangdongAbstract_lbl_df7de2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AgreementWithKwangdongAbstract_lbl_df7de2" xml:lang="en-US">AGREEMENT WITH KWANGDONG</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithKwangdongTextBlock" xlink:to="ptn_AgreementWithKwangdongTextBlock_lbl_ad13f2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_AgreementWithKwangdongTextBlock_lbl_ad13f2" xml:lang="en-US">AGREEMENT WITH KWANGDONG</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AgreementWithKwangdongTextBlock" xlink:label="ptn_AgreementWithKwangdongTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AgreementWithKwangdongTextBlock" xlink:to="ptn_AgreementWithKwangdongTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AgreementWithKwangdongTextBlock_lbl_2" xml:lang="en-US">[AGREEMENT WITH KWANGDONG]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_lbl_49a38d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrentAbstract_lbl_49a38d" xml:lang="en-US">PREPAID EXPENSES AND OTHER CURRENT ASSETS</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCurrentAssetsTextBlock" xlink:to="us-gaap_OtherCurrentAssetsTextBlock_lbl_2d51ca" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherCurrentAssetsTextBlock_lbl_2d51ca" xml:lang="en-US">PREPAID EXPENSES AND OTHER CURRENT ASSETS</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCurrentAssetsTextBlock" xlink:label="us-gaap_OtherCurrentAssetsTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCurrentAssetsTextBlock" xlink:to="us-gaap_OtherCurrentAssetsTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherCurrentAssetsTextBlock_lbl_2" xml:lang="en-US">Other Current Assets [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresAbstract_lbl_007314" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl_007314" xml:lang="en-US">FAIR VALUE MEASUREMENTS</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueDisclosuresTextBlock" xlink:to="us-gaap_FairValueDisclosuresTextBlock_lbl_a17a6e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl_a17a6e" xml:lang="en-US">FAIR VALUE MEASUREMENTS</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="us-gaap_FairValueDisclosuresTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueDisclosuresTextBlock" xlink:to="us-gaap_FairValueDisclosuresTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl_2" xml:lang="en-US">Fair Value Disclosures [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="us-gaap_InventoryDisclosureAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureAbstract" xlink:to="us-gaap_InventoryDisclosureAbstract_lbl_e98baa" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl_e98baa" xml:lang="en-US">INVENTORIES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl_108535" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl_108535" xml:lang="en-US">INVENTORIES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl_2" xml:lang="en-US">Inventory Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="us-gaap_PayablesAndAccrualsAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_PayablesAndAccrualsAbstract_lbl_84eee1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PayablesAndAccrualsAbstract_lbl_84eee1" xml:lang="en-US">ACCRUED EXPENSES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:to="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl_2a7f25" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl_2a7f25" xml:lang="en-US">ACCRUED EXPENSES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:to="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl_2" xml:lang="en-US">Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl_a475b9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl_a475b9" xml:lang="en-US">COMMITMENTS AND CONTINGENCIES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl_2" xml:lang="en-US">Commitments and Contingencies Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_StockholdersEquityAndRedeemableConvertiblePreferredStockAbstract" xlink:label="ptn_StockholdersEquityAndRedeemableConvertiblePreferredStockAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_StockholdersEquityAndRedeemableConvertiblePreferredStockAbstract" xlink:to="ptn_StockholdersEquityAndRedeemableConvertiblePreferredStockAbstract_lbl_1d2a0a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_StockholdersEquityAndRedeemableConvertiblePreferredStockAbstract_lbl_1d2a0a" xml:lang="en-US">REDEEMABLE CONVERTIBLE PREFERRED STOCK ESCROWED PROCEEDS AND STOCKHOLDERS EQUITY</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl_9bf318" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl_9bf318" xml:lang="en-US">REDEEMABLE CONVERTIBLE PREFERRED STOCK, ESCROWED PROCEEDS, AND STOCKHOLDERS' EQUITY</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl_10a3f8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl_10a3f8" xml:lang="en-US">INCOME TAXES</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl_94705a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl_94705a" xml:lang="en-US">INCOME TAXES</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl_2" xml:lang="en-US">Income Tax Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:label="us-gaap_ConsolidationPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationPolicyTextBlock" xlink:to="us-gaap_ConsolidationPolicyTextBlock_lbl_be4df6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl_be4df6" xml:lang="en-US">Principles of Consolidation</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PreviouslyIssuedFinancialStatementsPolicyTextBlock" xlink:label="ptn_PreviouslyIssuedFinancialStatementsPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PreviouslyIssuedFinancialStatementsPolicyTextBlock" xlink:to="ptn_PreviouslyIssuedFinancialStatementsPolicyTextBlock_lbl_eee7f3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PreviouslyIssuedFinancialStatementsPolicyTextBlock_lbl_eee7f3" xml:lang="en-US">Revision of Previously Issued Financial Statements</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl_1e9713" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl_1e9713" xml:lang="en-US">Use of Estimates</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl_405fd2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl_405fd2" xml:lang="en-US">Cash and Cash Equivalents</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MarketableSecuritiesPolicy" xlink:label="us-gaap_MarketableSecuritiesPolicy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesPolicy" xlink:to="us-gaap_MarketableSecuritiesPolicy_lbl_385d1e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesPolicy_lbl_385d1e" xml:lang="en-US">Marketable Securities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:to="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl_62d974" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy_lbl_62d974" xml:lang="en-US">Fair Value of Financial Instruments</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="us-gaap_ConcentrationRiskCreditRisk" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskCreditRisk" xlink:to="us-gaap_ConcentrationRiskCreditRisk_lbl_9415e6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl_9415e6" xml:lang="en-US">Credit Risk</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:to="us-gaap_TradeAndOtherAccountsReceivablePolicy_lbl_a2b6ca" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy_lbl_a2b6ca" xml:lang="en-US">Trade Account Receivables</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl_a3637f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl_a3637f" xml:lang="en-US">Property and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:to="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl_4f2fb9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl_4f2fb9" xml:lang="en-US">Impairment of Long-Lived Assets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeasesPolicyTextBlock" xlink:to="us-gaap_LesseeLeasesPolicyTextBlock_lbl_119b10" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl_119b10" xml:lang="en-US">Leases</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock_lbl_9b415c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl_9b415c" xml:lang="en-US">Revenue Recognition</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl_fdd60b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl_fdd60b" xml:lang="en-US">Research and Development Costs</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AccruedLiabilitiesPolicyTextBlock" xlink:label="ptn_AccruedLiabilitiesPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AccruedLiabilitiesPolicyTextBlock" xlink:to="ptn_AccruedLiabilitiesPolicyTextBlock_lbl_5d815f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AccruedLiabilitiesPolicyTextBlock_lbl_5d815f" xml:lang="en-US">Accrued Expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl_10a80f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl_10a80f" xml:lang="en-US">Stock-Based Compensation</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl_234cb1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl_234cb1" xml:lang="en-US">Income Taxes</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock_lbl_6e3776" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl_6e3776" xml:lang="en-US">Net Loss per Common Share</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:to="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl_b956aa" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl_b956aa" xml:lang="en-US">Translation of foreign currencies</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ScheduleOfSalesTableTextBlock" xlink:label="ptn_ScheduleOfSalesTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ScheduleOfSalesTableTextBlock" xlink:to="ptn_ScheduleOfSalesTableTextBlock_lbl_25e3b1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ScheduleOfSalesTableTextBlock_lbl_25e3b1" xml:lang="en-US">Schedule of sales</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock" xlink:label="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock" xlink:to="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock_lbl_5c5cb5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock_lbl_5c5cb5" xml:lang="en-US">Schedule of prepaid expenses and other current assets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock_lbl_243d21" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock_lbl_243d21" xml:lang="en-US">Schedule of fair value asset measurement</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:to="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl_17e54d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl_17e54d" xml:lang="en-US">Schedule of inventory</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl_f8d5de" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl_f8d5de" xml:lang="en-US">Schdule of Accrued Expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ScheduleOfInventoryPurchaseCommitmentsTableTextBlock" xlink:label="ptn_ScheduleOfInventoryPurchaseCommitmentsTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ScheduleOfInventoryPurchaseCommitmentsTableTextBlock" xlink:to="ptn_ScheduleOfInventoryPurchaseCommitmentsTableTextBlock_lbl_c1274f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ScheduleOfInventoryPurchaseCommitmentsTableTextBlock_lbl_c1274f" xml:lang="en-US">Schedule of inventory purchase commitments</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ScheduleOfEquityDistributionAgreementTableTextBlock" xlink:label="ptn_ScheduleOfEquityDistributionAgreementTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ScheduleOfEquityDistributionAgreementTableTextBlock" xlink:to="ptn_ScheduleOfEquityDistributionAgreementTableTextBlock_lbl_194d6a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ScheduleOfEquityDistributionAgreementTableTextBlock_lbl_194d6a" xml:lang="en-US">Equity Distribution Agreement</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ScheduleOfStockPurchaseWarrantsTableTextBlock" xlink:label="ptn_ScheduleOfStockPurchaseWarrantsTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ScheduleOfStockPurchaseWarrantsTableTextBlock" xlink:to="ptn_ScheduleOfStockPurchaseWarrantsTableTextBlock_lbl_32a205" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ScheduleOfStockPurchaseWarrantsTableTextBlock_lbl_32a205" xml:lang="en-US">Outstanding Stock Purchase Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:to="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl_9e2c16" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl_9e2c16" xml:lang="en-US">Weighted average assumption</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl_f02d04" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl_f02d04" xml:lang="en-US">Stock option activity</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_lbl_416fd4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_lbl_416fd4" xml:lang="en-US">Restricted Stock Units</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl_3788f7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl_3788f7" xml:lang="en-US">Accumulated deficit</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_DescriptionOfSalesBasedPayments" xlink:label="ptn_DescriptionOfSalesBasedPayments" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_DescriptionOfSalesBasedPayments" xlink:to="ptn_DescriptionOfSalesBasedPayments_lbl_a93040" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_DescriptionOfSalesBasedPayments_lbl_a93040" xml:lang="en-US">Description of sales-based payments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl_d385ac" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl_d385ac" xml:lang="en-US">Cash and cash equivalents</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl_5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl_5" xml:lang="en-US">[Cash and Cash Equivalents, at Carrying Value]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl_b8867d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl_b8867d" xml:lang="en-US">Total current liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl_203725" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ProductOrServiceAxis_lbl_203725" xml:lang="en-US">Product Or Service Axis</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductMember" xlink:label="us-gaap_ProductMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductMember" xlink:to="us-gaap_ProductMember_lbl_82fddc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductMember_lbl_82fddc" xml:lang="en-US">Product Revenue</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_RevenuesGross" xlink:label="ptn_RevenuesGross" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_RevenuesGross" xlink:to="ptn_RevenuesGross_lbl_9a9d21" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_RevenuesGross_lbl_9a9d21" xml:lang="en-US">Gross product sales</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ProductSalesAllowancesAndAccruals" xlink:label="ptn_ProductSalesAllowancesAndAccruals" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ProductSalesAllowancesAndAccruals" xlink:to="ptn_ProductSalesAllowancesAndAccruals_lbl_35620b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ProductSalesAllowancesAndAccruals_lbl_35620b" xml:lang="en-US">Product sales allowances and accruals</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl_b01ee6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl_b01ee6" xml:lang="en-US">Potential number of common shares excluded from diluted EPS</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MarketRiskBenefitLiabilityAmount" xlink:label="us-gaap_MarketRiskBenefitLiabilityAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketRiskBenefitLiabilityAmount" xlink:to="us-gaap_MarketRiskBenefitLiabilityAmount_lbl_fbe9ae" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketRiskBenefitLiabilityAmount_lbl_fbe9ae" xml:lang="en-US">Liability for the warrants amount</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_lbl_464aaf" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_lbl_464aaf" xml:lang="en-US">Contingently redeemable warrants amount</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl_2a37d9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl_2a37d9" xml:lang="en-US">Additional paid-in capital</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl_5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl_5" xml:lang="en-US">[Additional Paid in Capital, Common Stock]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CumulativeEarningsDeficit" xlink:label="us-gaap_CumulativeEarningsDeficit" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CumulativeEarningsDeficit" xlink:to="us-gaap_CumulativeEarningsDeficit_lbl_f54623" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CumulativeEarningsDeficit_lbl_f54623" xml:lang="en-US">Increased accumulated deficit</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ServicingLiabilityAtFairValueOtherChangesInFairValue" xlink:label="us-gaap_ServicingLiabilityAtFairValueOtherChangesInFairValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ServicingLiabilityAtFairValueOtherChangesInFairValue" xlink:to="us-gaap_ServicingLiabilityAtFairValueOtherChangesInFairValue_lbl_e500b6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ServicingLiabilityAtFairValueOtherChangesInFairValue_lbl_e500b6" xml:lang="en-US">Change in fair value of the warrant liabilities</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OfferingExpenses" xlink:to="ptn_OfferingExpenses_lbl_b0ba4f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_OfferingExpenses_lbl_b0ba4f" xml:lang="en-US">Offering expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OfferingExpenses" xlink:label="ptn_OfferingExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OfferingExpenses" xlink:to="ptn_OfferingExpenses_lbl_8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OfferingExpenses_lbl_8" xml:lang="en-US">[Offering expenses]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromHedgeFinancingActivities" xlink:label="us-gaap_ProceedsFromHedgeFinancingActivities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromHedgeFinancingActivities" xlink:to="us-gaap_ProceedsFromHedgeFinancingActivities_lbl_8a3d43" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromHedgeFinancingActivities_lbl_8a3d43" xml:lang="en-US">Cash flows from financing activities</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_lbl_14e47a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_lbl_14e47a" xml:lang="en-US">Cash flow from operations decreased</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesRestrictedStock" xlink:label="us-gaap_WeightedAverageNumberOfSharesRestrictedStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesRestrictedStock" xlink:to="us-gaap_WeightedAverageNumberOfSharesRestrictedStock_lbl_969741" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesRestrictedStock_lbl_969741" xml:lang="en-US">Weighted average vested restricted stock units</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_MoneyMarketAccountsAndTreasuryBills" xlink:label="ptn_MoneyMarketAccountsAndTreasuryBills" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_MoneyMarketAccountsAndTreasuryBills" xlink:to="ptn_MoneyMarketAccountsAndTreasuryBills_lbl_c1b49b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_MoneyMarketAccountsAndTreasuryBills_lbl_c1b49b" xml:lang="en-US">Money market account and treasury bills</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForPurchaseOfOtherAssets1" xlink:label="us-gaap_PaymentsForPurchaseOfOtherAssets1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForPurchaseOfOtherAssets1" xlink:to="us-gaap_PaymentsForPurchaseOfOtherAssets1_lbl_67a89a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForPurchaseOfOtherAssets1_lbl_67a89a" xml:lang="en-US">Payable the settlement of certain purchase commitments</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivablePurchase" xlink:label="us-gaap_AccountsReceivablePurchase" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivablePurchase" xlink:to="us-gaap_AccountsReceivablePurchase_lbl_d97c50" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivablePurchase_lbl_d97c50" xml:lang="en-US">Acounts receiveble</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PaymentsToSalesBasedMilestonePayments" xlink:label="ptn_PaymentsToSalesBasedMilestonePayments" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PaymentsToSalesBasedMilestonePayments" xlink:to="ptn_PaymentsToSalesBasedMilestonePayments_lbl_330e69" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PaymentsToSalesBasedMilestonePayments_lbl_330e69" xml:lang="en-US">Sales-based milestone payments</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalDeferredPurchasePrice" xlink:label="us-gaap_SupplementalDeferredPurchasePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalDeferredPurchasePrice" xlink:to="us-gaap_SupplementalDeferredPurchasePrice_lbl_23bb2c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalDeferredPurchasePrice_lbl_23bb2c" xml:lang="en-US">Upfront purchase price amount</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDispositionOfAssets1" xlink:to="us-gaap_GainLossOnDispositionOfAssets1_lbl_4c8af9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_lbl_4c8af9" xml:lang="en-US">Gain of the sale</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermPurchaseCommitmentAmount" xlink:label="us-gaap_LongTermPurchaseCommitmentAmount" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermPurchaseCommitmentAmount" xlink:to="us-gaap_LongTermPurchaseCommitmentAmount_lbl_74d0c6" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermPurchaseCommitmentAmount_lbl_74d0c6" xml:lang="en-US">Gain on the purchase commitment</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInDeferredRevenueAndCustomerAdvancesAndDeposits" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenueAndCustomerAdvancesAndDeposits" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDeferredRevenueAndCustomerAdvancesAndDeposits" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenueAndCustomerAdvancesAndDeposits_lbl_9b1b14" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenueAndCustomerAdvancesAndDeposits_lbl_9b1b14" xml:lang="en-US">Company License Agreement Recievables</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForRestructuring" xlink:label="us-gaap_PaymentsForRestructuring" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRestructuring" xlink:to="us-gaap_PaymentsForRestructuring_lbl_64bc30" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRestructuring_lbl_64bc30" xml:lang="en-US">Upfront Payments</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireReceivables" xlink:label="us-gaap_PaymentsToAcquireReceivables" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireReceivables" xlink:to="us-gaap_PaymentsToAcquireReceivables_lbl_1c4372" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireReceivables_lbl_1c4372" xml:lang="en-US">Milestone payment receivable</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OfficersCompensation" xlink:label="us-gaap_OfficersCompensation" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficersCompensation" xlink:to="us-gaap_OfficersCompensation_lbl_96f467" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OfficersCompensation_lbl_96f467" xml:lang="en-US">Recievable under company agreement</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_TaxExpense" xlink:label="ptn_TaxExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_TaxExpense" xlink:to="ptn_TaxExpense_lbl_2ccf4c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_TaxExpense_lbl_2ccf4c" xml:lang="en-US">Tax Expense</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UpfrontPaymentOfLess" xlink:label="ptn_UpfrontPaymentOfLess" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UpfrontPaymentOfLess" xlink:to="ptn_UpfrontPaymentOfLess_lbl_3d14d4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UpfrontPaymentOfLess_lbl_3d14d4" xml:lang="en-US">Upfront payment of less</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OfficersCompensation" xlink:to="us-gaap_OfficersCompensation_lbl_b21858" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OfficersCompensation_lbl_b21858" xml:lang="en-US">Recievable under company agreement</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRestructuring" xlink:to="us-gaap_PaymentsForRestructuring_lbl_1cd351" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsForRestructuring_lbl_1cd351" xml:lang="en-US">Upfront payments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_taxexpenses" xlink:to="ptn_taxexpenses_lbl_30aa71" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_taxexpenses_lbl_30aa71" xml:lang="en-US">Tax Expense</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_taxexpenses" xlink:label="ptn_taxexpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_taxexpenses" xlink:to="ptn_taxexpenses_lbl_4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_taxexpenses_lbl_4" xml:lang="en-US">[Tax Expense]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireReceivables" xlink:to="us-gaap_PaymentsToAcquireReceivables_lbl_27ac97" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PaymentsToAcquireReceivables_lbl_27ac97" xml:lang="en-US">Milestone payment receivable</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PrepaidClinicalStudyCosts" xlink:label="ptn_PrepaidClinicalStudyCosts" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PrepaidClinicalStudyCosts" xlink:to="ptn_PrepaidClinicalStudyCosts_lbl_36601d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PrepaidClinicalStudyCosts_lbl_36601d" xml:lang="en-US">Clinical / regulatory costs</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PrepaidInsurancePremiums" xlink:label="ptn_PrepaidInsurancePremiums" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PrepaidInsurancePremiums" xlink:to="ptn_PrepaidInsurancePremiums_lbl_d3b3da" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PrepaidInsurancePremiums_lbl_d3b3da" xml:lang="en-US">Insurance premiums</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_VyleesiContractualAdvances" xlink:label="ptn_VyleesiContractualAdvances" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_VyleesiContractualAdvances" xlink:to="ptn_VyleesiContractualAdvances_lbl_530916" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_VyleesiContractualAdvances_lbl_530916" xml:lang="en-US">Vyleesi contractual advances</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherPrepaidExpenseCurrent" xlink:label="us-gaap_OtherPrepaidExpenseCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherPrepaidExpenseCurrent" xlink:to="us-gaap_OtherPrepaidExpenseCurrent_lbl_1b04a1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherPrepaidExpenseCurrent_lbl_1b04a1" xml:lang="en-US">Other</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssets" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssets" xlink:to="us-gaap_PrepaidExpenseAndOtherAssets_lbl_c891dc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseAndOtherAssets_lbl_c891dc" xml:lang="en-US">Total prepaid expenses and other current assets</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl_dc50dc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl_dc50dc" xml:lang="en-US">Fair Value By Fair Value Hierarchy Level Axis</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl_c8bae5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl_c8bae5" xml:lang="en-US">Level 1</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl_28399f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl_28399f" xml:lang="en-US">Level 2</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl_3c10b7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl_3c10b7" xml:lang="en-US">Level 3</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MoneyMarketFundsAtCarryingValue" xlink:label="us-gaap_MoneyMarketFundsAtCarryingValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MoneyMarketFundsAtCarryingValue" xlink:to="us-gaap_MoneyMarketFundsAtCarryingValue_lbl_0fecca" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MoneyMarketFundsAtCarryingValue_lbl_0fecca" xml:lang="en-US">Cash Equivalents - Money market funds</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CashEquivalentsTreasuryBillAtCarryingValue" xlink:label="ptn_CashEquivalentsTreasuryBillAtCarryingValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CashEquivalentsTreasuryBillAtCarryingValue" xlink:to="ptn_CashEquivalentsTreasuryBillAtCarryingValue_lbl_ed2bb9" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CashEquivalentsTreasuryBillAtCarryingValue_lbl_ed2bb9" xml:lang="en-US">Cash Equivalents - Treasury bill</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_MarketableSecuritiesTreasuryBillAtCarryingValue" xlink:label="ptn_MarketableSecuritiesTreasuryBillAtCarryingValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_MarketableSecuritiesTreasuryBillAtCarryingValue" xlink:to="ptn_MarketableSecuritiesTreasuryBillAtCarryingValue_lbl_8de066" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_MarketableSecuritiesTreasuryBillAtCarryingValue_lbl_8de066" xml:lang="en-US">Marketable securities - Treasury bill</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CarryingValueDuringTheYear" xlink:to="ptn_CarryingValueDuringTheYear_lbl_22cf93" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_CarryingValueDuringTheYear_lbl_22cf93" xml:lang="en-US">Total</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CarryingValueDuringTheYear" xlink:label="ptn_CarryingValueDuringTheYear" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CarryingValueDuringTheYear" xlink:to="ptn_CarryingValueDuringTheYear_lbl_5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CarryingValueDuringTheYear_lbl_5" xml:lang="en-US">[Total]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryRawMaterials" xlink:label="us-gaap_InventoryRawMaterials" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterials" xlink:to="us-gaap_InventoryRawMaterials_lbl_1fd0da" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryRawMaterials_lbl_1fd0da" xml:lang="en-US">Raw materials</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryFinishedGoods" xlink:label="us-gaap_InventoryFinishedGoods" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoods" xlink:to="us-gaap_InventoryFinishedGoods_lbl_8ec4d2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryFinishedGoods_lbl_8ec4d2" xml:lang="en-US">Finished goods</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl_fbdaa2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InventoryNet_lbl_fbdaa2" xml:lang="en-US">Inventories</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CostClinicalStudy" xlink:to="ptn_CostClinicalStudy_lbl_d1c77e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_CostClinicalStudy_lbl_d1c77e" xml:lang="en-US">Clinical / regulatory costs</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CostClinicalStudy" xlink:label="ptn_CostClinicalStudy" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CostClinicalStudy" xlink:to="ptn_CostClinicalStudy_lbl_2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CostClinicalStudy_lbl_2" xml:lang="en-US">[Clinical / regulatory costs]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OtherResearchRelatedExpenses" xlink:label="ptn_OtherResearchRelatedExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OtherResearchRelatedExpenses" xlink:to="ptn_OtherResearchRelatedExpenses_lbl_936653" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OtherResearchRelatedExpenses_lbl_936653" xml:lang="en-US">Other research related expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedProfessionalFeesCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent_lbl_e31d97" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl_e31d97" xml:lang="en-US">Professional services</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_PersonalCost" xlink:label="ptn_PersonalCost" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_PersonalCost" xlink:to="ptn_PersonalCost_lbl_36106b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_PersonalCost_lbl_36106b" xml:lang="en-US">Personal cost</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AccruedSellingExpenses" xlink:label="ptn_AccruedSellingExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AccruedSellingExpenses" xlink:to="ptn_AccruedSellingExpenses_lbl_8260a0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AccruedSellingExpenses_lbl_8260a0" xml:lang="en-US">Selling expenses</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_lbl_e0b314" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl_e0b314" xml:lang="en-US">Other</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_lbl_7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl_7" xml:lang="en-US">[Other Accrued Liabilities, Current]</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_TotaAcrruedLiabilities" xlink:to="ptn_TotaAcrruedLiabilities_lbl_6fd934" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="ptn_TotaAcrruedLiabilities_lbl_6fd934" xml:lang="en-US">Total</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_TotaAcrruedLiabilities" xlink:label="ptn_TotaAcrruedLiabilities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_TotaAcrruedLiabilities" xlink:to="ptn_TotaAcrruedLiabilities_lbl_8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_TotaAcrruedLiabilities_lbl_8" xml:lang="en-US">[Total 1]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl_8b0b75" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl_8b0b75" xml:lang="en-US">Plan Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CurrentMember" xlink:label="ptn_CurrentMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CurrentMember" xlink:to="ptn_CurrentMember_lbl_750d9b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CurrentMember_lbl_750d9b" xml:lang="en-US">Current</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OneToThreeYearsMember" xlink:label="ptn_OneToThreeYearsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OneToThreeYearsMember" xlink:to="ptn_OneToThreeYearsMember_lbl_69e7d1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OneToThreeYearsMember_lbl_69e7d1" xml:lang="en-US">1 - 3 Years</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_FourToFiveYearsMember" xlink:label="ptn_FourToFiveYearsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_FourToFiveYearsMember" xlink:to="ptn_FourToFiveYearsMember_lbl_d1b440" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_FourToFiveYearsMember_lbl_d1b440" xml:lang="en-US">4 - 5</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdvancesOnInventoryPurchases" xlink:label="us-gaap_AdvancesOnInventoryPurchases" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvancesOnInventoryPurchases" xlink:to="us-gaap_AdvancesOnInventoryPurchases_lbl_50ad5b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvancesOnInventoryPurchases_lbl_50ad5b" xml:lang="en-US">Inventory purchase commitments</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl_22795a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl_22795a" xml:lang="en-US">Other Liabilities Current</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AccruedOtherLongTermLiabilities" xlink:label="ptn_AccruedOtherLongTermLiabilities" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AccruedOtherLongTermLiabilities" xlink:to="ptn_AccruedOtherLongTermLiabilities_lbl_8ff42c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AccruedOtherLongTermLiabilities_lbl_8ff42c" xml:lang="en-US">Accrued Other long-term Liabilities</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CumulativeFromInceptionMember" xlink:label="ptn_CumulativeFromInceptionMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CumulativeFromInceptionMember" xlink:to="ptn_CumulativeFromInceptionMember_lbl_b1d438" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CumulativeFromInceptionMember_lbl_b1d438" xml:lang="en-US">Cumulative from inception</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityGrossProceedsShares" xlink:label="ptn_EquityGrossProceedsShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityGrossProceedsShares" xlink:to="ptn_EquityGrossProceedsShares_lbl_63b51a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityGrossProceedsShares_lbl_63b51a" xml:lang="en-US">Equity Gross proceeds, Shares</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromOtherEquity" xlink:label="us-gaap_ProceedsFromOtherEquity" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromOtherEquity" xlink:to="us-gaap_ProceedsFromOtherEquity_lbl_e853f0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromOtherEquity_lbl_e853f0" xml:lang="en-US">Equity Gross proceeds, Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityFeesShares" xlink:label="ptn_EquityFeesShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityFeesShares" xlink:to="ptn_EquityFeesShares_lbl_3aeb95" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityFeesShares_lbl_3aeb95" xml:lang="en-US">Equity Fees, Shares</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromFeesReceived" xlink:to="us-gaap_ProceedsFromFeesReceived_lbl_cd0279" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ProceedsFromFeesReceived_lbl_cd0279" xml:lang="en-US">Equity Fees, Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromFeesReceived" xlink:label="us-gaap_ProceedsFromFeesReceived" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromFeesReceived" xlink:to="us-gaap_ProceedsFromFeesReceived_lbl_5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromFeesReceived_lbl_5" xml:lang="en-US">[Proceeds from Fees Received]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityExpensesShares" xlink:label="ptn_EquityExpensesShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityExpensesShares" xlink:to="ptn_EquityExpensesShares_lbl_638f19" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityExpensesShares_lbl_638f19" xml:lang="en-US">Equity Expenses, Shares</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityExpensesProceeds" xlink:to="ptn_EquityExpensesProceeds_lbl_6c8f66" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="ptn_EquityExpensesProceeds_lbl_6c8f66" xml:lang="en-US">Equity Expenses, Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityExpensesProceeds" xlink:label="ptn_EquityExpensesProceeds" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityExpensesProceeds" xlink:to="ptn_EquityExpensesProceeds_lbl_7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityExpensesProceeds_lbl_7" xml:lang="en-US">[Equity Expenses, Proceeds]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityNetProceedsShares" xlink:label="ptn_EquityNetProceedsShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityNetProceedsShares" xlink:to="ptn_EquityNetProceedsShares_lbl_1d02bc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityNetProceedsShares_lbl_1d02bc" xml:lang="en-US">Equity Net proceeds, Shares</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityNetProceedsProceeds" xlink:label="ptn_EquityNetProceedsProceeds" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityNetProceedsProceeds" xlink:to="ptn_EquityNetProceedsProceeds_lbl_2b322d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityNetProceedsProceeds_lbl_2b322d" xml:lang="en-US">Equity Net proceeds, Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_MayTwoThousandTwentyTwoWarrantsMember" xlink:label="ptn_MayTwoThousandTwentyTwoWarrantsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_MayTwoThousandTwentyTwoWarrantsMember" xlink:to="ptn_MayTwoThousandTwentyTwoWarrantsMember_lbl_759a09" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_MayTwoThousandTwentyTwoWarrantsMember_lbl_759a09" xml:lang="en-US">May 2022 Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OctoberTwoThousandTwentyTwoPrivateWarrantsOneMember" xlink:label="ptn_OctoberTwoThousandTwentyTwoPrivateWarrantsOneMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OctoberTwoThousandTwentyTwoPrivateWarrantsOneMember" xlink:to="ptn_OctoberTwoThousandTwentyTwoPrivateWarrantsOneMember_lbl_57413e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OctoberTwoThousandTwentyTwoPrivateWarrantsOneMember_lbl_57413e" xml:lang="en-US">October 2022 private Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OctoberTwoThousandTwentyTwoPlacementAgentWarrantsTwoMember" xlink:label="ptn_OctoberTwoThousandTwentyTwoPlacementAgentWarrantsTwoMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OctoberTwoThousandTwentyTwoPlacementAgentWarrantsTwoMember" xlink:to="ptn_OctoberTwoThousandTwentyTwoPlacementAgentWarrantsTwoMember_lbl_6709fd" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OctoberTwoThousandTwentyTwoPlacementAgentWarrantsTwoMember_lbl_6709fd" xml:lang="en-US">October 2022 Placement Agent Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OctoberTwoZeroTwoThreePrivateWarrantsMember" xlink:label="ptn_OctoberTwoZeroTwoThreePrivateWarrantsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OctoberTwoZeroTwoThreePrivateWarrantsMember" xlink:to="ptn_OctoberTwoZeroTwoThreePrivateWarrantsMember_lbl_069c8e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OctoberTwoZeroTwoThreePrivateWarrantsMember_lbl_069c8e" xml:lang="en-US">October 2023 Private Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_OctoberTwoZeroTwoThreePlacementAgentWarrantsMember" xlink:label="ptn_OctoberTwoZeroTwoThreePlacementAgentWarrantsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_OctoberTwoZeroTwoThreePlacementAgentWarrantsMember" xlink:to="ptn_OctoberTwoZeroTwoThreePlacementAgentWarrantsMember_lbl_03d80c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_OctoberTwoZeroTwoThreePlacementAgentWarrantsMember_lbl_03d80c" xml:lang="en-US">October 2023 Placement Agent Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_JanuaryTwoZeroTwoFourPrivateWarrantsMember" xlink:label="ptn_JanuaryTwoZeroTwoFourPrivateWarrantsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_JanuaryTwoZeroTwoFourPrivateWarrantsMember" xlink:to="ptn_JanuaryTwoZeroTwoFourPrivateWarrantsMember_lbl_0049a5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_JanuaryTwoZeroTwoFourPrivateWarrantsMember_lbl_0049a5" xml:lang="en-US">January 2024 Private Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_JanuaryTwoZeroTwoFourPlacementAgentWarrantsMember" xlink:label="ptn_JanuaryTwoZeroTwoFourPlacementAgentWarrantsMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_JanuaryTwoZeroTwoFourPlacementAgentWarrantsMember" xlink:to="ptn_JanuaryTwoZeroTwoFourPlacementAgentWarrantsMember_lbl_71afdf" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_JanuaryTwoZeroTwoFourPlacementAgentWarrantsMember_lbl_71afdf" xml:lang="en-US">January 2024 Placement Agent Warrants</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SharesOfCommonStock" xlink:label="ptn_SharesOfCommonStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SharesOfCommonStock" xlink:to="ptn_SharesOfCommonStock_lbl_80e793" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SharesOfCommonStock_lbl_80e793" xml:lang="en-US">Shares of Common Stock</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ExercisePricePerShareWarrantsOutstanding" xlink:label="ptn_ExercisePricePerShareWarrantsOutstanding" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ExercisePricePerShareWarrantsOutstanding" xlink:to="ptn_ExercisePricePerShareWarrantsOutstanding_lbl_56b4f7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ExercisePricePerShareWarrantsOutstanding_lbl_56b4f7" xml:lang="en-US">Exercise Price per Share</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_LatestTerminationDate" xlink:label="ptn_LatestTerminationDate" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_LatestTerminationDate" xlink:to="ptn_LatestTerminationDate_lbl_ef4c5c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_LatestTerminationDate_lbl_ef4c5c" xml:lang="en-US">Latest Termination Date</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl_8d2750" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl_8d2750" xml:lang="en-US">Expected option life (years)</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl_81f88d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl_81f88d" xml:lang="en-US">Volatility factor</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl_74fff7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl_74fff7" xml:lang="en-US">Risk-free interest rate</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberBeginningBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberBeginningBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberBeginningBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberBeginningBalance_lbl_e058c3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberBeginningBalance_lbl_e058c3" xml:lang="en-US">Number of Options Outstanding, Beginning</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumberEndingBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumberEndingBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumberEndingBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumberEndingBalance_lbl_b6050a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumberEndingBalance_lbl_b6050a" xml:lang="en-US">Number of Options Exercisable</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberEndingBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberEndingBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberEndingBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberEndingBalance_lbl_b654d5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumberEndingBalance_lbl_b654d5" xml:lang="en-US">Number of Options Expected to vest</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberEndingBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberEndingBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberEndingBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberEndingBalance_lbl_16ed1a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumberEndingBalance_lbl_16ed1a" xml:lang="en-US">Number of Options Outstanding, Ending</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceBeginningBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceBeginningBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceBeginningBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceBeginningBalance_lbl_3a8af0" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceBeginningBalance_lbl_3a8af0" xml:lang="en-US">Weighted Average Exercise Price Outstanding, Beginning</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl_68a2b8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl_68a2b8" xml:lang="en-US">Weighted Average Exercise Price Granted</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_lbl_93405e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_lbl_93405e" xml:lang="en-US">Weighted Average Exercise Price Forfeited</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl_7ca04f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl_7ca04f" xml:lang="en-US">Weighted Average Exercise Price Exercised</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl_a98b18" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice_lbl_a98b18" xml:lang="en-US">Weighted Average Exercise Price Expired</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceEndingBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceEndingBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceEndingBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceEndingBalance_lbl_539cb2" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceEndingBalance_lbl_539cb2" xml:lang="en-US">Weighted Average Exercise Price Outstanding, Ending</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisableWeightedAverageExercisePrice" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisableWeightedAverageExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisableWeightedAverageExercisePrice" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisableWeightedAverageExercisePrice_lbl_65634f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisableWeightedAverageExercisePrice_lbl_65634f" xml:lang="en-US">Weighted Average Exercise Price Exercisable</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedExercisePrice" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedExercisePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedExercisePrice" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedExercisePrice_lbl_f4429b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedExercisePrice_lbl_f4429b" xml:lang="en-US">Weighted Average Exercise Price Options Expected to vest</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_lbl_4ef613" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_lbl_4ef613" xml:lang="en-US">Weighted Average Remaining Term in Years Options outstanding at beginning of year</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl_ecc896" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl_ecc896" xml:lang="en-US">Weighted Average Remaining Term in Years Options outstanding at end of year</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl_2a6edc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl_2a6edc" xml:lang="en-US">Weighted Average Remaining Term in Years Options exercisable at end of year</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_lbl_e73dfa" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_lbl_e73dfa" xml:lang="en-US">Weighted Average Remaining Term in Years Options Expected to vest</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsVestedAndOutstandingAggregateIntrinsicValue" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsVestedAndOutstandingAggregateIntrinsicValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsVestedAndOutstandingAggregateIntrinsicValue" xlink:to="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsVestedAndOutstandingAggregateIntrinsicValue_lbl_559b56" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsVestedAndOutstandingAggregateIntrinsicValue_lbl_559b56" xml:lang="en-US">Aggregate Intrinsic Value Options Expected to vest</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValue" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValue" xlink:to="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValue_lbl_fe62b3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValue_lbl_fe62b3" xml:lang="en-US">Aggregate Intrinsic Value Options Expected to outstanding</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValueExpected" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValueExpected" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValueExpected" xlink:to="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValueExpected_lbl_531b06" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementBySharesBasedPaymentAwardOptionsOutstandingAndOutstandingAggregateIntrinsicValueExpected_lbl_531b06" xml:lang="en-US">Aggregate Intrinsic Value Options Expected to Expected</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityBeginningBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityBeginningBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityBeginningBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityBeginningBalance_lbl_658fe8" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityBeginningBalance_lbl_658fe8" xml:lang="en-US">Outstanding at beginning of year</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl_57827c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl_57827c" xml:lang="en-US">Granted</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures_lbl_91b7e4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures_lbl_91b7e4" xml:lang="en-US">Forfeited</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures_lbl_4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures_lbl_4" xml:lang="en-US">[Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations_lbl_fc4194" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExpirations_lbl_fc4194" xml:lang="en-US">Expired</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVested" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVested" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVested" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVested_lbl_69e1bd" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVested_lbl_69e1bd" xml:lang="en-US">Vested</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEndingBalance" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEndingBalance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEndingBalance" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEndingBalance_lbl_987d72" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEndingBalance_lbl_987d72" xml:lang="en-US">Outstanding at ending of year</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl_9db7ea" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl_9db7ea" xml:lang="en-US">Award Type Axis</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="us-gaap_RelatedPartyTransactionAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionAxis_lbl_4e87cb" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionAxis_lbl_4e87cb" xml:lang="en-US">Related Party Transaction Axis</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl_77c874" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl_77c874" xml:lang="en-US">Related Party [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_TwentyTwentyThreeEquityDistributionAgreementMember" xlink:label="ptn_TwentyTwentyThreeEquityDistributionAgreementMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_TwentyTwentyThreeEquityDistributionAgreementMember" xlink:to="ptn_TwentyTwentyThreeEquityDistributionAgreementMember_lbl_a8789a" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_TwentyTwentyThreeEquityDistributionAgreementMember_lbl_a8789a" xml:lang="en-US">2023 Equity Distribution Agreement [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SecuritiesPurchaseAgreementPlanMember" xlink:label="ptn_SecuritiesPurchaseAgreementPlanMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SecuritiesPurchaseAgreementPlanMember" xlink:to="ptn_SecuritiesPurchaseAgreementPlanMember_lbl_9789c5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SecuritiesPurchaseAgreementPlanMember_lbl_9789c5" xml:lang="en-US">Securities Purchase Agreement Plan [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesBAndCRedeemableConvertiblePreferredStockMember" xlink:label="ptn_SeriesBAndCRedeemableConvertiblePreferredStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesBAndCRedeemableConvertiblePreferredStockMember" xlink:to="ptn_SeriesBAndCRedeemableConvertiblePreferredStockMember_lbl_a60b67" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesBAndCRedeemableConvertiblePreferredStockMember_lbl_a60b67" xml:lang="en-US">Series B and C Redeemable Convertible Preferred Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ExecutiveOfficersMember" xlink:label="ptn_ExecutiveOfficersMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ExecutiveOfficersMember" xlink:to="ptn_ExecutiveOfficersMember_lbl_219020" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ExecutiveOfficersMember_lbl_219020" xml:lang="en-US">Executive Officers</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ConvertibleSeriesAPreferredStocksMember" xlink:label="ptn_ConvertibleSeriesAPreferredStocksMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ConvertibleSeriesAPreferredStocksMember" xlink:to="ptn_ConvertibleSeriesAPreferredStocksMember_lbl_0303c7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ConvertibleSeriesAPreferredStocksMember_lbl_0303c7" xml:lang="en-US">Convertible Series A Preferred Stocks</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesBConvertiblePreferredStockMember" xlink:label="ptn_SeriesBConvertiblePreferredStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesBConvertiblePreferredStockMember" xlink:to="ptn_SeriesBConvertiblePreferredStockMember_lbl_d84206" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesBConvertiblePreferredStockMember_lbl_d84206" xml:lang="en-US">Series B Convertible Preferred Stock</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SecuritiesPurchaseAgreementMember" xlink:label="ptn_SecuritiesPurchaseAgreementMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SecuritiesPurchaseAgreementMember" xlink:to="ptn_SecuritiesPurchaseAgreementMember_lbl_78e1a1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SecuritiesPurchaseAgreementMember_lbl_78e1a1" xml:lang="en-US">Securities Purchase Agreement [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesBRedeemableConvertiblePreferredStockMember" xlink:label="ptn_SeriesBRedeemableConvertiblePreferredStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesBRedeemableConvertiblePreferredStockMember" xlink:to="ptn_SeriesBRedeemableConvertiblePreferredStockMember_lbl_a22561" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesBRedeemableConvertiblePreferredStockMember_lbl_a22561" xml:lang="en-US">Series B Redeemable Convertible Preferred Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SeriesCRedeemableConvertiblePreferredStockMember" xlink:label="ptn_SeriesCRedeemableConvertiblePreferredStockMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SeriesCRedeemableConvertiblePreferredStockMember" xlink:to="ptn_SeriesCRedeemableConvertiblePreferredStockMember_lbl_a6b43c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SeriesCRedeemableConvertiblePreferredStockMember_lbl_a6b43c" xml:lang="en-US">Series C Redeemable Convertible Preferred Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_TwentyElevenStockIncentivePlanMember" xlink:label="ptn_TwentyElevenStockIncentivePlanMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_TwentyElevenStockIncentivePlanMember" xlink:to="ptn_TwentyElevenStockIncentivePlanMember_lbl_bed292" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_TwentyElevenStockIncentivePlanMember_lbl_bed292" xml:lang="en-US">2011 Stock Incentive Plan [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_PresidentMember" xlink:label="srt_PresidentMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_PresidentMember" xlink:to="srt_PresidentMember_lbl_5a391c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_PresidentMember_lbl_5a391c" xml:lang="en-US">President and CEO [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CFOandCOOMember" xlink:label="ptn_CFOandCOOMember" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CFOandCOOMember" xlink:to="ptn_CFOandCOOMember_lbl_7bff67" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CFOandCOOMember_lbl_7bff67" xml:lang="en-US">CFO and COO [Member]</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_EquityDistributionAgreementDescription" xlink:label="ptn_EquityDistributionAgreementDescription" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_EquityDistributionAgreementDescription" xlink:to="ptn_EquityDistributionAgreementDescription_lbl_3eb33e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_EquityDistributionAgreementDescription_lbl_3eb33e" xml:lang="en-US">Description of equity distribution agreement</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockOptionPlanExpense" xlink:label="us-gaap_StockOptionPlanExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionPlanExpense" xlink:to="us-gaap_StockOptionPlanExpense_lbl_6e891b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockOptionPlanExpense_lbl_6e891b" xml:lang="en-US">Stock based compensation, options</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_NumberOfShareVestingRestrictedUnits" xlink:label="ptn_NumberOfShareVestingRestrictedUnits" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_NumberOfShareVestingRestrictedUnits" xlink:to="ptn_NumberOfShareVestingRestrictedUnits_lbl_aa3db1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_NumberOfShareVestingRestrictedUnits_lbl_aa3db1" xml:lang="en-US">Vesting of restricted share units</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AggregateValueOfShareVestingRestrictedUnits" xlink:label="ptn_AggregateValueOfShareVestingRestrictedUnits" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AggregateValueOfShareVestingRestrictedUnits" xlink:to="ptn_AggregateValueOfShareVestingRestrictedUnits_lbl_47c116" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AggregateValueOfShareVestingRestrictedUnits_lbl_47c116" xml:lang="en-US">Vesting of restricted share units value aggregate</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_WarrantToPurchaseCommonStock" xlink:label="ptn_WarrantToPurchaseCommonStock" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_WarrantToPurchaseCommonStock" xlink:to="ptn_WarrantToPurchaseCommonStock_lbl_87582c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_WarrantToPurchaseCommonStock_lbl_87582c" xml:lang="en-US">Number of common stock share</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl_1c76d3" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl_1c76d3" xml:lang="en-US">Exercise price per share</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpenses" xlink:label="us-gaap_CostsAndExpenses" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_CostsAndExpenses_lbl_2276f7" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostsAndExpenses_lbl_2276f7" xml:lang="en-US">Fees and expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_GrossProceeds" xlink:label="ptn_GrossProceeds" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_GrossProceeds" xlink:to="ptn_GrossProceeds_lbl_7d50e5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_GrossProceeds_lbl_7d50e5" xml:lang="en-US">Gross proceeds</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_VotingOfSharesDescription" xlink:label="ptn_VotingOfSharesDescription" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_VotingOfSharesDescription" xlink:to="ptn_VotingOfSharesDescription_lbl_986a83" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_VotingOfSharesDescription_lbl_986a83" xml:lang="en-US">Voting of shares description</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssuedPricePerShare" xlink:to="us-gaap_SharesIssuedPricePerShare_lbl_4fec78" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl_4fec78" xml:lang="en-US">Exercise price</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_DescriptionOfCommission" xlink:label="ptn_DescriptionOfCommission" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_DescriptionOfCommission" xlink:to="ptn_DescriptionOfCommission_lbl_864fdb" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_DescriptionOfCommission_lbl_864fdb" xml:lang="en-US">Description of commission</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UnvestedPerformancesBasedRestrictedStockUnit" xlink:label="ptn_UnvestedPerformancesBasedRestrictedStockUnit" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UnvestedPerformancesBasedRestrictedStockUnit" xlink:to="ptn_UnvestedPerformancesBasedRestrictedStockUnit_lbl_f1394c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UnvestedPerformancesBasedRestrictedStockUnit_lbl_f1394c" xml:lang="en-US">Unvested performance-based restricted stock</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UnvestedPerformanceBasedStockOptionsGrantedToExecutiveOfficersAndOtherEmployees" xlink:label="ptn_UnvestedPerformanceBasedStockOptionsGrantedToExecutiveOfficersAndOtherEmployees" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UnvestedPerformanceBasedStockOptionsGrantedToExecutiveOfficersAndOtherEmployees" xlink:to="ptn_UnvestedPerformanceBasedStockOptionsGrantedToExecutiveOfficersAndOtherEmployees_lbl_e8203d" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UnvestedPerformanceBasedStockOptionsGrantedToExecutiveOfficersAndOtherEmployees_lbl_e8203d" xml:lang="en-US">Unvested performance-based stock options granted to executive officers and other employees</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UnvestedPerformanceBasedStockOptionsGranted" xlink:label="ptn_UnvestedPerformanceBasedStockOptionsGranted" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UnvestedPerformanceBasedStockOptionsGranted" xlink:to="ptn_UnvestedPerformanceBasedStockOptionsGranted_lbl_1dc9ec" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UnvestedPerformanceBasedStockOptionsGranted_lbl_1dc9ec" xml:lang="en-US">Unvested performance-based stock options granted</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockExpense" xlink:label="us-gaap_RestrictedStockExpense" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockExpense" xlink:to="us-gaap_RestrictedStockExpense_lbl_78dd3c" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockExpense_lbl_78dd3c" xml:lang="en-US">Stock based compensation, restricted stock units</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVesteOutstandingNumber" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVesteOutstandingNumber" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVesteOutstandingNumber" xlink:to="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVesteOutstandingNumber_lbl_457664" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVesteOutstandingNumber_lbl_457664" xml:lang="en-US">Outstanding vested restricted stock unit</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_DescriptionOfSecuritiesPurchaseAgreement" xlink:label="ptn_DescriptionOfSecuritiesPurchaseAgreement" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_DescriptionOfSecuritiesPurchaseAgreement" xlink:to="ptn_DescriptionOfSecuritiesPurchaseAgreement_lbl_086060" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_DescriptionOfSecuritiesPurchaseAgreement_lbl_086060" xml:lang="en-US">Description of securities purchase agreement</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl_57c46b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl_57c46b" xml:lang="en-US">Convertible preferred stock were outstanding</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromGrantors" xlink:label="us-gaap_ProceedsFromGrantors" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromGrantors" xlink:to="us-gaap_ProceedsFromGrantors_lbl_7f3a99" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromGrantors_lbl_7f3a99" xml:lang="en-US">Total gross proceeds</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivablePurchase" xlink:to="us-gaap_AccountsReceivablePurchase_lbl_816fb1" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AccountsReceivablePurchase_lbl_816fb1" xml:lang="en-US">Account to release</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LegalFees" xlink:label="us-gaap_LegalFees" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalFees" xlink:to="us-gaap_LegalFees_lbl_7aa0f4" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LegalFees_lbl_7aa0f4" xml:lang="en-US">Fee</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="us-gaap_StockRepurchasedDuringPeriodShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockRepurchasedDuringPeriodShares" xlink:to="us-gaap_StockRepurchasedDuringPeriodShares_lbl_aab964" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockRepurchasedDuringPeriodShares_lbl_aab964" xml:lang="en-US">Warrants to purchase up</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl_98b11b" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl_98b11b" xml:lang="en-US">Total gross proceeds from the offering</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityOtherShares" xlink:label="us-gaap_StockholdersEquityOtherShares" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityOtherShares" xlink:to="us-gaap_StockholdersEquityOtherShares_lbl_1aa30e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityOtherShares_lbl_1aa30e" xml:lang="en-US">Shares sold</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharePrice" xlink:to="us-gaap_SharePrice_lbl_b4b69f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharePrice_lbl_b4b69f" xml:lang="en-US">Share purchase price</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ExpiryOfShareIssuance" xlink:label="ptn_ExpiryOfShareIssuance" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ExpiryOfShareIssuance" xlink:to="ptn_ExpiryOfShareIssuance_lbl_471224" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ExpiryOfShareIssuance_lbl_471224" xml:lang="en-US">Expiry of share issuance</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_AggregateValue" xlink:label="ptn_AggregateValue" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_AggregateValue" xlink:to="ptn_AggregateValue_lbl_2232df" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_AggregateValue_lbl_2232df" xml:lang="en-US">Aggregate value</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockConvertibleConversionPrice" xlink:label="us-gaap_PreferredStockConvertibleConversionPrice" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockConvertibleConversionPrice" xlink:to="us-gaap_PreferredStockConvertibleConversionPrice_lbl_798cee" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockConvertibleConversionPrice_lbl_798cee" xml:lang="en-US">Conversion price</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleLiquidationPreferencePerShare" xlink:label="us-gaap_DebtInstrumentConvertibleLiquidationPreferencePerShare" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleLiquidationPreferencePerShare" xlink:to="us-gaap_DebtInstrumentConvertibleLiquidationPreferencePerShare_lbl_257584" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentConvertibleLiquidationPreferencePerShare_lbl_257584" xml:lang="en-US">Convertible shares</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAvailableForDistributions" xlink:label="us-gaap_CashAvailableForDistributions" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAvailableForDistributions" xlink:to="us-gaap_CashAvailableForDistributions_lbl_31179f" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAvailableForDistributions_lbl_31179f" xml:lang="en-US">Distributable value of dividend</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_CashAvailableForDistributionsAdditional" xlink:label="ptn_CashAvailableForDistributionsAdditional" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_CashAvailableForDistributionsAdditional" xlink:to="ptn_CashAvailableForDistributionsAdditional_lbl_f770d5" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_CashAvailableForDistributionsAdditional_lbl_f770d5" xml:lang="en-US">Distributable value of dividend additional</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_UnvestedPerformanceBasedRestrictedStockUnitsGranted" xlink:label="ptn_UnvestedPerformanceBasedRestrictedStockUnitsGranted" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_UnvestedPerformanceBasedRestrictedStockUnitsGranted" xlink:to="ptn_UnvestedPerformanceBasedRestrictedStockUnitsGranted_lbl_a63cdc" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_UnvestedPerformanceBasedRestrictedStockUnitsGranted_lbl_a63cdc" xml:lang="en-US">Unvested performance-based restricted stock units granted</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_ContributionOfNumberOfShare" xlink:label="ptn_ContributionOfNumberOfShare" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_ContributionOfNumberOfShare" xlink:to="ptn_ContributionOfNumberOfShare_lbl_7e62ed" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_ContributionOfNumberOfShare_lbl_7e62ed" xml:lang="en-US">Voluntarily contributed stock options number of share</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense_lbl_937124" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl_937124" xml:lang="en-US">Selling, general and administrative expenses</link:label>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAdjustmentOfWarrants" xlink:to="us-gaap_FairValueAdjustmentOfWarrants_lbl_971d50" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl_971d50" xml:lang="en-US">Fair value of the warrants</link:label>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl_82f214" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl_82f214" xml:lang="en-US">Income tax benefit</link:label>
    <link:loc xlink:type="locator" xlink:href="ptn-20240331.xsd#ptn_SaleValueOfTheTaxBenefitsToUnaffiliated" xlink:label="ptn_SaleValueOfTheTaxBenefitsToUnaffiliated" />
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ptn_SaleValueOfTheTaxBenefitsToUnaffiliated" xlink:to="ptn_SaleValueOfTheTaxBenefitsToUnaffiliated_lbl_9c645e" xlink:type="arc" />
    <link:label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="ptn_SaleValueOfTheTaxBenefitsToUnaffiliated_lbl_9c645e" xml:lang="en-US">Sale value of the tax benefits to unaffiliated</link:label>
  </link:labelLink>
</link:linkbase>
