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  <xs:element id="prph_A2024SecondFutureReceiptsFinancingMember" abstract="true" name="A2024SecondFutureReceiptsFinancingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="prph_A2024FutureReceiptsFinancingAddendumFirstTwoMonthsMember" abstract="true" name="A2024FutureReceiptsFinancingAddendumFirstTwoMonthsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_A2024FutureReceiptsFinancingAddendumRemainingTenMonthsMember" abstract="true" name="A2024FutureReceiptsFinancingAddendumRemainingTenMonthsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="prph_ProceedsFromSaleOfCompanyRightsTitleAndInterestToEmployeeRetentionCredit" abstract="false" name="ProceedsFromSaleOfCompanyRightsTitleAndInterestToEmployeeRetentionCredit" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_PaymentsOfIssuanceCostsForSaleOfCompanyRightsTitleAndInterestToEmployeeRetentionCredit" abstract="false" name="PaymentsOfIssuanceCostsForSaleOfCompanyRightsTitleAndInterestToEmployeeRetentionCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_EmployeeRetentionCreditPercentageOfImpairedAmountAllowedToBePutBackToTheCompany" abstract="false" name="EmployeeRetentionCreditPercentageOfImpairedAmountAllowedToBePutBackToTheCompany" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="prph_EmployeeRetentionCreditInterestRatePercentageOnImpairedAmountAllowedToBePutBackToTheCompany" abstract="false" name="EmployeeRetentionCreditInterestRatePercentageOnImpairedAmountAllowedToBePutBackToTheCompany" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="prph_ProceedsFromIncomeTaxRefundsPortionPassedThroughToBuyer" abstract="false" name="ProceedsFromIncomeTaxRefundsPortionPassedThroughToBuyer" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_PharmalozManufacturingInc.AndPharmalozRealEstateHoldingsInc.Member" abstract="true" name="PharmalozManufacturingInc.AndPharmalozRealEstateHoldingsInc.Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="prph_FormerChiefOperatingOfficerMember" abstract="true" name="FormerChiefOperatingOfficerMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_A2025DirectorsPlanMember" abstract="true" name="A2025DirectorsPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_A2022DirectorsPlanMember" abstract="true" name="A2022DirectorsPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_Amended2022DirectorsPlanMember" abstract="true" name="Amended2022DirectorsPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_Amended2010DirectorsPlanMember" abstract="true" name="Amended2010DirectorsPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_A2025PlanMember" abstract="true" name="A2025PlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="prph_TwoThousandEighteenStockIncentivePlanMember" abstract="false" name="TwoThousandEighteenStockIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CEOOptionsMember" abstract="false" name="CEOOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="prph_KeystoneELOCSharesMember" abstract="true" name="KeystoneELOCSharesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_EquivirLicenseAgreementMember" abstract="true" name="EquivirLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CommonStockIncreaseDecreaseInCapitalSharesReservedForFutureIssuance" abstract="false" name="CommonStockIncreaseDecreaseInCapitalSharesReservedForFutureIssuance" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="prph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrantDateFairValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrantDateFairValue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedWeightedAverageRemainingContractualTerm" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedWeightedAverageRemainingContractualTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="prph_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestExercised" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestExercised" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
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  <xs:element id="prph_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsVestedAndExercisableWeightedAverageExercisePrice1" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionsVestedAndExercisableWeightedAverageExercisePrice1" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="prph_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionsVestedAndExercisableWeightedAverageRemainingContractualTerm2" abstract="false" name="SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionsVestedAndExercisableWeightedAverageRemainingContractualTerm2" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
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  <xs:element id="prph_PhaseThreeMember" abstract="false" name="PhaseThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_NewDrugApplicationMember" abstract="false" name="NewDrugApplicationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_UpfrontLicenseFee" abstract="false" name="UpfrontLicenseFee" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_LicenseAgreementTerm" abstract="false" name="LicenseAgreementTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="prph_AdditionalPaymentOfFee" abstract="false" name="AdditionalPaymentOfFee" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_LicenseOrRoyaltyNetRevenuePercentage" abstract="false" name="LicenseOrRoyaltyNetRevenuePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="prph_NumberOfSites" abstract="false" name="NumberOfSites" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="prph_CollaborativeArrangementEstimatedAnnualProcedures" abstract="false" name="CollaborativeArrangementEstimatedAnnualProcedures" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_CollaborativeArrangementEstimatedMarketOpportunityValue" abstract="false" name="CollaborativeArrangementEstimatedMarketOpportunityValue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_CPMMember" abstract="false" name="CPMMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_OldBridgeNewJerseyMember" abstract="false" name="OldBridgeNewJerseyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_NewYorkSecondFloorLeaseMember" abstract="true" name="NewYorkSecondFloorLeaseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_NewYorkFirstFloorLeaseMember" abstract="true" name="NewYorkFirstFloorLeaseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_LesseeOperatingLeaseMonthlyBaseRent" abstract="false" name="LesseeOperatingLeaseMonthlyBaseRent" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_OperatingLeaseSurrenderSettlementAmountMonthly" abstract="false" name="OperatingLeaseSurrenderSettlementAmountMonthly" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_OperatingLeaseNumberOfSurrenderSettlementInstallments" abstract="false" name="OperatingLeaseNumberOfSurrenderSettlementInstallments" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="prph_OperatingLeaseLiabilityDecreaseFromLeaseTermination" abstract="false" name="OperatingLeaseLiabilityDecreaseFromLeaseTermination" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_OperatingLeaseRightOfUseAssetDecreaseFromLeaseTermination" abstract="false" name="OperatingLeaseRightOfUseAssetDecreaseFromLeaseTermination" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_OperatingLeaseNonRefundableSecurityDepositWriteoff" abstract="false" name="OperatingLeaseNonRefundableSecurityDepositWriteoff" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_FinanceLeaseCost" abstract="false" name="FinanceLeaseCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_DisposalGroupIncludingDiscontinuedOperationFinanceLeaseRightOfUseAssetAfterAccumulatedAmortization" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationFinanceLeaseRightOfUseAssetAfterAccumulatedAmortization" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_DisposalGroupIncludingDiscontinuedOperationFinanceLeaseRightOfUseAssetAccumulatedAmortization" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationFinanceLeaseRightOfUseAssetAccumulatedAmortization" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_DiagnosticServicesSegmentMember" abstract="false" name="DiagnosticServicesSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_ConsumerProductsSegmentMember" abstract="false" name="ConsumerProductsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_UnallocatedCorporateMember" abstract="false" name="UnallocatedCorporateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CommonStockPurchaseWarrantsMember" abstract="false" name="CommonStockPurchaseWarrantsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_ConsultingServicesMember" abstract="true" name="ConsultingServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CapitalLeasesMember" abstract="true" name="CapitalLeasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CurrentAndAccruedPayablesMember" abstract="true" name="CurrentAndAccruedPayablesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_ExistingLoanFromAffiliatesMember" abstract="true" name="ExistingLoanFromAffiliatesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_AccruedInterestMember" abstract="true" name="AccruedInterestMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_NoncashOrPartNoncashDivestitureCapitalExpendituresAvoided" abstract="false" name="NoncashOrPartNoncashDivestitureCapitalExpendituresAvoided" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_NoncashOrPartNoncashDivestitureEmployeeAnnualOverheadTransferred" abstract="false" name="NoncashOrPartNoncashDivestitureEmployeeAnnualOverheadTransferred" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_DisposalGroupIncludingDiscontinuedOperationRestrictedCash" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationRestrictedCash" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_DisposalGroupIncludingDiscontinuedOperationLongTermDebtNoncurrent" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationLongTermDebtNoncurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="prph_WarrantLiabilityFairValueDisclosure" abstract="false" name="WarrantLiabilityFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="prph_LoanAgreementsMember" abstract="true" name="LoanAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_AugustFutureFinancingAgreementMember" abstract="true" name="AugustFutureFinancingAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CollateralizedLoanMember" abstract="true" name="CollateralizedLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CollateralizedLoanTrancheOneMember" abstract="true" name="CollateralizedLoanTrancheOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_CollateralizedLoanTrancheTwoMember" abstract="true" name="CollateralizedLoanTrancheTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="prph_NoteMember" abstract="true" name="NoteMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
