
<PAGE>   1
_______________________________________________________________________________
_______________________________________________________________________________
                                      
                                      
                                      
                              SECURITY AGREEMENT
                                      
                          dated as of March 31, 1995
                                      
                                   Between
                                      
                                NEUROMED, INC.
                                  as Debtor
                                      
                                     and
                                      
                          NATIONSBANK OF TEXAS, N.A.
                               as Secured Party
                                      
                                      

_______________________________________________________________________________
_______________________________________________________________________________

<PAGE>   2
                              TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                                                     Page
                                                                                                                     ----         
<S>                                                                                                                  <C>
ARTICLE I.  GRANT

         1.1     Assignment and Grant of Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       1
         1.2     Description of Obligations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       4
         1.3     Debtor Remains Liable  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       4
         1.4     Delivery of Security Collateral  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       5

ARTICLE II.  REPRESENTATIONS AND WARRANTIES

         2.1     Representations and Warranties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       5

ARTICLE III.  COVENANTS

         3.1     Further Assurances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       7
         3.2     Equipment, Fixtures and Inventory  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       9
         3.3     Insurance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      10
         3.4     Place of Perfection; Records; Collection of Receivables, Chattel Paper and Instruments . . . .      10
         3.5     Transfers and Other Liens  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      11
         3.6     Brokerage Agreements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      11
         3.7     Rights to Dividends and Distributions  . . . . . . . . . . . . . . . . . . . . . . . . . . . .      12
         3.8     Right of Secured Party to Notify Issuers . . . . . . . . . . . . . . . . . . . . . . . . . . .      13
         3.9     Secured Party Appointed Attorney-in-Fact . . . . . . . . . . . . . . . . . . . . . . . . . . .      13

ARTICLE IV.  RIGHTS AND POWERS OF SECURED PARTY

         4.1     Secured Party May Perform  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      14
         4.2     Secured Party's Duties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      14
         4.3     Remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      14
         4.4     Further Approvals Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      16
         4.5     INDEMNITY AND EXPENSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      16
         4.6     Debtor Insolvency  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      17


</TABLE>



                                     - i -
<PAGE>   3
<TABLE>
<S>                                                                                                                  <C>
ARTICLE V.  MISCELLANEOUS

         5.1     Cumulative Rights  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      17
         5.2     Modifications; Amendments; Schedules; Etc. . . . . . . . . . . . . . . . . . . . . . . . . . .      17
         5.3     Continuing Security Interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      17
         5.4     MANDATORY ARBITRATION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      17
         5.5     GOVERNING LAW; TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      18
         5.6     WAIVER OF JURY TRIAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      19
         5.7     Secured Party's Right to Use Agents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      19
         5.8     No Interference, Compensation or Expense . . . . . . . . . . . . . . . . . . . . . . . . . . .      19
         5.9     Waivers of Rights Inhibiting Enforcement . . . . . . . . . . . . . . . . . . . . . . . . . . .      19
         5.10    Waiver of Subrogation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      19
         5.11    Notices and Deliveries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      20
                 (a) Manner of Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      20
                 (b) Addresses  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      20
                 (c) Effectiveness  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.12    Successors and Assigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.13    Loan Paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.14    Definitions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.15    Severability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.16    Obligations Not Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      21
         5.17    Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      22
         5.18    ENTIRE AGREEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      22



</TABLE>


                                     - ii -
<PAGE>   4
SCHEDULES:

         Schedule 1       - Inventory Locations
         Schedule 2       - Required Consents
         Schedule 3       - Bank Accounts
         Schedule 4       - Insurance
         Schedule 5       - Vendor Agreements
         Schedule 6       - Filing Locations
         Schedule 7       - Permits





                                    - iii -
<PAGE>   5
                               SECURITY AGREEMENT


         SECURITY AGREEMENT, dated as of March 31, 1995 (this "Agreement"),
made by Neuromed, Inc., a Florida corporation ("Debtor"), in favor of
NationsBank of Texas, N.A., a national banking association ("Secured Party").


                                  BACKGROUND.

         (1)     Secured Party and Quest Medical, Inc., a Texas corporation
("Borrower"), have entered into the Credit Agreement dated as of October 22,
1993 (as amended, the "Existing Credit Agreement"), the Security Agreement
dated May 28, 1993 ("Facility A Security Agreement"), the Security Agreement
dated as of October 22, 1993 ("Existing Security Agreement") and related
agreements.

         (2)     Secured Party and Borrower have entered into the First Amended
and Restated Credit Agreement dated as of March 31, 1995 (such agreement,
together with all amendments and restatements thereof, the "Credit Agreement")
which restates in its entirety the Existing Credit Agreement.  A portion of the
proceeds of advances under the Credit Agreement will be used to acquire all of
the capital stock of Debtor.

         (3)     It is the intention of the parties hereto that this Agreement
create a first priority security interest securing the payment of the
obligations set forth in Section 1.2.

         (4)     It is a condition precedent to the effectiveness of the Credit
Agreement that Debtor shall have executed and delivered this Security
Agreement.


                                   AGREEMENT.

         NOW, THEREFORE, in consideration of the premises set forth herein and
for other good and valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, and in order to induce Secured Party to make the
Advances under the Credit Agreement, Debtor hereby agrees with Secured Party as
follows:


ARTICLE I.  GRANT

         1.1     Assignment and Grant of Security.  Subject to the last
paragraph of this Section 1.1, Debtor hereby assigns and pledges to Secured
Party and hereby grants to Secured Party a security interest in, the entire
right, title and interest of Debtor, in and to the following assets of Debtor,
whether now owned or hereafter acquired ("Collateral"):

         (a)     all inventory in all of its forms, wherever located, now or
hereafter existing, including, but not limited to, (i) all raw materials and
work in process therefor, finished goods
<PAGE>   6
thereof, and materials used or consumed in the manufacture or production
thereof, (ii) goods in which Debtor has an interest in mass or a joint or other
interest or right of any kind (including, without limitation, goods in which
Debtor has an interest or right as consignee), and (iii) goods which are
returned to or repossessed by Debtor, and all accessions thereto and products
thereof and documents therefor (any and all such inventory, accessions,
products and documents being the "Inventory");

         (b)     all equipment (as defined in the Uniform Commercial Code) and
(whether or not included in such definition), all vehicles, machinery,
chattels, tools, parts, furniture, furnishings and supplies, of every nature,
wherever located, all additions, accessories and improvements thereto and
substitutions therefor and all accessories, parts and equipment which may be
attached to or which are necessary for the operation and use of such personal
property, together with all accessions thereto, and all rights under or arising
out of present or future contracts relating to the foregoing ("Equipment");

         (c)     all property so related to particular real estate that an
interest in it arises under the real estate law of the jurisdiction in which
such Collateral is located, including all equipment, fixtures and articles of
personal property now or hereafter attached to or used in or about any building
or buildings now erected or hereafter to be erected on any real property now or
hereafter owned or leased by Debtor (the "Property"), which are necessary to
the complete and comfortable use and occupancy of such building or buildings
for the purposes for which they were or are to be erected; all materials to be
delivered to the Property and used or to be used in connection with the
construction of any building to be constructed on the Property, including, but
not limited to, all masonry, siding, roof shingles, flooring, doors, windows,
tile, shutters, stoves, ovens, awnings, screens, cabinets, shades, blinds,
carpets, draperies, furniture, furnishings, plumbing, heating, air
conditioning, lighting, ventilating, refrigerating, cooking, laundry and
incinerating equipment and all fixtures and appurtenances thereto, and such
other goods and chattels and personal property as are ever used or furnished in
operating such buildings or the activities conducted therein, and all building
materials and equipment now or hereafter delivered to the Property and intended
to be installed thereon ("Fixtures");

         (d)     all general intangibles (as defined in the Uniform Commercial
Code), and (whether or not included in such definition) all contract rights
other than Receivables; all inventions, processes, production methods,
proprietary information and know-how; and all licenses or other agreements
granted to Debtor with respect to any of the foregoing; all information,
customer lists, advertising lists, advertising contracts, identification of
suppliers, data, plans, blueprints, specifications, designs, drawings, recorded
knowledge, surveys, engineering reports, test reports, manuals, materials
standards, processing standards, performance standards, telephone numbers and
telephone listings, catalogs, books, records, computer and automatic machinery
software and programs, and the like pertaining to operations by or the business
of Debtor; all field accounting information and all media in which or on which
any of the information or knowledge or data or records may be recorded or
stored and all computer programs used for the compilation or printout of such
information, knowledge, records or data; all licenses, consents, permits,
variances, certifications and approvals of all





                                       2
<PAGE>   7
Tribunals now or hereafter held by Debtor pertaining to operations or business
now or hereafter conducted; all rights to receive return of deposits and trust
payments; all rights to payment under letters of credit and similar agreements;
all tax refunds (including, without limitation, all federal and state income
tax refunds and benefits of net operating loss carry forwards); and all causes
of action, rights, claims and warranties now or hereafter owned or acquired by
Debtor ("General Intangibles");

         (e)     all of the following, to the extent that not included in
"General Intangibles":  trade secrets, all know-how, inventions, processes,
methods, information, data, plans, blueprints, specifications, designs,
drawings, engineering reports, test reports, materials standards, processing
standards and performance standards, and all computer and automatic machinery
software and programs directly related thereto, and all licenses or other
agreements to which Debtor is a party with respect to any of the foregoing
("Trade Secrets");

         (f)     all instruments and letters of credit (each as defined in the
Uniform Commercial Code), and (whether or not included in such definitions) all
promissory notes, drafts, bills of exchange and trade acceptances
("Instruments");

         (g)     all writings which evidence both a monetary obligation and a
security interest in or a lease of specific goods ("Chattel Paper");

         (h)     all documents, warehouse receipts, bills of lading, including,
without limitation, documents of title (as defined in the Uniform Commercial
Code) or other receipts covering, evidencing or representing any property
described in this Section 1.1 ("Documents");

         (i)     all accounts, contract rights, Chattel Paper, Documents,
Instruments and letters of credit, deposit accounts, general intangibles, tax
refunds and other obligations of any kind owing to Debtor, now or hereafter
existing, arising out of or in connection with the sale or lease of goods or
the rendering of services, and all rights now or hereafter existing in and to
all security agreements, leases, and other contracts securing or otherwise
relating to any such accounts, contract rights, Chattel Paper, Documents,
Instruments, deposit accounts, General Intangibles or obligations (any and all
such accounts, contract rights, Chattel Paper, Documents, Instruments, deposit
accounts, General Intangibles and obligations being the "Receivables");

         (j)     all licenses, permits and other similar rights now or
hereafter owned by Debtor (including but not limited to all licenses, permits
and similar rights issued by the FDA) and necessary to the operation of its
business, including but not limited to all licenses, permits and other rights
listed on Schedule 9;

         (k)     all rights, claims and benefits of Debtor against any Person
arising out of, relating to or in connection with any property described in
this Section 1.1 purchased by Debtor, including, without limitation, any such
rights, claims or benefits against any Person storing or transporting any
property described in this Section 1.1;





                                       3
<PAGE>   8
         (l)     the balance of every deposit account of Debtor under control
of Secured Party and each of its Affiliates and any other claim of Debtor
against Secured Party, now or hereafter existing, liquidated or unliquidated,
and all money, Instruments, securities, Documents, Chattel Paper, credits,
claims, demands, income, and any other property, rights and interests of Debtor
which at any time shall come into the possession or custody or under the
control of Secured Party or any of its agents, affiliates or correspondents,
for any purpose, and the proceeds of any thereof (Secured Party shall be deemed
to have possession of any of the Collateral in transit to or set apart for it
or any of its agents, affiliates or correspondents.  The holder of any
participation in the Obligations shall have a right of setoff with respect to
any obligation of such holder to Debtor to satisfy the Obligations);

         (m)     all agreements with vendors and other distributors of
Inventory, including but not limited to those described in Schedule 5;

         (n)     all insurance policies and bonds and claims and payments
thereunder;

         (o)     all property similar to the above hereafter acquired by Debtor;
and

         (p)     all accessions to, substitutions for and replacements,
proceeds and products of any and all of the foregoing Collateral (including,
without limitation, proceeds which constitute property of the types described
in this Section 1.1) and, to the extent not otherwise included, all (i)
payments under insurance (whether or not Secured Party is the loss payee
thereof), or any indemnity, warranty or guaranty, payable by reason of loss or
damage to or otherwise with respect to any of the foregoing Collateral and (ii)
cash.

         1.2     Description of Obligations.  This Agreement creates a first
priority security interest securing the payment and performance of the
Obligations, including, but not limited to any and all obligations now or
hereafter existing of Debtor, Borrower and each other Obligor under the Credit
Agreement and other Loan Papers, including any extensions, modifications,
substitutions, amendments and renewals thereof, whether for principal,
interest, fees, premium, expenses, indemnification or otherwise (all such
obligations of Debtor and each other Obligor being the "Obligations").  Without
limiting the generality of the foregoing, this Agreement secures the payment of
all amounts which constitute part of the Obligations and would be owed by
Debtor and each other Obligor to Secured Party under any Loan Paper, but for
the fact that they are unenforceable or not allowable due to the existence of a
bankruptcy, reorganization or similar proceeding involving Debtor or any other
Person (including all after, or that would have secured but for, the filing of
any petition in bankruptcy, or the commencement of any insolvency,
reorganization or like proceeding of Debtor or any other Obligor).

         1.3     Debtor Remains Liable.  Anything herein to the contrary
notwithstanding, (a)  Debtor shall remain liable under the contracts and
agreements included in the Collateral to the extent set forth therein to
perform all of its duties and obligations thereunder to the same extent as if
this Agreement had not been executed, (b) the exercise by Secured Party of any
of the Rights hereunder shall not release Debtor from any of its duties or
obligations under the





                                       4
<PAGE>   9
contracts and agreements included in the Collateral, and (c) Secured Party
shall not have any obligation or liability under the contracts and agreements
included in the Collateral by reason of this Agreement, nor shall Secured Party
be obligated to perform any of the obligations or duties of Debtor thereunder
or to take any action to collect or enforce any claim for payment assigned
hereunder.

         1.4     Delivery of Security Collateral.  All certificates or
instruments representing or evidencing the Collateral and which are issued in
the name of Debtor shall be delivered to and held by or on behalf of Secured
Party pursuant hereto and shall be in suitable form for transfer by delivery,
or shall be accompanied by duly executed instruments of transfer or assignment
in blank, all in form and substance satisfactory to Secured Party.  If an Event
of Default exists, Secured Party shall have the right, at any time during such
time in its discretion and without notice to Debtor, to (a) require the
issuance in the name of Debtor and delivery to Secured Party of certificates or
instruments evidencing the interest owned by Debtor in the issuer of such
certificate or instrument (if the security is subject to a Brokerage Agreement
and the Brokerage Agreement permits such issuance) and (b) transfer to or to
register in the name of Secured Party or any of its nominees any or all of the
Collateral.  In addition, Secured Party shall have the right at any time to
exchange certificates or instruments representing or evidencing Collateral for
certificates or instruments of smaller or larger denominations.


ARTICLE II.  REPRESENTATIONS AND WARRANTIES

         2.1     Representations and Warranties.  Debtor represents and
warrants, with respect to itself and the Collateral, as follows:

         (a)     All of the Equipment, Fixtures and Inventory pledged by Debtor
hereunder is located at the places specified on Schedule 1 hereto (as
supplemented from time to time by Debtor by written notice to Secured Party) or
Inventory in transit to a place specified on Schedule 1 hereto (as supplemented
from time to time by Debtor by written notice to Secured Party) or Inventory in
transit (i) for sale to a third-party purchaser that upon such sale will become
the obligor under a Receivable and (ii) pursuant to a sale in the ordinary
course of Debtor's business.  The chief place of business and chief executive
office of Debtor and the office where Debtor keeps all of its records
concerning the Receivables, are located at One Allentown Parkway, Allen, Texas
75002.  All Chattel Paper, promissory notes or other instruments evidencing the
Receivables have been delivered and pledged to Secured Party duly endorsed and
accompanied by such duly executed instruments of transfer or assignment as are
necessary for such pledge, to be held as pledged collateral.  Debtor has
possession and control of the Equipment and Inventory pledged by it hereunder.
The record owner of the real estate upon which the Equipment, Fixtures and
Inventory are located are indicated on Schedule 1.

         (b)     Debtor is the legal and beneficial owner of the Collateral
pledged by it free and clear of any Lien, security interest, option or other
charge or encumbrance except for the security interest created by this
Agreement and Permitted Liens.  No effective financing





                                       5
<PAGE>   10
statement or other similar document used to perfect and preserve a security
interest under the Laws of any jurisdiction covering all or any part of the
Collateral is on file in any recording office, except (i) such as may have been
filed in favor of Secured Party relating to this Agreement and (ii) financing
statements for which Debtor will provide to Secured Party on the Closing Date
proper original executed termination statements.  As of the date hereof, Debtor
(including any corporate or partnership predecessor) has no trade names and has
not existed or operated under any name other than "Neuromed, Inc.," since March
31, 1985.

         (c)     This Agreement and the pledge of the Collateral pursuant
hereto creates a valid and, upon filing of financing statements in the Uniform
Commercial Code records described on Schedule 6, perfected first priority
security interest in the Collateral (other than deposit accounts in financial
institutions which are not Secured Party or subject to a Broker Agreement),
securing the payment of the Obligations, and all filings and other actions
necessary or desirable to perfect and protect such security interest and such
priority have been duly taken (or will be taken).

         (d)     Except as described on Schedule 2, no consent of any other
Person and no authorization, approval or other action by, and no notice to or
filing with, any Tribunal is required (i) for the pledge by Debtor of the
Collateral pledged by it hereunder, for the grant by Debtor of the security
interest granted hereby or for the execution, delivery or performance of this
Agreement by Debtor, (ii) for the perfection or maintenance of the pledge,
assignment and security interest created hereby (including the first priority
nature of such pledge, assignment and security interest) or (iii) for the
exercise by Secured Party of the Rights provided for in this Agreement or the
remedies in respect of the Collateral pursuant to this Agreement.

         (e)     Schedule 3 is a complete and correct list of all deposit
accounts (demand, time, special or other) maintained by or in which Debtor has
an interest and correctly describes the financial institution in which such
account is maintained (including the specific branch), the address and ABA
number of such institution, the officer of such institution having primary
responsibility for Debtor's accounts, the account number and type (as
supplemented from time to time by Debtor by written notice to Secured Party).

         (f)     Debtor possesses all licenses and Permits, including but not
limited to all applicable certificates of occupancy, licenses and Permits, and
all health and sanitation permits, required for the operations of its business.
Schedule 7 is a complete and correct description of all of such licenses and
Permits.

         (g)     Schedule 4 is a complete and correct list of all insurance
policies for which Debtor is an insured or for which Debtor is a loss payee.

         (h)     Schedule 5 is a complete and correct list of all agreements
with each Person related to the resale and distribution of Inventory for each
Person who, during the preceding fiscal year, sold or distributed $25,000 or
more of Debtor's Inventory.





                                       6
<PAGE>   11
         (i)     Schedule 10 is a complete and correct list of all Acquisition
Documents, together with all modifications thereto.

         (j)     All Inventory of Debtor produced by Debtor in the United
States of America has been produced in compliance with the Fair Labor Standards
Act.

         (k)     Debtor's federal taxpayer identification number is 59-2071994.

         (l)     The value of the consideration received and to be received by
Debtor is reasonably worth at least as much as the liability and obligation of
Debtor hereunder, and such liability and obligation may reasonably be expected
to benefit Debtor directly or indirectly; Debtor is familiar with, and has
independently reviewed books and records regarding, the financial condition of
Borrower or any other Obligor and is familiar with the value of any and all
collateral intended to be created as security for the payment of the
Obligation; however, Debtor is not relying on such financial condition or the
collateral as an inducement to enter into this Agreement; and none of Secured
Party or any other Person has made any representation, warranty or statement to
Debtor in order to induce Debtor to execute this Agreement.

         (m)     There are no conditions precedent to the effectiveness of this
Agreement that have not been satisfied or waived.


ARTICLE III.  COVENANTS

         3.1     Further Assurances.  (a)  Debtor agrees that, where any
agreement intended to be Collateral existing as of the date hereof or hereafter
to which Debtor is a party contains any restriction prohibiting Debtor from
granting any security interest under this Agreement, Debtor will use its best
efforts to obtain the necessary consent to or waiver of such restriction from
any Person so as to enable Debtor to effectively grant to Secured Party such
security interest under this Agreement.

         (b)     Debtor agrees that from time to time, at the expense of
Debtor, Debtor will promptly execute and deliver all further instruments and
documents, and take all further action, that may be reasonably necessary or
desirable, or that Secured Party may reasonably request, in order to perfect
and protect any pledge, assignment or security interest granted or purported to
be granted hereby, and the priority thereof, or to enable Secured Party to
exercise and enforce its rights and remedies hereunder with respect to any
Collateral.  Without limiting the generality of the foregoing, upon written
request by Secured Party, Debtor will: (i) mark conspicuously each Chattel
Paper included in Receivables, and, at the request of Secured Party, each of
its records pertaining to the Collateral with the following legend:





                                       7
<PAGE>   12
         THIS INSTRUMENT IS SUBJECT TO A SECURITY INTEREST AND LIEN PURSUANT TO
         A SECURITY AGREEMENT DATED MARCH 31, 1995 (AS THE SAME MAY BE MODIFIED
         OR RESTATED) MADE BY NEUROMED, INC., IN FAVOR OF NATIONSBANK OF TEXAS,
         N.A.

or such other legend, in form and substance satisfactory to and as specified by
Secured Party, indicating that such Chattel Paper or Collateral is subject to
the pledge, assignment and security interest granted hereby; (ii) if any
Collateral shall be evidenced by a promissory note or other Instrument or be
Chattel Paper, deliver and pledge to Secured Party hereunder such note,
Instrument or Chattel Paper duly indorsed and accompanied by duly executed
instruments of transfer or assignment, all in form and substance satisfactory
to Secured Party; and (iii) execute and file such financing or continuation
statements, or amendments thereto, and such other instruments or notices, as
may be necessary or desirable, or as Secured Party may request, in order to
perfect and preserve the pledge, assignment and security interest granted (and
the priority thereof) or purported to be granted hereby.

         (c)     Debtor hereby authorizes Secured Party to file one or more
financing or continuation statements, and amendments thereto, relating to all
or any part of the Collateral without the signature of Debtor where permitted
by Law.  A photocopy or other reproduction of this Agreement or any financing
statement covering the Collateral or any part thereof shall be sufficient as a
financing statement where permitted by Law.

         (d)     Debtor will furnish to Secured Party from time to time
statements and schedules further identifying and describing the Collateral
(including information in connection with the protection, preservation,
maintenance or enforcement of the security interest) and such other reports in
connection with the Collateral as Secured Party may reasonably request, all in
reasonable detail; provided, if no Default or Event of Default exists, Secured
Party will not make more than one request in any six month period.

         (e)     Debtor shall not establish or maintain any deposit or similar
bank account not listed on Schedule 3 unless Secured Party receives prior
written notice thereof, Debtor executes and delivers to Secured Party
assignments of such account in such form as Secured Party may request and the
financial institution in which such account will be maintained delivers to
Secured Party acknowledgments of the assignment of such account in form and
substance satisfactory to Secured Party.

         (f)     In addition to such other information as shall be specifically
provided for herein, Debtor shall, if a Default or an Event of Default exists,
furnish to Secured Party such other information with respect to the Collateral
as Secured Party may reasonably request from time to time in connection with
the Collateral, including, without limitation, all documents and things in
Debtor's possession, or subject to its demand for possession, related to the
production and sale by Debtor, or any subsidiary, licensee or subcontractor
thereof, of products or services sold by or under the authority of Debtor,
including by way of example, without limiting the interest granted by this
Agreement:  (i) all lists and ancillary documents which identify and describe
any





                                       8
<PAGE>   13
of Debtor's customers, advertisers, or those of its Subsidiaries or licensees,
for products sold or services rendered, including without limitation, such
existing lists and ancillary documents which contain each customer's full name
and address, the identity of the Person or Persons having the principal
responsibility on each customer's behalf for ordering products or services of
the kind supplied by Debtor, the credit, payment, discount, delivery and other
sale terms applicable to such customer, together with detailed information
setting forth the total purchases and the patterns of such purchases; (ii) all
product and service specification documents and production and quality of
services sold; (iii) all documents which reveal the names and addresses of all
sources of supply, and all terms of purchase and delivery, for all materials
and components used in the production of products or provision of services
sold; and (iv) all documents constituting or concerning the then current or
proposed advertising and promotion by Debtor or its subsidiaries, licensees or
subcontractors of products or services sold, including, by way of example and
not in limitation, all documents which reveal the media used or to be used and
the cost for all such advertising conducted within the described period or
planned for such products or services.  In connection with its enforcement of
the security interest, Secured Party may use such information or transfer it to
any assignee or sublicensee permitted hereunder for such assignee's or
sublicensee's use.

         3.2     Equipment, Fixtures and Inventory.

         (a)     Debtor shall keep the Equipment, Fixtures and Inventory
pledged by it hereunder (other than Inventory sold in the ordinary course of
business) at the places therefor specified in Section 2.1(a) or, upon thirty
days' prior written notice to Secured Party, at such other places in such
jurisdiction where all action required by Section 3.1 shall have been taken
with respect to the Equipment, Fixtures and Inventory.

         (b)     Debtor shall cause the Equipment and Fixtures pledged by it
hereunder to be maintained and preserved in the same condition, repair and
working order as when new, ordinary wear and tear excepted, and shall
forthwith, or in the case of any loss or damage to any of the Equipment and
Fixtures as quickly as practicable after the occurrence thereof, make or cause
to be made all repairs, replacements, and other improvements in connection
therewith which are necessary or desirable to such end (if, pursuant to Section
3.3, Secured Party releases to Debtor insurance payments in respect of the loss
or damage).  Debtor shall promptly furnish to Secured Party a statement
respecting any loss or damage which singly equals or exceeds $25,000 to any of
the Equipment and Fixtures pledged by it hereunder.

         (c)     Debtor shall pay promptly when due or before penalty all
property and other taxes, assessments and governmental charges or levies
imposed upon, and all claims (including claims for labor, materials and
supplies) against, the Collateral pledged by it hereunder, except such taxes as
are being contested in good faith by appropriate proceedings for which adequate
reserves have been established in accordance with GAAP, except where the
failure to file such returns, pay such taxes or establish such reserves does
not involve unpaid or allegedly unpaid amounts, in aggregate, in excess of
$50,000.  Debtor shall comply with, and shall cause its licensees to comply
with, all requirements of the FDA Act and the Fair Labor Standards Act.





                                       9
<PAGE>   14
         3.3     Insurance.  Debtor shall, at its own expense, maintain
insurance with respect to the Collateral in accordance with the terms set forth
in Section 4.4 of the Credit Agreement.  Debtor further covenants and agrees to
keep the Collateral which is Equipment, Fixtures and Inventory and other
tangible personal property insured in such amounts, against such risks and with
such insurers as Secured Party may reasonably require.  All such policies of
insurance shall be written for the benefit of Secured Party and Debtor, as
their interests may appear, and shall provide for at least thirty Business
Days' prior written notice of cancellation to Secured Party.  Debtor shall
promptly furnish to Secured Party evidence of such insurance in form and
content satisfactory to Secured Party.  If Debtor fails to perform or observe
any applicable covenants as to insurance on any of such Collateral, Secured
Party may at its own option obtain insurance on only Secured Party's interest
in such Collateral, any premium thereby paid by Secured Party to become part of
the Obligations, bear interest prior to the existence of an Event of Default,
at the then applicable Prime Base Rate, and during the existence of an Event of
Default, at the lesser of (a) the Prime Base Rate, plus 3% and (b) the Highest
Lawful Rate.  In the event Secured Party maintains such substitute insurance,
the additional premium for such insurance shall be due on demand and payable by
Debtor to Secured Party in accordance with any notice delivered to Debtor by
Secured Party.  Debtor hereby grants Secured Party a security interest in any
refunds of unearned premiums in connection with any cancellation, adjustment or
termination of any policy of insurance required by Secured Party and in all
proceeds of such insurance and hereby appoints Secured Party its
attorney-in-fact to endorse any check or draft that may be payable to Debtor in
order to collect such refunds or proceeds.  Any such sums collected by Secured
Party shall be credited, except to the extent applied to the purchase by
Secured Party of similar insurance, to any amounts then owing on the
Obligations in accordance with the Credit Agreement.  If no Default under
Section 4.2, 5.5, 5.6, 5.9, 5.10 or 5.12 of the Credit Agreement or an Event of
Default exists, Lender shall deliver to Debtor all insurance payments in
respect of any covered loss and any refund of any premium or other payment;
provided Debtor uses the payment in respect of an insured loss to acquire a
replacement asset of similar value.

         3.4     Place of Perfection; Records; Collection of Receivables,
Chattel Paper and Instruments.

         (a)     Debtor shall keep its chief place of business and chief
executive office and the office where it keeps its records concerning the
Receivables, and the originals of all Chattel Paper, at the location therefor
specified in Section 2.1(a) or at such other location in the State of Texas as
Debtor shall have given written notice thereof to Secured Party no later than
30 days prior to the moving thereto.  Debtor shall deliver to Secured Party all
original Brokerage Agreements to be held by Secured Party as collateral.
Debtor will hold and preserve such records and Chattel Paper and will permit
representatives of Secured Party at any time during normal business hours to
inspect and make abstracts from and copies of such records and Chattel Paper.
Debtor shall deliver to Secured Party all Instruments to be held by Secured
Party as collateral.





                                       10
<PAGE>   15
         (b)     Except as otherwise provided in this Section 3.4(b), Debtor
shall continue to collect, at its own expense, all amounts due or to become due
Debtor under the Receivables, Chattel Paper and Instruments.  In connection
with such collections, Debtor may take (and, at Secured Party's direction,
shall take) such action as Debtor or Secured Party may deem reasonably
necessary or advisable to enforce collection of the Receivables, Chattel Paper
and Instruments; provided, however, that Secured Party shall have the right (if
an Event of Default exists) (without notice to Debtor) to notify the account
debtors or obligors under any Receivables, Chattel Paper and Instruments of the
assignment of such Receivables, Chattel Paper and Instruments to Secured Party
and to direct such account debtors or obligors to make payment of all amounts
due or to become due to Debtor thereunder directly to Secured Party and, at the
expense of Debtor, to enforce collection of any such Receivables, Chattel Paper
and Instruments, and to adjust, settle or compromise the amount or payment
thereof, in the same manner and to the same extent as Debtor might have done.
All amounts and proceeds (including Instruments) received by Debtor in respect
of the Receivables, Chattel Paper and Instruments shall be received in trust
for the benefit of Secured Party hereunder, shall be segregated from other
funds of Debtor and shall be forthwith paid over to Secured Party in the same
form as so received (with any necessary indorsement) to be held as cash
collateral and either (A) released to Debtor so long as no Default under
Section 4.2, 5.5, 5.6, 5.9, 5.10 or 5.12 of the Credit Agreement or Event of
Default exists or (B) if any Default under Section 4.2, 5.5, 5.6, 5.9, 5.10 or
5.12 of the Credit Agreement or Event of Default exists, applied as provided
herein.  Debtor shall not adjust, settle or compromise the amount or payment of
any Receivable, Chattel Paper or Instrument, release wholly or partly any
account debtor or obligor thereof, or allow any credit or discount thereon
except in accordance with Debtor's historical operating procedure.

         3.5     Transfers and Other Liens.  Debtor shall not (i) sell, assign
(by operation of Law or otherwise) or otherwise dispose of, or grant any option
with respect to, any of the Collateral, except as permitted under the Credit
Agreement and this Agreement, or (ii) create or permit to exist any Lien,
security interest, option or other charge or encumbrance upon or with respect
to any of the Collateral, except for the security interest under this Agreement
(and except as provided for in the Credit Agreement).  Debtor may sell
Inventory in the ordinary course of business.  Debtor may sell investments
subject to a Brokerage Agreement in which Secured Party has a security
interest; provided, that the proceeds of such sale are subject to a Brokerage
Agreement in which Secured Party has a perfected, first priority security
interest in favor of Secured Party and such sale is in the ordinary course of
Debtor's investment portfolio management.  Debtor shall not permit any
amendment, restatement or termination of any Brokerage Agreement without the
prior written consent of Secured Party.

         3.6     Brokerage Agreements.

         (a)     Debtor shall, if any of the shares, securities, moneys or
property previously held by a Person other than Debtor pursuant to a Brokerage
Agreement are received by Debtor, forthwith transfer and deliver to Secured
Party such shares, securities, moneys or property so received by Debtor
(together with the certificates for any such shares and securities duly
endorsed in blank or accompanied by undated stock powers duly executed in
blank), all of which





                                       11
<PAGE>   16
thereafter shall be held by Secured Party, pursuant to the terms of this
Agreement, as part of the Collateral; provided, that if no Event of Default
exists, Debtor may receive cash distributions and dividends (not consisting of
a distribution of or return of capital) declared and paid with respect to any
securities.

         (b)          (i)         For the better perfection of Secured Party's
         Rights in and to the Brokerage Agreements or any part thereof and to
         facilitate implementation of such Rights, Debtor shall, insofar as
         possible, if an Event of Default exists and upon the request of
         Secured Party (if Secured Party deems such action necessary to the
         perfection or priority of the Liens in the Collateral), cause the
         Brokerage Agreements to be transferred, registered or otherwise put
         into the name or names of such nominee or nominees of Secured Party as
         Secured Party shall from time to time direct.

                     (ii)         So long as no Event of Default exists (and
         after any Event of Default until, by notice to Debtor, Secured Party
         elects while the Event of Default is continuing to exercise the right
         to vote or consent), Debtor shall retain the right to exercise all
         voting, consensual and other power of ownership pertaining to the
         Brokerage Agreements owned by it for all purposes not inconsistent
         with the terms of this Agreement or any other Loan Paper; and Secured
         Party shall execute and deliver to Debtor or cause to be executed and
         delivered to Debtor all such proxies, powers of attorney, dividend and
         other orders, and all such instruments, without recourse, as Debtor
         may reasonably request for the purpose of enabling Debtor to exercise
         the rights and powers which it  is entitled to exercise pursuant to
         this Section 3.6.

                    (iii)         If any Event of Default exists, and whether
         or not Secured Party exercises any available Right to declare any
         Obligations due and payable or seeks or pursues any other relief or
         remedy available under applicable Laws or under any agreement relating
         to such Obligations, all distributions and dividends on any securities
         and payments and distributions in respect of each Brokerage Agreement
         shall be paid directly to Secured Party and retained by it as part of
         the Collateral subject to the terms of this Agreement, and, if Secured
         Party shall so request, Debtor agrees to execute and deliver to
         Secured Party appropriate additional dividend, distribution and other
         orders and documents to that end.

         3.7     Rights to Dividends and Distributions.  With respect to any
certificates, bonds, or other instruments or securities (including but not
limited to any certificate or participation issued in any proceeding under any
Debtor Relief Law) constituting a part of the Collateral, Secured Party shall
have authority if an Event of Default exists, without notice to Debtor, either
to have the same registered in Secured Party's name or in the name of a
nominee, and, with or without such registration, to demand of the issuer
thereof, and to receive and receipt for, any and all distributions (including
any stock or similar dividend or distribution) payable in respect thereof,
whether they be ordinary or extraordinary.  Except for any property maintained
in a Brokerage Account, if Debtor shall become entitled to receive or shall
receive any interest in or certificate (including, without limitation, any
interest in or certificate representing a





                                       12
<PAGE>   17
distribution in connection with any reclassification, increase, or reduction of
capital, or issued in connection with any reorganization), or any option or
rights arising from or relating to any of the Collateral, whether as an
addition to, in substitution of, as a conversion of, or in exchange for any of
the Collateral, or otherwise, Debtor agrees to accept the same as Secured
Party's agent and to hold the same in trust on behalf of and for the benefit of
Secured Party, and to deliver the same immediately to Secured Party in the
exact form received, with appropriate undated stock or similar powers, duly
executed in blank, to be held by Secured Party, subject to the terms hereof, as
Collateral.  Unless an Event of Default is in existence, Debtor shall be
entitled to receive all cash dividends paid in respect of any of the Collateral
(subject to the restrictions of any other Loan Paper).

         3.8     Right of Secured Party to Notify Issuers.  If an Event of
Default exists and at such other times as Secured Party is entitled to receive
dividends or distributions and other property in respect of or consisting of
Instruments and securities, Secured Party may notify each party to a Brokerage
Agreement and issuers of the Instruments and securities to make payments of all
dividends and distributions directly to Secured Party and Secured Party may
take control of all proceeds of any Instruments and securities.  Until Secured
Party elects to exercise such Rights, during the continuance of an Event of
Default, Debtor, as agent of Secured Party, shall collect and segregate all
dividends and distributions and other amounts paid or distributed with respect
to the Instruments and securities.

         3.9     Secured Party Appointed Attorney-in-Fact.  Debtor hereby
irrevocably appoints Secured Party Debtor's attorney-in-fact, with full
authority in the place and stead of Debtor and in the name of Debtor or
otherwise to take any action and to execute any instrument which Secured Party
may deem necessary or advisable to accomplish the purposes of this Agreement,
including, without limitation (provided that the actions listed in each clause
below other than the obtainment of insurance may only be taken or exercised if
an Event of Default exists):

         (a)     to obtain and adjust insurance required to be paid to Secured
Party pursuant to Section 3.3,

         (b)     to ask, demand, collect, sue for, recover, compromise, receive
and give acquittance and receipts for moneys due and to become due under or in
connection with the Collateral,

         (c)     to receive, indorse, and collect any drafts or other
Instruments, documents and Chattel Paper, in connection therewith, and

         (d)     to file any claims or take any action or institute any
proceedings which Secured Party may deem necessary or desirable for the
collection of any of the Collateral or otherwise to enforce compliance with the
terms and conditions of any Collateral or the rights of Secured Party with
respect to any of the Collateral.  DEBTOR HEREBY IRREVOCABLY GRANTS TO SECURED
PARTY DEBTOR'S PROXY (EXERCISABLE IF AN EVENT OF DEFAULT EXISTS) TO VOTE ANY
SECURITIES COLLATERAL AND APPOINTS





                                       13
<PAGE>   18
SECURED PARTY DEBTOR'S ATTORNEY-IN-FACT TO PERFORM ALL OBLIGATIONS OF DEBTOR
UNDER THIS AGREEMENT AND TO EXERCISE ALL OF SECURED PARTY'S RIGHTS HEREUNDER.
THE PROXY AND EACH POWER OF ATTORNEY HEREIN GRANTED, AND EACH STOCK POWER AND
SIMILAR POWER NOW OR THEREAFTER GRANTED (INCLUDING ANY EVIDENCED BY A SEPARATE
WRITING), ARE COUPLED WITH AN INTEREST AND ARE IRREVOCABLE PRIOR TO FINAL
PAYMENT IN FULL OF THE OBLIGATIONS.


ARTICLE IV.  RIGHTS AND POWERS OF SECURED PARTY

         4.1     Secured Party May Perform.  If Debtor fails to perform any
agreement contained herein, Secured Party may itself perform, or cause
performance of, such agreement, and the expenses of Secured Party incurred in
connection therewith shall be payable by Debtor under Section 4.5.

         4.2     Secured Party's Duties.  The powers conferred on Secured Party
hereunder are solely to protect its interest in the Collateral and shall not
impose any duty upon it or any Secured Party to exercise any such powers.
Except for the safe custody of any Collateral in its possession and the
accounting for moneys actually received by it hereunder, Secured Party shall
have no duty as to any Collateral, as to ascertaining or taking action with
respect to calls, conversions, exchanges, maturities, tenders or other matters
relative to any Collateral, whether or not Secured Party has or is deemed to
have knowledge of such matters, or as to the taking of any necessary steps to
preserve rights against prior parties or any other rights pertaining to any
reasonable care in the custody and preservation of any Collateral in its
possession if such Collateral is accorded treatment substantially equal to that
which Secured Party accords its own property.  Except as provided in this
Section 4.2, Secured Party shall not have any duty or liability to protect or
preserve any Collateral or to preserve rights pertaining thereto.  Nothing
contained in this Agreement shall be construed as requiring or obligating
Secured Party, and Secured Party shall not be required or obligated, to (a)
present or file any claim or notice or take any action, with respect to any
Collateral or in connection therewith or (b) notify Debtor of any decline in
the value of any Collateral.

         4.3     Remedies.  If any Event of Default exists:

         (a)     Secured Party may exercise in respect of the Collateral, in
addition to other rights and remedies provided for herein or otherwise
available to it, all the rights and remedies of a secured party on default
under the Uniform Commercial Code in effect in the State of Texas at that time
(the "UCC") (whether or not the Uniform Commercial Code applies to the affected
Collateral), and also may (i) require Debtor to, and Debtor hereby agrees that
it will at its expense and upon request of Secured Party forthwith, assemble
all or part of the Collateral as directed by Secured Party and make it
available to Secured Party at a place to be designated by Secured Party which
is reasonably convenient to both parties at public or private sale, at any of
Secured Party's offices or elsewhere, for cash, on credit or for future
delivery, and upon such





                                       14
<PAGE>   19
other terms as Secured Party may deem commercially reasonable.  Debtor agrees
that, to the extent notice of sale shall be required by Law, ten days' notice
to Debtor of the time and place of any public sale or the time after which any
private sale is to be made shall constitute reasonable notification.  Secured
Party shall not be obligated to make any sale of Collateral regardless of
notice of sale having been given.  Secured Party may adjourn any public or
private sale from time to time by announcement at the time and place fixed
therefor, and such sale may, without further notice, be made at the time and
place to which it was so adjourned.

         (b)     All cash proceeds received by Secured Party upon any sale of,
collection of, or other realization upon, all or any part of the Collateral
shall be applied as follows:

         First:  To the payment of all out-of-pocket costs and expenses
         incurred in connection with the sale of, collection of or other
         realization upon Collateral, including reasonable attorneys' fees and
         disbursements;

         Second:  To the payment of the Obligations in such order and in such
         manner consistent with applicable Laws as Secured Party in its
         discretion shall decide (with Debtor remaining liable for any
         deficiency); and

         Third:  To the extent of the balance (if any) of such proceeds, to
         Debtor or other Person legally entitled thereto.

         (c)     All payments received by Debtor under or in connection with
any Collateral shall be received in trust for the benefit of Secured Party,
shall be segregated from other funds of Debtor and shall be forthwith paid over
to Secured Party in the same form as so received (with any necessary
indorsement).

         (d)     Because of the FDA Act, the Securities Act of 1933, as amended
("Securities Act") and other Laws, including without limitation state blue sky
Laws, or contractual restrictions or agreements imposed by any licensor or
licensee of certain Rights, there may be legal restrictions or limitations
affecting Secured Party in any attempts to dispose of the Collateral and the
enforcement of its Rights hereunder.  For these reasons, Secured Party is
hereby authorized by Debtor, but not obligated, if any Event of Default exists,
to sell or otherwise dispose of any of the Collateral at private sale, subject
to an investment letter, or in any other manner which will be in compliance
with the FDA Act, will not require the Collateral, or any part thereof, to be
registered in accordance with the Securities Act, and the rules and regulations
promulgated under the foregoing, and each other Law applicable to the
Collateral.  Secured Party is also hereby authorized by Debtor, but not
obligated, to take such actions, give such notices, obtain such consents, and
do such other things as Secured Party may deem required or appropriate under
the FDA Act, Securities Act or other Laws or contractual restrictions or
agreements in the event of a sale or disposition of any Collateral.  Debtor
clearly understands that Secured Party may in its discretion approach a
restricted number of potential purchasers and that a sale under such
circumstances may yield a lower price for the Collateral than would otherwise
be obtainable if same were registered and sold in the open market.  No





                                       15
<PAGE>   20
sale so made in good faith by Secured Party shall be deemed to be not
"commercially reasonable" because so made.  Debtor agrees that in the event
Secured Party shall, if an Event of Default exists, sell the Collateral or any
portion thereof at any private sale or sales, Secured Party shall have the
right to rely upon the advice and opinion of appraisers and other Persons,
which appraisers and other Persons are acceptable to Secured Party, as to the
best price reasonably obtainable upon such a private sale thereof.  In the
absence of fraud, such reliance shall be conclusive evidence that Secured Party
handled such matter in a commercially reasonable manner under applicable Law.

         4.4     Further Approvals Required.

         (a)     In connection with the exercise by Secured Party of its Rights
hereunder that effects the disposition of or use of any Collateral, it may be
necessary to obtain the prior consent or approval of Tribunals and other
Persons to a transfer or assignment of Collateral, including, without
limitation, the FDA.

         (b)     Debtor hereby agrees, if an Event of Default exists, to
execute, deliver, and file, and hereby appoints (to the extent permitted under
applicable Law) Secured Party as its attorney-in-fact, if an Event of Default
exists, to execute, deliver, and file on Debtor's behalf and in Debtor's name,
all applications, certificates, filings, instruments, and other documents
(including without limitation any application for an assignment or transfer of
control or ownership) that may be necessary or appropriate, in Secured Party's
opinion, to obtain such consents, waivers, or approvals.  Debtor further agrees
to use its best efforts to obtain the foregoing consents, waivers, and
approvals, including receipt of consents, waivers, and approvals under
applicable agreements prior to a Default or Event of Default.  Debtor
acknowledges that there is no adequate remedy at Law for failure by it to
comply with the provisions of this Section 4.4(b) and that such failure would
not be adequately compensable in damages, and therefore agrees that this
Section 4.4(b) may be specifically enforced.

         4.5     INDEMNITY AND EXPENSES.  (a)  DEBTOR AGREES TO INDEMNIFY
SECURED PARTY FROM AND AGAINST ANY AND ALL CLAIMS, LOSSES AND LIABILITIES
(INCLUDING REASONABLE ATTORNEYS' FEES) GROWING OUT OF OR RESULTING FROM THIS
AGREEMENT (INCLUDING, WITHOUT LIMITATION, ENFORCEMENT OF THIS AGREEMENT),
EXCEPT CLAIMS, LOSSES OR LIABILITIES RESULTING FROM SECURED PARTY'S GROSS
NEGLIGENCE OR WILLFUL MISCONDUCT.

         (b)     Debtor will upon demand pay to Secured Party the amount of any
and all reasonable expenses, including the reasonable fees and expenses of its
counsel and of any experts and agents, which Secured Party may incur in
connection with (i) the administration of this Agreement, (ii) the custody,
preservation, use or operation of, or the sale of, collection from, or other
realization upon, any of the Collateral, (iii) the exercise or enforcement of
any of the Rights of Secured Party hereunder or (iv) the failure by Debtor to
perform or observe any of the provisions hereof.  Any payments so made shall be
a part of the Obligation, shall be payable





                                       16
<PAGE>   21
upon demand, and shall bear interest (i) if no Event of Default exists, at the
Prime Base Rate, and (ii) if an Event of Default exists, at the lesser of (A)
the Prime Base Rate plus 3% and (B) the Highest Lawful Rate.

         4.6     Debtor Insolvency.  Should Debtor become insolvent, fail to
pay its debts generally as they become due, voluntarily seek, consent to, or
acquiesce in the benefits of any Debtor Relief Law or become a party to or be
made the subject of any proceeding provided for by any Debtor Relief Law (other
than as a creditor or claimant) that could suspend or otherwise adversely
affect the rights of Secured Party granted hereunder, then, the Obligations
shall be, as between Debtor and Secured Party, a fully matured, due, and
payable obligation (without regard to whether Borrower is then in default under
the Credit Agreement or whether any part of the Obligations is then due and
owing by Borrower to Secured Party), and Secured Party shall have all of the
remedies and rights provided herein all as though an Event of Default existed.


ARTICLE V.  MISCELLANEOUS

         5.1     Cumulative Rights.  All Rights of Secured Party under the Loan
Papers are cumulative of each other and of every other Right which Secured
Party may otherwise have at Law or in equity or under any other contract or
other writing for the enforcement of the security interest herein or the
collection of the Obligations.  The exercise of one or more Rights shall not
prejudice or impair the concurrent or subsequent exercise of other Rights.

         5.2     Modifications; Amendments; Schedules; Etc.  No amendment or
waiver of any provision of this Agreement, and no consent to any departure by
Debtor here from, shall in any event be effective unless the same shall be in
writing and signed by Secured Party, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given.  Upon any change in any material information disclosed on any schedule,
Debtor shall promptly prepare and deliver to Secured Party a replacement
schedule, indicating its effective date, in form and substance satisfactory to
Secured Party and amendments to and additional financing statements as Secured
Party may require to preserve and perfect a first priority security interest in
the Collateral.

         5.3     Continuing Security Interest.  This Agreement shall create a
continuing security interest in the Collateral and shall (a) remain in full
force and effect until the later of (i) the final payment in full of the
Obligations and all amounts payable under this Agreement and (ii) the
expiration or termination of the obligations of Secured Party to extend credit
to Debtor, (b) be binding upon Debtor, its successors and assigns, and (c)
inure to the benefit of, and be enforceable by, Secured Party and its
successors, transferees and assigns.  Upon any such termination, Secured Party
will, at Debtor's expense, execute and deliver to Debtor such documents as such
Debtor shall reasonably request to evidence such termination.

         5.4     MANDATORY ARBITRATION.  (a) ANY CONTROVERSY OR CLAIM BETWEEN
OR AMONG THE PARTIES HERETO INCLUDING BUT NOT LIMITED




                                       17
<PAGE>   22
TO THOSE ARISING OUT OF OR RELATING TO THIS AGREEMENT OR ANY RELATED AGREEMENTS
OR INSTRUMENTS, INCLUDING ANY CLAIM BASED ON OR ARISING FROM AN ALLEGED TORT,
SHALL BE DETERMINED BY BINDING ARBITRATION IN ACCORDANCE WITH THE FEDERAL
ARBITRATION ACT (OR IF NOT APPLICABLE, THE APPLICABLE STATE LAW), THE RULES OF
PRACTICE AND PROCEDURE FOR THE ARBITRATION OF COMMERCIAL DISPUTES OF JUDICIAL
ARBITRATION AND MEDIATION SERVICES, INC. ("JAMS"), AND THE "SPECIAL RULES" SET
FORTH BELOW.  IN THE EVENT OF ANY INCONSISTENCY, THE SPECIAL RULES SHALL
CONTROL.  JUDGMENT UPON ANY ARBITRATION AWARD MAY BE ENTERED IN ANY COURT
HAVING JURISDICTION.  ANY PARTY TO THIS AGREEMENT MAY BRING AN ACTION,
INCLUDING A SUMMARY OR EXPEDITED PROCEEDING, TO COMPEL ARBITRATION OF ANY
CONTROVERSY OR CLAIM TO WHICH THIS AGREEMENT APPLIES IN ANY COURT HAVING
JURISDICTION OVER SUCH ACTION.

         (b)     Special Rules.  The arbitration shall be conducted in Dallas,
Texas and administered by JAMS who will appoint an arbitrator; if JAMS is
unable or legally precluded from administering the arbitration, then the
American Arbitration Association will serve.  All arbitration hearings will be
commenced within ninety days of the demand for arbitration; further, the
arbitrator shall only, upon a showing of cause, be permitted to extend the
commencement of such hearing for up to an additional sixty days.

         (c)     Reservations of Rights.  Nothing in this Agreement or any
other Loan Paper shall be deemed to (i) limit the applicability of any
otherwise applicable statutes of limitation or repose and any waivers contained
in this Agreement; or (ii) be a waiver by Secured Party of the protection
afforded to it by 12 U.S.C. Section  91 or any substantially equivalent state
law; or (iii) limit the right of Secured Party hereto (A) to exercise self help
remedies such as (but not limited to) setoff, or (B) to foreclose against any
real or personal property collateral, or (C) to obtain from a court provisional
or ancillary remedies such as (but not limited to) injunctive relief or the
appointment of a receiver.  Secured Party may exercise such self help rights,
foreclose upon such property, or obtain such provisional or ancillary remedies
before, during or after the pendency of any arbitration proceeding brought
pursuant to this Agreement.  At Secured Party's option, foreclosure under a
deed of trust or mortgage may be accomplished by any of the following:  the
exercise of a power of sale under the deed of trust or mortgage, or by judicial
sale under the deed of trust or mortgage, or by judicial foreclosure.  Neither
this exercise of self help remedies nor the institution or maintenance of an
action for foreclosure or provisional or ancillary remedies shall constitute a
waiver of the right of any party, including the claimant in any such action, to
arbitrate the merits of the controversy or claim occasioning resort to such
remedies.

         5.5     GOVERNING LAW; TERMS.  THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS, EXCEPT TO THE
EXTENT THAT THE VALIDITY OR PERFECTION OF THE SECURITY INTEREST HEREUNDER, OR
REMEDIES HEREUNDER, IN RESPECT OF





                                       18
<PAGE>   23
ANY PARTICULAR COLLATERAL ARE GOVERNED BY THE LAWS OF A JURISDICTION OTHER THAN
THE STATE OF TEXAS.  UNLESS OTHERWISE DEFINED HEREIN OR IN THE CREDIT
AGREEMENT, TERMS USED IN ARTICLE 9 OF THE UCC ARE USED HEREIN AS THEREIN
DEFINED.

         5.6     WAIVER OF JURY TRIAL.  SECURED PARTY AND DEBTOR HEREBY WAIVE
TRIAL BY JURY IN ANY JUDICIAL PROCEEDINGS INVOLVING, DIRECTLY OR INDIRECTLY,
ANY MATTER (WHETHER IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING OUT OF,
RELATED TO, OR CONNECTED WITH THIS AGREEMENT OR THE RELATIONSHIP ESTABLISHED
HEREUNDER.

         5.7     Secured Party's Right to Use Agents.  Secured Party may
exercise its Rights under this Agreement through an agent or other designee.

         5.8     No Interference, Compensation or Expense.  Secured Party may
exercise its Rights under this Agreement without payment of any rent, license
fee or compensation of any kind to Debtor.

         5.9     Waivers of Rights Inhibiting Enforcement.  Debtor waives (a)
any claim that, as to any part of the Collateral, a public sale, should the
Secured Party elect so to proceed, is, in and of itself, not a commercially
reasonable method of sale for such Collateral, (b) except as otherwise provided
in this Agreement, TO THE EXTENT PERMITTED BY APPLICABLE LAW, NOTICE OR
JUDICIAL HEARING IN CONNECTION WITH SECURED PARTY'S DISPOSITION OF ANY OF THE
COLLATERAL INCLUDING ANY AND ALL PRIOR NOTICE AND HEARING FOR ANY PREJUDGMENT
REMEDY OR REMEDIES AND ANY SUCH RIGHT THAT DEBTOR WOULD OTHERWISE HAVE UNDER
THE CONSTITUTION OR ANY STATUTE OF THE UNITED STATES OR OF ANY STATE, AND ALL
OTHER REQUIREMENTS AS TO THE TIME, PLACE AND TERMS OF SALE OR OTHER
REQUIREMENTS WITH RESPECT TO THE ENFORCEMENT OF SECURED PARTY'S RIGHTS
HEREUNDER and (c) all rights of redemption, appraisal or valuation.

         5.10    Waiver of Subrogation.  Debtor shall not assert, enforce, or
otherwise exercise (a) any right of subrogation to any of the rights or Liens
of Secured Party or any other beneficiary against Borrower or any other Obligor
on the Obligations or any collateral or other security, or (b) any right of
recourse, reimbursement, contribution, indemnification, or similar right
against Borrower or any other Obligor on all or any part of the Obligations,
and Debtor hereby waives any and all of the foregoing rights and the benefit
of, and any right to participate in, any collateral or other security given to
Secured Party or any other beneficiary to secure payment of the Obligations.
The provisions of this Section 5.10 shall survive the termination of this
Agreement, and any satisfaction and discharge of Borrower and each other
Obligor by virtue of any payment, court order, or Law.  Debtor hereby waives
all rights by which it might be entitled to require suit on an accrued right of
action in respect of any of the Obligations or require suit against Borrower,
any other Obligor or others, whether arising pursuant to Section





                                       19
<PAGE>   24
34.02 of the Texas Business and Commerce Code, as amended, Section 17.001 of
the Texas Civil Practice and Remedies Code, as amended, or Rule 31 of the Texas
Rules of Civil Procedure, as amended, or otherwise.

         5.11    Notices and Deliveries.

         (a)     Manner of Delivery.  All notices, communications and materials
to be given or delivered pursuant to this Agreement shall, except in those
cases where giving notice by telephone is expressly permitted, be given or
delivered in writing.  All written notices, communications and materials shall
be sent by registered or certified mail, postage prepaid, return receipt
requested, by telecopier, or delivered by hand.  In the event of a discrepancy
between any telephonic notice and any written confirmation thereof, such
written confirmation shall be deemed the effective notice except to the extent
Secured Party or Debtor has acted in reliance on such telephonic notice.

         (b)     Addresses.  All notices, communications and materials to be
given or delivered pursuant to this Agreement shall be given or delivered at
the following respective addresses and telecopier and telephone numbers and to
the attention of the following individuals or departments:

         (i)     if to Debtor, to it at:

                 Neuromed, Inc.
                 One Allentown Parkway
                 Allen, Texas  75002

                 Telecopier No.:  (214) 390-9687
                 Telephone No.:   (214) 390-9800

                 Attention:  F. Robert Merrill III

         (ii)    if to Secured Party, to it at:

                 NationsBank of Texas, N.A.
                 NationsBank Plaza
                 901 Main Street
                 7th Floor
                 Dallas, Texas  75202

                 Telecopier No.:  (214) 508-3139
                 Telephone No.:   (214) 508-1389

                 Attention:  Commercial Banking




                                       20
<PAGE>   25
or at such other address or, telecopier or telephone number or to the attention
of such other individual or department as the party to which such information
pertains may hereafter specify for the purpose in a notice to the other
specifically captioned "Notice of Change of Address".

         (c)     Effectiveness.  Each notice, communication and any material to
be given or delivered to Secured Party or Debtor pursuant to this Agreement
shall be effective or deemed delivered or furnished (i) if sent by certified
mail, return receipt requested, on the fifth Business Day after such notice,
communication or material is deposited in the mail, addressed as above
provided, (ii) if sent by telecopier, when such notice, communication or
material is transmitted to the appropriate number determined as above provided
in this Section 5.11 and the appropriate receipt is received or otherwise
acknowledged, (iii) if sent by hand delivery or overnight courier, when left at
the address of the addressee addressed as above provided, and (iv) if given by
telephone, when communicated to the individual or any member of the department
specified as the individual or department to whose attention notices,
communications and materials are to be given or delivered except that notices
of a change of address, telecopier or telephone number or individual or
department to whose attention notices, communications and materials are to be
given or delivered shall not be effective until received.

         5.12    Successors and Assigns.  All of the provisions of this
Agreement shall be binding and inure to the benefit of the parties thereto and
their respective successors and assigns.

         5.13    Loan Paper.  This Agreement is a Loan Paper executed pursuant
to the Credit Agreement and shall (unless otherwise expressly indicated herein)
be construed, administered and applied in accordance with the terms and
provisions thereof.

         5.14    Definitions.  Capitalized terms not otherwise defined herein
have the meaning specified in the Credit Agreement and, to the extent of any
conflict, terms as defined in the Credit Agreement shall control (provided,
that a more expansive or explanatory definition shall not be deemed a
conflict).

         5.15    Severability.  If any provision of any Loan Paper is held to
be illegal, invalid, or unenforceable under present or future Laws during the
term thereof, such provision shall be fully severable, the appropriate Loan
Paper shall be construed and enforced as if such illegal, invalid, or
unenforceable provision had never comprised a part thereof, and the remaining
provisions thereof shall remain in full force and effect and shall not be
affected by the illegal, invalid, or unenforceable provision or by its
severance therefrom.  Furthermore, in lieu of such illegal, invalid, or
unenforceable provision there shall be added automatically as a part of such
Loan Paper a legal, valid, and enforceable provision as similar in terms to the
illegal, invalid, or unenforceable provision as may be possible.

         5.16    Obligations Not Affected.  To the fullest extent permitted by
applicable Law, the obligations of Debtor under this Agreement shall remain in
full force and effect without regard to, and shall not be impaired or affected
by:





                                       21
<PAGE>   26
         (a)     any amendment or modification or addition or supplement to any
Loan Paper, any instrument delivered in connection therewith or any assignment
or transfer thereof;

         (b)     any exercise, non-exercise, or waiver by Secured Party of any
Right, remedy, power or privilege under or in respect of, or any release of any
guaranty, any collateral or the Collateral or any part thereof provided
pursuant to, this Agreement or any Loan Paper;

         (c)     any waiver, consent, extension, indulgence or other action or
inaction in respect of this Agreement or any Loan Paper or any assignment or
transfer of any thereof; or

         (d)     any bankruptcy, insolvency, reorganization, arrangement,
readjustment, composition, liquidation or the like of Debtor, or any other
Person, whether or not Debtor shall have notice or knowledge of any of the
foregoing.

         5.17    Counterparts.  This Agreement may be executed in any number of
counterparts, each of which when so executed and delivered shall be deemed an
original, but all such counterparts together shall constitute but one and the
same instrument.

         5.18    ENTIRE AGREEMENT.  THIS WRITTEN AGREEMENT, TOGETHER WITH THE
OTHER LOAN PAPERS, REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY
NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL
AGREEMENTS OF THE PARTIES.  THERE ARE NO UNWRITTEN ORAL AGREEMENTS AMONG THE
PARTIES.

         IN WITNESS WHEREOF, Debtor and Secured Party have caused this
Agreement to be duly executed and delivered as of the date first above written.


                                 DEBTOR:

                                 NEUROMED, INC.


                                 By:___________________________________________
                                         F. Robert Merrill III, Vice President

                                 SECURED PARTY:

                                 NATIONSBANK OF TEXAS, N.A.


                                 By:___________________________________________
                                         Jay C. Henry, Vice President






                                       22
<PAGE>   27

                             "SCHEDULES OMITTED"
