
<PAGE>   1





________________________________________________________________________________
________________________________________________________________________________





                               LICENSE AGREEMENT

                           Dated as of March 31, 1995

                                    Between

                                 NEUROMED, INC.
                                  as Licensor

                                      and

                   NATIONSBANK OF TEXAS, NATIONAL ASSOCIATION
                                  as Licensee





________________________________________________________________________________
________________________________________________________________________________
<PAGE>   2
                               LICENSE AGREEMENT


         LICENSE AGREEMENT, dated March 31, 1995, by and between Neuromed,
Inc., a Florida corporation ("Licensor"), and NationsBank of Texas, National
Association, a national banking association ("Licensee").

                              W I T N E S S E T H:

         WHEREAS, Licensor presently owns and will hereafter acquire right,
title, and interest (including rights and interests pursuant to licenses)
throughout the world in various Trademarks, Patents, Copyrights and Trade
Secrets (hereinafter, collectively, the "Intellectual Property");

         WHEREAS, Licensee and Quest Medical, Inc., a Texas corporation
("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, being the "Credit Agreement");

         WHEREAS, Licensor is a wholly-owned subsidiary of Borrower;

         WHEREAS, as security for the payment and performance of the
Obligations which are owed by Licensor and each other Obligor to Licensee
pursuant to the Loan Papers, Licensor has agreed to grant or cause to be
granted to Licensee, security interests in, and pledges and assignments of, all
assets of Licensor, including all cash, Inventory, Receivables, Equipment,
Permits and the Intellectual Property, a license to use the Intellectual
Property and Permits and certain other collateral, to secure the Obligations;

         WHEREAS, Licensee desires a license to use the Intellectual Property
and Permits in all countries of the world solely if an Event of Default exists
to enable Licensee to exercise its rights and remedies with respect to the
Collateral under the Security Agreement;

         WHEREAS, Licensor desires to grant Licensee the foregoing license to
so use the Intellectual Property and Permits; and

         WHEREAS, the parties acknowledge the excellent reputation for quality
of products sold under the Intellectual Property and Permits, and desire to
safeguard, promote and enhance that reputation by ensuring the future quality
of materials, workmanship, and performance of the Inventory with respect to
which Licensee has been granted a security interest, pledge and assignment and
may exercise its rights and remedies under the Security Agreement and
Intellectual Property Agreement, if an Event of Default exists.
<PAGE>   3
                                   AGREEMENT.

         NOW, THEREFORE, in consideration of the above premises and of the
mutual covenants herein contained, and other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, and intending to
be legally bound, the parties hereto agree as follows:


ARTICLE I.  DEFINITIONS

         1.1     "Collateral" has the same definition provided in the Security
                 Agreement.

         1.2     "Effective Date" means March 31, 1995.

         1.3     "Equipment" has the same definition provided in the Security
                 Agreement.

         1.4     "Intellectual Property Agreement" means the Intellectual
                 Property Security Agreement and Assignment dated March 31,
                 1995 between Licensor and Licensee.

         1.5     "Inventory"  has  the same definition provided in the Security
                 Agreement.

         1.6     "Permits" means all licenses, permits and other similar rights
                 now or hereafter owned by Licensor (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 2.

         1.7     "Receivables" has the same definition provided in the Security
                 Agreement.

         1.8     "Security Agreement" means the Security Agreement dated March
                 31, 1995 between Licensor and Licensee.

         1.9     Unless otherwise defined in this Agreement, all capitalized
                 terms herein shall have the same definition provided in the
                 Credit Agreement, the Intellectual Property Agreement and the
                 Security Agreement.


ARTICLE II.  GRANTS TO LICENSEE AND RELATED MATTERS

         2.1     Licensor hereby grants to Licensee an irrevocable,
non-exclusive royalty-free right and license to use the Intellectual Property
and Permits worldwide including, without limitation, the Intellectual Property
identified in Schedule 1 and Permits identified on Schedule 2, if an Event of
Default exists, and to enable Licensee to exercise its rights and remedies
under the





                                      -2-
<PAGE>   4
Security Agreement and Intellectual Property Agreement with respect to
Collateral, including, without limitation, the right to use the Intellectual
Property and Permits on or in connection with the operation and disposition of
any Collateral and the disposition, maintenance or further production,
manufacturing or processing of the Inventory, the operation and maintenance of
the Equipment and the collection of Receivables as Licensee reasonably deems
necessary or appropriate in the exercise of its rights and remedies under the
Security Agreement and Intellectual Property Agreement with respect to
Collateral.

         The parties acknowledge and agree that the Intellectual Property and
Permits are the sole and exclusive property of Licensor, subject to the terms
and conditions stated in this Agreement, the Security Agreement and the
Intellectual Property Agreement.  Other than in connection with any security
interest in the Intellectual Property and Permits that Licensor has granted to
Licensee pursuant to the Security Agreement and the Intellectual Property
Agreement or any rights and remedies of Licensee under the Security Agreement
or the Intellectual Property Agreement, Licensee shall not challenge Licensor's
ownership of the Intellectual Property and Permits.  Licensor expressly retains
all rights to license third parties to use the Intellectual Property and
Permits for any purpose whatsoever not in violation of the Loan Papers and
which are not exclusive as to prevent Licensee from using any of the
Intellectual Property and Permits as provided in the Security Agreement and
Intellectual Property Agreement.

         2.2     The license granted to Licensee hereunder shall include the
right of Licensee to grant sublicenses to others to use the Intellectual
Property and Permits if an Event of Default exists, and to enable such
sublicensees to exercise any rights and remedies of Licensee under the Security
Agreement and the Intellectual Property Agreement with respect to Collateral,
including, without limitation, the right to grant sublicenses to others to use
the Intellectual Property and Permits on or in connection with the operation
and disposition of any Collateral, the disposition, maintenance or further
production, manufacturing or processing of Inventory, the operation and
maintenance of the Equipment and the collection of Receivables as Licensee
reasonably deems necessary or appropriate in the exercise of the rights and
remedies of Licensee under the Security Agreement and the Intellectual Property
Agreement.  In any country where sublicenses are incapable of registration or
where registration of a sublicense will not satisfactorily protect the rights
of Licensor and Licensee, Licensee shall also have the right to designate other
parties as direct licensees of Licensor to use the Intellectual Property and
Permits if an Event of Default exists and to enable such direct licensees to
exercise any rights and remedies of Licensee under the Security Agreement and
the Intellectual Property Agreement including, without limitation, the right to
use the Intellectual Property and Permits on or in connection with the
operation and disposition of any Collateral, the disposition, maintenance or
further production, manufacturing or processing of Inventory, the operation and
maintenance of the Equipment and the collection of Receivables as such
licensees reasonably deem necessary or appropriate and Licensor agrees to enter
into direct written licenses with the parties as designated on the same terms
as would be applicable to a sublicense, and any such direct license may,
depending on the relevant local requirements, be either (a) in lieu of a
sublicense or (b) supplemental to a sublicense.  In either case, the parties
hereto shall cooperate to determine what shall be necessary or appropriate in
the circumstances.  For each sublicense to a sublicensee and





                                      -3-
<PAGE>   5
direct license to a licensee, Licensor appoints Licensee its agent for the
purpose of exercising quality control over the sublicensee.  Licensor shall
execute this Agreement in any form, content and language suitable for
recordation, notice and/or registration in all available and appropriate
agencies of foreign countries as Licensee may require.

         2.3     In connection with the assignment or other transfer (in whole
or in part) of its obligations under the Security Agreement and the
Intellectual Property Agreement to any other Person, Licensee may assign the
license granted herein without Licensor's consent and upon such assignment or
transfer such other Person shall thereupon become vested with all rights and
benefits in respect thereof granted to Licensee under this Agreement.

         2.4     The parties hereto shall take reasonable action to preserve
the confidentiality of the Intellectual Property and Permits which is not
otherwise public information; provided, that Licensee shall not have any
liability to any Person for any disclosure of the Intellectual Property or
Permits upon and after any realization upon Collateral under the Security
Agreement or the Intellectual Property Agreement or otherwise as part of
Licensee's enforcement of remedies under the Loan Papers.


ARTICLE III.  QUALITY CONTROL

         3.1     Licensor shall refrain from using the Intellectual Property
and Permits in a form and manner or for a subject matter as to (a) reduce the
value of the Intellectual Property or Permits or (b) cause injury to Licensor's
business, reputation or goodwill.

         3.2     If an Event of Default exists and Licensee exercises its
rights or remedies under the license granted herein:

         (a)     Licensee may use the Trademarks licensed hereby in such form
and manner as previously used by Licensor, and shall need not notify Licensor
of any change in the form or substance of the display of a Trademark licensed
hereby.  Licensee shall take reasonable action to apply trademark notice or
other marking as may be required under applicable Law of each territory and
country where each Trademark is used, or as otherwise appropriate, in
connection with use of each of the Trademarks licensed hereunder.  Licensee
shall have the right to register any and all Trademarks in any and all
countries on and after the Effective Date.

         (b)     Licensee may dispose of any Inventory and any other
manufactured products under any of the Intellectual Property or Permits
licensed hereby, provided the Inventory and any other manufactured products so
disposed of by it or any other Person acting on behalf of Licensee shall comply
in any material respect with (i) quality standards and specifications,
including labelling specifications, employed by Licensor in commerce prior to
the Effective Date, or, where no such standards and specifications exist, a
level of quality comparable to the quality standards generally accepted for
other leading competitive brands of the same item of Inventory in the same
markets from time to time; or (ii) a level of quality comparable to that





                                      -4-
<PAGE>   6
which may be adopted by Licensor for its or its other licensees' products.
Licensee shall maintain quality control commensurate with the quality standards
of Licensor at the Effective Date or, if quality control improves after the
Effective Date, commensurate with such improved quality standards.


ARTICLE IV.  TERM AND TERMINATION

         4.1     This Agreement is effective as of the Effective Date and,
unless sooner terminated under the provisions set forth in this Article IV, is
perpetual and irrevocable.

         4.2     The license granted in Article II with respect to any
Intellectual Property and Permits may be terminated only upon the event that
the Obligations which are owed by Licensor and each other Obligor to Licensee,
and which are secured in part by the Collateral of Licensor under the Security
Agreement and the Intellectual Property Agreement and by the license granted
herein, are finally and fully satisfied and paid in accordance with all terms
and conditions of the Loan Papers at the time of such termination.  If after
termination of this Agreement, there occurs a rescission of payment of any of
the Obligations or the restoration of such payments by Licensee or any other
Person upon the insolvency, bankruptcy or reorganization of Licensor or any
other Person, this Agreement shall be reinstated as though such payment had not
been made and remain in full force and effect in accordance with the terms of
the preceding sentence.

         4.3     Upon termination of this Agreement, Licensee shall, and shall
cause any sublicensee, to cease all use of any and all of the Intellectual
Property and Permits and not thereafter use any of them in any other manner
whatsoever, subject to reinstatement under Section 4.2.

         4.4     Upon termination (or reinstatement) of this Agreement, the
parties shall perform all other acts which may be necessary or useful to render
effective the termination (or reinstatement) of the interest of Licensee in the
Intellectual Property and Permits, including but not limited to the
cancellation of any registration or recordation (or the reinstatement by
registration or recordation) of this Agreement, or any summary thereof.


ARTICLE V.  RECORDATION OF AGREEMENT

         5.1     The parties shall cooperate to determine what may or shall be
required to satisfy the laws or regulations throughout the world with respect
to the recordation and validation of this Agreement, or otherwise to render
this Agreement and the Intellectual Property and Permits effective, and shall
execute all documents which may be necessary or desirable to implement this
Section 5.1, including registered user statements or other documents suitable
for filing with the appropriate government authorities of any country.





                                      -5-
<PAGE>   7
ARTICLE VI.  REPRESENTATION AND WARRANTIES

         6.1     Licensor represents and warrants that it is the owner of the
Intellectual Property identified in Schedule 1 and Permits identified on
Schedule 2 and has the right to grant the rights and license granted herein.


ARTICLE VII.  PRODUCT LIABILITY INSURANCE

         7.1     Licensor shall maintain product liability insurance covering
liabilities for its activities pursuant to this Agreement, of at least such
amounts as is required by the Loan Papers.


ARTICLE VIII.  MISCELLANEOUS

         8.1     Failure of either party to insist upon strict performance of
the terms, conditions, and provisions of this Agreement shall not be deemed a
waiver of such terms, conditions or provisions or a waiver of future compliance
therewith.  No waiver of any terms, conditions, or provisions hereof shall be
deemed to have been made unless expressed in writing and signed by the waiving
party.

         8.2     Any sale, transfer or other disposition of ownership of any
Intellectual Property or Permits by Licensor shall be subject to this Agreement
and the Intellectual Property Agreement and any purchaser or transferee shall
specifically state in writing that it is assuming this Agreement and that it
will be bound by all of the terms and conditions of this Agreement and the
Intellectual Property Agreement (this sentence is not a consent by Licensee to
any sale, transfer or other disposition (other than the grant of a license
permitted pursuant to Section 2.1) of any interest in Intellectual Property or
Permits).  After giving effect to such sale, transfer or other disposition,
this Agreement and the Intellectual Property Agreement shall be valid, binding,
and enforceable in accordance with its terms against such purchaser or
transferee.  A sale, transfer or other disposition of any shares of the capital
stock of Licensor shall not be deemed to be a sale, transfer or other
disposition of ownership of any Intellectual Property or Permits.

         8.3     Except as otherwise may be expressly provided in this
Agreement or any other Loan Paper, Licensee shall not be construed to be and
shall not represent itself as an agent of Licensor.

         8.4     (a)      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





                                      -6-
<PAGE>   8
and any written confirmation thereof, such written confirmation shall be deemed
the effective notice except to the extent Licensor or Licensee has acted in
reliance on such telephonic notice.

                 (b)      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:

              To Licensor:              Neuromed, Inc.
                                        One Allentown Parkway
                                        Allen, Texas  75002
                                        U.S.A.
  
                                        Attention:  F. Robert Merrill III
  
              To Licensee:              NationsBank of Texas, National 
                                        Association
                                        NationsBank Plaza
                                        901 Main Street, 7th Floor
                                        Dallas, Texas  75202
                                        U.S.A.
  
                                        Attention:  Commercial Banking
  
         8.5     This Agreement shall be governed by and construed in
accordance with the internal laws of the State of Texas, U.S.A.

         8.6     (a)      Licensor hereby irrevocably submits to the
non-exclusive jurisdiction of any United States Federal or Texas State court
sitting in Dallas County, Texas, U.S.A. in any action or proceeding arising out
of or relating to this Agreement, and Licensor hereby irrevocably agrees that
all claims in respect of such action or proceeding may be heard or determined
in any such court and hereby irrevocably waives any objection it may now or
hereafter have as to the venue of any such suit, action or proceeding brought
in such court or that such court is an inconvenient forum.

                 (b)      Nothing in this Section 8.6 shall limit the right of
Licensee to bring any action or proceeding against Licensor or its property in
the courts of any other jurisdiction or any party's rights under Section 8.10
of the Credit Agreement.

                 (c)      Any judicial proceeding by Licensor against Licensee
involving, directly or indirectly, any matter in any way arising out of,
related to, or connected with this Agreement shall be brought only in a court
in Dallas County, Texas, U.S.A.





                                      -7-
<PAGE>   9
         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their respective duly authorized officers as of the date written
above.


                                      NEUROMED, INC.
                                  
______________________________
Witness
                                      By: ______________________________________
                                          F. Robert Merrill III, Vice President
                                  
______________________________
Witness


                                      NATIONSBANK OF TEXAS, NATIONAL ASSOCIATION
                                  
______________________________
Witness
                                      By: ______________________________________
                                          Jay C. Henry, Vice President
                                  
______________________________
Witness






                                      -8-
<PAGE>   10
STATE OF TEXAS    )        
                  )        
COUNTY OF DALLAS  )        


         This instrument was acknowledged before me on March ___, 1995 by F.
Robert Merrill III, Vice President of Neuromed, Inc., a Florida corporation, on
behalf of said corporation.



                                     ___________________________________________
                                     Notary Public in and for the State of Texas





STATE OF TEXAS    )        
                  )        
COUNTY OF DALLAS  )        


         This instrument was acknowledged before me on March ___, 1995 by Jay
C. Henry, Vice President of NationsBank of Texas, National Association, a
national banking association, on behalf of said association.



                                     ___________________________________________
                                     Notary Public in and for the State of Texas





                                      -9-
<PAGE>   11

                             "SCHEDULES OMITTED"
