<PAGE>   1
                                                                   EXHIBIT 10.93

                               LICENSE AGREEMENT
                               -----------------

        THIS AGREEMENT, entered into and effective as of the 1st day of
September, 1997 (the "Effective Date") by and between TRISTRATA TECHNOLOGY,
INC., a Delaware corporation having its principal place of business at 1105
North Market Street, Suite 1300, P.O. Box 8985, Wilmington, Delaware 19899
(hereinafter referred to as "LICENSOR") and COLLAGEN CORPORATION, California
corporation having a principal place of business at 2500 Faber Place, Palo Alto,
CA 94303 (hereinafter referred to as "LICENSEE");

                                    RECITALS
                                    --------

        WHEREAS, LICENSEE in the course of its business sells cosmetic and skin
care products and is interested in obtaining from LICENSOR a license to make,
have made, use, distribute and/or sell Licensed Products (as hereinafter
defined) under the Licensed Patent Rights (as hereinafter defined); and WHEREAS,
LICENSOR owns or has the right to grant licenses under the Licensed Patent
Rights (as hereinafter defined) for use in connection with the Licensed Products
(as hereinafter defined), subject to: (i) any pre-existing exclusive rights of
Westwood Pharmaceuticals, Inc. and Westwood-Squibb Pharmaceuticals, Inc.
("Westwood") that presently exist or hereafter may be determined to exist by a
court of competent jurisdiction pursuant to two separate license agreements
between [*] and Westwood effective as of October 7, 1977 and December 4, 1992
respectively (the "Westwood License Agreements"); and (ii) subject to the
pre-existing rights of Avon Products, Inc. and certain of its affiliated
companies ("Avon") pursuant to a certain license agreement, effective April 1994
between LICENSOR and Avon (the "Avon License Agreement"); and

        WHEREAS, to LICENSEE's knowledge and belief, the Licensed Patent Rights
(as hereinafter defined) are valid and enforceable; and


* Confidential treatment has been requested with respect to certain portions of
  this exhibit. Confidential portions have been omitted from the public filing
  and have been filed separately with the Securities and Exchange Commission.
<PAGE>   2


     WHEREAS, subject to, and upon, all of the terms and conditions of this
Agreement, LICENSOR is willing to grant to LICENSEE a non-exclusive license to
make, have made, use and sell the Licensed Products (as hereinafter defined)
under the Licensed Patent Rights (as hereinafter defined);

     NOW, THEREFORE, in consideration of the foregoing premises and of the
mutual covenants, promises and agreements set forth herein, LICENSOR and
LICENSEE hereby mutually agree as follows:

                              ARTICLE I -- GENERAL

     1.01      All capitalized terms used in this Agreement (other than the
names of parties and Article headings) shall have the meanings established for
such terms herein.

     1.02      LICENSEE acknowledges that LICENSEE has been advised by LICENSOR
of the rights granted by Eugene Van Scott, M.D. and Ruey J. Yu, Ph.D., O.M.D.,
pursuant to the Westwood License Agreements, and of the rights granted by
Licensor to Avon pursuant to the Avon License Agreement, and that LICENSEE has
been provided with copies of the relevant portions of the Westwood License
Agreements and the Avon License Agreement and that, notwithstanding anything to
the contrary in this Agreement, LICENSEE's rights are hereby subject to any
rights of Westwood under the Westwood License Agreements and subject to any
rights of Avon under the Avon License Agreement, and so not include any of such
rights;

     1.03      LICENSEE, represents that it has examined and evaluated the value
of the rights of LICENSOR in the Licensed Patent Rights (as defined in Section
2.09), and LICENSEE believes to the best of its knowledge, as of the Effective
date of this Agreement, that the Licensed Patent Rights are valid and
enforceable and is desirous of obtaining a license from LICENSOR under said
Licensed Patent Rights upon all of the terms and conditions set forth in this
Agreement.

                           ARTICLE II -- DEFINITIONS

     2.01     "Excluded Channel of Trade" shall mean: (1) direct marketing of
Licensed Products (as defined in Section 2.08



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<PAGE>   3

below) by door-to-door sales representatives to consumers; and (2) mail order 
sales generated as a result of a door-to-door sales representative's direct 
contact with a consumer.

     2.02      "FDA" shall mean the United States Food and Drug Administration.

     2.03      "Prescription Drug" shall mean a pharmaceutical product which
may only be dispensed to a user pursuant to a medical doctor's prescription and
as further defined by the regulations, statutes, orders or actions promulgated
by or under the authority of the FDA.

     2.04      "Over-the-Counter Product" shall mean a pharmaceutical product
that may be purchased by a user without a medical doctor's prescription
therefor and as further defined by the regulations, statutes orders or actions
promulgated by or under the authority of the FDA.

     2.05      "Cosmetic Product" shall mean: (i) and article intended to be
rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise
topically applied to the human body or any part thereof, for cleansing,
beautifying, promoting attractiveness, or altering the appearance of the human
skin, and (ii) articles intended for use as a component of any such articles
and as further defined by the regulations, statutes, orders or actions
promulgated by or under the authority of the FDA.

     2.06      "Licensed Lactic Products" shall mean any Prescription,
Over-the-Counter or Cosmetic composition or preparation comprising lactic acid
and/or its metallic salts, as the only alpha hydroxyacid in such compositions
or prescriptions, for topical application to the human skin within the scope of
the Licensed Patent Rights (as defined below).

     2.07      "Licensed Glycolic Products" shall mean any Prescription,
Over-the-Counter or Cosmetic composition or preparation comprising glycolic
acid and/or its salts, as the only alpha hydroxyacid in such compositions or
preparations, for topical application to the human skin within the scope of the
Licensed Patent Rights (as defined below).


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<PAGE>   4
        2.08    "Licensed Products" shall mean, collectively, Licensed Lactic
Products and Licensed Glycolic Products. Notwithstanding anything contained
herein to the contrary, except as provided in the last sentence of Section 2.11
below, no rights are granted to LICENSEE hereunder to combine: (1) lactic acid
with any other alpha hydroxyacid; or (2) glycolic acid with any other alpha
hydroxyacid; or (2) glycolic acid with any other alpha hydroxyacid.

        2.09    "Licensed Patent Rights" shall mean, subject to the specific
exclusions set forth in Sections 1.02, 2.08, 2.10 and 2.11, those portions of
the United States patents and United States patent applications set forth in
Schedule A hereto and all issued divisions, continuations, continuations-in-
part, reexaminations, reissues and extensions thereof, covering only:

                (1)  Prescription, Over-the-Counter and Cosmetic preparations
and compositions for topical application to the human skin comprising lactic
acid and/or its metallic salts for: (a) the treatment of human skin wrinkles,
including fine lines on the human skin; and (b) the alleviation of the signs of 
dermatological aging; and

                (2)  Prescription, Over-the-Counter and Cosmetic preparation
and compositions for topical application to the human skin comprising glycolic
acid and or its salts for: (a) the treatment of human skin wrinkles, including
fine lines on the human skin; and/or (b) the alleviation of the signs of
dermatological aging.

        2.10    Notwithstanding anything herein to the contrary, "Licensed
Patent rights" shall not include any rights to any patents or patent
applications that do not relate to:

                [*]



* Confidential treatment has been requested with respect to certain portions of
  this exhibit. Confidential portions have been omitted from the public filing
  and have been filed separately with the Securities and Exchange Commission.

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<PAGE>   5
          [*]

     2.11      LICENSEE hereby recognizes and acknowledges that no rights are
conveyed herein under the Licensed Patent Rights to make, have made, use, sell
or otherwise distribute Licensed Products: (1) that contain lactic acid and/or
its salts in combination with any of the alpha hydroxyacids set forth in
Schedule B hereto; (2) that contain the "Substance" as set forth in the
definition of "Substance" set forth in Schedule C hereto; and (3) that contain
the "Substance" as set forth in the definition of "Substance" set forth in
Schedule D hereto. LICENSEE hereby covenants and agrees that it  shall not make,
have made, use sell or otherwise distribute otherwise Licensed Products that
fall within the exclusions set forth in paragraphs (1), (2) and (3) above of
this Section 2.11 as long as LICENSOR, its affiliates, assigns and/or [*] have
issued or pending patents covering the exclusions set forth in paragraphs 1, 2
and 3 above of this Section 2.11, or unless LICENSEE receives the prior written
agreement of LICENSOR. Notwithstanding this Section 2.11 and Schedule B hereto,
LICENSEE may include in the Licensed Products under this Agreement citric acid
solely as a non-active ingredient for the purposes of adjusting product pH; as a
product stabilizer; and/or as a product preservative.

     2.12      "Territory" shall mean the territories set forth on Exhibit G
hereto.

     2.13      An "Affiliate" of LICENSEE shall mean any of those wholly owned
entities of LICENSEE listed on Schedule E hereto, as said Schedule E may from
time to time be amended by written agreement of both LICENSOR and LICENSEE.
Affiliates of 


* Confidential treatment has been requested with respect to certain portions of
  this exhibit. Confidential portions have been omitted from the public filing
  and have been filed separately with the Securities and Exchange Commission.


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<PAGE>   6
LICENSEE shall be subject to all of the provisions of this Agreement.

     2.14      An "Affiliate" of LICENSOR shall mean any person, corporation,
partnership or other entity which directly or indirectly controls, is
controlled by, or is under certain common control with, LICENSOR.

                          ARTICLE III -- LICENSE GRANT

     3.01      Subject to all of the terms and provisions of this Agreement,
LICENSOR grants to LICENSEE and Affiliates of LICENSEE (as defined in Section
2.14) under the Licensed Patent Rights a non-exclusive license to make, have
made, use, sell, have sold, import, export, have imported, have exported,
distribute, have distributed and offer sale in the Territory Licensed
Products, except through the Excluded Channel of Trade.

     3.02      Notwithstanding any provision herein to the contrary, no right
is granted or otherwise conveyed by this Agreement to any entity to make, have
made, use, sell or otherwise dispose of Licensed Products in the Territory
other than to (1) LICENSEE to make, have made, use, sell, have sold, import,
export, have imported, have exported, distribute, have distributed and offer
for sale Licensed Products under the Marks; and (2) to the extent provided in
Schedule E to this Agreement as said Schedule E may be amended from time to
time by written agreement of LICENSOR and LICENSEE, to the Affiliates of
LICENSEE to make, have made, use, sell, have sold, import, export, have
imported, have exported, distribute, have distributed and offer for sale
Licensed Products under the Marks.

     3.03      Notwithstanding any provision herein to the contrary, no right
is granted or otherwise conveyed herein by LICENSOR to LICENSEE or to any
Affiliate of LICENSEE to make, have made, use, sell or otherwise dispose of
Licensed Products other than those which are sold and/or distributed under the
brand name(s) and/or trademarks of LICENSEE or an Affiliate of LICENSEE listed
on Schedule F hereto (the "Marks"), as said Schedule F may from time to time be
amended by LICENSEE. LICENSEE agrees that it 


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<PAGE>   7
will not make, have made, use, distribute or sell Licensed Products other than
under the Marks.

     3.04  As a condition to receiving the license under the Licensed Patent
Rights hereunder, each Affiliate of LICENSEE must first execute and deliver to
LICENSOR a written instrument in a form acceptable to LICENSOR pursuant to
which such Affiliate of LICENSEE agrees to be bound by all of the terms and
provisions of this Agreement applicable to LICENSEE. LICENSEE hereby
unconditionally guarantees the compliance and performance by each Affiliate of
LICENSEE with all of the provisions of this Agreement, including, without
limitation, the payments of all amounts due to LICENSOR pursuant to any of the
provisions of this Agreement.

     3.05  The term of this Agreement and of the license granted hereunder
shall commence as of the Effective Date and shall expire or terminate upon the
expiration of the last to expire of the Licensed Patent Rights, or when the
last remaining Licensed Patent Right is declared invalid or unenforceable by a
competent court of law or administrative agency, or upon the earlier
termination of this Agreement pursuant to any of the provisions of Article VII
of this Agreement.

     3.06  LICENSOR specifically reserves the right to, and to grant licenses
to others to, make, have made, use, sell or otherwise dispose of Licensed
Products within or without the Territory on such terms as LICENSOR may deem
appropriate.

     3.07  Notwithstanding any provision contained in this Agreement to the
contrary: (1) the license granted hereunder to LICENSEE to make, have made, use
and sell Prescription Products shall terminate automatically and without the
need for any notice or other action by LICENSOR, unless LICENSEE has filed
either a New Drug Application or Abbreviated New Drug Application with the FDA
by January 1, 2002 for the particular Prescription Products to be included
under this Agreement; and (2) the license granted hereunder to make, have made,
use and sell Over-the-Counter Products shall terminate automatically and
without the need for any notice or other action by LICENSOR, unless LICENSEE
has commenced

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<PAGE>   8
marketing for sale by January 1, 2000 the particular Over-the-Counter Products
to be included under this Agreement. In the event that LICENSEE fails to meet
the date contingencies set forth in paragraphs (1) or (2) of this Section 3.07
above, the LICENSEE recognizes that no license is granted for those particular
Prescription Products and/or those particular Over-the-Counter Products, as the
case may be, which fail to meet the applicable date contingency set forth above
and LICENSEE further covenants that it will not make, have made, use or sell
such products that are within the scope of the Licensed Patent Rights.

     3.08  No license, express or implied, is granted hereunder to any other
patent rights or under any other patents or technology owned, used, or
otherwise controlled by LICENSOR or any Affiliate of LICENSOR.

                 ARTICLE IV -- PAYMENTS, ROYALTIES AND REPORTS

     4.01  In consideration for the license granted to LICENSEE hereunder,
LICENSEE and permitted Affiliates of LICENSEE shall pay to LICENSOR in the
manner set forth below, annual royalties on Net Sales of Licensed Products (as
defined in Section 2.08 above), payable quarterly, made during such quarter by
LICENSEE or Affiliates of LICENSEE, according to the following schedule:

          (a)  [  *  ] on Net Sales of Prescription Drugs which are
Licensed Products; plus

          (b)  [  *  ] on Net Sales of Over-the-Counter Products
which are Licensed Products; plus

          (c)  [  *  ] on Net Sales of Cosmetic Products which are
Licensed Products.

     4.02  Notwithstanding the royalty rate set forth in Section 4.01 above, in
consideration of the license granted to LICENSEE hereunder, LICENSEE will pay to
LICENSOR a minimum annual royalty of [  *  ] for the calendar year 1998, payable
in four equal amounts of [  *  ] on a quarterly basis on January 1, 1998, April
1, 1998, July 1, 1998 and October 1, 1998. Commencing January 1, 1999

        * Certain information on this page has been omitted and filed
          separately with the Commission. Confidential treatment has been
          requested with respect to the omitted portions.


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the minimum annual royalty shall increase as follows: [  *  ] for the calendar
year 1999; [  *  ] for the calendar year 2000; and [  *  ] for the calendar year
2001 and for each calendar year thereafter that this Agreement is in effect.
Such minimum annual royalties shall be paid in equal quarterly amounts on
January 1, April 1, July 1 and October 1 of each such calendar year. Such
minimum annual royalty payments are creditable against the royalties due from
LICENSEE's sale of Licensed Products for the same year. Upon the execution of
this Agreement, LICENSEE shall pay to LICENSOR a license fee of [  *  ] in
consideration of LICENSOR's administrative and related costs. The license fee
shall be creditable against any royalties due from LICENSEE's sales of Licensed
Products in the calendar years 1998 and 1999 in the form of eight (8) separate
credits in the amount of [  *  ] which shall be deducted from the eight (8)
minimum annual royalty payments due to LICENSOR for the calendar years 1998 and
1999.

          4.03  LICENSOR and LICENSEE agree that the methodology used to
calculate the payments and royalties set forth herein in fair, reasonable and
the most administratively convenient way to make the calculations, as of the
Effective Date of this Agreement.

          4.04  For purposes of this Agreement, "Net Sales" shall mean the gross
amounts received by LICENSEE or an Affiliate of LICENSEE from, or on account of,
the sale of Licensed Products to independent third parties in the Territory in
which there is a valid issued patent or pending application as set forth in
Schedule A, less the aggregate of the following amounts: (i) discounts,
including cash discounts, off-invoices allowances taken by customers of LICENSEE
or rebates actually allowed or granted, provided that LICENSEE does not receive
any payments or consideration for such discounts, off-invoice allowances or
rebates and (ii) credits or allowances actually granted by LICENSEE or an
Affiliate of LICENSEE upon claims or returns. Sales are considered made for the
purposes of this

        * Certain information on this page has been omitted and filed
          separately with the Commission. Confidential treatment has been
          requested with respect to the omitted portions.

                                       9
<PAGE>   10
Agreement when invoiced by LICENSEE or an Affiliate of LICENSEE to an
independent third-party.

          4.05  During the term of this Agreement as specified in Section 3.05,
LICENSEE shall, and shall cause its Affiliates to, maintain complete and
accurate records of all sales and transfers of Licensed Products and all
payments due to LICENSOR hereunder. LICENSEE shall deliver to LICENSOR within
forty-five (45) days after the close of each calendar quarter, a true and
accurate written report, certified as true and correct by an officer of
LICENSEE, setting forth the gross dollar amounts received by LICENSEE and
Affiliates of LICENSEE for the sales or transfers of Licensed Products,
separated by category (i.e., Prescription Products, Over-the-Counter Products
and Cosmetic Products); the calculation of Net Sales (including a separate
statement of the amounts deducted pursuant to clauses (i) and (ii) of Section
4.04 to determine Net Sales); and the computation of the royalties to be paid
to LICENSOR by LICENSEE and Affiliates of LICENSEE for such period. Each such
report shall segregate the gross and net dollar sales amounts separately for
LICENSEE and each Affiliate of LICENSEE.

          4.06  Simultaneously with providing the report required in Section
4.05, LICENSEE shall pay to LICENSOR in United States Dollars the entire amount
of royalties due to LICENSOR for the calendar quarter on account of which such
report is made and submitted, after deducting the minimum annual royalty
payment made for the quarter applicable to the report.

          4.07  LICENSOR shall have the right, at its own expense, to request
an audit of any quarterly period ending not more than three (3) years prior to
the date of such request, and to appoint an independent accountant to perform
such audit, provided, however, that such independent accountant shall not have
been engaged by a material competitor of LICENSEE prior to the time of the
request for such audit. The independent accountant appointed by LICENSOR shall
have access to the business records of LICENSEE and Affiliates of LICENSEE
which are necessary or appropriate to


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verify the royalties payable to LICENSOR pursuant to this Agreement. The
independent accountant shall keep confidential information received from
LICENSEE or its Affiliates, except for information necessary for disclosure to
LICENSOR to report on the accuracy of LICENSEE's reports. In the event that a
deficiency of [  *  ] is discovered between the actual
royalty payment due to LICENSOR and the amount of the royalty payment specified
in the written report submitted by LICENSEE to LICENSOR pursuant to Section
4.05, LICENSEE shall bear the costs of the audit conducted by LICENSOR.

          4.08  All payments of royalties and other amounts due to LICENSOR
pursuant to any of the provisions of this Agreement shall be made to LICENSOR
by wire transfer at the principal place of business of LICENSOR as specified in
or pursuant to the provisions of Article XIII of this Agreement.

          4.09  No amounts due hereunder shall be withheld by LICENSEE or
Affiliates of LICENSEE, whether due to a claim of set-off or any other claim by
LICENSEE of any amount due to LICENSEE from LICENSOR, except in the event of a
bona fide dispute with respect to a previous overpayment made by LICENSEE to
LICENSOR due to a miscalculation by LICENSEE of the amounts actually due under
Section 4.01 of this Agreement provided, however, that such claim of
overpayment is made by LICENSEE within twelve (12) months of the date of the
alleged overpayment.

            ARTICLE V - REPRESENTATIONS AND WARRANTIES; LIMITATIONS

          5.01  LICENSOR represents that it has the full authority to grant to
LICENSEE the rights with respect to the Licensed Patent Rights in accordance
with the provisions of this Agreement.

          5.02  LICENSOR MAKES NO REPRESENTATIONS TO LICENSOR, EXTENDS NO
WARRANTIES OF ANY NATURE, WRITTEN OR ORAL, EXPRESS OR IMPLIED, INCLUDING,
WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE AND HEREBY DISCLAIMS ANY AND ALL WARRANTIES, AND LICENSOR
ASSUMES NO LIABILITIES OR RESPONSIBILITIES OF ANY NATURE WHATSOEVER WITH

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.




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RESPECT TO THE MANUFACTURE, DISTRIBUTION, SALE, USE OR OTHER DISPOSITION BY
LICENSEE OR ANY AFFILIATE OF LICENSEE, OR ANY VENDEE OR OTHER TRANSFEREE OR USER
OF ANY OF THE LICENSED PRODUCTS OR OTHER PRODUCTS WHICH INCORPORATE, OR ARE
FORMULATED OR MANUFACTURED BY USE OF, ANY OF THE LICENSED PATENT RIGHTS OR ANY
OTHER INFORMATION FURNISHED BY OR IN CONNECTION WITH THIS AGREEMENT.

        5.03 LICENSOR MAKES NO REPRESENTATION OR WARRANTY CONCERNING THE
LICENSED PRODUCTS HEREIN AND IN NO EVENT SHALL LICENSOR OR ANY AFFILIATE OF
LICENSOR BE LIABLE OR RESPONSIBLE TO LICENSEE FOR ANY INDIRECT, SPECIAL OR
CONSEQUENTIAL DAMAGES.

        5.04 Without limiting the disclaimers set forth in Sections 5.02 and
5.03, nothing in this Agreement shall be construed as:

                (a) a warranty or representation by LICENSOR as to the validity
     or scope of any patent right included within the Licensed Patent Rights;

                (b) a warranty or representation by LICENSOR that anything made,
     used or sold or otherwise disposed of by LICENSEE under this Agreement is
     or will be free from infringement of patents of third persons;

                (c) a requirement or obligation that LICENSOR furnish to
     LICENSEE any technical or manufacturing information concerning Licensed
     Products, or any of the substance of pending patent applications other than
     those included in the Licensed Patent Rights;

                (d) a grant by LICENSOR of any right to use in advertising,
     publicity, or otherwise a trademark, trade name, image or likeness of
     LICENSOR or its Affiliates, or any name, image or likeness of their
     respective employees, officers, or the inventors of any of the patents or
     patent applications included within the Licensed Patent Rights:

                (e) a representation or warranty by LICENSOR as to the
     usefulness, fitness, merchantability or suitability of any product to be
     manufactured sold or otherwise distributed by LICENSEE or any Affiliate of



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<PAGE>   13
     LICENSEE.

          5.05 Without limiting or altering any of the disclaimers set forth in
this Article 5, LICENSOR represents to LICENSEE that, to the best of LICENSOR'S
knowledge and belief, LICENSOR has granted to LICENSEE all of the patent rights
owned or controlled by LICENSOR and its Affiliates necessary for LICENSEE to
practice the Licensed Patent Rights as defined herein.

          5.06 Without limiting or altering the disclaimers set forth in this
Article V, LICENSOR represents that, as of the date of the execution of this
Agreement, LICENSOR is unaware of any issued patents in the Territory owned by
third-parties (hereinafter "Third Party Patents") which contain claims or
elements of claims necessary to perform the elements encompassed by the methods
disclosed in the Licensed Patent Rights. Notwithstanding this Section 5.06,
LICENSOR makes no representation to LICENSEE that any particular product
composition or formulation made, used or sold by LICENSEE under this Agreement
is or will be free from infringement of the patents or intellectual property
rights of any third-party. LICENSEE specifically acknowledges that it bears the
sole responsibility to ensure that particular product compositions and
formulations do not infringe the patents of any third-party and that LICENSOR
shall have no obligation or responsibility therefor.

     ARTICLE VI -- TRANSFERABILITY OR RIGHTS AND OBLIGATIONS

          6.01 LICENSOR may assign any or all of its rights and obligations
hereunder, in whole or in part, without the prior written consent of LICENSEE.

          6.02 LICENSEE may assign its rights and obligations under this
Agreement only upon a writing signed by LICENSOR consenting to such assignment,
which consent by LICENSOR shall not be unreasonably withheld. Any attempt to
transfer, assign or sublicense which is not in accordance with the terms of
this Agreement shall be void.

          6.03 The provisions of this Agreement shall be binding upon and inure
to the benefit of all successors and permitted assigns of the parties hereto.


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<PAGE>   14


                      ARTICLE III - TERMINATION FOR BREACH


     7.01     Prior to the expiration of the term of this Agreement, LICENSOR
may, at its option, terminate this Agreement and the license granted hereunder
upon prior written notice to LICENSEE if LICENSEE fails to pay within thirty
(30) days of the due date any amount required to be paid hereunder or if
LICENSEE breaches any of the other covenants or provisions of this Agreement.
Notwithstanding the foregoing, unless the breach is not capable of being cured,
LICENSEE shall have thirty (30) days from receipt of notice from LICENSOR to pay
such overdue amount in full or to cure such other breach to LICENSOR and thereby
avoid termination under this Section. If: (1) the breach is not capable of being
cured; (2) the overdue amount is not paid with interest at the rate of [  *  ]
(but not to exceed the maximum amount of interest permitted by applicable law)
from the date due to the date paid; or (3) such other breach is not cured within
thirty (30) days, then this Agreement and all licenses granted hereby will
terminate immediately and automatically without any further notice or action on
the part of LICENSOR. In the event that the interest rate specified in this
Section exceeds the maximum rate of interest permitted by applicable law, such
rate shall in such instance be reduced to the maximum permitted rate.

     7.02     In the event the LICENSEE or any Affiliate of LICENSEE shall
become insolvent; be declared bankrupt; voluntarily file or have filed against
it a petition for bankruptcy or reorganization; unless such petition is
dismissed within sixty (60) days of filing; enter into an arrangement for the
benefit of creditors; entered into a procedure of winding up to dissolution; or
should a trustee or receiver be appointed for its respective business assets or
operations, LICENSOR may immediately terminate this Agreement and the license
granted hereby, effective upon written notice to LICENSEE.

     7.03     LICENSEE shall have the right, at its sole discretion, to
terminate this Agreement upon ninety (90) days notice, in writing, to LICENSOR.

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.



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<PAGE>   15
     7.04      Under no circumstances (including, without limitation, a
termination for any reason whatsoever) shall LICENSOR be obligated to refund
any payments theretofore made by LICENSEE hereunder. Notwithstanding the
foregoing sentence, LICENSOR agrees to refund and/or to credit to LICENSEE any
amounts paid by LICENSEE to LICENSOR under this Agreement that are in excess of
the amounts actually due under Section 4.01 as a result of LICENSEE's
miscalculation of the amounts due, provided that LICENSEE gives notice of and
demonstrates to LICENSOR's satisfaction, the miscalculation within twelve (12)
months of the date of the alleged overpayment.

     7.05      Except as otherwise specifically provided herein, expiration or
termination of this Agreement and of the license granted hereby for any reason
shall be without prejudice to:

               (a)  the right of LICENSOR to receive all payments accrued and
unpaid as of the effective date of such termination or to receive any payments
or other amounts which may accrue after the date of termination; and

               (b)  any other rights, remedies or obligations which LICENSOR
may then or thereafter have under this Agreement or otherwise.

     7.05      Upon the termination (but not expiration) of this Agreement,
LICENSEE and its Affiliates shall cease all use of the Licensed Patent Rights.
Notwithstanding the foregoing, LICENSEE and its Affiliates shall for a period
of ninety (90) days following the effective date of termination be entitled to
distribute and sell within the Territory through their regular channels of
distribution any stock of completed Licensed Products then in their possession,
subject to the payment of royalties and other provisions of Section 4 of this
Agreement.

     7.06      The provisions of Section 7.03 through Section 7.05 survive
termination or expiration of this Agreement.


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<PAGE>   16

                    ARTICLE VIII - THIRD-PARTY INFRINGEMENT

     8.01  LICENSEE shall promptly notify LICENSOR after becoming aware of any
third-party infringement of the License Patent Rights hereunder.

     8.02  LICENSOR shall have the sole right, but not the obligation, to
institute and control the prosecution of a suit or to take any other action for
infringement of any of the Licensed Patent Rights. LICENSEE agrees to take no
action with respect to any third-party infringement of Licensed Patent Rights
unless expressly authorized to do so in writing by LICENSOR. LICENSEE agrees
to, and to cause each of the Affiliates of LICENSEE to, cooperate with LICENSOR
in all respects, to make employees of LICENSEE and any Affiliate of LICENSEE
available to testify, to make available any records, papers, information,
specimens and the like, and to join in any such suit as a voluntary plaintiff,
upon LICENSOR's request. Any recovery or settlement obtained as a result of
such suit or other action shall be retained by LICENSOR for its own use and
benefit, and LICENSEE shall have no rights whatsoever in any such recovery or
settlement, however, LICENSOR agrees to provide reasonable compensation to
LICENSEE and/or its Affiliates for costs incurred by LICENSEE and/or its
Affiliates for making employees available to testify and/or making available
any documentary evidence.

     8.03  Notwithstanding the provisions of Section 8.02 above, LICENSOR
agrees to use reasonable efforts to enforce the Licensed Patent Rights
hereunder against infringement by third-parties in such a manner as LICENSOR
deems reasonably necessary and appropriate under the circumstances.

     8.04 Neither LICENSEE nor any Affiliate shall foster or encourage any
infringement of the Licensed Patent Rights by any third-party. If LICENSEE
and/or any of its Affiliates shall engage in such conduct, LICENSOR shall have
the right to deem such conduct a material breach of this Agreement, which
breach shall be a basis of termination of this Agreement and of the license
granted herein, pursuant to Section 7.01 of this Agreement.

                                       16
<PAGE>   17
                             ARTICLE IX -- MARKINGS

          9.01      LICENSEE agrees to, and to cause Affiliates of LICENSEE to,
mark in a conspicuous location all Licensed Products and/or the containers or
packaging for any Licensed product sold by LICENSEE or any Affiliate of
LICENSEE with the word "Patent" or "Patents" and the number or numbers of at
least one of the Licensed Patent Rights applicable thereto, as may be agree to
between LICENSOR and LICENSEE, and with such additional legends, markings and
notices as may be required by any law or regulation of any jurisdiction in the
Territory or as LICENSOR may reasonably specify for purposes of compliance with
any such law or regulation. LICENSEE and any Affiliate of LICENSEE shall mark
any Licensed Products (and/or the containers or packaging therefor) using a
process covered by any patent included in the Licensed Patent Rights with the
number of at least one such patent, as may be agreed to between LICENSOR and
LICENSEE, and, with respect to Licensed Patent Rights, to respond to any request
for disclosure under 35 U.S.C. Section 287(b)(4)(B) by only notifying LICENSOR
of the request for disclosure and the identity of the person or entity making
such request for disclosure.

                      ARTICLE X -- INTEGRATION; AMENDMENT

          10.01     This Agreement represents the entire understanding between
the parties, and supersedes all prior or contemporaneous discussions,
proposals, negotiations, understandings and other agreements, express or
implied, between LICENSOR and LICENSEE with respect to the subject matter of
this Agreement, and there are no representations, promises, conditions,
provisions or terms, whether written or oral, with respect thereto, other than
those specifically set forth in this Agreement.

          10.02     No provision in this Agreement may be amended, altered,
modified, discharged or terminated, except by a writing signed by a duly
authorized representative of LICENSOR and LICENSEE.


                                       17
<PAGE>   18
                         ARTICLE XI -- INDEMNIFICATION

          11.01     LICENSEE and Affiliates of LICENSEE operating under this
Agreement pursuant to Section 3.04 hereof shall jointly and severally defend,
indemnify and hold harmless LICENSOR and the Affiliates of LICENSOR, and the
officers, agents and employees of LICENSOR and its Affiliates, and the inventors
(collectively the "Indemnified Parties") from and against any and all
liabilities, damages, losses, claims, suits, proceedings, demands, recovery,
costs and expenses (including, without limitation, the fees and expenses of
counsel, litigation expenses, and court costs) which arise out of or relate to,
or are alleged to arise out of or relate to: (i) use by LICENSEE or any
Affiliate of LICENSEE of any of the inventions or information included in the
Licensed Patent Rights contrary to the exclusions contained in Sections 2.03 and
2.04 of this Agreement; (ii) any personal injury, death or property damage which
arise out of or relate to or are alleged to arise out of or relate to the
manufacture, distribution, sale or use of products manufactured, sold or
otherwise distributed by LICENSEE or any Affiliate of LICENSEE; or (iii) any
breach by LICENSEE or any Affiliate of LICENSEE of any representation, warranty
or covenant set forth in this Agreement.

          11.02     During the term of this Agreement, and for such later term
extending beyond the expiration of the term of this Agreement as LICENSEE or any
Affiliate of LICENSEE may be selling Licensed Products, and for a period of
[  *  ] after the expiration of the shelf-life of the last of the Licensed
Products sold by LICENSEE or any Affiliate of LICENSEE shall maintain: (1) all
insurance and/or bonds required by law; and (2) comprehensive general liability
insurance, including product liability insurance, written on an occurrence basis
at the levels currently maintained by LICENSEE, [  *  ] excess coverage for
bodily injury, including death and property damage. Such amounts shall be
subject to reasonable increases upon the fifth and tenth anniversaries of the
date hereof to account for inflation and other

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.

                                       18
<PAGE>   19
relevant factors. The insurance coverage required by this Section 11.02 shall
be provided with respect to all claims for damages to person or property
arising out of the manufacture, formulation, processing, fabrication, sale or
use of any of the Licensed Products, regardless of when such claims are made or
when the underlying damages or injuries occur or manifest themselves.  The
policies of insurance shall: (a) include an endorsement naming LICENSOR and its
Affiliates and their respective officers, employees and agents as additional
named insureds; and (b) provide that notice be given to LICENSOR not less than
thirty (30) days prior to any cancellation or material change in any of such
policies.

     11.03  The indemnity and insurance obligations of LICENSEE and the
Affiliates of LICENSEE under this Agreement shall survive the termination or
expiration of this Agreement and of the licenses granted pursuant to this
Agreement in order to indemnify and hold harmless the Indemnified Parties (as
defined in Section 11.01) with respect to any claims for which the Indemnified
Parties are entitled to indemnification, irrespective of whether any such claim
arose prior or subsequent to the effective date of termination or expiration.

                  ARTICLE XII -- PRESS RELEASES AND PUBLICITY    

     12.01  Neither LICENSOR nor LICENSEE shall issue a press release or public
announcement concerning, or otherwise disclose, the terms of this Agreement
without the prior specific written consent of the other party.  LICENSOR and
LICENSEE specifically covenant and agree that the financial terms of this
Agreement are strictly confidential and disclosure of said financial terms to
third-parties is strictly prohibited. Each employee, agent or representative of
LICENSOR and LICENSEE who are given access to the terms of this Agreement will
be informed that the terms contained herein are confidential and disclosure of
said terms to third-parties is strictly prohibited. Notwithstanding the
foregoing, LICENSOR and/or LICENSEE may disclose in a press release, to
potential licensees, or otherwise, the fact that this

                                       19
<PAGE>   20
Agreement has been executed and entered into on mutually agreeable terms
without disclosing the amount of the payments, the royalty rates hereunder or
any of the other specific terms of this Agreement.

     12.02  Notwithstanding Section 12.01, LICENSOR or LICENSEE may disclose
the terms of this Agreement in response to: (a) an order from a court or
governmental agency; (b) in response to a request by a party in litigation,
provided an appropriate protective order has been entered; or (c) if such
disclosure is necessary to comply with any other laws or regulations applicable
to LICENSOR or LICENSEE.

                            ARTICLE XIII -- NOTICES

     13.01  It will be a sufficient giving of any notice, request, report,
statement, disclosure, or other communication hereunder, to LICENSOR or to
LICENSEE, if the party giving it deposits a copy thereof in a post office in
a registered or certified envelope, postage prepaid, or with overnight courier,
prepaid, receipt requested, addressed to the other party at its address set
forth below or at any other address the other party may hereafter designate in
writing in accordance with the provisions hereof. Unless otherwise specified in
this Agreement or otherwise designated in writing, payments to be made pursuant
to any of the provisions of this Agreement will be transmitted to the address
to which notice is to be given hereunder, or wired to the bank account of
LICENSOR as requested by LICENSOR. The respective addresses for the parties
are: 

     If to LICENSEE:     COLLAGEN CORPORATION
                         2500 Faber Place
                         Palo Alto, CA  94303

                         Attention:  President

     If to LICENSOR:     TRISTRATA TECHNOLOGY INCORPORATED
                         1105 North Market Street
                         Suite 1300, P.O. Box 8985
                         Wilmington, Delaware 99899

                         Attention:  President

                                       20
<PAGE>   21
                         With a copy to:          TriStrata, Inc.
                                                  4 Research Way
                                                  Princeton, NJ 08540

                                                  Attention:  President

                              Notice to LICENSEE shall be deemed notice to each
Affiliate of LICENSEE for all purposes, and LICENSOR shall not be required to
give any separate notice to any Affiliate of LICENSEE.


                 ARTICLE XIV - APPLICABLE LAW AND JURISDICTION

     14.01     All matters affecting the interpretation validity, and
performance of this Agreement shall be governed by the laws of the State of
Delaware without regard to its conflict of law principles.

     14.02     The United States District Court for the District of Delaware, if
a basis for Federal court jurisdiction is present, and otherwise a state court
of the State of Delaware, shall have exclusive jurisdiction and venue over any
dispute arising under or relating to this Agreement, and LICENSEE and the
Affiliates of LICENSEE consent to the jurisdiction and venue of such courts.
Each of LICENSOR and LICENSEE and Affiliates of LICENSEE submits to personal
jurisdiction and venue in the State of Delaware in any action or proceeding
arising under or relating to this Agreement and hereby agrees not to assert by
way of pleading, motion or otherwise in any such suit, action or proceeding,
that such party is not personally subject to the jurisdiction of any such court
and such action or proceeding is brought in an inconvenient forum, that the
venue of the suit, action or proceeding is improper or that this Agreement may
not be enforced in or by such court. In furtherance of such submission to
jurisdiction, each of LICENSOR and LICENSEE and Affiliates of LICENSEE hereby
agrees that, without in any manner limiting or restricting other methods of
obtaining personal jurisdiction over such party, personal jurisdiction over
LICENSOR or LICENSEE in any



                                       21
<PAGE>   22

action or proceeding arising out of or relating to this Agreement may be
obtained over such party within or without the jurisdiction of any court
located in the State of Delaware (including a United States Federal District
Court in such state) and that any process, notice of motion, or other
application to any court in connection with any such action or proceeding may
be served upon such party by registered or certified mail to, or by personal
service upon such party at the last address of such party as specified in, or
in accordance with the provisions of, Article XIII of this Agreement.

          Each of the Affiliates of LICENSEE shall be bound by the provisions
of this Section 14.02.

     14.03  In any action commenced to enforce this Agreement or as a result of
a breach of this Agreement, the prevailing party in such action shall be
entitled to recover the cost of such action, including attorneys' fees,
incurred as a result of the action to enforce and/or remedy the breach of this
Agreement.

                           ARTICLE XV - MISCELLANEOUS

     15.01     (a) If any provision of this Agreement or the application of any
provision of this agreement to any person or under any circumstances shall be
held to be invalid, unenforceable or in conflict with the law of any
jurisdiction, the validity and enforceability of the remaining provisions and
the application thereof to any another person or under any other circumstance
shall not be affected by such holding.

               (b) Any provision of this Agreement which is held to be invalid
or unenforceable by a court of competent jurisdiction in any jurisdiction
shall, as to such jurisdiction, be ineffective only to the extent of such
invalidity or unenforceability.

     15.02  The waiver by either party, whether express or implied, of any
provision of this Agreement, or of any breach or default by the other party,
shall not be construed to be a continuing waiver of such provision or of any
succeeding breach or default, or a waiver of any other provision of this
Agreement.

                                       22
<PAGE>   23
     15.03     Nothing contained in this Agreement shall be construed to
constitute or imply a joint venture, partnership, or principal-agent
relationship between LICENSOR and LICENSEE. Neither party by virtue of this
Agreement shall have any right, power or authority to act or create any
obligation, express or implied, on behalf of the other party. Neither LICENSEE,
nor any Affiliate of LICENSEE, nor any of the employees of LICENSEE  or of any
Affiliate of LICENSSEE shall in any manner be deemed an employee or an agent of
LICENSOR for any purpose whatsoever.

     15.04     The provisions of this Agreement are solely for the benefit of
LICENSOR and LICENSEE, their authorized Affiliates, and their permitted
successors and assignees (as defined herein), and no such provision shall be
construed or applied to confer any rights or benefits on any other person.

     15.05     This Agreement may be simultaneously executed in several
counterparts, each of which shall be an original and all of which shall
constitute but one and the same instrument. Both parties hereto may sign the
same counterpart or each party hereto may sign a separate counterpart of this
Agreement.

     15.06     Article, section and paragraph headings in this Agreement are
for reference purposes only and shall not in any way affect the construction or
interpretation of any provision of this Agreement.

     IN WITNESS WHEREOF, the parties have duly executed this Agreement as of
the date first written above.

LICENSOR                                LICENSEE
TRISTRATA TECHNOLOGY, INC.              COLLAGEN CORPORATION


By     /s/ EUGENE VAN SCOTT               By     /s/ GARY S. PETERSMEYER
  -------------------------------         -------------------------------

Title       President                   Title           CEO
      ---------------------------             ---------------------------

Dated   9/26/97                         Dated    9/22/97
      ---------------------------             ---------------------------

Attest:   [SIG]                         Attest:  /s/ ANN SHINE-RING
        -------------------------               -------------------------




                                       23
<PAGE>   24
SCHEDULE A - ISSUED U.S. PATENTS

[*]


SCHEDULE A - U.S. PATENT APPLICATIONS

[*]


SCHEDULE A - ISSUED FOREIGN PATENTS


EUROPEAN COUNTRIES:

[*]


AUSTRALIA:

[*]



* Confidential treatment has been requested with respect to certain portions of
  this exhibit. Confidential portions have been omitted from the public filing
  and have been filed separately with the Securities and Exchange Commission.

                                       24
<PAGE>   25
     JAPAN:

     [*]

     MEXICO:

     [*]


SCHEDULE A -- FOREIGN PATENT APPLICATIONS

     EUROPEAN COUNTRIES:

     [*]

     CANADA:

     [*]

     JAPAN:

     [*]

     BRAZIL:

     [*]


* Confidential treatment has been requested with respect to certain portions of
  this exhibit. Confidential portions have been omitted from the public filing
  and have been filed separately with the Securities and Exchange Commission.






                                       25
<PAGE>   26
                                   SCHEDULE B


     Products containing as an active ingredient thereof a mixture of [  *  ]

                 *Certain information on this page has been omitted
                  and filed separately with the Commission.
                  Confidential treatment has been requested with
                  respect to the omitted portions.
          













                                       26
<PAGE>   27
                                   SCHEDULE C

     "Substance" shall mean reaction products prepared by reacting at least one
member selected from the group consisting of [  *  ]

                 *Certain information on this page has been omitted
                  and filed separately with the Commission.
                  Confidential treatment has been requested with
                  respect to the omitted portions.







                                       27
<PAGE>   28
                                   SCHEDULE D

          A. "Substance" shall mean lactic acid and/or [  *  ]

          B. "Amphoteric Material" or "Pseudoamphoteric Material" shall mean
any material which can function as [  *  ].

* Certain information on this page has been omitted and filed separately with
the Commission. Confidential treatment has been requested with respect to the
omitted portions.


                                       28
<PAGE>   29
                      SCHEDULE E -- AFFILIATES OF LICENSEE

          1.   Aesthetic Technologies Corporation

          2.   Collagen International, Inc.



                                       29

<PAGE>   30
                          SCHEDULE F -- LICENSEE NAMES

                               1.   REFINITY(TM)



                                       30
<PAGE>   31
                            SCHEDULE G -- TERRITORY

           1.  [  *  ]
        
           2.  [  *  ]

           3.  [  *  ]

           4.  [  *  ]

           5.  [  *  ]

           6.  [  *  ]
 
           7.  [  *  ]

           8.  [  *  ]

           9.  [  *  ]

          10.  [  *  ]

          11.  [  *  ]

          12.  [  *  ]

          13.  [  *  ]

          14.  [  *  ]

          15.  [  *  ]

          16.  [  *  ]


* Certain information on this page has been omitted and filed separately with
the Commission. Confidential treatment has been requested with respect to the
omitted portions.


                                       31