EXHIBIT NO. 10.2




   CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
                EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

                            STOCK PURCHASE AGREEMENT
                            ------------------------

     THIS STOCK PURCHASE AGREEMENT  (the "Agreement") is made as of the 24th day
of August, 2001 (the "Execution Date"), by and between Atrix Laboratories, Inc.,
a Delaware  corporation having offices at 2579 Midpoint Drive, Fort Collins,  CO
80525-4417 (hereinafter, the "Investor"), and CollaGenex Pharmaceuticals,  Inc.,
a Delaware corporation having offices at 41 University Drive,  Newtown, PA 18940
(hereinafter, "CGPI").

     THE PARTIES HEREBY AGREE AS FOLLOWS:

1.   PURCHASE AND SALE OF STOCK.

     1.1.  SALE  AND  ISSUANCE  OF  COMMON  STOCK.  Subject  to  the  terms  and
           conditions of this Agreement, at the Closing (defined below) Investor
           will  purchase  and the  CGPI will sell and issue to Investor 330,556
           shares of CGPI Common Stock (the "Shares") for the purchase price per
           share  equal to [**] the Nasdaq  National  Market  System [**] for an
           aggregate purchase price of $2,999,994.03 (the "Purchase Price").

     1.2.  CLOSING.  The purchase and sale of the Shares shall take place at the
           offices of the Investor, 2579 Midpoint Drive, Fort Collins,  Colorado
           80525, on the "Effective  Date", as  such  term  is  defined  in  the
           License Agreement of even date  herewith  between the parties  hereto
           (the "License  Agreement"), or at such other times and places as CGPI
           and Investor mutually  agree upon in writing  (which times and places
           are designated as the "Closing").  At the Closing, CGPI shall deliver
           to its transfer  agent,  American Stock  Transfer & Trust  Company, a
           letter, in the form of Exhibit A, which letter directs American Stock
           Transfer  &  Trust  Company   to  deliver   promptly  to  Investor  a
           certificate representing the Shares.

     1.3.  PURCHASE PRICE.  At the Closing,  the Purchase Price shall be paid by
           Investor to CGPI in immediately available funds by wire transfer to a
           bank account  designated by CGPI two (2)  business  days prior to the
           Closing Date or, if not so  designated, then by certified or official
           bank check payable  in  immediately  available  funds to the order of
           CGPI in such amount.

     1.4.  DEFINITION.

                (a) The  following  terms,  as used herein,  have the  following
                    meanings:

                    "Affiliate"  shall have the  meaning  defined in Rule 501 of
                    Regulation D as promulgated under the 1933 Act.

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                    "Closing Date" means the date of the Closing.

                    "Common  Stock" means the Common  Stock,  par value $.01 per
                    share of CGPI.

                    "GAAP" means generally accepted accounting principles in the
                    United States.

                    "Material Adverse Effect" means a material adverse effect on
                    the condition  (financial or otherwise),  business,  assets,
                    results of operations of CGPI and its subsidiaries  taken as
                    a whole.

                    "1934 Act" means the  Securities  Exchange  Act of 1934,  as
                    amended,   and  the   rules  and   regulations   promulgated
                    thereunder.

                    "1933 Act" means the Securities Act of 1933, as amended, and
                    the rules and regulations promulgated thereunder.

                    "Person" shall mean an individual, corporation, partnership,
                    trust,  business  trust,  association,  joint stock company,
                    joint venture, pool, syndicate, sole proprietorship, and any
                    other form of entity not specifically listed herein.

                    "SEC"   shall  mean  the  U.S.   Securities   and   Exchange
                    Commission.

2.   REPRESENTATIONS AND WARRANTIES OF CGPI. CGPI hereby represents and warrants
     to Investor that:

     2.1.  ORGANIZATION, GOOD STANDING AND QUALIFICATION.  CGPI is a corporation
           duly organized,  validly existing and in good standing under the laws
           of the State of Delaware and has all  requisite  corporate  power and
           authority to carry on its  business  as now  conducted.  CGPI is duly
           qualified to  transact  business  and is in  good  standing  in  each
           jurisdiction in which the failure to so qualify would have a Material
           Adverse Effect.

     2.2.  CAPITALIZATION. The authorized capital of CGPI consists of:


           (a) PREFERRED STOCK.  5,000,000  shares of preferred stock,  $.01 par
               value, of which (i) 200,000 shares have been designated  Series D
               Convertible  Preferred  Stock,  of which  200,000  are issued and
               outstanding; and (ii) 4,800,000 shares are undesignated,  none of
               which are issued and outstanding.

           (b) COMMON  STOCK.  25,000,000  shares  of  Common  Stock,  of  which
               10,669,017 shares were issued and outstanding on August 15, 2001.

     2.3.  AUTHORIZATION.  All  corporate  action  on  the  part  of  CGPI,  its
           officers,  directors  and   stockholders   necessary   for   (i)  its
           authorization, execution and delivery of this


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           Agreement, (ii) the  performance of all obligations of CGPI hereunder
           and (iii) the authorization,  issuance (or  reservation for issuance)
           and delivery of the Common Stock being sold hereunder,  to the extent
           that the foregoing requires  performance  on or prior to the Closing,
           has been taken. This Agreement, assuming due authorization, execution
           and delivery by Investor,  constitutes  the valid and legally binding
           obligation of CGPI,  enforceable  against CGPI in accordance with its
           terms,  except  as  such  enforcement may be  limited  by  applicable
           bankruptcy,  insolvency,  reorganization,  moratorium or similar laws
           affecting  the  enforcement  of  creditors' rights  generally  or  by
           equitable  principles  relating  to  enforceability  (regardless  of
           whether considered in a proceeding at law or in equity).

     2.4.  VALID ISSUANCE OF COMMON  STOCK.  The Shares,  when  issued  against
           payment thereof in accordance with this  Agreement,  will be duly and
           validly issued, fully paid and nonassessable  and, based in part upon
           the  representations of the Investor in this Agreement and except for
           requisite  Federal securities  and state  blue sky  filings,  will be
           issued in compliance with all applicable federal and state securities
           laws.

     2.5.  SEC FILINGS.  CGPI  has  registered  its  Common  Stock  pursuant  to
           Section 12 of the 1934 Act, and the  Common  Stock is  quoted  on the
           Nasdaq  National  Market.  CGPI has filed all 1934 Act  reports for a
           period of at least twelve (12) months immediately preceding the offer
           or sale of the  Shares.  CGPI's filings  with the SEC  complied as of
           their respective  filing  dates,  or  in  the  case  of  registration
           statements,  their  respective  effective  dates,  as to form  in all
           material  respects  with  all applicable requirements of the 1933 Act
           and  the  1934  Act  and   the  rules   and  regulations  promulgated
           thereunder.  None of such  filings,  including,  without  limitation,
           any exhibits, financial  statements or schedules included therein, at
           the time filed, or in the case of registration  statements,  at their
           respective filing dates, contained any untrue statement of a material
           fact  or  omitted  to  state  a  material fact  required to be stated
           therein or necessary to make the statements  therein, in light of the
           circumstances under which they were made, not misleading. The audited
           financial statements of CGPI included in CGPI's Annual Report on Form
           10-K for the year ended  December  31, 2000  comply as to form in all
           material respects with the published rules and regulations of the SEC
           with respect thereto, and such audited financial  statements (i) were
           prepared from the books and  records of CGPI,  (ii) were  prepared in
           accordance with GAAP applied on a consistent  basis (except as may be
           indicated  therein  or in the notes or  schedules  thereto) and (iii)
           present fairly the financial position of CGPI as of the dates thereof
           and the results of  operations  and cash flows for the  periods  then
           ended.  The  unaudited  financial  statements   included   in  CGPI's
           Quarterly Reports on Form 10-Q for the quarterly  periods ended March
           31, 2001 and June 30, 2001 comply as to form in all material respects
           with the  published  rules  and  regulations of the SEC with  respect
           thereto;  and such unaudited  financial  statements (i) were prepared
           from the books and records of CGPI, (ii) were  prepared in accordance
           with GAAP,  except as otherwise permitted  under the 1934 Act and the
           rules  and  regulations  thereunder, on a consistent basis (except as
           may be  indicated  therein or in the notes or schedules  thereto, and
           except that they do not contain footnotes and other


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<PAGE>

           presentation items that may be  required  by GAAP) and (iii)  present
           fairly the financial position of CGPI as of the dates thereof and the
           results  of operations  and  cash  flows  (or  changes  in  financial
           condition)  for the  periods  then ended,  subject to normal year-end
           adjustments  and any other  adjustments  described  therein or in the
           notes or schedules thereto.

     2.6.  LITIGATION. Except as disclosed in CGPI's filings with the SEC, there
           is  no  action,  suit  or  proceeding  before  or  by  any  court  or
           governmental agency or body,  domestic or foreign, now pending or, to
           the knowledge of CGPI,  threatened, against or affecting CGPI, or any
           of its  properties,  which could reasonably be expected, individually
           or in the aggregate, (i) to have a Material Adverse Effect or (ii) to
           result  in  the  issuance  of  an  order  restraining,  enjoining  or
           otherwise  prohibiting  or  making illegal the consummation of any of
           the transactions contemplated by this Agreement.

     2.7.  NO DEFAULT.  Except as disclosed in CGPI's filings with the SEC, CGPI
           is not in default in the  performance or  observance  of any material
           obligation,  agreement,   covenant  or  condition  contained  in  any
           indenture,  mortgage,  deed of trust or other  material  agreement or
           instrument to which it is a party or by which it or its  property may
           be bound and which is filed as an exhibit to CGPI's 1934 Act reports,
           except  for  defaults  that have not had and would not  reasonably be
           expected  to  have,  individually  or  in  the  aggregate, a Material
           Adverse Effect.

     2.8.  SUBSEQUENT  EVENTS; UNDISCLOSED LIABILITIES.  Since  June  30,  2001,
           CGPI  has  not  incurred  any  liability or obligation, contingent or
           otherwise,  that taken  as  a  whole, is material in the aggregate to
           CGPI,  except  (i) in the ordinary course of business consistent with
           past  practices, or (ii) as reflected  in or reserved  against in the
           balance sheet of CGPI as of June 30, 2001.  Since June 30, 2001, CGPI
           has conducted  its  business  in  the  ordinary  course  of  business
           consistent  with past  practices, and there has not been any Material
           Adverse  Effect and  there  is  no  condition   existing  that  could
           reasonably be expected to result in a Material Adverse  Effect on the
           business of CGPI.

     2.9.  CONSENTS AND APPROVALS. No material consent, approval, qualification,
           order  or  authorization  of,  or  filing  with,  any local, state or
           federal  governmental  authority  or any third  party,  including any
           approval under the  Hart-Scott-Rodino  Antitrust  Improvements Act of
           1976, as amended, is required on the part of CGPI in connection  with
           CGPI's valid execution, delivery or performance of this Agreement, or
           the offer, sale or  issuance  of the  Shares by CGPI,  other than the
           filings that have been made  prior to the  Closing,  except  that any
           notices of sale  required  to be  filed by CGPI  with  the SEC  under
           Regulation D of the 1933 Act and filings required by the rules of the
           Nasdaq  National  Market,  or  such  post-closing  filings  as may be
           required under applicable state securities laws, which will be timely
           filed within the applicable periods therefor.

     2.10. COMPLIANCE WITH LAWS AND COURT ORDERS.  CGPI  is  not in violation of
           any  applicable law, rule, regulation, judgment, injunction, order or
           decree except for


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           violations that have not had and would not  reasonably be expected to
           have, individually or in the aggregate, a Material Adverse Effect.

     2.11. NO CONFLICT.  Except  for  rights  to  anti-dilution  protection  for
           holders  of  CGPI's  Series  D  Preferred  Stock,  the  execution and
           delivery of this Agreement and CGPI's performance of its  obligations
           under  this  Agreement  will  not  (i)  violate  any  applicable law,
           ordinance,  rule  or  regulation  of any  governmental  authority or
           (ii) conflict  with or result in a breach of the terms and conditions
           of,  or   constitute  any  default  under,  CGPI's   Certificate   of
           Incorporation or By-laws, or any contract, agreement or instrument to
           which CGPI or any  subsidiary  is a  party  or by  which  CGPI or any
           Subsidiary or any of their respective  property if bound,  except, in
           each case, for violations, conflicts  or  breaches which individually
           or in the aggregate would not have a Material Adverse Effect.

     2.12. INSURANCE.  CGPI has in full force  and  effect  fire  and  casualty,
           general  liability  and product  liability  insurance  policies, with
           extended  coverage, in  amounts  customary  for  companies  similarly
           situated to CGPI.

3.   REPRESENTATIONS AND WARRANTIES OF INVESTOR.  Investor hereby represents and
     warrants to CGPI that:

     3.1.  ORGANIZATION   AND   EXISTENCE.  Investor  is  a   corporation   duly
           incorporated, validly existing and in good standing under the laws of
           Delaware and has all requisite corporate power and authority to carry
           on its business as now conducted.

     3.2.  CORPORATE  AUTHORIZATION.   Investor  has  full  corporate  power and
           authority  to execute  and  deliver  this  Agreement and  perform its
           obligations  hereunder.  The  execution,  delivery and performance by
           Investor of this Agreement have been duly authorized by all requisite
           corporate  action.   This  Agreement,  assuming  due   authorization,
           execution  and  delivery  by CGPI, constitutes  the valid and legally
           binding  obligation  of  Investor,  enforceable  against  Investor in
           accordance with its terms,  except as such enforcement may be limited
           by applicable bankruptcy,  insolvency,  reorganization, moratorium or
           similar laws affecting the enforcement of creditors' rights generally
           or by equitable  principles relating to enforceability (regardless of
           whether considered in a proceeding at law or in equity).

     3.3.  PURCHASE  ENTIRELY  FOR OWN  ACCOUNT.  Investor  is  sophisticated in
           transactions of this type and  capable of  evaluating  the merits and
           risks of the transactions described  herein,  and has the capacity to
           protect its own interests.  Investor  has  not been formed solely for
           the purpose of entering into the  transactions described herein.  The
           Shares to be received by Investor will be acquired for investment for
           Investor's  own  account,  not  as a nominee or agent, and not with a
           view  to  the  resale or distribution  of any part thereof,  and that
           Investor   has   no  present  intention  of  selling,  granting   any
           participation  in, or otherwise  distributing the same.  By executing
           this Agreement, Investor further  represents  that Investor does  not
           have  any  contract, undertaking,  agreement  or arrangement with any
           person to sell,


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           transfer or  grant  participation  to  such  person  or  to any third
           person, with respect to any of the Shares.

     3.4.  RESTRICTED SECURITIES. Investor understands that the shares of Common
           Stock it is purchasing are characterized  as "restricted  securities"
           under the federal securities laws inasmuch as they are being acquired
           from CGPI in a transaction  not  involving a public offering and that
           under such laws and  applicable  regulations  such securities  may be
           resold  without  registration  under the 1933 Act only  under certain
           limited  circumstances.  Investor represents that it is familiar with
           SEC Rule 144,  as  presently  in effect,  and understands  the resale
           limitations imposed thereby and by the 1933 Act.

           Investor agrees that it shall not sell or  otherwise  transfer any of
           the Shares  without  registration  under the 1933 Act, or pursuant to
           Rule 144 under the 1933 Act,  or  pursuant  to an  opinion of counsel
           reasonably  satisfactory  to CGPI that an exemption from registration
           is available, and fully  understands and agrees that it must bear the
           total  conomic risk of its purchase for an indefinite  period of time
           because of the restricted nature of the Shares.  Investor understands
           that  CGPI  is  under  no  obligation  to  register the Shares on its
           behalf.  Investor  understands the lack of liquidity and restrictions
           on transfer of the Shares and that this  investment  is suitable only
           for a person or entity of  adequate financial  means that has no need
           for liquidity of this  investment and that can afford a total loss of
           its investment.

     3.5.  LEGENDS.  Investor acknowledges that the certificates  evidencing the
           Shares shall bear the following or  substantially  similar legend and
           such other  legends as may be  required  by state or other applicable
           securities laws:

               "THE  SHARES   EVIDENCED  BY  THIS   CERTIFICATE  HAVE  NOT  BEEN
               REGISTERED  UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED  (THE
               "ACT"), OR THE SECURITIES ACT OF ANY STATE. THE SHARES MAY NOT BE
               SOLD,  TRANSFERRED FOR VALUE, PLEDGED,  HYPOTHECATED OR OTHERWISE
               ENCUMBERED  IN THE ABSENCE OF AN EFFECTIVE  REGISTRATION  OF THEM
               UNDER THE ACT  AND/OR THE  SECURITIES  ACT OF ANY STATE OR IN THE
               ABSENCE OF AN OPINION  OF  COUNSEL  ACCEPTABLE  TO CGPI THAT SUCH
               REGISTRATION IS NOT REQUIRED UNDER SUCH ACT OR ACTS."

               "Until the  Separation  Time (as defined in the Rights  Agreement
               referred to below),  this certificate also evidences and entitles
               the holder hereof to certain Rights as set forth in a Shareholder
               Protection Rights  Agreement,  dated as of September 15, 1997 (as
               such may be amended from time to time,  the "Rights  Agreement"),
               between  CollaGenex  Pharmaceuticals,  Inc. (the  "Company")  and
               American  Stock Transfer & Trust  Company,  as Rights Agent,  the
               terms of which are hereby  incorporated herein by reference and a
               copy of which is on file at the  principal  executive  offices of
               the Company.  Under  certain  circumstances,  as set forth in the
               Rights


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               Agreement,  such Rights may be redeemed,  may become  exercisable
               for  securities or assets of the Company or securities of another
               entity,  may be  exchanged  for  shares of Common  Stock or other
               securities or assets of the Company,  may expire, may become void
               (if they are "Beneficially  Owned" by an "Acquiring Person" or an
               Affiliate or Associate thereof,  as such terms are defined in the
               Rights  Agreement,  or by any transferee of any of the foregoing)
               or may be evidenced by separate certificates and may no longer be
               evidenced by this  certificate.  The Company will mail or arrange
               for the mailing of a copy of the Rights  Agreement  to the holder
               of this certificate without charge after the receipt of a written
               request therefor."

     3.6.  REMOVAL OF LEGENDS

           (a) The first legend  endorsed on a  certificate  pursuant to Section
               3.5  shall  be  removed  (i)  if  the  shares  of  Common   Stock
               represented by such  certificate  shall have been resold under an
               effective  registration statement under the 1933 Act or otherwise
               lawfully  sold in a public  transaction,  (ii) if such shares are
               transferred  in compliance  with Rule 144  promulgated  under the
               1933  Act,  or (iii) if the  holder  of such  shares  shall  have
               provided  CGPI with an opinion of counsel,  in form and substance
               acceptable  to CGPI and its counsel,  stating that a public sale,
               transfer  or  assignment  of  such  shares  may be  made  without
               registration.

           (b) Any  legend  endorsed  on a  certificate  as  required  by  state
               securities  laws pursuant to Section 3.5 shall be removed if CGPI
               receives an order of the appropriate state authority  authorizing
               such removal or if the holder of such shares  provides  CGPI with
               an opinion of counsel,  in form and substance  acceptable to CGPI
               and its counsel, stating that such state legend may be removed.

     3.7.  ACCREDITED INVESTOR. Investor is an "accredited investor" (as defined
           in Rule 501(a)  under the 1933 Act) and has the  financial ability to
           bear the economic  risks of its  investment,  has  adequate means for
           providing for its current needs and contingencies and has no need for
           liquidity with respect to its investment in CGPI.

     3.8.  CONSENTS  AND  APPROVALS.  Except  for  Schedule 13D or 13G under the
           Securities  Exchange  Act of  1934,  no  material  consent, approval,
           qualification, order or authorization  of, or filing with, any local,
           state or federal governmental authority or any third party, including
           any  approval  under the Hart-Scott-Rodino Antitrust Improvements Act
           of 1976,  as  amended,  is  required  on the part of the  Investor in
           connection   with  the  Investor's   valid   execution,   delivery or
           performance of this Agreement.

     3.9.  LEGAL  PROCEEDINGS,  ETC.   There  is   no   legal,   administrative,
           arbitration   or  other   action   or   proceeding   or  governmental
           investigations  pending,  or to the Investor's  knowledge  threatened
           against the Investor which could reasonably be expected to


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           result  in  the  issuance  of  an  order  restraining,  enjoining  or
           otherwise  prohibiting  or  making illegal the consummation of any of
           the transactions contemplated by this Agreement.

     3.10. AVAILABILITY OF  FUNDS.  Investor  has  or  will  have  available  at
           Closing, sufficient funds to pay the Purchase Price for the Shares.

4.   COVENANT  RELATING TO RULE 144. CGPI will file reports in  compliance  with
     the 1934 Act, will comply with all rules and  regulations of the Commission
     applicable  in  connection  with the use of Rule 144 and  take  such  other
     actions  and  furnish  the  Investor  with such  other  information  as the
     Investor  may  request  in order to avail  itself of such rule or any other
     rule or regulation of the Commission  allowing  Investor to sell the Shares
     without registration, and will, at its own expense, upon the request of the
     Investor, deliver to the Investor a certificate, signed by CGPI's principal
     financial  officer,  stating (a) CGPI's name,  address and telephone number
     (including area code), (b) CGPI's Internal  Revenue Service  identification
     number, (c) CGPI's Commission file number, (d) the number of shares of each
     class of stock  outstanding as shown by the most recent report or statement
     published by CGPI,  and (e) whether CGPI has filed the reports  required to
     be filed under the 1934 Act for a period of at least ninety (90) days prior
     to the date of such  certificate  and in addition has filed the most recent
     annual report required to be filed  thereunder.  If at any time CGPI is not
     required to file reports in  compliance  with either  Section 13 or Section
     15(d) of the 1934 Act, CGPI at its expense will,  upon the written  request
     of the Investor,  make available  adequate current public  information with
     respect to CGPI within the  meaning of  paragraph  (c)(2) of Rule 144.  The
     covenants set forth in this Section 4 shall survive the Closing.

5.   PIGGYBACK REGISTRATION RIGHTS.

     5.1.  REGISTRATION  RIGHTS.  If (but without any obligation  to do so) CGPI
           proposes to register any of its stock or other  securities  under the
           1933 Act in connection with an  underwritten  public offering of such
           securities (other than a registration  relating solely to the sale of
           securities  to  participants  in a CGPI  stock  plan, a  registration
           relating  to  a  corporate  reorganization or other transaction under
           Rule 145 of the 1933 Act, a  registration  on  any form that does not
           include substantially the same information as would be required to be
           included in a registration statement covering the sale of the Shares,
           a  registration  in which the only Common  Stock being  registered is
           Common  Stock  issuable  upon  conversion of debt securities that are
           also  being  registered,  or  Common  Stock  issued  or to be  issued
           pursuant to an equity  line  financing),  CGPI  shall,  at such time,
           promptly give Atrix  written  notice of such  registration.  Upon the
           written request of Atrix given within  twenty (20) days after mailing
           of such  notice by CGPI,  CGPI  shall,  subject to the  provisions of
           Section  5.2 and  Section  5.6  hereof,  use commercially  reasonable
           efforts  to  cause  to  be  registered  under the 1933 Act all of the
           Shares that Atrix has requested to be registered.

     5.2.  RIGHT  TO  TERMINATE  REGISTRATION.  CGPI  shall  have  the  right to
           terminate or withdraw any registration  initiated by it under Section
           5.1 prior to the


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           effectiveness  of  such registration whether or not Atrix has elected
           to include  securities  in such  registration.  The  expenses of such
           withdrawn registration shall be borne by CGPI.

     5.3.  ATRIX TO PROVIDE INFORMATION.  It  shall  be a condition precedent to
           the obligations of CGPI to take any action pursuant to this Section 5
           with respect to the registration  of the Shares that Atrix furnish to
           CGPI such information  regarding itself, the Shares, and the intended
           method of distribution of such Shares as shall be reasonably required
           to effect the registration of such Shares.

     5.4.  PAYMENT OF EXPENSES.  All expenses other than  underwriting discounts
           and commissions incurred in connection with registrations, filings or
           qualifications   pursuant  to  this  Section  5,  including,  without
           limitation,   all   registration,   filing   and  qualification  fees
           (including "blue sky" fees),  printers' and accounting fees, fees and
           disbursements of counsel for CGPI shall be borne by CGPI.

     5.5.  ADDITIONAL  AGREEMENTS.  In  the  event  of  an  underwritten  public
           offering, the right of the Investor to registration  pursuant to this
           Section 5 is conditioned  upon such Investor's  participation in such
           underwriting, the inclusion of such securities in the underwriting to
           the extent provided herein and Investor entering into an underwriting
           agreement  with the  underwriter or  underwriters  selected  for such
           underwriting  by the Company (together with the Company and the other
           holders distributing their securities through such underwriting), and
           such other  documents, agreements and certificates as shall be deemed
           necessary by the underwriter in connection with such public offering.

     5.6.  REGISTRATION  PRIORITY.  Notwithstanding  any other provision of this
           Section 5, if the underwriter  advises the Company in writing that in
           its  good  faith  judgment  the  number  of  shares  requested  to be
           registered  exceeds the  number of  shares  which can be sold in such
           offering: (a) the number of shares so requested to be included in the
           offering  will be reduced to that  number of shares which in the good
           faith judgment of the underwriter can be sold in  such  offering  and
           (b) such  reduced  number of  shares will be  allocated  first to the
           securities  CGPI proposes to sell;  second to those CGPI stockholders
           having  registration  rights  pursuant  to the  terms of that certain
           Registration  Rights  Agreement  dated  September  29,  1995 and that
           certain  Stockholders  and  Registration Rights Agreement dated March
           19, 1999 in accordance with the terms of each such agreement;  third,
           to those CGPI stockholders having registration rights pursuant to the
           terms of those certain Registration Rights Agreements dated March 12,
           2001 in accordance with the terms of each such agreement; and fourth,
           to Atrix, with respect to the Shares.

     5.7.  TERMINATION OF  REGISTRATION  RIGHTS.  Atrix shall not be entitled to
           exercise any right provided for in this Section 5 at such time as all
           of the Shares can be sold pursuant to Rule 144(k) of the 1933 Act.


                                       9
<PAGE>

6.   CONDITIONS TO CLOSING.

     6.1.  CONDITIONS  OF  INVESTOR  TO  CLOSING;  DELIVERIES  TO INVESTOR.  The
           obligations  of  Investor to consummate the transactions contemplated
           by this Agreement are subject to the satisfaction, at or prior to the
           Closing, of each of the following conditions:

           (a) A certificate  from a duly authorized  officer of CGPI certifying
               that the representations and warranties of CGPI set forth in this
               Agreement  shall be true and correct as of the Closing Date as if
               made on and as of the Closing Date.

           (b) The Effective Date of the License Agreement shall have occurred.

           (c) Investor   shall  have  received  the   following   documents  or
               deliveries  at or before the  Closing,  each of which shall be in
               full force and effect:

               (i)  evidence of the  delivery  of the letter to CGPI's  transfer
           agent pursuant to Section 1.2 above; and

               (ii) a certificate  signed by the chief executive officer and the
           corporate  secretary of CGPI certifying (x) to  resolutions  duly and
           validly  adopted  by the Board of  Directors of CGPI  evidencing  its
           authorization of the execution and delivery of this Agreement and the
           issuance of the  Shares  to  Investor,  and the  consummation  of the
           transactions  contemplated  hereby and that such resolutions have not
           been  amended  and  remain  in  full force and effect, and (y) to the
           names and  signatures of the persons  authorized on behalf of CGPI to
           execute and deliver this Agreement.

     6.2.  CONDITIONS OF CGPI TO CLOSING; DELIVERIES TO CGPI. The obligations of
           CGPI  to  consummate  the transactions contemplated by this Agreement
           are subject to the satisfaction,  at or prior to the Closing, of each
           of the following conditions:

           (a) A  certificate  from  a  duly  authorized   officer  of  Investor
               certifying  that the  representations  and warranties of Investor
               set forth in this  Agreement  shall be true and correct as of the
               Closing Date as if made on and as of the Closing Date.

           (b) The Effective Date of the License Agreement shall have  occurred.

           (c) CGPI shall have received the following documents or deliveries at
               or before the  Closing,  each of which shall be in full force and
               effect:

               (i) a certificate  signed by the chief executive  officer and the
           corporate  secretary  of  Investor certifying (x) to resolutions duly
           and validly  adopted by the Board of Directors of Investor evidencing
           its authorization of the execution and delivery of this Agreement and
           the  consummation  of  the  transactions contemplated hereby and that
           such resolutions have not been amended and remain


                                       10
<PAGE>

           in full force and effect, and (y) to the names and  signatures of the
           persons  authorized on behalf of Investor to execute and deliver this
           Agreement; and

               (ii) the consideration payable by Investor at Closing as provided
           in Section 1.3 in immediately available funds.

7.   TERMINATION.

     7.1.  TERMINATION.  This  Agreement may be terminated prior to the Closing:

           (a) By mutual written consent of CGPI and Investor.

           (b) In the event that the Effective Date under the License  Agreement
               shall not have occurred on or prior to August 24, 2001.

     7.2.  EFFECT OF  TERMINATION.  In the  event  of the  termination  of  this
           Agreement as provided in Section 7.1,  this  Agreement shall be of no
           further force or effect;  provided, however that the  termination  of
           this Agreement shall not relieve any party from any liability for any
           willful and knowing breach of this Agreement.

8.   MISCELLANEOUS.

     8.1.  SUCCESSORS AND ASSIGNS.  This  Agreement  may not be assigned without
           the  prior  written  consent of the  non-assigning  party;  provided,
           however, that without prior written approval, Investor may assign any
           and  all  of  its  rights and interest under this Agreement to one or
           more of its Affiliates and designate one or more of its Affiliates to
           perform its obligations under this Agreement; provided such Affiliate
           expressly acknowledges and confirms the  representations,  warranties
           and information  set  forth  in  Sections  3.4,  3.5  and 3.7 of this
           Agreement.  Any purported  assignment in violation of this  provision
           shall be null and void.  The terms and  conditions of this  Agreement
           shall inure to the  benefit  of and be  binding  upon the  respective
           permitted successors  and  assigns  of the  parties.  Nothing in this
           Agreement,  express or  implied, is intended to confer upon any party
           other than the  parties  hereto or their  respective  successors  and
           assigns any rights, remedies, obligations, or liabilities under or by
           reason  of  this  Agreement,  except  as  expressly  provided in this
           Agreement.

     8.2.  THIRD PARTY  PURCHASER.  A  third-party  purchaser of the Shares from
           Investor  will not be  subject  to any of the terms of this Agreement
           other than those imposed by the federal and state securities laws.

     8.3.  GOVERNING LAW.  This  Agreement  shall  be  governed by and construed
           under  the  laws of the State of Delaware (irrespective of its choice
           of law principles).

     8.4.  COUNTERPARTS.   This  Agreement  may  be  executed  in  two  or  more
           counterparts,  each of which shall be deemed an  original, but all of
           which together shall  constitute  one and the same  instrument.


                                       11
<PAGE>

     8.5.  TITLES AND SUBTITLES. The titles and subtitles used in this Agreement
           are  used  for  convenience  only  and  are  not to be  considered in
           construing or interpreting this Agreement.

     8.6.  NOTICES.  All notices, requests and other communications to any party
           hereunder shall be in writing (including  facsimile transmission) and
           shall be deemed to have been given if delivered personally, mailed by
           certified mail (return receipt requested) or sent by cable, telegram,
           telecopier or recognized overnight delivery service to the parties at
           the  following  addresses or at such other addresses as  specified by
           the parties by like notice:

                If to Investor:
                Atrix Laboratories, Inc.
                2579 Midpoint Drive
                Fort Collins, Colorado 80525
                Attn:  Dr. Charles P. Cox, Senior Vice President of
                        Corporate Development
                Fax:  (970) 482-9765
                Phone:  (970) 482-5868

                With a copy to:

                Morrison & Foerster LLP
                370 17th Street, Suite 5200
                Denver, Colorado 80202
                Attn:  Warren L. Troupe, Esq.
                Fax:  (303) 592-1510
                Phone:  (303) 592-1500

                If to CGPI:

                CollaGenex Pharmaceuticals, Inc.
                41 University Drive
                Newtown, PA 18940
                Attn:  Brian M. Gallagher, Ph.D.
                Chairman, President and Chief Executive Officer
                Telephone: (215) 579-7388
                Facsimile:  (215) 579-8577

                With a copy to:

                William J. Thomas, Esq.
                Hale and Dorr LLP
                650 College Road East
                Princeton, New Jersey 08540


                                       12
<PAGE>

           Notice so given shall be deemed  given and received (i) if by mail on
           the  fourth  calendar  day after  posting;  (ii) by  cable, telegram,
           telecopier,   telex  of  personal  delivery  on  the  date  of actual
           transmission  or (as the case may be)  personal  or other delivery or
           one business day after transmission (if transmitted and received on a
           non-business day);  and (iii) if by  overnight  courier,  on the next
           business  day  following  the  day  such  notice  is delivered to the
           courier service.

     8.7.  FINDERS  FEE.  Each  party  represents that it neither is nor will be
           obligated for any finders' fee or  commission in connection with this
           transaction. Investor agrees to indemnify and hold harmless CGPI from
           any liability for any  commission or compensation  in the nature of a
           finders'  fee (and  costs  and  expenses  of  defending  against such
           liability  or  asserted  liability) for which  Investor or any of its
           officers, partners, employees or representatives is responsible. CGPI
           agrees to indemnify and hold harmless Investor from any liability for
           any  commission or compensation  in the nature of a finders' fee (and
           the  costs  and  expenses  of  defending  against  such  liability or
           asserted  liability) for which CGPI or any of its officers, employees
           or representatives is responsible.

     8.8.  EXPENSES.  CGPI and the Investor shall pay their own respective costs
           and  expenses  incurred  with respect to the  negotiation, execution,
           delivery  and  performance  of this  Agreement  and  the transactions
           contemplated hereby.

     8.9.  AMENDMENTS AND WAIVERS.  Any  term  of  this Agreement may be amended
           and  the  observance  of  any  term  of  this Agreement may be waived
           (either   generally   or  in  a   particular   instance   and  either
           retroactively or prospectively),  only  with  the  written consent of
           CGPI  and  the  Investor.    Any  amendment  or  waiver  effected  in
           accordance  with this  paragraph shall be binding on the Investor and
           CGPI.

     8.10. SEVERABILITY.  If one or  more  provisions of this Agreement are held
           to be  unenforceable  under applicable  law, such provision  shall be
           excluded from this Agreement and the balance of this  Agreement shall
           be  interpreted  as if such  provision  were so excluded and shall be
           enforceable in accordance with its terms.

     8.11. ENTIRE  AGREEMENT.  This Agreement  constitutes the entire  agreement
           between the parties with  respect to the  subject  matter  hereof and
           supersedes  all prior  agreements and  understandings,  both oral and
           written,  between  the  parties  with  respect to the  subject matter
           hereof.  No  representation,   inducement,   promise,  understanding,
           condition  or warranty  not set forth  herein has been made or relied
           upon  by  either  party intended to confer upon any person other than
           the parties hereto any rights or remedies hereunder.

                                    * * * * *



                                       13
<PAGE>



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



ATRIX LABORATORIES, INC.                        COLLAGENEX PHARMACEUTICALS, INC.
a Delaware corporation                          a Delaware corporation


                                                By:   /s/ Brian M. Gallagher
By:   /s/ David R. Bethune                         -----------------------------
   ----------------------------------                 Brian M. Gallagher, Ph.D.
      David R. Bethune, Chairman and                  Chairman, President and
      Chief Executive Officer                         Chief Executive Officer




                                       14
<PAGE>



                                    EXHIBIT A

                 LETTERHEAD OF COLLAGENEX PHARMACEUTICALS, INC.



                                 August 24, 2001


American Stock Transfer & Trust Company
Transfer Agent and Registrar
40 Wall Street
New York, New York 10005
Attention:  Craig Leibell

     Re: CollaGenex Pharmaceuticals, Inc. - Share Issuance Instructions
         --------------------------------------------------------------

Ladies and Gentlemen:

          CollaGenex  Pharmaceuticals,  Inc., a Delaware  corporation  ("CGPI"),
proposes to issue three hundred thirty thousand five hundred fifty-six (330,556)
shares of its  common  stock,  par value  $.01 per share  (the  "Common  Stock")
pursuant to a Stock Purchase Agreement between CGPI and Atrix Laboratories, Inc.

          1. You are  hereby  irrevocably  authorized  and  directed,  as CGPI's
Transfer Agent and Registrar, to register and countersign, as an original issue,
one certificate  representing an aggregate of 330,556 shares of the Common Stock
in the name of Atrix Laboratories, Inc.

          2. You are  further  directed to deliver  the above  referenced  share
certificate to the following address, by registered mail:

                       Atrix Laboratories, Inc.
                       2579 Midpoint Drive
                       Fort Collins, CO 80525-4417
                       Attn: Brian G. Richmond
                       Chief Financial Officer

          3. The   above-referenced   certificate   shall   bear   the   legends
substantially similar to the following:

          "THE SHARES  EVIDENCED BY THIS  CERTIFICATE  HAVE NOT BEEN  REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"),  OR THE SECURITIES ACT
OF ANY  STATE.  THE  SHARES MAY NOT BE SOLD,  TRANSFERRED  FOR  VALUE,  PLEDGED,
HYPOTHECATED OR OTHERWISE ENCUMBERED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION
OF THEM UNDER THE ACT AND/OR THE  SECURITIES  ACT OF ANY STATE OR IN THE ABSENCE
OF AN OPINION OF COUNSEL  ACCEPTABLE TO THE ISSUER THAT SUCH REGISTRATION IS NOT
REQUIRED UNDER SUCH ACT OR ACTS."

                                      A-1
<PAGE>

          "Until  the  Separation  Time  (as  defined  in the  Rights  Agreement
referred to below),  this  certificate  also  evidences  and entitles the holder
hereof  to  certain  Rights  as set  forth in a  Shareholder  Protection  Rights
Agreement,  dated as of September  15, 1997 (as such may be amended from time to
time, the "Rights  Agreement"),  between CollaGenex  Pharmaceuticals,  Inc. (the
"Company") and American Stock  Transfer & Trust  Company,  as Rights Agent,  the
terms of which are hereby  incorporated  herein by reference and a copy of which
is on file at the  principal  executive  offices of the Company.  Under  certain
circumstances,  as set  forth  in  the  Rights  Agreement,  such  Rights  may be
redeemed,  may become  exercisable  for  securities  or assets of the Company or
securities  of another  entity,  may be exchanged  for shares of Common Stock or
other securities or assets of the Company,  may expire, may become void (if they
are "Beneficially  Owned" by an "Acquiring  Person" or an Affiliate or Associate
thereof, as such terms are defined in the Rights Agreement, or by any transferee
of any of the foregoing) or may be evidenced by separate certificates and may no
longer be  evidenced by this  certificate.  The Company will mail or arrange for
the mailing of a copy of the Rights  Agreement to the holder of this certificate
without charge after the receipt of a written request therefor."

          Please acknowledge receipt of these instructions below.

                                  Very truly yours,



                                  By:    /s/ Brian M. Gallagher
                                     -------------------------------------
                                  Name:  Brian M. Gallagher, Ph.D.
                                  Title: Chairman, President and Chief Executive
                                         Officer



American Stock Transfer & Trust Company
as Transfer Agent and Registrar



By:
   -------------------------------
Name:
     -----------------------------
Title:
      ----------------------------



                                      A-2