<PAGE>
                                                                   Exhibit 10.69

                [LETTERHEAD OF TEVA PHARMACEUTICALS CURACAO N.V.]

                                 October 8, 2003


VIA FACSIMILE AND REGULAR MAIL

Impax Laboratories, Inc.
3753 Castor Avenue
Philadelphia, PA 19124

Attention: Barry Edwards, Co-CEO

Re:  Strategic Alliance Agreement between Impax Laboratories, Inc. and Teva
     Pharmaceuticals Curacao N.V. effective June 27, 2001 ("AGREEMENT").

Dear Barry:

         As you know, Teva Pharmaceuticals Curacao N.V. ("TEVA") exercised its
option under Section 4.1 of the Agreement to add the Optional Products
(Omeprazole DR, 10, 20 and 40 mg) to the Agreement as Tier 1 Products. The
Omeprazole 40 mg is specifically excluded from this letter agreement. All
defined terms used herein shall have the same meaning as set forth in the
Agreement.

         This will confirm that only with respect to the Optional Products for
the Territory of the U.S., the Parties have agreed to the following:

     (a) During the period set forth in the table below, the Impax Margin shall
         be in an amount set forth opposite each period:
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------
                             PERIOD                                                IMPAX MARGIN
-----------------------------------------------------------------------------------------------------------------
<S>                                                                                    <C>
*Commencing on the Launch Date and ending eighteen (18) months                  [XXX]* % of the Profit
 from the Launch Date
-----------------------------------------------------------------------------------------------------------------
*Commencing eighteen (18) months from the Launch Date and ending                [XXX]* % of the Profit
 twenty-four (24) months from the Launch Date
-----------------------------------------------------------------------------------------------------------------
*Commencing twenty-four (24) months from the Launch Date and                    [XXX]* % of the Profit
 thereafter
-----------------------------------------------------------------------------------------------------------------
</TABLE>

     (b) For purposes of Section 12 of the Agreement, Impax further represents
         and warrants that:

         (1) prior to filing its ANDA for the Optional Products, it obtained an
             objectively reliable written opinion of independent and competent
             outside counsel that each of the Orange Book patents with respect
             to the Optional Products was invalid, unenforceable, or would not
             be infringed by the manufacture, use, sale, offer for sale in the
             U.S., or importation into the U.S. of Impax's omeprazole
             formulation;

--------
* Filed under an application for confidential treatment.
<PAGE>

         (2) it has obtained an updated written opinion regarding U.S. patents
             4,786,505 and 4,853,230, reflecting the claim construction adopted
             by the Southern District of New York in AstraZeneca v. Andrx et
             al., dated October 16, 2002, and reported at 222 F.Supp.2d 423
             (SDNY 2002);

         (3) it has obtained an objectively reliable written opinion of
             independent and competent outside counsel that U.S. patent
             6,013,281 is invalid, unenforceable, or would not be infringed by
             the manufacture, use, sale, offer for sale in the U.S., or
             importation into the U.S. of Impax's omeprazole formulation;

         (4) it actually relied upon the opinion referred to in subparagraph
             (1), above in deciding whether to file an ANDA containing a
             paragraph IV certification with respect to each of the Orange Book
             listed patents with respect to the Optional Products; and

         (5) it actually relied upon the opinions referred to in subparagraphs
             (1), (2) and (3), above in deciding whether to make, use, sell or
             offer to sell the Optional Products within the U.S. prior to the
             expiration of each of the relevant patents.

     (c) Only upon the commencement or amendment of any Intellectual Rights
         Suit, directly arising from the launch of the Optional Products in the
         U.S. by Teva and/or its Affiliates, Sections 11.5, 14.1, 15.3 and 15.4
         of the Agreement shall not apply and the following shall apply instead:

         (1) Teva shall have the obligation to assume direction and control of
             any such Intellectual Rights Suit directly arising from the launch
             of the Optional Products in the U.S. by Teva and/or its Affiliates
             as well as any pending or future intellectual property suit
             involving the same patents at issue in such Intellectual Rights
             Suit (collectively referred to herein as the "OPTIONAL PRODUCT
             LAUNCH LITIGATION") and the defense of claims arising therefrom,
             including without limitation, the selection of legal counsel;
             provided, however, that Teva shall obtain the prior written consent
             of Impax prior to ceasing to defend, settling or otherwise
             disposing of any such Optional Product Launch Litigation, said
             consent not to be unreasonably withheld or delayed. Furthermore,
             Teva shall provide Impax with copies of all pleadings and other
             litigation documents and shall consult with Impax in connection
             with litigation strategy. Impax shall fully cooperate with Teva in
             the defense or prosecution of any such Optional Product Launch
             Litigation (regardless of which Party is a named party to that
             litigation). Subject to the last sentence of subparagraph (2)
             below, Teva shall bear one-hundred percent (100%) of all
             Intellectual Rights Legal Expenses in connection with the defense
             and/or arising out of a judgment or settlement of any Optional
             Product Launch Litigation.
<PAGE>


         (2) Teva shall indemnify, defend and hold harmless Impax for any
             Intellectual Rights Legal Expenses of any Optional Product Launch
             Litigation to the extent not attributable in whole or in part to
             any untrue representation or warranty of Impax or breach of a
             covenant made by Impax hereunder or under the Agreement. Further,
             in such case, fifty percent (50%) of any Intellectual Rights Legal
             Expenses paid by Teva in connection with any Optional Product
             Launch Litigation, or the above indemnity, shall be set-off,
             credited or reimbursed ("SET-OFF") against any Impax Margin or
             Revised Impax Margin related to the Optional Products; provided,
             that the amount of the Set-Off shall in no event exceed the Impax
             Margin or Revised Impax Margin related to the Optional Products.
             Notwithstanding the foregoing, to the extent such Intellectual
             Rights Legal Expenses are attributable in whole or in part to any
             untrue representation or warranty of Impax or breach of a covenant
             made by Impax hereunder or under the Agreement, then in such case
             Impax shall be responsible for one hundred percent (100%) of all
             such Intellectual Rights Legal Expenses.

         (3) Each Party shall obtain the prior written consent of the other
             Party prior to ceasing to defend, settling or otherwise disposing
             of any intellectual property dispute related to the Optional
             Products. Each Party further agrees that it will not whether in the
             context of litigation or otherwise related thereto, without the
             prior written consent of the other Party, enter into any agreement
             or arrangement with any third party which in any way compromises,
             relinquishes, waives, or otherwise affects, in whole or in part,
             the rights of the other Party.

         Also, this will confirm that the Parties have agreed that any payments
due to Teva under Section 2.15 of the Agreement for the 3rd and 4th Calendar
Quarter of 2003 shall be made to Teva on or before May 14, 2004, without
interest.

         Finally, this will also confirm that the Parties have agreed that for
purposes of Section 14.6 of the Agreement, any insurance premiums of up to
[XXX]* U.S. Dollars (U.S. $ [XXX]*) per year paid by Impax for product liability
insurance coverage will be included in the Manufacturing Costs for the Optional
Products. Without derogating from Impax's obligation under Section 14.6 of the
Agreement to maintain throughout the Term sufficient product liability insurance
coverage to satisfy its obligations under the Agreement, Teva hereby waives
forever the provision in Section 14.6 of the Agreement requiring Impax
specifically to increase on January 1, 2004 its product liability insurance
coverage to [XXX]* U.S. Dollars (U.S. $[XXX]*).


--------
* Filed under an application for confidential treatment.
<PAGE>

         Except as otherwise specifically provided herein, the Agreement shall
remain in full force and effect.

         This letter amendment shall become effective as of November 1, 2003.

         Please sign below as an acknowledgement of the above and return a
signed copy to me via facsimile and the original by overnight mail.

         Thank you.

                                               Regards,

                                               Teva Pharmaceuticals Curacao N.V.

                                                      /s/ Ido Weinstein
                                               ---------------------------------
                                               By: Ido Weinstein
                                               Managing Director

Acknowledged and Agreed
This 8th day of Oct., 2003

Impax Laboratories, Inc.

     /s/ Barry Edwards
---------------------------
By:  Barry Edwards
     Co-CEO