UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                    FORM 8-K

                             CURRENT REPORT PURSUANT
                          TO SECTION 13 OR 15(D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

     Date of report (Date of earliest event reported)  July 6, 2005
                                                     --------------------------

                            Impax Laboratories, Inc.
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             (Exact Name of Registrant as Specified in Its Charter)

                                    Delaware
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                 (State or Other Jurisdiction of Incorporation)

           0-27354                                     65-0403311
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  (Commission File Number)                  (IRS Employer Identification No.)


           30381 Huntwood Avenue                             Hayward, CA 94544
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 (Address of Principal Executive Offices)                       (Zip Code)

                                 (510) 476-2000
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              (Registrant's Telephone Number, Including Area Code)


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          (Former Name or Former Address, if Changed Since Last Report)

     Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

     |_| Written communications pursuant to Rule 425 under the Securities Act
(17 CFR 230.425)

     |_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
CFR 240.14a-12)

     |_| Pre-commencement communications pursuant to Rule 14d-2(b) under the
Exchange Act (17 CFR 240.14d-2(b))

     |_| Pre-commencement communications pursuant to Rule 13e-4(c) under the
Exchange Act (17 CFR 240.13e-4(c))





ITEM 1.01.  ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.

         On July 6, 2005, the Company and HSBC Bank USA, National Association,
as trustee (the "Trustee"), entered into a Supplemental Indenture (the
"Supplemental Indenture") that amends the Indenture dated as of June 27, 2005
between the Company and the Trustee (the Indenture"). The Indenture governs the
Company's 3.50% Convertible Senior Subordinated Debentures Due 2012 (the "3.50%
Debentures"). The Indenture was reported in the Company's Current Report on Form
8-K filed with the Securities and Exchange Commission on June 27, 2005, as
amended on June 28, 2005 (the "June 28, 2005 Form 8-K/A").

         The purpose of the Supplemental Indenture was to evidence the parties
agreement to: (i) the calculation of the Average Closing Price, as defined in
the Indenture, at $15.919 and (ii) the Make-Whole Premium Table as defined in
the Indenture. The Average Closing Price was defined in the Indenture as the
average of the Closing Sale Prices, as defined in the Indenture, of the
Company's common stock for the ten Trading Days, as defined in the Indenture,
beginning on and including June 20, 2005. Each 3.50% Debenture will be
convertible into Company common stock at an initial conversion price per share
equal to 130% of the Average Closing Price, subject to adjustment as provided in
the Indenture.

         Under the Indenture, if a holder elects to convert 3.50% Debentures
within a period of 30 Trading Days after the effective date of a Fundamental
Change, as defined in the Indenture --consisting generally of a transaction
constituting a change of control of the Company or approval by the shareholders
of a plan of liquidation or dissolution of the Company--the holder will be
entitled to receive a "make-whole" premium consisting of additional shares of
the Company's common stock (or, if the Company so elects, the same consideration
offered in connection with the Fundamental Change).

         The Make-Whole Premium Table sets forth the number of additional shares
to be paid depending upon the effective date of the Fundamental Change and the
price paid per share of common stock in the Fundamental Change, determined as
provided in the Indenture.

         The foregoing description of the terms of the Indenture and the
Supplemental Indenture is qualified in its entirety by reference to the full
text of those documents. For more information, see the Indenture filed as
Exhibit 4.2 to the June 28, 2005 Form 8-K/A and the Supplemental Indenture filed
as Exhibit 4.1 hereto, the provisions of which are incorporated herein by
reference.

ITEM 9.01.        FINANCIAL STATEMENTS AND EXHIBITS

                  (c)  Exhibits.

4.1 Supplemental Indenture, dated as of July 6, 2005, to the Indenture, dated as
of June 27, 2005, between the Company and HSBC Bank USA, National Association,
as trustee.






                                   SIGNATURES


         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                          Impax Laboratories, Inc.

Date: July 7, 2005
                                          By: /s/ Arthur A. Koch, Jr.
                                              ---------------------------------
                                              Arthur A. Koch, Jr.
                                              Chief Financial Officer