IMPAX Signs Agreement With ANDRX and Teva for Generic Formulations of Wellbutrin® SR and ZYBAN®

July 31, 2003

HAYWARD, Calif. (July 31, 2003) – IMPAX Laboratories, Inc. (NASDAQ NM: IPXL) announced today that it has entered into an Exclusivity Transfer Agreement with Andrx Corporation (NASDAQ:ADRX) and a subsidiary of Teva Pharmaceutical Industries Ltd. (NASDAQ:TEVA) pertaining to pending Abbreviated New Drug Applications (ANDAs) for bioequivalent versions of Wellbutrin® SR and Zyban® (Bupropion Hydrochloride) 100 mg and 150 mg Extended Release Tablets filed by Andrx, as well as by the Company. Pursuant to the Company's existing strategic alliance agreement with Teva, Teva has U.S. marketing rights to IMPAX's versions of these products. Wellbutrin SR and Zyban, marketed by GlaxoSmithKline, had U.S. sales of over $1.7 billion for the twelve-month period ended May 31, 2003 according to NDCHealth.

The parties believe that the Andrx ANDAs for the products are entitled, under the Hatch-Waxman Act, to a 180-day period of marketing exclusivity. Under the Exclusivity Transfer Agreement, Andrx will continue to seek approval of its ANDAs. The agreement provides, among other things, that if Andrx is unable to launch its own products within a defined period of time, and IMPAX is able to market its products, Andrx will enable IMPAX to launch its own products through Teva, with the parties sharing certain payments with Andrx relating to the sale of the products for a 180-day period. Should Andrx launch its own products prior to the Impax product launch, it will share with IMPAX certain payments for a 180-day period.

“We are pleased that our technology has enabled us to provide patients affordable alternatives to both Wellbutrin SR and Zyban,” said Barry R. Edwards, Co-Chief Executive Officer of IMPAX. “This agreement with Andrx and Teva provides us with an opportunity to bring our products to the market earlier than would be possible alone.”

Andrx and IMPAX have both obtained favorable summary judgment decisions that their formulations of the products do not infringe GlaxoSmithKline's patents. GlaxoSmithKline, however, has appealed both decisions.

The transactions that are contemplated by the Exclusivity Transfer Agreement are subject to all necessary government approvals.

IMPAX has 20 applications pending at the FDA, including three tentatively approved that address approximately $6.2 billion in U.S. branded product sales for the twelve months ended May 31, 2003. Fifteen of these filings were made under Paragraph IV of the Hatch-Waxman Amendments.