IMPAX ANDA Filing for Generic Version of Wellbutrin SR® 200mg Tablets Accepted by FDA

May 28, 2003

May 28, 2003 -- IMPAX Laboratories, Inc. (Nasdaq:IPXL) today announced that the United States Food and Drug Administration (FDA) has accepted the Company's filing of an Abbreviated New Drug Application (ANDA) for a generic version of Wellbutrin SR® (Bupropion Hydrochloride) 200mg Tablets. GlaxoSmithKline (Glaxo) markets Wellbutrin SR® for the treatment of depression. U.S. sales of Wellbutrin SR® 200mg Tablets were approximately $46 million in the twelve months ended December 31, 2002, according to IMS Health. Glaxo received FDA approval of this product in June 2002.

IMPAX's application includes a certification under Paragraph IV of the Hatch-Waxman Amendments stating the Company's belief that its Bupropion Hydrochloride 200mg Extended Release Tablet product does not infringe certain Glaxo listed patents on Wellbutrin SR® Tablets. FDA's acceptance of the IMPAX ANDA for filing means that the Agency has made a threshold determination that the application is sufficiently complete to permit a substantive review.

Larry Hsu, Ph.D., President of IMPAX, said, “This application complements our previous ANDAs for Bupropion HCl 100mg and 150mg Extended Release Tablets. We expect to reach our objective of filing six new applications in 2003.”

IMPAX has twenty ANDAs pending at the FDA, including three tentatively approved, that address more than $6.4 billion in U.S. branded product sales for the twelve months ended December 31, 2002. Fifteen of these filings were made under Paragraph IV of the Hatch-Waxman Amendments.

IMPAX Laboratories, Inc. is a technology based specialty pharmaceutical company applying its formulation expertise and drug delivery technology to the development of controlled-release and specialty generics in addition to the development of branded products. IMPAX markets its generic products through its Global Pharmaceuticals division and intends to market its branded products through the IMPAX Pharmaceuticals division. Additionally, where strategically appropriate, IMPAX has developed marketing partnerships to fully leverage its technology platform. IMPAX Laboratories is headquartered in Hayward, California, and has a full range of capabilities in its Hayward and Philadelphia facilities. For more information, please visit the Company's Web site at: