IMPAX Comments on Purdue Pharma Lawsuit Related to Its Generic Version of Oxycontin

April 26, 2002

April 26, 2002 -- IMPAX Laboratories, Inc. (Nasdaq:IPXL) today announced that Purdue Pharma L.P. has filed a lawsuit against the Company alleging patent infringement related to IMPAX's filing of an Abbreviated New Drug Application (ANDA) for a generic version of Oxycontin® (Oxycodone HCI) Extended Release 80 mg Tablets. The lawsuit was filed in the United States Southern District Court of New York.

Purdue Pharma L.P. markets Oxycontin for the management of moderate to severe pain. U.S. sales of Oxycontin Extended Release 80 mg Tablets were over $400 million in 2001.

IMPAX announced that the U.S. Food and Drug Administration (FDA) had accepted the Company's filing of the ANDA for a generic version of Oxycontin on February 26, 2002. In that application, which was made under Paragraph IV of the Hatch-Waxman Amendments, IMPAX stated that the Company believes its generic version of Oxycontin® (Oxycodone HCI) Extended Release 80 mg Tablets does not infringe Purdue Pharma L.P.'s listed patents for Oxycontin.

"Based on our knowledge and experience with the ANDA process, we anticipated this lawsuit as an attempt to delay the approval process," stated Barry R. Edwards, Co-Chief Executive Officer of IMPAX Laboratories. "Our ANDA included a certification that states IMPAX believes its product does not infringe Purdue Pharma's patents. We intend to vigorously defend our product and reiterate that this is a tactic by Purdue Pharma to delay our approval."

IMPAX currently has 14 Abbreviated New Drug Application (ANDA) filings pending at the FDA that address more than $8 billion in U.S. branded product sales during 2001. Nine of these filings were made under Paragraph IV of the Hatch-Waxman Amendments, one of which has received tentative approval from FDA.

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 niche 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. 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: