IMPAX Comments on Wyeth's Lawsuit Related to Generic Versions of Effexor XR(R)

April 7, 2006

HAYWARD, Calif.--(BUSINESS WIRE)--April 7, 2006--IMPAX Laboratories, Inc. (OTC: IPXL) today announced that Wyeth (NYSE: WYE), has filed a lawsuit against the Company in the United States District Court for the District of Delaware alleging patent infringement related to IMPAX's filing of an Abbreviated New Drug Application (ANDA) for generic versions of Effexor XR(R) 37.5mg, 75mg and 150mg capsules. IMPAX's submission includes a Paragraph IV certification stating the Company believes its product does not infringe upon Wyeth's listed patents.

Wyeth markets Effexor XR for the treatment of depression. According to Wolters Kluwer Health, U.S. sales of Effexor XR Capsules were approximately $2.5 billion in the 12 months ended January 31, 2006.

"We intend to vigorously defend our ANDA," commented Barry R. Edwards, IMPAX's chief executive officer. "This suit is par for the course for branded pharmaceutical manufacturers attempting to keep patients from access to less expensive medications, even though their patents aren't applicable or will have expired."

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:

"Safe Harbor" statement under the Private Securities Litigation Reform Act of 1995:

To the extent any statements made in this news release contain information that is not historical, these statements are forward-looking in nature and express the beliefs and expectations of management. Such statements are based on current expectations and involve a number of known and unknown risks and uncertainties that could cause IMPAX's future results, performance or achievements to differ significantly from the results, performance or achievements expressed or implied by such forward-looking statements. Such risks and uncertainties include, but are not limited to, possible adverse effects resulting from the delisting of IMPAX's stock, IMPAX's delay in filing its 2004 Form 10-K, its Form 10-Q for each of the first three quarters of 2005, and its Form 10-K for 2005, IMPAX's ability to obtain sufficient capital to fund its operations, the difficulty of predicting FDA filings and approvals, consumer acceptance and demand for new pharmaceutical products, the impact of competitive products and pricing, IMPAX's ability to successfully develop and commercialize pharmaceutical products, IMPAX's reliance on key strategic alliances, the uncertainty of patent litigation, the availability of raw materials, the regulatory environment, dependence on patent and other protection for innovative products, exposure to product liability claims, fluctuations in operating results and other risks detailed from time to time in IMPAX's filings with the Securities and Exchange Commission. Forward-looking statements speak only as to the date on which they are made, and IMPAX undertakes no obligation to update publicly or revise any forward-looking statement, regardless of whether new information becomes available, future developments occur or otherwise.

CONTACT: IMPAX Laboratories, Inc.
Barry R. Edwards, 215-933-0360
Larry Hsu, Ph.D., 510-476-2000, Ext. 1111
Arthur Koch, 215-933-0351
Investor Relations Contacts:
Lippert/Heilshorn & Associates, Inc.
Kim Sutton Golodetz, 212-838-3777
Bruce Voss, 310-691-7100
SOURCE: IMPAX Laboratories, Inc.