IMPAX Granted FDA 180-Day Exclusivity for Metformin HCl Extended Release Tablets, 500mg; Selectively Waived to TEVA Pharmaceuticals USA Inc.

June 18, 2004

HAYWARD, Calif.--(BUSINESS WIRE)--June 18, 2004--IMPAX Laboratories, Inc. (Nasdaq:IPXL) announced that the U.S. Food and Drug Administration (FDA) has granted IMPAX a second tier 180-day exclusivity related to its pending ANDA for a generic version of Glucophage XR(R), Metformin HCl Extended Release Tablets, 500mg. Impax has selectively waived its rights to this exclusivity to Teva Pharmaceuticals USA Inc. and will be sharing in the profits of Teva's Metformin HCl Extended Release Tablets as provided for in the Strategic Alliance Agreement between IMPAX and Teva signed in June 2001. It is believed at least one other company may participate in this second tier of exclusivity. According to IMS Health, U.S. market sales of Glucophage XR 500mg and the other marketed generic and authorized generic versions were approximately $430 million in the twelve months ended March 31, 2004.

IMPAX currently has 14 applications pending at the FDA, including five tentatively approved, which address approximately $5.2 billion in U.S. product sales for the twelve months ended March 31, 2004, based on NDCHealth data. Twelve 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: www.impaxlabs.com.

"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, 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) 933-0323 Ext. 4360
             Larry Hsu, (510) 476-2000 Ext. 1111
             Cornel C. Spiegler, (215) 289-2220 Ext. 1706
             www.impaxlabs.com
               or
             Investor Relations Contacts:
             Lippert/Heilshorn & Associates, Inc.
             Kim Sutton Golodetz (kgolodetz@lhai.com)
             (212) 838-3777
             Bruce Voss (bvoss@lhai.com)
             (310) 691-7100
             www.lhai.com

    SOURCE: IMPAX Laboratories, Inc.