Exhibit 99.1




                                                         
COMPANY CONTACTS:                                           INVESTOR RELATIONS CONTACTS:
IMPAX Laboratories, Inc.                                    Lippert/Heilshorn & Associates, Inc.
- ------------------------                                    ------------------------------------
Barry R. Edwards, CEO                                       Kim Sutton Golodetz (kgolodetz@lhai.com)
(215) 933-0323 Ext. 4360                                    (212) 838-3777
Larry Hsu, Ph.D. President                                  Bruce Voss (bvoss@lhai.com)
(510) 476-2000 Ext. 1111                                    (310) 691-7100
Cornel C. Spiegler, CFO                                     www.lhai.com
(215) 289-2220 Ext. 1706                                    ------------
www.impaxlabs.com
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                        IMPAX RECEIVES FINAL FDA APPROVAL
                            FOR GENERIC PROAMATINE(R)

                          EIGHTH ANDA APPROVAL IN 2004



HAYWARD, CALIF. (MAY 28, 2004) - IMPAX LABORATORIES, INC. (NASDAQ NM: IPXL)
announced that the U.S. Food and Drug Administration (FDA) has granted final
marketing approval to the Company's Abbreviated New Drug Application (ANDA) for
its generic version of PROAMATINE(R), Midodrine Hydrochloride 2.5 and 5 mg
Tablets. Shire Pharmaceuticals Group plc (NASDAQ NM: SHPGY) markets PROAMATINE
for treatment of symptomatic orthostatic hypotension. According to NDCHealth,
U.S. market sales of PROAMATINE 2.5 and 5 mg and the two other marketed generic
versions were approximately $50 million in the twelve months ended March 31,
2004.

"This is our eighth ANDA approval this year," said Larry Hsu, Ph.D. IMPAX's
President. "We are pleased to add Midodrine Hydrochloride Tablets to our growing
portfolio of products. This product will be marketed by our Global
Pharmaceuticals division."

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.

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