<PAGE>
Exhibit 99.1
Contact: Robert Siegfried/Jeremy Fielding
Kekst and Company
212-521-4800
FOR IMMEDIATE RELEASE
---------------------
ENDO PHARMACEUTICALS AND ALGOS COMPLETE MERGER
-- Endo Pharmaceuticals Holdings Inc. Strengthens Position as Leading
Company in Growing Pain Management Market --
Chadds Ford, PA, July 17, 2000 - Endo Pharmaceuticals Holdings Inc., a fully
integrated, specialty pharmaceutical company with market leadership in pain
management, and Algos Pharmaceutical Corporation (NASDAQ: ALGO), a leader in
developing proprietary pain management products, announced today that the
shareholders of Algos had approved their merger, strengthening Endo's position
as the leader in this rapidly growing market.
The combined company will be named Endo Pharmaceuticals Holdings Inc., and its
common stock will be traded on the NASDAQ under the stock symbol ENDP and the
warrants being issued to the Algos shareholders in the merger will be traded on
NASDAQ under the symbol ENDPW.
Carol A. Ammon, president and chief executive officer of Endo Pharmaceuticals,
said, "I am excited about the opportunities that the merger will generate for
the shareholders, customers and employees of both companies. This transaction
creates a company that is well placed to capitalize on the dynamic and growing
market for pain management products. With leading brands in this sector, such as
Percocet(R), Percodan(R) and Lidoderm(R), our strong research capability, and
Algos' technology, we are now better positioned to create our next generation of
pain management drugs.
<PAGE>
John W. Lyle, Chairman of the Board of Endo, stated, "Endo's existing sales and
marketing infrastructure and demonstrated regulatory expertise will allow us to
accelerate the development and commercialization of our product pipeline."
"The first and ongoing priority for the Board and management is to continue to
increase the value of Endo, and build value for the shareholders of the combined
company," concluded Ms. Ammon.
About Endo
Endo is a fully integrated specialty pharmaceutical company with market
leadership in pain management. The company researches, develops, produces and
markets both branded and generic pharmaceutical products primarily for the
treatment of pain. Endo has a portfolio of thirteen branded products that
includes established brands such as Percocet(R) and Percodan(R), opioid
analgesics that treat moderate-to-severe pain.
To the extent any statements made in this release contain information that is
not historical, these statements are essentially forward-looking and are subject
to risks and uncertainties. As a result of such risks and uncertainties, which
include, but are not limited to, the difficulty of predicting FDA approvals,
risks with respect to technology and product development, the effect of
competing products and prices, uncertainties regarding intellectual property
protection, changes in operating results and other risks discussed from time to
time in Algos Pharmaceutical's and Endo's filings with the Securities and
Exchange Commission, actual results may differ materially from those expressed
or implied by such forward-looking statements.
# # #
2
