1
                      [SOLVAY PHARMACEUTICALS LETTERHEAD]




    SOLVAY GROUP ANNOUNCES AGREEMENT TO ACQUIRE UNIMED PHARMACEUTICALS, INC.
                           TO STRENGTHEN ITS MARKETING
                   PRESENCE AMONG U.S. PRIMARY CARE PHYSICIANS

Solvay Pharmaceuticals, Inc. of Marietta, Ga., jointly with Unimed
Pharmaceuticals, Inc. of Buffalo Grove, Ill. (Nasdaq: UMED) announced today that
they have entered into an agreement whereby Solvay Pharmaceuticals will acquire
all outstanding shares of Unimed Pharmaceuticals. The acquisition is part of the
Solvay Group's strategy to rapidly expand its pharmaceutical business in the
U.S.

The board of directors of Unimed has unanimously agreed that the proposed
acquisition by Solvay Pharmaceuticals is fair and in the best interest of the
Unimed stockholders. The directors have also stated their intent to tender their
shares upon the commencement of the tender offer.

Pursuant to a merger agreement entered into among Unimed, Solvay Pharmaceuticals
and a wholly owned subsidiary of Solvay Pharmaceuticals, the subsidiary will
commence a tender offer for all of the outstanding shares of Unimed common
stock, including the associated stock purchase rights, at a price of $12.00 per
share in cash. If the tender offer is successfully completed, the subsidiary
will merge with and into Unimed and each share of Unimed common stock not
purchased pursuant to the tender offer will be converted into the right to
receive $12.00 per share in cash. The net value of the planned transaction is
about $123 million.

Commenting on the acquisition, Alois Michielsen, CEO of Solvay Group said,
"Unimed Pharmaceuticals fits very well with the strategic objective of
broadening our presence in the U.S. pharmaceutical business. This acquisition
will contribute to our plan to rapidly increase the total number of our U.S.
sales representation from 450 at the end of 1998 to over 1,000 people in year
2000, selling existing drugs from Solvay
   2
Pharmaceuticals and Unimed Pharmaceuticals as well as products recently acquired
by Solvay Pharmaceuticals."

Jurgen Ernst, President of Solvay's world-wide Pharmaceuticals activities added,
"Indeed, in order to quickly and effectively maximize sales potential for both
ACEON(R) Tablets and TEVETEN(R) Tablets, the two anti-hypertensive drugs
acquired by Solvay in May 1999, Solvay Pharmaceuticals will sell ACEON(R)
Tablets through its own primary care sales force. However, TEVETEN(R) Tablets
will be sold by

Unimed Pharmaceuticals representatives, whose current number will be increased
very significantly. Unimed Pharmaceuticals also will strengthen Solvay
Pharmaceuticals' current portfolio of Hormone Replacement Therapies (HRT) by
including male HRT and providing an early entree into the emerging area of
andropause."

Solvay Pharmaceuticals, Inc. President and CEO David A. Dodd added, "We intend
to optimize marketing of Unimed Pharmaceuticals' portfolio of products as well
as some additional products that we've acquired or are developing. The current
employees of Unimed Pharmaceuticals will play a vital role in building this new
venture."

Unimed Pharmaceuticals Chairman Dr. John N. Kapoor stated, "Unimed
Pharmaceuticals has made significant progress since 1991 when I first became
involved with the company. It is time for Unimed Pharmaceuticals to become part
of a much larger organization so that the company and its employees can continue
to grow.

Robert E. Dudley, Unimed Pharmaceuticals' President and CEO added, "The
synergies that will be created by joining this global group of companies will
enable us to maximize the potential of our products."

Consummation of the tender offer and the merger is subject to the expiration or
termination of the applicable waiting period under the Hart-Scott-Rodino
Antitrust Improvements Act of 1976, as amended. Consummation of the tender offer
is also subject to the valid tender of more than 50 percent of the voting power
(determined on a fully diluted basis) of all the securities of Unimed entitled
to vote generally in the election of directors or in connection with a merger.
The closing of the merger is expected to occur as soon as possible after the
satisfaction of the conditions set forth in the merger agreement.

Unimed Pharmaceuticals is an emerging Chicago-area pharmaceutical company. The
company focuses on drugs that have multiple indications and fall within the
therapeutic areas of endocrinology, urology, HIV and other infectious diseases.

The Solvay Group is an international chemical and pharmaceutical group based in
Brussels, Belgium. Its members employ some 33,000 people in 46 countries. Its
1998 turnover worldwide was 7.5 billion EUR ($8.7 billion) from four operating
sectors: Chemicals, Plastics, Processing, and Pharmaceuticals. Solvay
Pharmaceuticals, Inc., a member of the Solvay Group, is a research-based
pharmaceutical company active in
   3
the therapeutic areas of cardiology, women's health, gastroenterology and mental
health.

To the extent any statements made in this release deal with information that is
not historical, these statements are necessarily forward-looking. As such, they
are subject to the occurrence of many events outside of Unimed Pharmaceuticals'
control and are subject to various risk factors that could cause Unimed
Pharmaceuticals' results to differ materially from those expressed in any
forward-looking statement. The risk factors include, without limitation, the
risk that holders of 50 percent of Unimed's voting securities will not tender
their shares of Unimed common stock into the tender offer, the ability of Unimed
Pharmaceuticals to obtain stockholder approval of the transaction and satisfy
other conditions for the acquisition, including obtaining regulatory approvals
(including the expiration or termination of the applicable waiting period under
federal antitrust approval). Additional risks include the inherent risk of
competition in the marketplace, clinical outcomes in drug development programs,
regulatory risks and risks related to proprietary rights and market acceptance
and other risk factors described in Unimed Pharmaceuticals' Form 10-K and 10-Q
as filed with the SEC.