Contact:       Sandra Menta
               610-738-6376
               Cephalon, Inc.

FOR IMMEDIATE RELEASE
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    Cephalon Announces Offering of $100 Million of Convertible Exchangeable
                                Preferred Stock

     West Chester, PA -- August 13, 1999 -- Cephalon, Inc. (NASDAQ: CEPH)
announced today that it has entered into a purchase agreement providing for the
sale to certain initial purchasers of 2,000,000 shares of convertible
exchangeable preferred stock at $50 per share (the "Preferred Stock") in a
private offering to certain institutional investors expected to close August 18,
1999.

     The Company has granted the initial purchasers a 45-day option to purchase
up to an additional 500,000 shares of the Preferred Stock .  Dividends on the
Preferred stock will be cumulative at the annual rate of $3.625 per share.  The
Preferred Stock will be convertible into shares of Common Stock of the Company
at a conversion price of $17.92 per share, subject to adjustment in certain
circumstances.  The Preferred Stock will be exchangeable, at the option of the
Company, into 7 1/4% Convertible Debentures which will also be convertible into
shares of Common Stock of the Company.  The Preferred Stock and the Debentures,
if issued, will be redeemable by the Company at declining redemption prices
commencing in August 2001.

     The Company stated that it intends to use the proceeds of the offering to
fund the further development and marketing of PROVIGIL(R) (modafinil) Tablets
[C-IV], preclinical and clinical development and other research and development
activities, the settlement of legal proceedings, working capital, and other
corporate purposes.  The Company may also use a portion of its available funds
for acquisitions, although no such acquisitions are currently contemplated, or
to prepay its revenue sharing notes.

          The securities to be offered will not be registered under the
Securities Act or any state securities laws and, unless so registered, may not
be offered or sold in the United States except pursuant to an exemption from, or
in a transaction not subject to, the registration requirements of the Securities
Act and applicable state securities laws.

          Cephalon, Inc., headquartered in West Chester, PA, is an international
biopharmaceutical company dedicated to the discovery, development and marketing
of products to treat neurological disorders, sleep disorders and cancer.

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Cephalon Announces Offering of $100 Million
of Convertible Exchangeable Preferred Stock
Page 2

     In addition to historical facts or statements of current condition, this
press release may contain forward-looking statements.  Forward-looking
statements provide the company's current expectations or forecasts of future
events.  These may include statements regarding anticipated scientific progress
on its research programs, development of potential pharmaceutical products,
prospects for regulatory approval, manufacturing development and capabilities,
market prospects for its products, sales and earnings projections, and other
statements regarding matters that are not historical facts.  You may identify
some of these forward-looking statements by the use of words in the statements
such as "anticipate," "estimate," "expect," "project," "intend," "plan,"
"believe" or other words and terms of similar meaning.  The company's
performance and financial results could differ materially from those reflected
in these forward-looking statements due to general financial, economic,
regulatory and political conditions affecting the biotechnology and
pharmaceutical industries as well as more specific risks and uncertainties such
as those set forth below and in its reports on Form 8-K, 10-Q and 10-K filed
with the U.S. Securities and Exchange Commission.  Given these risks and
uncertainties, any or all of these forward-looking statements may prove to be
incorrect.  Therefore, you are cautioned not to place too much reliance on any
such factors or forward-looking statements.  Furthermore, Cephalon does not
intend (and it is not obligated) to update publicly any forward-looking
statements, whether as a result of new information, future events or otherwise.
This discussion is permitted by the Private Securities Litigation Reform Act of
1995.

  NOTE:  Cephalon's press releases are posted on the Internet at the company's
Web site at http://www.cephalon.com.  They are also available by fax 24 hours a
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day at no charge by calling PR Newswire's Company News On-Call at 800-758-5804,
extension 134563.

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