Penwest Second Quarter 2008 Financial Results Conference Call

DANBURY, Conn., July 23, 2008 (PRIME NEWSWIRE) -- Penwest Pharmaceuticals Co.
(Nasdaq:PPCO) will conduct a conference call on Tuesday, August 5th, at 11:00
a.m. EDT to review its financial results for the second quarter of 2008, which
will be released earlier that day. Operational developments and financial
outlook will also be discussed on the call.

The conference call will include remarks by Jennifer L. Good, President and
Chief Executive Officer, and Benjamin L. Palleiko, Senior Vice President,
Corporate Development and Chief Financial Officer.

Domestic Telephone Number: 888-277-5064
International Telephone Number: 706-679-2324
The conference ID is 56400747.
Please dial in 10 minutes prior to the scheduled start time. The conference call
will also be accessible live and as a replay on the Investor Relations section
of the Penwest Web site at www.penwest.com.

About Penwest Pharmaceuticals

Penwest is a drug development pharmaceutical company dedicated to bringing to
the marketplace innovative products that help improve the lives of patients. The
Company's goal is to identify, develop and commercialize prescription products
that address unmet medical needs, primarily for disorders of the nervous system.
Penwest is currently applying its drug development and drug delivery expertise
to a pipeline of potential products that are in various stages of development
and that it intends to commercialize independently or through third party
alliances.

Penwest Forward-Looking Statement

The matters discussed herein contain forward-looking statements that involve
risks and uncertainties, which may cause the actual results in future periods to
be materially different from any future performance suggested herein. For this
purpose, any statements contained herein that are not statements of historical
fact may be deemed to be forward-looking statements. Without limiting the
foregoing, the words "believes," "anticipates," "plans," "expects," "intends,"
"potential" and similar expressions are intended to identify forward-looking
statements. Important factors that could cause results to differ materially
include: risks relating to the commercial success of Opana ER, including our
reliance on Endo Pharmaceuticals Inc. for the commercial success of Opana ER and
risks of generic competition; the need for capital; regulatory risks relating to
drugs in development, including the timing and outcome of regulatory submissions
and regulatory actions; uncertainty of success of collaborations; the timing of
clinical trials; whether the results of clinical trials will warrant further
clinical trials, warrant submission of an application for regulatory approval
of, or warrant the regulatory approval of, the product that is the subject of
the trial; whether the patents and patent applications owned by us will protect
the Company's products and technology; actual and potential competition; and
other risks as set forth under the caption Risk Factors in Penwest's Quarterly
Report on Form 10-Q filed with the Securities and Exchange Commission on May 12,
2008, which risk factors are incorporated herein by reference.

The forward-looking statements contained in this press release speak only as of
the date of the statements made. Penwest disclaims any intention or obligation
to update any forward-looking statements.

TIMERx is a registered trademark of Penwest. All other trademarks referenced
herein are the property of their respective owners.

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CONTACT: Penwest Pharmaceuticals Co.
Investors:
Ben Palleiko
(203) 796-3750
(877) 736-9378

Kekst and Company
Media:
John Patteson
(212) 521-4800