Leading Proxy Advisory Firms RiskMetrics Group and Glass Lewis Recommend Penwest...

Leading Proxy Advisory Firms RiskMetrics Group and Glass Lewis Recommend Penwest
Shareholders Vote Against All Three Dissident Proxy Proposals

Firms Unconvinced by Dissidents' Wind-Down Proposal

Penwest Urges Shareholders to Vote FOR Its Director Nominees and
AGAINST Dissidents' Proposals On the WHITE Proxy Card, Despite
Recommendations to Vote for Dissident Nominee Tang
DANBURY, Conn., June 1, 2009 (GLOBE NEWSWIRE) -- Penwest Pharmaceuticals Co.
(Nasdaq:PPCO) today issued the following statement addressing recently issued
proxy advisory firm reports regarding the contested election at the Company's
2009 Annual Meeting of Shareholders that takes place on June 10. Penwest urges
shareholders to vote FOR the Company's director nominees - W. James O'Shea and
Joseph Edelman - and to reject the proposals put forth by Tang Capital
Management and Perceptive Life Sciences by voting the WHITE proxy card today.

"We are pleased that RiskMetrics Group and Glass Lewis & Co., like Penwest,
disagree with the dissidents' proposed strategy to wind down the Company's
operations and have recommended that shareholders vote against the proposal. We
are also pleased that both RiskMetrics and Glass Lewis have validated the
Company's position further by recommending that Penwest shareholders vote
against the dissidents' proposals for supermajority Board voting and for fixing
the annual meeting date at April 30," the Company said.

RiskMetrics stated in its analysis:

"...we do not find there is compelling evidence that an immediate
wind down of substantially all of the company's operations is in
the best interests of shareholders."

"...we do not believe that imposing a supermajority voting
threshold is necessary or advisable. We believe such a
requirement has the potential to stalemate the board on important
decisions..."
In its report, Glass Lewis echoed RiskMetrics' recommendation to Penwest
shareholders to Vote AGAINST the dissidents' proposals:

"...we are not fully convinced with respect to the Dissident's
plan to wind down the Company's operations" and "...we believe the
Company raised sufficient concerns regarding the wind down. In
addition, we believe the Company has made a reasonable case in
term of its potentials in areas other than the Opana ER royalty
stream [sic]."

"We find the language of this proposal to be overly restrictive
and limiting to the board of directors...we believe a majority
vote standard is appropriate for the vast majority of decisions
taken by the board of directors and a 75% (Proposal 5) or 81%
(Proposal 6) threshold would unduly limit the flexibility of the
board in these matters."
The Company noted that, "Despite recommending that shareholders support the
dissidents' proposal for supermajority Board voting, a third proxy advisory
firm, Proxy Governance, acknowledged that such a proposal 'carries significant
risk of unintended consequences' and recommended against the proposals to wind
down the Company and fix the annual meeting date at April 30.

"All three of these firms supported director nominee Joseph Edelman, who is
running unopposed, but failed to recognize the qualifications of our director
nominee, W. James O'Shea, and his clear superiority over the dissidents' nominee
Kevin Tang. Mr. O'Shea is an experienced pharmaceutical executive and a
highly-respected, independent industry expert with a strong track record in
hands-on executive and operating roles at public companies. We urge shareholders
to support his re-election.

"RiskMetrics and Glass Lewis further recommended that shareholders withhold
their votes from the dissidents' third nominee, Andrew Levin.

"Given these recommendations, Penwest continues to urge shareholders to vote for
value by allowing the Company to continue to implement its strategy for 2009,
under the guidance of experienced, highly qualified directors. Like the leading
proxy advisory firms, we believe that our shareholders deserve better than what
the dissidents propose for Penwest's future. We urge you to vote the WHITE proxy
card today in support of Penwest's director nominees, Mr. O'Shea and Mr.
Edelman, and against the dissidents' shareholder proposals."

PLEASE USE THE WHITE PROXY CARD TO VOTE TODAY - BY TELEPHONE, BY INTERNET OR BY
SIGNING, DATING AND RETURNING THE ENCLOSED WHITE PROXY CARD. YOUR BOARD URGES
YOU NOT TO SIGN OR RETURN ANY GOLD OR OTHER PROXY CARD SENT TO YOU BY TANG
CAPITAL OR PERCEPTIVE.

About Penwest Pharmaceuticals

Penwest is a drug development company focused on identifying and developing
products that address unmet medical needs, primarily for rare disorders of the
nervous system. Penwest is currently developing A0001, a coenzyme Q analog drug
candidate for inherited mitochondrial respiratory chain diseases. Penwest is
also applying its drug delivery technologies and drug formulation expertise to
the formulation of product candidates under licensing collaborations with
partners.

Penwest Forward-Looking Statements

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," "appears," "estimates," "projects," "targets," "may," "could," 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 Annual
Report on Form 10-Q filed with the Securities and Exchange Commission on May 11,
2009, 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, and these statements should not be
relied upon as representing the Company's estimates or views as of any date
subsequent to the date of this letter.

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

INFORMATION CONCERNING PARTICIPANTS

Information required to be disclosed with regard to the Company's directors,
director nominees, officers and employees who, under the rules of the Securities
and Exchange Commission (the "SEC"), are considered to be "participants" in the
Company's solicitation of proxies from its shareholders in connection with its
2009 Annual Meeting of Shareholders (the "Annual Meeting") may be found in the
Company's Proxy Statement for its 2009 Annual Meeting of Shareholders, as filed
with the SEC on May 7, 2009 (the "2009 Proxy Statement").

Security holders may obtain a free copy of the 2009 Proxy Statement and other
documents (when available) that the Company files with the SEC at the SEC's
website at www.sec.gov. Security holders may also obtain a free copy of these
documents by writing the Company at Penwest Pharmaceuticals Co., 39 Old
Ridgebury Road, Suite 11, Danbury, CT 08610, attn: Corporate Secretary, or by
telephoning the Company at (877) 736-9378.

We have circulated a WHITE proxy card together with our definitive proxy
statement. We urge shareholders to vote FOR our nominees on the WHITE proxy card
and not to sign or return a green, gold or other colored proxy card to the
Company.

-0-
CONTACT: MacKenzie Partners
Investors:
Mark Harnett
Laurie Connell
(212) 929-5500

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