Release issued 13th November 2001

CAMBRIDGE, UK, AND PATTERSON, NY, NOVEMBER 13, 2001 -- Arakis Limited and Penwest Pharmaceuticals Company (NASDAQ: PPCO), announced today that they have entered into a three-year strategic alliance to develop up to six orally delivered Performance Enhanced Medicines (PEMs) for the treatment of pain conditions.

These new pain treatment products will be jointly developed in the clinic during the period of the alliance. The products will be created by combining Penwest's proprietary oral drug delivery capability with Arakis' unique ability to enhance known pharmacological agents through the use of new biological information. In addition, both companies will leverage their significant experience in the conception and development of novel pain products.

Pain management is a major market of unmet medical need, which current medical practice suggests is best addressed early on in order to minimize the potential for long-term chronic problems. The pathology of pain is complex and results from a wide variety of contributing factors, making treatment with single analgesic agents unsatisfactory in many patients. As a consequence, pain physicians seek a palette (broad array) of pharmacological agents that can be used to target different pain syndromes. N addition, they require active ingredients to be delivered to the required site of action in a controlled manner to produce maximum relief of pain with minimum side effects. Arakis and Penwest therefore believe that their joint areas of expertise are ideally suited to creating and developing a range of clinically relevant pain product opportunities.

Dr. Andy Richards, Chief Executive Officer of Arakis Ltd., said, "Pain is a large and increasingly important therapy area and is well suited to the experience and technology of both companies. This deal marks a change in Arakis's partnering model away from single PEM opportunities into larger therapeutic alliances and enables us to build upon our current relationships. We are delighted that we are able to conclude our first such alliance with Penwest with whom we have a strong relationship and whose technologies are well proven."

Tod R. Hamachek, Chairman and Chief Executive Officer of Penwest, said, "Pain management is an area where drug delivery can truly provide better medicines and is one we have targeted for future R&D and commercial investment. Our experience in the area has been gained through the development of pain products currently in our portfolio, which are based upon our patented TIMERx® formulations. We believe that more product opportunities in the pain area exist and we are confident that the Arakis PEM approach will facilitate our joint effort to discover them."

Arakis and Penwest's strategic alliance follows the companies' agreement in November 2000 to jointly develop AD 121, a novel chronotherapeutic version of an established product, using Penwest's TIMERx technology platform. AD 121 is indicated for the treatment of rheumatoid arthritis.

Notes for Editors

Arakis Ltd

Arakis is an emerging pharmaceutical company, founded in March 2000 to create, protect, develop and commercialize innovative market orientated, therapeutic products - which are termed Performance Enhanced Medicines (PEMs). Arakis is exploiting advances in the understanding of disease biology alongside a novel product development approach to generate a wave of new therapies that are suited patient needs and which are even more relevant as trends in healthcare lead towards "personalized medicine". For further information visit www.arakis.com.

Penwest Pharmaceuticals Co.

Penwest is engaged in the research, development and commercialization of novel drug delivery technologies. Based on its experience in developing and manufacturing ingredients for orally-administered pharmaceutical products, Penwest has developed its proprietary TIMERx® controlled release delivery technology, which can be applied to a broad range of drugs.

The matters discussed herein contain forward-looking statements that involve risks and uncertainties, which may cause Penwest's 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,"" intend," "potential" and similar expressions are intended to identify forward-looking statements. Such risks and uncertainties include e the need for the Company to raise capital in order to fund increasing R&D spending and the risk that Penwest will not be able to raise such funds or will only be able to raise such funds on unfavorable terms; dependence on collaborators to, among other things, sell products for which the Company receives royalties and advance clinical development and commercialization of products: the ability to enter into additional collaborations; uncertainty of success of collaborations; the risk of patent litigation; regulatory risks relating to TIMERx® drugs in development; the timing of clinical trials; actual and potential competition; the timing and outcome of regulatory approval of products and other risks as set forth under the caption "Risk Factors" in Penwest's Current Report on Form 8-K filed with the Securities and Exchange Commission on July 25, 2001, and which risk factors are incorporated herein by reference.

(17th June 2009) Penwest Enters Into Third Research and Development Agreement With Otsuka Pharmaceutical

(10th June 2009) Penwest and Endo Grant Valeant Pharmaceuticals Exclusive License to Market Opana(r) ER in Canada, Australia and New Zealand

(25th February 2009) Penwest Begins Phase Ib Clinical Trial of A0001, Dosing Underway of Compound for the Treatment of Mitochondrial Diseases

(25th November 2008) Penwest Enters Into Second Research and Development Agreement With Otsuka Pharmaceutical

(4th November 2008) Penwest Reports Third Quarter 2008 Financial Results