Exhibit 23.1

            Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form
S-8 No. 33-66739) pertaining to the Savings Plan of Penwest Pharmaceuticals Co.
of our report dated June 17, 2004, with respect to the financial statements and
schedule of the Penwest Pharmaceuticals Co. Savings Plan included in this Annual
Report (Form 11-K) for the year ended December 31, 2003.

                                                           /s/ Ernst & Young LLP
Stamford, Connecticut
June 28, 2004