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                                                                      Exhibit 24

                                POWER OF ATTORNEY


         KNOW ALL MEN BY THESE PRESENT, that each person whose signature appears
below constitutes and appoints Tod R. Hamachek and Jennifer L. Good and each of
them, severally as attorney-in-fact for him or her in any and all capacities, to
sign the Annual Report on Form 10-K of Penwest Pharmaceuticals Co. for the
fiscal year ended December 31, 1999, and to file same and any amendments, with
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, hereby ratifying and confirming all that
said attorney-in-fact, or his substitute or substitutes, may do or cause to be
done virtue hereof.


SIGNATURE                                                     DATE
- ---------                                                     ----

/s/ Paul E. Freiman                                           March 17, 2000
- -----------------------------------------------------         --------------
Paul E. Freiman, Director

/s/ Jere E. Goyan, Ph.D.                                      March 17, 2000
- -----------------------------------------------------         --------------
Jere E. Goyan, Ph.D., Director

/s/ Rolf H.Henel                                              March 17, 2000
- -----------------------------------------------------         --------------
Rolf H. Henel, Director

/s/ Robert J. Hennessey                                       March 17, 2000
- -----------------------------------------------------         --------------
Robert J. Hennessey, Director

/s/ N. Stewart Rogers                                         March 17, 2000
- -----------------------------------------------------         --------------
N. Stewart Rogers, Director

/s/ John N. Staniforth, Ph.D.                                 March 17, 2000
- -----------------------------------------------------         --------------
John N. Staniforth, Ph.D., Director

/s/ Anne M. VanLent                                           March 17, 2000
- -----------------------------------------------------         --------------
Anne M. VanLent, Director