X0303 4 2009-03-06 0 0001047188 PENWEST PHARMACEUTICALS CO PPCO 0001178579 TANG KEVIN C 4401 EASTGATE MALL SAN DIEGO CA 92121 0 0 1 0 0001232621 TANG CAPITAL MANAGEMENT LLC 4401 EASTGATE MALL SAN DIEGO CA 92121 0 0 1 0 0001191935 TANG CAPITAL PARTNERS LP 4401 EASTGATE MALL SAN DIEGO CA 92121 0 0 1 0 Common Stock 2009-03-06 4 P 0 101500 1.4621 A 5832336 I By LP Common Stock 2009-03-06 4 P 0 207800 1.3903 A 6040136 I By LP Common Stock 2009-03-09 4 P 0 296362 1.3898 A 6336498 I By LP Common Stock 2009-03-10 4 P 0 35000 1.43 A 6371498 I By LP Common Stock 225000 I As Trustee The securities are held by Tang Capital Partners, LP. Kevin C. Tang is the sole manager of Tang Capital Management, LLC, which is the general partner of Tang Capital Partners, LP. Mr. Tang disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. The securities are held by Kevin C. Tang as Trustee of the Tang Family Trust and as Trustee of the Tang Advisors, LLC Profit Sharing Plan. /s/ Kevin C. Tang 2009-03-10 /s/ Kevin C. Tang, Managing Member 2009-03-10 /s/ Kevin C. Tang, as Managing Member of Tang Capital Management, LLC, General Partner 2009-03-10