Offer to Purchase
All Outstanding Shares of Common Stock
Penwest Pharmaceuticals Co.
$5.00 Net Per Share in Cash
West Acquisition Corp.
an indirect wholly-owned subsidiary of
Endo Pharmaceuticals Holdings Inc.
THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, AT THE END
OF FRIDAY, SEPTEMBER 17, 2010, UNLESS THE OFFER IS EXTENDED (SUCH DATE AND TIME, AS IT MAY BE
EXTENDED, THE “EXPIRATION DATE”).
August 20, 2010
To Brokers, Dealers, Commercial Banks,
Trust Companies and Other Nominees:
We have been engaged by West Acquisition Corp., a Delaware corporation (“Purchaser”) and an indirect wholly-owned
subsidiary of Endo Pharmaceuticals Holdings Inc., a Delaware corporation (“Endo”), to act as Information Agent in connection
with Purchaser’s offer to purchase all outstanding shares of common stock, par value $0.001 per share (“Shares”), of Penwest
Pharmaceuticals Co., a Washington corporation (“Penwest”), at a price of $5.00 per Share, net to the seller in cash (less any
required withholding taxes and without interest) upon the terms and subject to the conditions set forth in the Offer to Purchase,
dated August 20, 2010 (as it may be amended or supplemented from time to time, the “Offer to Purchase”), and in the related
Letter of Transmittal (as it may be amended or supplemented from time to time, the “Letter of Transmittal” and, together with the
Offer to Purchase, the “Offer”) enclosed herewith. Please furnish copies of the enclosed materials to those of your clients for
whom you hold Shares registered in your name or in the name of your nominee.
The Offer is not subject to any financing condition, but is conditioned upon a number of other conditions as set forth in
the Offer to Purchase. See Section 13 of the Offer to Purchase.
Enclosed herewith are the following documents:
1. Offer to Purchase, dated August 20, 2010;
2. Letter of Transmittal for your use in accepting the Offer and tendering Shares and for th