Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ENDO PHARMACEUTICALS HOLDINGS INC
   2. Issuer Name and Ticker or Trading Symbol
PENWEST PHARMACEUTICALS CO [PPCO] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
100 ENDO BOULEVARD		 3. Date of Earliest Transaction (Month/Day/Year)
11/04/2010
(Street)

CHADDS FORD, PA 19317		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, par value $0.001 per share 11/04/2010   P   3,173,334 A (1) 33,627,009 I owned through wholly owned corporation

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Options $ 2.62 11/04/2010   P   928   03/13/2009 12/31/2010 Options 928 (1) 1,576 I owned through wholly owned corporation
Options $ 3.05 11/04/2010   P   398   06/11/2009 12/31/2010 Options 398 (1) 1,576 I owned through wholly owned corporation
Options $ 3.81 11/04/2010   P   250   01/22/2009 12/31/2010 Options 250 (1) 1,576 I owned through wholly owned corporation

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ENDO PHARMACEUTICALS HOLDINGS INC
100 ENDO BOULEVARD
CHADDS FORD, PA 19317		     X    
West Acquisition Corp.
100 ENDO BOULEVARD
CHADDS FORD, PA 19317		     X    

Signatures

 /s/ Caroline B. Manogue   11/08/2010
**Signature of Reporting Person Date
 /s/ Caroline B. Manogue   11/08/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Reflects shares of common stock, par value $0.001 per share ("Shares"), not tendered in the tender offer pursuant to the Agreement and Plan of Merger, dated August 9, 2010, by and among the Company, Endo Pharmaceuticals Holdings Inc. ("Parent") and West Acquisition Corp., a Delaware corporation and an indirect wholly-owned subsidiary of Parent ("Purchaser"), and deemed acquired at a price of $5.00 per Share, net to the seller in cash, without interest and less any required withholding taxes, pursuant to the consummation of the merger of the Purchaser with and into the Company (the "Merger"). At the effective time of the Merger, the aforementioned shares and options were cancelled and ceased to exist and each share of the Purchaser converted into shares of the Company. Purchaser's separate corporate existence ceased and the Company survived as an indirect wholly owned subsidiary of the Parent.

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