Exhibit 10.23B

February 10, 2012

Watson Pharmaceuticals, Inc.

(on behalf of Coventry Acquisition, LLC)

311 Bonnie Circle

Corona, CA 92880

Attention: David A. Buchen,

Executive Vice President, General Counsel,

    and Secretary

RE: Second Closing under the March 3, 2010 Purchase and Collaboration Agreement

Dear Mr. Buchen:

I write in reference to Section 7.4 of the Purchase and Collaboration Agreement
(the “Agreement”) dated as of March 3, 2010, entered into by and among Columbia
Laboratories, Inc., (“Columbia”), Watson Pharmaceuticals, Inc., (“Watson”), and
Coventry Acquisition, Inc., a wholly-owned Subsidiary of Watson (“Coventry”).
Capitalized terms used and not otherwise defined in this letter shall have the
meanings respectively ascribed thereto in the Agreement.

Buyer and Seller desire to effect the Second Closing under the Agreement, but
Completion of PTB US Development has not occurred. Pursuant to Sections 7.4 and
11.8 of the Agreement, Buyer and Seller jointly hereby agree to waive Completion
of PTB US Development as a condition to the Second Closing Date. Each of Buyer
and Seller further agree to immediately consummate the Second Closing on the
date hereof by making each of the deliveries required to be made, and taking
each of the actions required to be taken, by it under Section 3.3(a) or (b), as
applicable.

Buyer and Seller acknowledge and agree that, except for the waiver above, the
Agreement remains in full force and effect, as if the conditions waived
hereunder had been satisfied in accordance therewith.

Sincerely yours,

/s/    Frank C. Condella, Jr.

 

Frank C. Condella, Jr.

President and Chief Executive Officer

 

/s/ David A. Buchen

Accepted and agreed to by

Watson Pharmaceuticals, Inc.

(on behalf of Coventry Acquisition, LLC)

 

cc Latham & Watkins LLP

     Attention: R. Scott Shean