Registration Rights Agreement Joinder with respect to the Registration Rights Agreement for Sky Growth Acquisition Corporation

Exhibit 4.5

Registration Rights Agreement Joinder

with respect to the

Registration Rights Agreement

for

Sky Growth Acquisition Corporation

$490,000,000 7 ³/₈% Senior Notes due 2020

September 28, 2012

Xxxxxxx, Xxxxx & Co.,

As representative of the several Purchasers

named in Schedule A hereto (the “Purchasers”)

c/o Goldman, Sachs & Co.

000 Xxxx Xxxxxx,

Xxx Xxxx, Xxx Xxxx 00000

Ladies and Gentlemen:

Reference is hereby made to that certain Registration Rights Agreement, dated as of September 28, 2012 (the “Registration Rights Agreement”), between Sky Growth Acquisition Corporation, a Delaware corporation, and Xxxxxxx, Xxxxx & Co., as representative of the Purchasers, providing for the issuance and sale of the Securities (as defined therein). As a condition to the consummation of the offering of the Securities, in the event that the Merger Date occurs at the Time of Delivery (as defined in the Purchase Agreement referenced in the Registration Rights Agreement), each of Par Pharmaceutical Companies, Inc., a Delaware corporation (the “Company”), and each Guarantor (as defined in the Registration Rights Agreement) has agreed to join in the Registration Rights Agreement as of the date hereof. Unless otherwise defined herein, capitalized terms used but not defined herein shall have the respective meanings given them in the Registration Rights Agreement.

The Company and each Guarantor hereby agrees for the benefit of the Purchasers, as follows:

1. Each of the undersigned hereby acknowledges that it has received and reviewed a copy of the Registration Rights Agreement and all other documents it deems necessary to review in order to enter into this Registration Rights Agreement Joinder, and acknowledges and agrees to (i) join and become a party to the Registration Rights Agreement as indicated by its signature below; (ii) be bound by all covenants, agreements, representations, warranties and acknowledgements attributable to the Company or a Guarantor, as the case may be, in the Registration Rights Agreement, as of the date hereof, as if made by, and with respect to, each signatory hereto; and (iii) perform all obligations and duties required of the Company or a Guarantor, as the case may be, pursuant to the Registration Rights Agreement.

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2. This Registration Rights Agreement Joinder does not cancel, extinguish, limit or otherwise adversely affect any right or obligation of the parties under the Registration Rights Agreement. The parties hereto acknowledge and agree that all of the provisions of the Registration Rights Agreement shall remain in full force and effect.

3. The provisions of Section 9(c), (f) and (i) of the Registration Rights Agreement shall apply mutatis mutandis to this Registration Rights Agreement Joinder.

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PAR PHARMACEUTICAL COMPANIES, INC.
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Executive Vice President and Chief Financial Officer
PAR PHARMACEUTICAL, INC.
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Executive Vice President and Chief Financial Officer
ANCHEN INCORPORATED
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Executive Vice President and Chief Financial Officer
ANCHEN PHARMACEUTICALS, INC.
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Executive Vice President and Chief Financial Officer
PAR, INC.
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Vice President and Chief Financial Officer
KALI LABORATORIES, INC.
By:		/s/ Xxxxxxx Xxxxxxxx
Name:		Xxxxxxx Xxxxxxxx
Title:		Chief Financial Officer and Treasurer and Secretary

Accepted as of the date hereof, on its own behalf and on behalf of the other Purchasers:
XXXXXXX, SACHS & CO.
By:		/s/ Xxxxxxx, Xxxxx & Co.
Name:		Xxxxxx Xxxxxx
Title:		Authorized Signatory

Schedule A

Xxxxxxx, Xxxxx & Co.

Xxxxxxx Lynch, Pierce, Xxxxxx & Xxxxx Incorporated

Deutsche Bank Securities Inc.

Citigroup Global Markets Inc.

RBC Capital Markets, LLC

BMO Capital Markets Corp.