Exhibit 5.1

November 14, 2011

AmerisourceBergen Corporation

1300 Morris Drive

Chesterbrook, PA 19087

Ladies and Gentlemen:

We have acted as counsel to AmerisourceBergen Corporation, a Delaware corporation (the “Company”), and the additional registrants listed on Exhibit A hereto (the “Guarantors”) in connection with (i) the issuance and sale by the Company of $500,000,000 aggregate principal amount of its 3.500% Senior Notes due 2021 (the “Notes”) pursuant to the terms of an Underwriting Agreement, dated November 8, 2011 (the “Underwriting Agreement”), by and among the Company, the Guarantors and J.P. Morgan Securities LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC, as representatives of the several underwriters named on Schedule 1 to the Underwriting Agreement and (ii) the filing of the above-referenced Registration Statement (the “Form S-3”) and Post-Effective Amendments Nos. 1, 2 and 3 thereto (together with the Form S-3, the “Registration Statement”) on September 30, 2009, November 4, 2009, December 1, 2010 and November 3, 2011, respectively, under the Securities Act of 1933, as amended (the “Act”), with the Securities and Exchange Commission (the “Commission”), pursuant to which the Notes and the Guarantees (as hereinafter defined) are registered under the Act.

The Notes were issued under that certain Indenture, dated as of November 19, 2009, by and between the Company and U.S. Bank National Association, as trustee (the “Trustee”), as supplemented and amended by a Second Supplemental Indenture thereto, dated as of the date hereof, by and among the Company, the Guarantors and the Trustee (as so supplemented and amended, the “Indenture”), and will be jointly and severally guaranteed (the “Guarantees”) by the Guarantors.

In connection with this opinion letter, we have examined:

AmerisourceBergen Corporation

November 14, 2011

Page 2

We have assumed, without any independent investigation or verification of any kind, the genuineness of all signatures, the legal capacity of all natural persons, the authenticity of the documents submitted to us as originals, the conformity with the originals of all documents submitted to us as certified, facsimile or photostatic copies and the authenticity of the originals of all documents submitted to us as copies. As to any facts that are material to the opinions hereinafter expressed that we did not independently establish or verify, we have relied without investigation upon the representations of the Company and the Guarantors contained in the Underwriting Agreement and upon certificates of officers of the Company and officers of the Guarantors.

We have also assumed, without any independent investigation or verification of any kind, that the Indenture has been duly authorized, executed and delivered by the Trustee, that the Indenture constitutes a legal, valid and binding obligation of the Trustee, and that the Trustee has the requisite organizational and legal power and authority to perform its obligations under the Indenture.

Based upon the foregoing, we are of the opinion that the Notes and the Guarantees constitute valid and binding obligations of the Company and the Guarantors, as applicable.

The opinions expressed above are subject to the following limitations and qualifications:

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AmerisourceBergen Corporation

November 14, 2011

Page 3

We hereby consent to the filing of this opinion as Exhibit 5.1 to the Company’s Current Report on Form 8-K being filed on the date hereof and incorporated by reference into the Registration Statement. In giving such consent, we do not hereby admit that we are acting within the category of persons whose consent is required under Section 7 of the Act or the rules or regulations of the Commission thereunder.

Very truly yours,

/s/ Morgan, Lewis & Bockius LLP

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Exhibit A

List of Guarantors