Hatch-Waxman Letters

The "Drug Price Competition and Patent Term Restoration Act of 1984," also known as the Hatch-Waxman Amendments, established the approval pathway for generic drug products, under which applicants can submit an abbreviated new drug application (ANDA) under section 505(j) of the Federal Food, Drug, and Cosmetic Act (FD&C Act). The Hatch-Waxman Amendments include provisions that involve patents and exclusivities related to new drug applications, and 180-day exclusivity for certain ANDA applicants. As a general matter, the Food and Drug Administration (FDA or the Agency) has implemented these statutory provisions within the context of application-specific decisions. In certain circumstances, FDA has received requests from applicants and other stakeholders for FDA’s communications related to such decisions. FDA intends to publish “frequently requested” communications (5 U.S.C. §552(a)(2)(D)). FDA may also, proactively, publish communications that it determines may be of general interest after addressing any concerns related to the disclosure of proprietary information.

The following letters provide information regarding generic drug approvals: 

• Dear Cyclosporine ANDA Applicants Letter, February 2022 (PDF - 268 KB)
• Determination of Suboxone Exclusivity, July 2018 (PDF - 547 KB)
• Determination of Losartan Potassium (Cozaar) and Losartan Potassium and Hydrochlorothiazide (Hyzaar) Exclusivity, March 2010 (PDF - 55 KB)
• Determination of Nateglinide Exclusivity, September 2009 (PDF - 90 KB) 
• Determination of Dorzolamide-Timolol Maleate Ophthalmic Solution Exclusivity, September 2008 (PDF - 160 KB)
• Determination of Acarbose Exclusivity, May 2008 (PDF - 526 KB) 
• Determination of Ramipril Exclusivity, May 2008 (PDF - 363 KB) 
• Determination of Granisetron Exclusivity, April 2008 (PDF - 44 KB)

The following archived letters provide historical information about the Hatch Waxman Amendments: 

• Implementation of the Drug Price Competition and Patent Term Restoration Act.   Preliminary Guidance, (Letter dated 10/11/1984)
• Letter on the response to 12/20/1984 letter from the Pharmaceutical Manufacturers Association about the Drug Price Competition and Patent Term Restoration Act, (Letter dated 3/26/1985)
• Fourth of a series of letters providing informal notice to all affected parties about policy developments and interpretations regarding the Act.  Three-year exclusivity provisions of Title I, (letter dated 10/31/1986)
• Fifth of a series of letters providing informal notice about the Act, discussing the statutory mechanism by which ANDA applicants may make modifications in approved drugs where clinical data is required, (letter dated 4/10/1987)
• Sixth of a series of informal notice letters about the Act discussing 3-and 5-year exclusivity provisions of sections 505(c)(3)(D) and 505(j)(4)(D) of the FD&C Act, (letter dated 4/28/1988)
• Seventh of a series of letters about the Act providing guidance on the "130-day exclusivity" provision of section 505(j)(4)(B)(iv) of the FD&C, (letter dated 7/29/1988)
• Court Decisions, ANDA Approvals, and 180-Day Exclusivity Under the Hatch-Waxman Amendments to the Federal Food, Drug, and Cosmetic Act, March 2000