Generic Animal Drugs: Proven Safe and Effective

As with other human and animal drugs, generic animal drugs must comply with the Federal Food, Drug, and Cosmetics Act and applicable Food and Drug Administration (FDA) regulations. To market a generic animal drug, a company must first obtain approval of the drug from FDA Center for Veterinary Medicine (CVM), via an Abbreviated New Animal Drug Application (ANADA).

To obtain approval, the generic animal drug must have the same active ingredient as the pioneer drug. A generic animal drug typically also has the same strength, dosage form, and route of administration as the pioneer. A generic drug is required to have the same labeling as the pioneer drug, including warnings and safety information, with the exception of information that is specific only to the generic drug, such as the product trade name and the manufacturer’s name.

For a New Animal Drug Application (NADA; pioneer animal drug) to obtain FDA approval, the sponsor must present study data to show the product is safe and effective. Under the provisions of the Federal Food Drug and Cosmetic Act as amended by the Generic Animal Drug and Patent Term Restoration Act, an ANADA may be submitted for a generic version of an approved new animal drug (pioneer product). New target animal safety data, drug effectiveness data and human food safety data are not required for an ANADA. However, generic animal drug sponsors must show in vivo "bioequivalence" to the pioneer drug. Based on the formulation characteristics of certain generic product dosage forms, CVM will grant a waiver from the requirement to conduct an in vivo bioequivalence study. Specifically, the generic product needs to be a true solution containing the same active and inactive ingredients in the same concentrations and dosage form as the pioneer product. The withdrawal period and Warning statements on the generic labeling will be the same as for the pioneer product.

"Bioequivalent" means the drug has comparable bioavailability to the pioneer drug — i.e., it delivers the same amount of active ingredient to the bloodstream in the same amount of time. To demonstrate bioequivalence, a sponsor must conduct a study in each species for which the drug is indicated. Alternatively, if the generic drug contains the same active and inactive ingredients as the pioneer and is a solution, the sponsor can request that FDA waive the bioequivalence study requirements because both drugs would be rapidly absorbed into the bloodstream and therefore, bioequivalent.

Like pioneer animal drugs, a generic animal drug must satisfy the rigorous manufacturing methods, processes and quality controls to obtain FDA approval. As with human drugs, the manufacture of pioneer and generic animal drugs must meet the standards of current "Good Manufacturing Practices." The FDA Office of Regulatory Affairs, the same office that inspects human drug facilities, conducts inspections of pioneer and generic animal drug manufacturing facilities. CVM will not approve a drug application unless the manufacturing facility passes inspection.

As with pioneer animal drugs, the generic animal drug ingredients and finished product must meet U.S. Pharmacopeia (USP) specifications, where applicable, or other stringent specifications as applied to the pioneer product and approved by CVM. The generic animal drug must demonstrate stability over the shelf life of the product.

For more information on animal drugs, including generic animal drugs, visit the CVM website at