This draft revised guidance document describes how the Center for Veterinary Medicine (CVM) intends to evaluate requests for waiving the requirement for submitting data demonstrating the bioequivalence of animal drugs in soluble powder oral dosage form products and Type A medicated articles. It expands upon CVM’s Bioequivalence Guidance,particularly the section on Criteria for Waiver of In Vivo Bioequivalence Study.

　　This guidance is applicable to generic investigational new animal drug (JINAD) files and abbreviated new animal drug applications (ANADAs). Although the recommendations in this guidance reference generic drug applications, the general principles described may also be applicable to new animal drug applications (NADAs), investigational new animal drug (INAD) files, and supplemental NADAs.

　　The recommendations in this draft revised guidance are premised on the assumption that a sponsor will be bridging between identical dosage forms (e.g., Type A medicated article for use in complete feed to Type A medicated article for use in complete feed; soluble powder for use in drinking solution to soluble powder for use in drinking solution). Therefore, it is not appropriate to use the recommendations in this guidance to compare the solubility of two drug products where the active pharmaceutical ingredient (API) will be administered in differing manners (e.g., drinking water versus complete feed, complete feed for administration throughout the day versus top dress). CVM encourages sponsors to contact the Center to discuss that type of comparison.

　　In general, FDA’s guidance documents do not establish legally enforceable responsibilities. Instead, guidances describe the Agency’s current thinking on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited. The use of the word should in Agency guidances means that something is suggested or recommended, but not required.