ABSTRACT
Applicants submitting a new drug application (NDA) or new animal drug application
(NADA) under the provisions of section 505(b) in the Federal Food, Drug, and Cosmetic
Act (FDC Act) are required to document bioavailability (BA) [21 CFR 320.21(a)]. If approved,
an NDA drug product may subsequently become a reference listed drug (RLD). Under
section 505(j) of the Act, a sponsor of an abbreviated new drug application (ANDA) or
abbreviated new animal drug application (ANADA) must document first pharmaceutical
equivalence and then bioequivalence (BE) to be deemed therapeutically equivalent to an RLD.
Defined as relative BA, BE is documented by comparing the performance of the generic (test)
and listed (reference) products. (Pharmaceutical equivalents are drugs that have the same
active ingredient in the same strength, dosage form, and route of administration, and have
comparable labeling and meet compendia or other standards of identity, strength, quality,
purity, and potency.)
