Equivalence codes

This system allows users to quickly determine if the Food and Drug Administration has evaluated a particular drug and determined it to be therapeutically equivalent to another drug.

A: drug products FDA considers therapeutically equivalent to other pharmaceutically equivalent products;

AA: drug products for which there are no known or suspected bioequivalence problems (also AN, AO, AP, AT, depending on dosage form);

AB: drug products for which actual or potential bioequivalence problems have been resolved with adequate in vivo and/or in vitro evidence supporting bioequivalence;

B: drug products that FDA considers not to be therapeutically equivalent to other pharmaceutically equivalent products; in other words, actual or potential bioequivalence problems have not been resolved by adequate evidence of bioequivalence.

Source: Approved Drug Products. 16th ed. Rockville, MD: U.S. Department of Health and Human Services; 1996.