Pharmaceutical equivalents: Drug products that contain the same active ingredient(s), dosage form, route of administration, and amount of active ingredient while meeting the same standards (i.e., strength, quality, purity, and identity). They may differ in characteristics such as shape, scoring configuration, release mechanisms, packaging, excipients (including colors, flavors, preservatives), expiration time, and, within certain limits, labeling. Being pharmaceutical equivalents is a requirement to be therapeutic equivalents (e.g., to be a generic to the reference listed drug).

Therapeutic equivalents: Pharmaceutical equivalents for which bioequivalence has been demonstrated, and they can be expected to have the same clinical effect and safety profile when administered to patients under the conditions specified in the labeling.
FDA’s criteria for therapeutically equivalent drug products are:

1. Approved as safe and effective
2. Pharmaceutical equivalents in that they (a) contain identical amounts of the same active drug ingredient in the same dosage form and route of administration and (b) meet compendial or other applicable standards of strength, quality, purity, and identity
3. Bioequivalent in that (a) they do not present a known or potential bioequivalence problem, and they meet an acceptable in vitro standard, or (b) if they do present such a known or potential problem, they are shown to meet an appropriate bioequivalence standard
4. Adequately labeled
5. Manufactured in compliance with Current Good Manufacturing Practice regulations