(170d) QbD for Generic Drugs: Modified Release Drug Products

The Office of Generic Drugs ensures the therapeutic equivalence and quality of generic drug product pharmaceuticals. This is based principally upon a regulatory paradigm that requires pharmaceutically equivalent drug products containing the same active ingredient, dosage form, and strength (among other things), to be shown to be bioequivalent to the brand name product. Also under this paradigm, the batch to batch quality of generic drug products is ensured based upon batch release testing to empirically derived specifications. While this approach has been used with great success toward bringing the availability of high quality of generic drug products, the vast majority of pharmaceuticals approved using this framework have been solution and immediate release oral products, which are inherently simple in design. Drug products however, have increased in design complexity, to encompass modified (oral) release products, transdermal delivery systems, among others complex dosage forms. As these pharmaceuticals have increased in their design complexity, approaches adopted to ensure the equivalence and quality of generic drug product pharmaceuticals, must likewise evolve.

FDA's Pharmaceutical cGMPs for the 21st Century: A Risk-Based Approach and Process Analytical Technology Initiatives are meant to enhance and modernize the regulation of pharmaceutical manufacturing and product quality. As a result of these initiatives and the trend of increasingly complex pharmaceuticals, OGD is currently implementing approaches to enhance the assessment of generic drug products, based upon a paradigm that places increased emphasis on ?quality by design? as opposed to relying solely upon ?quality by testing?. Under this enhanced review system, in addition to relying upon ?bioequivalence by testing? to the brand name, these increasingly complex generic drug products will be evaluated to ensure their ?bioequivalence by design? based upon on an understanding of the critical quality attributes needed to provide an equivalent exposure profile essential toward ensuring equivalent clinical characteristics in the target patient population. This enhanced review framework also provides for a batch to batch quality control strategy, not solely upon batch release testing, but upon an understanding of formulation and process design, the application of process analytical technology for continuous monitoring, and where relevant, performance-based specifications.