Workshop Summary: AAPS Workshop on Special Dosage Forms—What’s New with In Vitro Drug Release?

International Perspectives on the Drug Release of Special Dosage Forms This workshop was co-sponsored by FDA and FIP. This kick-off presentation introduced the workshop by providing background and objectives. The workshop focused on modified-release drug forms and included regulatory perspectives and specific presentations for orally disintegrating tablets, chewable oral drug products, ophthalmic products, aerosol drug products, drug-eluting stents, and parenteral products including nanoparticles, microspheres, and liposomes. Each product is classified (sections in each of Tiers 1–3), and tests including product quality tests (identity, strength, potency, and quality) and product performance tests (in vitro release) are carried out. Examples were given for product quality tests and product performance tests for each Tier 1 classification. The most complex test for each Tier 1 classification tends to be product performance in determining an in vitro release method that is predictive of in vivo performance is complex. Other complex initiatives exist for transdermal products such as leak testing, which is critical to ensure understanding of potential toxicology issues. USP Apparatus 5, 6, and 7 are generally sufficient for evaluation of the release of patches. The discussion of aerosol drug products highlighted the importance of particle size testing, and particles <5 μm are ideal for effective performance for this Tier 1 classification. Mucosal products have multiple applications, and much work has been performed around in vitro release testing for this Tier 1 classification. To date, none have been standardized and various apparatus have been utilized for analyses of this class of products (mini-paddles have been employed but are not standardized). There are many USP chapters readily available to provide insight to the testing of oral, aerosol, injectable, mucosal, and skin drug products. Some are finalized and many are in development phases. FIP has committed to revise the publication “FIP/AAPS Guidelines for Dissolution/In Vitro Release Testing of Novel/Special Dosage Forms” during the 2010 calendar year.