Today, I would like to draw your attention to a couple of recent changes to the USP Dissolution Testing monograph that you may need to be aware of. Two new draft USP General Chapters on Topical and Transdermal Drug products have been published in the Pharmacopeial Forum Vol. 35, No. (3) May-June 2009
. The General Chapters are: <3> Topical and Transdermal Products-Product Quality Tests
; and <725> Topical and Transdermal Products-Product Performance Tests
. You can find these if you follow the links provided above.
These are important developments since dissolution testing is plying a very important role in the pharmaceutical industry during drug development, quality control and stability programs. The test is used in order to assure consistent product (batch) quality within a defined set of specification criteria and all products must pass to be on the market. Initially, the dissolution testing procedure was developed for immediate release solid oral dosage form products and later it was extended for extended/controlled/modified release solid oral dosage form products. Recently, the application of dissolution testing has widened to a variety of "novel" or "special" dosage forms, such as suspensions, orally disintegrating tablets, chewable tablets, chewing gums, transdermal patches, semisolid topical preparations, suppositories, implants, injectable micro-particulate formulations, and liposomes. It is referred to as the "drug release test". Until now, because of significant differences in formulation design among these novel/special dosage forms, it was not possible to develop a single test protocol that could be used to study the drug release properties of all products. Rather, different apparatus, procedures, and techniques have been employed on a case-by-case basis. The two new draft USP General Chapters on Topical and Transdermal Drug products have been published in Pharmacopeial Forum 35(3) May-June 2009 to address this need.