TOPICAL PRODUCT DEVELOPMENT SHOULD INCLUDE IN VITRO RELEASE TESTING

TOPICAL PRODUCT DEVELOPMENT SHOULD INCLUDE IN VITRO RELEASE TESTING where meaningful test standards can be developed and applied, according to a consensus reached at a May 24-26 workshop on the scale-up of liquid and semi-solid disperse systems co- sponsored by the American Association of Pharmaceutical Scientists (AAPS), FDA and the U.S. Pharmacopeia. Schering-Plough Pharmaceutical Sciences VP Allan Kaplan voiced the general meeting consensus that both manufacturers and FDA would benefit from establishing in vitro release test standards for the products. "Ideally," Kaplan said, "this in vitro test should relate to an in vivo parameter." The development and use of meaningful in vitro release test methods for evaluating and regulating liquids and semi-solid products was a focal point of the three-day conference. Kaplan, who chaired a working group on quality assurance/quality control testing, emphasized the "benefit during the development either of a new product or a generic drug, of somehow including this as part of your formulation program." In reaching a consensus from the workshop discussion on release rate testing of topical/liquid products, Kaplan cautioned that his working committee was "very careful" to recognize that "we are in the infant stage. We are probably where dissolution was in the 1960s." Incorporating workable in vitro or in situ release testing methods into the development program on the products, he maintained, "will provide information to the agency, but also information for [the industry(BRACKET). We will get more degrees of freedom" and gain "a chance to make [scale-up] changes that we feel are logical" without having to do, "perhaps, a clinical study." FDA Office of Generic Drugs Director Roger Williams described the search for valid surrogates for clinical tests for the topicals/liquids as "the heart" of the conference. "I don't think anybody here would be enthusiastic about doing clinical trials to document scale-up or a site change or a formulation change or a minor change in process or equipment," Williams said. The generic office head added that "even in the instance when we do look at clinical trials to document bioavailability and bioequivalence, I have a lot of problems with them. I don't think they are validated. I think they lack sensitivity. They are very expensive. They are very cumbersome. They are difficult for the generic industry."