Dr. Krishnaiah Yellela of FDA/CDER organized a course on “Product Quality of Transdermal Systems” which Dr. Bozena Michniak-Kohn spoke at earlier this month. The venue was the FDA’s White Oak campus in Silver Spring, MD. The White Oak campus of the FDA was impressive with many new buildings and excellent laboratory facilities and equipment.
The plenary speaker was the well-known dermatologist Dr. Howard Maibach from USC San Francisco and speakers included academicians, practicing physicians as well as FDA scientists. Tours of the FDA DPQR laboratories were also on the two day agenda.
Dr. Michniak-Kohn’s topic was “Skin Models for In Vivo Performance Testing of Transdermal Drug Delivery Systems”. Dr. Michniak-Kohn was also a panelist during the afternoon discussion.
In vitro methods are often preferred over in vivo for permeability testing of compounds in transdermal drug delivery systems due to lower costs, less variability in data and easier handling. Several approaches are being used including the use of human skin membranes, tissue engineered human skin models, as well as non-biological models. These models are useful for routing testing of transdermal formulations each with its limitations as well as benefits. Dr. Michniak-Kohn’s presentation addressed the usefulness of several models and discussed how they can be applied to transdermal drug permeability testing.