Immobilized Artificial Membrane Chromatography

The development of a simple, rapid method to predict drug transport across biological barriers has been a long-standing objective in the pharmaceutical sciences. Typical barriers to drug transport include the membranes in the intestinal tract, lungs, and eye, the blood-brain barrier, and many others. In addition to these “internal” barriers, the skin is an “external” barrier that molecules must penetrate if transdermal drug delivery is to be successful. The prediction of drug transport through any of these biological-membrane barriers is typically a lengthy process that requires substantial experimental effort; however, the experiments are frequently complicated by significant variability that makes the methods unreliable or useful for only a small class of compounds. This chapter describes a new approach for predicting drug transport through human skin. The method utilizes high-performance liquid chromatography (HPLC) columns packed with a stationary phase containing immobilized membrane lipids (i. e., phosphatidylcholine).