Analysis of factors governing drug absorption and their improvement

Abstract

Drugs have to be absorbed through various mucosal membranes including the gastrointestinal (GI) mucosa to express their systemic effects. However, there are a number of factors governing mucosal absorption of drugs and, for drugs with low bioavailability, the reason for the low bioavailability should be analyzed and clarified to improve the bioavailability. This review deals with the results of our biopharmaceutical studies to analyze factors controlling drug absorption and our trials to improve the absorption, especially from the GI tract and oral cavity. © 2009 The Pharmaceutical Society of Japan.