Drug Partitioning and Transport Across Biological Barriers

Abstract

This chapter addresses drug partitioning and transport across biological barriers. In order to exert a therapeutic response, drug molecules must interact with target receptors. Drug transport across biological barriers is influenced by the partitioning of the drug molecule between aqueous and lipid phases. Factors that influence the type of journey the drug molecules experience include the following: the ability of drug molecules to partition into biological fluids and tissues, the site of the target receptor, the route of administration, and the delivery system used to deliver the drug. The chapter then introduces drug–target receptor interactions, highlighting factors influencing the partitioning of drug molecules and describing the biological barriers drug molecules encounter during delivery. It explores the main transport mechanisms by which drug molecules are transported across these biological barriers.