Abstract

This chapter discusses the role of cell- and tissue-based in vitro models for drug permeability during the early stages of drug development. A general description of different experimental methods, as well as all factors, affects the drug permeability, and the permeability calculation procedures are described in detail. Finally, the importance of standardization protocols for in vitro methods, the application of the three Rs policy in experimental procedures and the biosecurity systems in most of the cell and tissue in vitro methods are clearly remarked.