Pharmaceutical scientists in industry and academia will appreciate this single reference for its detailed experimental procedures for conducting biopharmaceutical studies. This well-illustrated guide allows them to establish, validate, and implement commonly used in situ and in vitro model systems. Chapters provide ready access to these methodologies for studies of the intestinal, buccal, nasal and respiratory, vaginal, ocular, and dermal epithelium as well as the endothelial and elimination barriers.