This chapter contains sections titled: Introduction Rationale General Design Principle for Controlled-Release Drug Delivery Systems Physicochemical and Biological Factors Influencing Design and Performance of Controlled-Release Formulations Controlled-Release Oral Dosage Forms Design and Fabrication of Controlled-Release Dosage Forms Technologies for Developing Transdermal Dosage Forms Ocular Controlled-Release Dosage Forms Vaginal and Uterine Controlled-Release Dosage Forms Release of Drugs from Controlled-Release Dosage Forms Summary References