Controlled release technology enhances the beneficial effects of drugs, agrochemicals and other biologically active agents. This monograph offers background on its terms, concepts, mathematical and chemical principles, and advantages. It treats each of the major techniques for achieving controlled release: diffusion, biodegradation, osmosis and mechanical systems, and describes and compares the numerous materials used in controlled release devices. In addition, the book presents techniques for device preparation and evaluation, and describes the most significant commercially available controlled release products.