Book excerpt: Despite advances in the development of new drugs, a drug may never reach the target organ, or it may be difficult to achieve the necessary level of drug in the body. Large doses can result in serious side effects and can harm normal, as well as diseased, cells and organs, and for this reason it is vital that controlled release and the targeting of delivery systems must evolve in parallel to drug research. Chemical Aspects of Drug Delivery Systems reflects the modern challenge to devise effective drug delivery and targeting systems, giving particular emphasis to recent innovations in the field. Delivery systems described include carbohydrate derivatives, novel nonionic surfactant vesicles and various polymers, including polyacrylates and aqueous shellac solutions, as well as hydrogels. In addition, many of the key issues, such as the understanding of biosystems and targets and the development of materials to provide the deserved carrier and excipient properties for controlled, targeted drug delivery, are considered in depth. This book will be of equal interest to undergraduate, graduate, researcher and those in the pharmaceutical industries, and it complements two previous RSC Special Publications, Encapsulation and Controlled Release and Excipients and Delivery Systems for Pharmaceutical Formulations.