Recent advances in cell and molecular biology are providing exciting opportunities for the rational design of novel highly specific and effective therapeutic agents. These opportunities will often only be turned into clinical success through strategies which ensure the delivery of such agents to the desired site of action. This is achieved via processes which prevent loss of drug activity, avoid toxicity and provide cost- effective and convenient therapy. This book addresses some of the biological opportunities and scientific challenges for the site-specific delivery of drugs, and indicates the formidable obstacles which face the pharmaceutical industry and academia alike. The Editors aim to demonstrate, through the contributions of leading international researchers, that site-specific delivery is as important an element in drug design as is the interaction with the pharmacological receptor. Pharmaceutical scientists, biotechnologists and cell and molecular biologists working in the field of rational drug design will find this an invaluable and timely addition to the literature.