Use of polymers has become indispensable in the field of drug delivery. Polymers play a crucial role in modulating drug delivery to exploit maximum therapeutic benefits and have been fundamental in the successful development of several novel drug delivery systems that are now available. This book provides details of the applications of polymeric drug delivery systems that will be of interest to researchers in industries and academia. It describes the development of polymeric systems ranging from the conventional dosage forms up to the most recent smart systems. The regulatory and intellectual property aspects as well as the clinical applicability of polymeric drug delivery systems are also discussed. Each different drug delivery route is discussed in a separate chapter of the book. All major routes of drug delivery have been covered to provide the reader with a panoramic as well as an in-depth view of the developments in polymer-based drug delivery systems. Appendices are included which incorporate useful pharmaceutical properties of the polymers and important polymeric applications for various drug delivery routes.