Today, gastroretentive systems are becoming an increasingly important part of the therapeutic arsenal, particularly in the management of chronic diseases such as diabetes, cardiovascular and infectious diseases. This book provides a comprehensive review of the technological and biopharmaceutical aspects of GRDFs. The first chapter provides an anatomical and physiological overview of the digestive system, with a special focus on the gastric universe, the stomach, and the factors that can influence gastric emptying. The second chapter focuses on solid oral sustained-release forms. Chapter 3 consists of a review of the literature on sustained-release gastric forms: interest, candidate molecules, pharmaceutical parameters influencing gastro-retention and technology of high-density and bioadhesive systems. The fourth chapter is devoted to floating gastro-retentive systems. Chapter 5 describes the in vitro and in vivo evaluation methods of gastroretentive systems. Finally, this book isintended for post-graduate students in pharmaceutical sciences.