Gastric emptying is a complex process and one of the most important obstacles in the better absorption and enhances bioavailability of oral drug delivery system. In recent years various scientific and technological advancements have been made in the research and development of oral drug delivery systems to overcoming physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying time (GET). In order to avoid such adversities, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hour via floating drug delivery system. Floating delivery systems or hydro dynamically controlled systems are low density systems that have sufficient buoyancy to float over the gastric content and remain buoyant in the stomach. The recent development of these systems includes their physiological and formulation variables affecting the gastric retention and to design the single and multiple-unit floating systems and their formulation, evaluation aspects are covered in detail. This article aims at reviewing the numerous techniques that has been designed till date for optimizing floating drug delivery system (FDDS), and also summarize the evaluation of FDDS of tablet dosage forms
