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 Diverse attempts were being currently used including swelling and expanding system, polymeric bio adhesive systems, modified-shape systems, high density system and other delayed gastric emptying devices. The purpose of this review was to systemize recent approaches on floating drug delivery systems along with the principle mechanism of floatation to acquired gastric retention.
