Drug Delivery to Absorption Window through Floating Microspheres:A Review

In the recent years, particularly in the last two decades Scientific and technological advancements have been made in the research and development of rate-controlled oral drug delivery systems by overcoming physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying times (GET). In order to formulate gastroretentive dosage forms, which will allow the delivery of restricted 'absorption window' drugs which are absorbed in a particular portion of the GI tract. Several approaches are currently being used to prolong the GRT including floating drug delivery systems (FDDS), also known as hydrodynamically balanced systems (HBS), swelling and expanding systems, polymeric bioadhesive systems, modified-shape systems, high-density systems, and other delayed gastric emptying devices. In this review, the current status of floating microspheres/hollow microspheres (micro balloons), their evaluation parameter, advantages, application, limitation manufacturing parameters and future potential for oral sustained release drug delivery are discussed.