REVIEW ON GASTRO- RETENTIVE DRUG DELIVERY SYSTEMS

The main goal of any drug delivery system is to achieve desired concentration of the drug in blood or tissue, which is therapeutically effective and non toxic for a prolonged period. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. The success of controlled oral drug deliveries is associated with some physiological adversities like short gastric residence time and unpredictable gastric emptying time. Prolonged gastric residence increases duration of drug release, reduces drug waste, and improves drug solubility in gastric pH. This has triggered attention towards development of gastro retentive drug delivery technologies to deliver narrow absorption window drugs with improved bioavailability. The present review addresses briefly about the current status of various leading gastro retentive drug delivery technologies, developed until now, i.e. high density (sinking), floating, bio- or mucoadhesive, expandable, unfoldable, super porous hydrogel, magnetic systems etc. In addition, important factors controlling gastro retention, advantages and finally, future potential are discussed.