RECENT ADVANCEMENT IN GASTRO RETENTIVE DRUG DELIVERY SYSTEM – A REVIEW
Archana D. Kajale*, Dr. Anil V. Chandewar
Department of Pharmaceutics P. Wadhwani College of Pharmacy Yavatmal. (M.S). 445001, India.
Gastro retentive systems can remain in the gastric region for several hours and hence significantly prolong the gastric residence time of drugs. Prolonged gastric retention improves bioavailability, reduces drug waste, and improves solubility for drugs that are less soluble in a high pH environment. Gastro retentive systems (GRDDS) are designed on the basis of delayed gastric emptying and CR principles, and are intended to restrain and localize the drug delivery device in the stomach or within the upper parts of the small intestine until all the drug is released. Various mechanisms (approaches) of achieving gastric retention include floatation or buoyancy, mucoadhesion, sedimentation, expansion, and geometry. Other approaches include co administration of drugs or fatty acid salts, or sham feeding of indigestible or enzyme-digestible hydrogels that convert the motility pattern of the stomach to a fed state. GRDDS have great potential in improving the bioavailability of drugs that exhibit an absorption window. The single unit dosage form increase the bioavailability of some drugs but have some disadvantages and these disadvantages can be overcome by formulating the drug in multiple unit floating drug delivery system which have all the advantage of single unit system. Due to complexity of pharmacokinetics and pharmacodynamics parameters, in vivo studies are required to establish the optional dosage form for a specific drug. Another promising area of research for gastro retentive drug delivery system is eradication of Helicobacter pylori, which is now believed to be causative bacterium of chronic gastritis and peptic ulcers.