Abstract
Increasing number of novel drug delivery systems are being employed for therapeutic use. Gastro retentive drug delivery systems have potential to permit improved penetration through the mucus layer which results in better concentration of drug at the specific site , ensuring optimal bioavailability of a poorly absorbed drug with a desired release profile. This drug delivery system potentially overcomes the drawback of non-site specificity and short gastric resident time that are usually associated with oral route of administration. At present, numerous approaches are being utilized to prolong the gastric residence time, including floating systems, magnetic system swellable/ expanding systems, gastric mucohedhesive systems, sedimentation/ high density system by incorporating suitable polymers in dosage form. This study describes the different structural components like polymers and other excipients (formulation variables) that can be used to formulate the suitable and effective gastro-retentive drug delivery system. In the light of recent developments, different formulation variables that have direct effect on gastric residence time like floating, high density, bioadhesion, expending and magnetic properties of GRDDS are discussed in detail in this review.
