Polymeric Innovations in Gastroretentive Drug Delivery Systems: An Updated Review

Abstract

Gastroretentive Drug Delivery Systems (GRDDS) are specifically engineered to enhance gastric residence time, thereby improving the bioavailability of drugs characterized by a narrow absorption window, reduced solubility under alkaline conditions, or those requiring local gastric action. Among the various GRDDS approaches, floating drug delivery systems are extensively investigated, primarily due to their capacity to remain buoyant in gastric fluids without significantly altering gastric emptying rates. Polymers play a pivotal role in the successful design of GRDDS, contributing to buoyancy, swelling behavior, mucoadhesion, and controlled drug release. A wide range of polymeric materials has been employed. Natural polymers, such as chitosan, guar gum, xanthan gum, sodium alginate, and pectin, offer biocompatibility, gel-forming properties, and adhesion capabilities. Semi-synthetic polymers like hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC), and sodium carboxymethyl cellulose (NaCMC) enhance swelling, matrix integrity, and release control. Synthetic polymers, including polyvinyl alcohol (PVA), Eudragit® grades, and polyvinylpyrrolidone (PVP), provide structural strength, pH-dependent release, and improved solubility. Through strategic selection and combination of these polymers, researchers can achieve predictable gastric retention and finely tuned release profiles, establishing GRDDS as a versatile and effective approach for oral controlled drug delivery.