Brief overview of gastro-retentive drug delivery system

English oral delivery of drugs was the most commonly used modality because of patient compliance and ease of administration. After oral administration of any drug, its bioavailability is affected by its residence time in the stomach. This variability may lead to unpredictable times when achieving peak plasma levels. The purpose of writing this review on gastro-retentive drug delivery systems was to comply with the recently become leading methodologies in site-specified orally administrated controlled releasing drug delivery. GRDDS can improve the controlled delivery of drugs that have an absorption window by continuously releasing the drug for a prolonged period before it reaches its absorption site. Different innovative approaches like magnetic field assisted gastro-retention, plug type swelling system, muco-adhesion technique, and floating system with or without effervescence are being applied to fabricate GRDDS. Recently applied gastrointestinal technologies such as expandable, super porous hydrogel; bio\mucoadhesive, magnetic, ion-exchange resins; and low- high-density systems have also been examined along their merits and demerits. The purpose of factors related to GRDDS, its advantages and disadvantages, and emphasis is given on its significance over conventional forms of drug deliveries. The classification, formulation, objectives, methods, and results consideration for gastro retention drug delivery system.