Abstract: 
To increase the therapeutic efficacy of medications with a limited absorption window, unstable at alkaline pH, soluble in acidic environments, and localized stomach activity, a variety of gastroretentive drug delivery systems (GRDDS) have been employed. In this overview, we go over the physiological state of the stomach, and different GRDDS techniques.

Keywords: GRDDS, Therapeutic Efficacy, Acidic Environments.