In recent years, many attempts have been made to enhance the drug bioavailability and
therapeutic effectiveness of oral dosage forms. In this context, various gastroretentive drug
delivery systems (GRDDS) have been used to improve the therapeutic efficacy of drugs that
have a narrow absorption window, are unstable at alkaline pH, are soluble in acidic
conditions, and are active locally in the stomach. In this review, we discuss the physiological
state of the stomach and various factors that affect GRDDS. Recently applied gastrointestinal …