Abstract :
Gastroretentive dosage form (GRDF) has played an important role in the past few periods in improving the limitation of most predictable and oral controlled release drug delivery system related to fast gastric-emptying time. GRDF system can be defined as a system which remains in the stomach for an adequate time interval against all the physiological barriers, and releases active moiety in a well-ordered manner. This paper gives an overview of the parameters affecting gastric emptying as well as on the main thoughts used to design pharmaceutical dosage forms with prolonged gastric residence times. In particular, bioadhesive, size-increasing, and floating drug delivery systems are presented, and their major advantages and limitations are discussed. Both single and multiple-unit dosage forms with dual working arrangements are reviewed. Dual-working classifications are more efficient than the traditional systems.