Abstract
Most convention route for drug delivery is oral route but the bioavailability is very poor by this route. To overcome hazards or limitations of oral route a new & novel approach of Gastro-retentive drug delivery have been developed. By using this system drugs having local effect or high absorption in stomach with narrow therapeutic window have higher GRT so prolonged and mostly sustained effect in stomach. The variability in drug concentration can also overcome by this technique. Several approaches have been developed to formulate expandable, floating, non-floating, expanding type of dosage forms and various others which have been discussed in this review. It also includes advantages, disadvantages, and suitable, unsuitable candidates for GRDDS. In-vitro &In-vivo Evaluation techniques are also discussed here. It also include future trends of GRDDS.
