Volume :
7
Issue :
1
Abstract :
In recent years, many efforts have been made in order to improve drug bioavailability after oral administration. Gastroretentive drug-delivery systems (GRDDS) provide a mean for controlled release of compounds that are absorbed by active transport in the upper intestine. They have the potential to prolong the gastric retention time and provide controlled/sustained release of a drug at the absorption site, thereby improving the bioavailability. Several approaches are used to increase the gastric residence time, namely bioadhesive or mucoadhesive systems, expandable systems, high-density systems, floating systems, superporous hydrogels and magnetic systems. The present review highlights some of the drugs that can benefit from gastroretentive strategies, such as the factors that influence gastric retention time and the mechanism of action of gastroretentive systems, as well as their classification into single and multiple unit systems. In the future, it is expected that they will become of significance in drug therapies.