ABSTRACT:
Super porous hydrogel (SPH) swells very rapidly in a shorter period of time (due to the presence of interconnected microscopic pores) to an equilibrium size and contains highly porous structure. Hydrogels are they are water insoluble. The swelling properties of hydrogels are mainly related to the network elasticity, the presence of hydrophilic functional groups, the cross-link density, and porosity. The first approach for SPH synthesis involves cross-linking of co-monomers using multifunctional co-monomer, which acts as cross-linking agent. They maintain their integrity in the harsh stomach environment, while releasing the pharmaceutical active ingredient. The fast swelling property is based on water absorption through open porous structure by capillary force. The retention of the dosage form in the stomach prolongs overall GI transit time, thus resulting in improved oral bioavailability of the drug. Because these hydrogels absorb a large volume of environmental fluids, which expand their volume considerably over a very short time, their sheer bulk hinders their transport to the next organ via the narrow pylorus. This unique swelling property allows them to be used as gastric retention carriers, providing sustained release through long/maximium residence in the stomach region.