Superporous Hydrogel Tablets of Atenolol for Gastro-retention

Gastro-retentive drug delivery system can retain the drug in the gastric region for several hours which enhances drug release and improves bioavailability. Atenolol, an antihypertensive drug has short half-life, limited bioavailability, highly unstable at basic pH and is extensively absorbed from the stomach. These features triggered the need of developing gastroretentive system. In the present study a superporous hydrogel was developed as a gastroretentive drug delivery system. Chitosan / poly (vinyl alcohol) interpenetrating polymer network (IPN) type superporous hydrogels were prepared using a gas foaming method employing glyoxal as the cross-linking agent. SPH tablets of atenolol were prepared by direct compression incorporating microcrystalline cellulose, magnesium stearate, talc and sodium bicarbonate, etc. and evaluated. The superporous hydrogels were highly sensitive to pH of swelling media and showed fast swelling and good porosity. SPH tablets of atenolol showed good precompressional and post-compressional properties. Formulation IV exhibited good swelling ratio and sustained release of drug over the period of 12 h through gastro-retention.