The purpose of this study was to develop a bilayer floating drug delivery system of Diltiazem Hydrochloride (DTZ). Floating drug delivery systems can remain in the gastric region for several hours and therefore prolong the astric residence time of drugs and improve drug bioavailability. In this study novel bilayer formulation of floating tablet comprising drug contained core and floated outer layer was prepared. The tablets were prepared by direct compression technique, using polymers such as Hydroxypropyl ethylcellulose (HPMC), Ethyl cellulose and Tragacanth alone or in combination, and other standard excipients. Sodium bicarbonate was incorporated as a gas-generating agent. Floating properties, drug release and release kinetic were assessed. The results of buoyancy and release studies showed that a combination of HPMC, tragacanth and sodium bicarbonate favors the preparation of the outer layer of bilayer floating controlled release DTZ tablets. The linear regression analysis and model fitting demonstrated that the optimized formulation followed linear probability model. Overall it was possible to control the release of highly soluble DTZ by combining the floating and bilayered tablet tools.
Hoda Varasteghan, Javad Shokri, Solmaz Asnaashari and Yousef Javadzadeh