Floating microspheres (Paperback)

Gastroretentive dosage forms have potential for use as controlled-release drug delivery systems. Multiple unit systems avoid the 'all-or-none' gastric emptying nature of single unit systems. A type of multi-unit floating ziprasidone HCL Monohydrate microspheres was prepared by the ionotropic gelation method with NaHCO3 as gas-forming agents being used as gas-forming agent and Eudragit L-100 and Eudragit S-100 as polymer. The solution was dropped to 1% CaCl2 solution containing 10% acetic acid for CO2 gas and gel formation. The effects of gas-forming agents on bead size and floating properties were investigated. As gas-forming agents increased, the size and floating properties increased. Bead porosity and volume average pore size, as well as the surface and cross-sectional morphology of the beads were examined with Scanning Electron Microscopy. The micromeritic properties of microspheres were found to be much improved. In-vitro drug release studies were performed and drug release kinetics were evaluated using the linear regression method.