FORMULATION CHARACTERIZATION AND IN VITRO EVALUATION OF BUOYANT MICROBEADS OF SELECTED ANTIMIGRAINE AND ANTIEMETIC AGENTS
Soumya Stanly*, Dr. Mathan S.** and Dr. Shaiju S. Dharan***
The main objective of current work is to reduce dosing frequency and improve patient compliance by designing and systematically evaluating controlled release buoyant micro beads of rizatriptan benzoate and domperidone. The limitations of conventional dosage forms can be attenuated by designing it in the form of mucoadhesive buoyant microbeads which prolong the gastric residence time at the absorption site to facilitate intimate contact with the absorption surface and thereby improve and enhance the bioavailability. The six formulations F1, F2, F3, F4C, F5C and F6C of Rizatriptan benzoate and Domperidone loaded buoyant mucoadhesive microbeads were successfully fabricated by ionotropic gelation technique using sodium alginate as the hydrophilic carrier in combination with chitosan polymer as drug release and mucoadhesive modifier in varying concentrations respectively, by adding drops of drugs loaded sodium alginate dispersion into calcium chloride solution which aid as cross-linking agent at optimum conditions. The microbeads were then evaluated for drug content, size, drug release rate, drying rate, swelling ratio, encapsulation efficiency, buoyancy duration and mucoadhesive properties using appropriate methods. Particle size distribution of drug loaded formulations were measured by an optical microscope and surface morphology of optimized microbeads was determined by SEM analysis. No significant drug-polymer interactions were observed in FT-IR studies. The in vitro wash-off test indicated that the sodium alginate micro beads had good mucoadhesive strength. The buoyancy and drug release of optimized batch was retained for longer duration up to 12 h. In vitro drug release profile of microbeads was examined and the optimized batch exhibited zero order kinetic and well fitted to higuchi model. The study demonstrated that the formulation of controlled release buoyant mucoadhesive microbeads of rizatriptan benzoate and domperidone is a promising approach in reducing the frequency of dosing. Also ionotropic gelation technique offers a flexible and easily controllable process in a cost effective manner and had better drug release for long duration of time.
Keywords: Calcium carbonate, Calcium chloride, Chitosan, Controlled release, Domperidone, Ionotropic gelation technique, Sodium alginate, Sodium bicarbonate, Rizatriptan benzoate.
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