Formulation and Evaluation of Sustained release Ondansetron hydrochloride pellets by extrusion spheronization technique

The aim of the present study was designed and develops model sustained release pellets formulations for Ondansetron HCL. Ondansetron HCL is widely used in the management of vomiting sensation at the time of cancer chemotherapy. The bioavailability of Ondansetron HCL is high and protein binding was found to be 91-93 %. The half-life of Ondansetron hydrochloride is about 7 hours. But the short half-life of Ondansetron hydrochloride leads to poor compliance and adverse reactions; that is why Ondansetron hydrochloride in sustained release dosage form is needed to achieve better therapeutic effects and to improve patient compliance. Ondansetron hydrochloride at different drug to polymer ratios was prepared by extrusion and spheronization technique. The influence of the proportion of the polymer on the release rate of the drug from the pellets was studied. The in-vitro release studies of pellets were carried out in 0.1N HCL for 12 hours. The release data was fitted to various mathematical models such as, Higuchi, Korsmeyer-Peppas, First-order, and Zero-order to evaluate the kinetics and mechanism of the drug release. Kinetic modeling of in-vitro dissolution profiles revealed the release mechanism ranges from Quasi-Fickian transport to Anomalous (non-Fickian transport), which was only dependent on the type and amount of polymer used. The drug release of the optimized formulation (F5) follows Zero order kinetics and the mechanism was found to be diffusion controlled. The compatability studies were performed by using FTIR and DSC which reveals that there is no interaction between the drug and the polymer/excipients mixture.