Formulation and Evaluation of Floating Pellets of Omeprazole by Extrusion Spheronization Method

Abstract

Objective: The aim of the present study was design, develop and to evaluate a model of floating sustained release pellets formulations for Omeprazole by extrusion and spheronization technique.
 Methods: Omeprazole at different drug to polymer ratios were prepared by extrusion and spheronization technique and the release rate of the drug from the pellets was studied. Further, the in-vitro release studies of pellets were carried out in 0.1N HCL for 12 hours. Prepared pellets were subjected to characterization by different techniques such as loose bulk density, tapped bulk density, compressibility index and angle of repose. To optimize the formulation on the basis of acceptable pellet properties friability, drug content, moisture content, and loss on drying and in-vitro drug release tests were done. In addition, the compatibility studies were performed by using FTIR and DSC.
 Results: These above studies indicated that the drug release can be modulated by varying the concentration of the polymer. The resulting formulation produced robust pellets with acceptable drug content and low friability. Further, 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 FTIR and DSC studies reveal that there is no interaction between the drug and the polymer/excipients mixture.
 Keywords: Floating, Ethyl cellulose, HPMC, Pellets, Omeprazole.