DESIGN AND EVALUATION OF PROLONGED RELEASE GLICLAZIDE MATRIX TABLETS by FATHELRAHMAN ABDELRAZIQ ABDELKAREEM ADAM

The prolonged release gliclazide matrix tablets were prepared using polymeric materials, namely, HPMC, Kollidon SR, Carbopol with Xanthan gum, Eudragit RSPO and Eudragit RLPO. HPMC, Kollidon SR and Carbopol with Xanthan gum were able to retard gliclazide release from matrix tablets in a concentration dependent manner, but the rate of retardation differed among the polymers. On the other hand, drug release from matrix tablets containing Eudragit RSPO and Eudragit RLPO, was independent of the amount of polymer used, and no consistent drug release pattern was observed. Among the various types of polymers and concentrations studied, the dissolution profile of matrix tablets containing 6% HPMC (formulation H2) was found to be similar to that of Diamicron MR tablets as indicated by the values of similarity factor and difference factor. In addition, the drug release of formulation H2, was not affected by changes in pH but affected drastically by changes in the stirring rate. Prior to the in vivo study, a simple, sensitive, and specific isocratic HPLCUV method for the determination of gliclazide concentration in rabbit plasma was developed and validated. A liquid-liquid extraction method was used in the sample treatment. The assay method was used in the pharmacokinetic study of gliclazide, comparing formulation H2 and Diamicron MR as a reference product. Four rabbits were used in the in vivo evaluation. There was no statistically significant difference between formulation F2 and Diamicron MR in the values of Tmax, Cmax and AUC. In conclusion, the rate and extent of