Design And Evaluation Of Gel Matrix Sustained Release Tablet Of Gliclazide

Gliclazide (GL) is an oral antihyperglycaeraic agent widely used in the management of non-insulin-dependent diabetes raellitus (NIDDM or type-2 diabetes). It stimulates the secretion of insulin but doesn't increase the synthesis of insulin in the pancreas . It is effective for those patients who have the function of insulin secretion internally. To reduce the side effects and maintain relatively constant plasma concentration, a sustained released tablet of once daily administration was designed and prepared by using hydroxypropylmethylcellulose(HPMC) as basic matrix material.According to literature, UV spectrophotomatry was developed for in vitro assay during the studies of physicochemical properties, content and release. High-performance liquid chromatography was applied in the determination of plasma concentration in dogs. The extraction recovery of Gliclazide was 78. 77+6. 14%.In the preformulation researches the physicochemical properties of gliclazide were investigated, which benefit dosage form design. On the basis of pharmaceutical preformulation studies , single-factor tests were carried and base on tests about the influence of formulation and manufacture process on the release of gliclazide, optimal formulation modified to release drug over 12hr was obtained by orthogonal design test. Drug released mainly by erosion combined with diffusion from HPMC matrix in the first stage and mainly bytablet erosion during the later period. Stability studies of preparation demonstrated that light, temperature and moisture had little effect on gliclazide sustained release tablet(SRT). The studies of pharmacokinetics of gliclazide SRT in dogs verified that desired formulation was achieved. The plasma concentration maintained for about 24hr. It's Relative bioavailability was 112.81%, The result of statistics analysis showed that gliclazide SRT was bioequivalent with reference preparation. The release of SRT in vitro was correlative with absorption fraction in vivo.