Formulation and Characterization of Bilayer Tablets of Gliclazide as Sustained Release and Sitagliptin as Immediate Release

Abstract

Sitagliptin Phosphate and Gliclazide are selected based on the literature survey. The drugs are useful in the management of Type-2 Diabetes Mellitus. The results of FTIR study and DSC study confirmed that there is no chemical interaction or no incompatibility between the drugs and excipients. The values of Angle of Repose, Bulk Density, Tapped Bulk Density, Carr s Index and Hausner s, ratio were found to be within the pharmacopoeial limit. The granules of all formulations (F1S-F6S) and (F1G-F6G) have excellent flow properties and were suitable for compression. The Immediate release tablets of Sitagliptin Phosphate were successfully prepared by wet granulation method using various proportions and combinations of superdisintegrants. Gliclazide is poorly water soluble drug. For increasing the solubility and dissolution behavior, Gliclazide was prepared as solid dispersion with B-Cyclodextrin (1:5) ratio. Gliclazide sustained release tablets were prepared by the wet granulation method with solid dispersion of Gliclazide B CD; (1:5) using different concentrations of rate controlling polymer HPMC K4 MCR and other tableting excipients. For all the formulations, the Postcompression evaluation results of Friability, Hardness, Drug content uniformity and Weight variation were within pharmacopoeial limit. Among all the IR tablets of Sitagliptin Phosphate, F6S was selected, because it showed quick disintegration and higher amount of drug released 100.64% within 30 minutes. In Gliclazide SR trial tablets, the in vitro results FSG showed that the highest % of drug release (maximum release 85% at 12 hrs) than other batches. Hence, F5G was selected for bilayer formulation. The bilayer tablet (FBS6G5) was developed with the selected formulation of Sitagliptin IR (F6S) and Gliclazide SR (F5G) tablets. The results of post compression evaluation of the optimized bilayer tablets were within the pharmacopoeial limit. newline