Research Article Design and In-Vitro Evaluation of Metformin Hydrochloride (SR) and Glimepiride (IR) As Bilayered Tablets

The present research work was an attempt to design bilayered tablets to improve the oral therapeutic efficacy which contains two anti diabetic drugs. Bilayered tablets have been developed consisting of Metformin hydrochloride as extended release layer, glimepiride as immediate release layer. Total of 12 formulations were developed in which metformin hydrochloride 1-5 formulations and 6-12 for glimepiride formulations. From which formulation 5 containing HPMCK100M of metformin hydrochloride and formulation 12 of glimepiride where optimized and compressed into bilayered tablets. Hydroxypropylmethylcellulose and Hydrogenated castor oil was used as drug release retarding agents in order to get the extended release profile of metformin hydrochloride over a period of 12 h. Glimepiride immediate release layer was formulation using different excipients. Stability of the drug release profiles at 1 month in 40◦C and 75%RH suggesting that HPMC K100M based sustained release formulation 5 was stable. In various invitro drug release kinetics studies Higuchi model was found to be the best fitted in all dissolution profile having higher correlation coefficient 0.995 followed by Peppas model and first order release, Slope of vergnaurd model obtained is 0.399. Indicates fickian diffusion and the rate of matrix erosion of metformin hydrochloride tablets were found to 0.062 /min from the tablets.