Development and Quality Assessment of Sustained Release Tablets Containing Metformin Using Hydrophilic Polymers

The aim of the current research is to prepare and test sustained-release (SR) tablets of Metformin hydrochloride using hydrophilic polymers such as Hydroxypropyl Methylcellulose (HPMC), Xanthan gum and Eudragit RSPO so as to attain sustained glycemic control in diabetic animal models. The wet granulation method is used to prepare tablets and the physicochemical properties such as weight variation, hardness, friability, thickness and uniformity of drug content are determined and all are found to be within acceptable limits. In vitro drug release showed a release of Metformin is controlled over 12 hours with release kinetics consistent with the Korsmeyer-Peppas model, reflecting diffusion and erosion. Sustained drug absorption is observed in streptozotocin-induced diabetic Wistar rats in which in vivo pharmacokinetic analysis of the SR formulations demonstrated a long Tmax and half-life (t1/2) and higher area under the plasma concentration-time curve (AUC) than immediate-release Metformin. One-way ANOVA and Tukey post-hoc statistical analysis showed that there are significant differences between formulations (p