Formulation and Evaluation of Bilayer Tablet of Metformin Hydrochloride and Sitagliptin Phosphate Using Tamarind Seed Mucilage

The main aim of present study is to formulate and evaluated bilayer tablet of Metformin Hydrochloride and Sitagliptin Phosphate as fixed dose combination tablets for effective treatment of type II diabetes mellitus. Here an attempt was made to reduce the dose, dosage frequency and reduce side effect of Metformin Hydrochloride and to provide synergistic action of drugs. Preformulation studies including drug excipient compatibility were conducted for both drugs. Different formulation of sustained release, Metformin Hydrochloride was prepared by using natural hydrophilic polymer e.g. Tamarind seed mucilage and were evaluated. Sitagliptin Phosphate immediate release formulations were prepared using synthetic superdisintegrants microcrystalline cellulose and were evaluated. Based on the in-vitro dissolution data MF3 & SG8 were selected as the best formulations from Metformin Hydrochloride and Sitagliptin Phosphate respectively. Bilayer tablet were prepared by slightly compressing Metformin Hydrochloride (MF3) and then final compression was made by placing Sitagliptin Phosphate (SG8) layer on it with final hardness 5.0 and they were evaluated. From the bilayer tablet % cumulative drug release of Sitagliptin Phosphate release 98.6 % in 30 minutes and second layer Metformin Hydrochloride release 97.9 % in 12 hrs. From the study, it was found that, Tamarind seed mucilage has good polymeric activity which was able to sustain the release for 12 hours.