Author(s): Sumalatha Nallagundla *, Nallagundla H S Reddy , Sandhya Resu
The aim of the study is to develop and validate a simple, accurate, precise and rapid isocratic reverse-phase high-performance liquid chromatographic method for simultaneous determination of Metformin and Sitagliptin in bulk and tablet formulations. Chromatographic separation was supported on Symmetry C18 column (4.6×150mm) 5µ column with a blend of methanol: phosphate buffer (70:30) as mobile phase at a flow rate of 1 ml/min. UV detection was performed at 271 nm using HPLC Waters Separation module 2695, with Empower software version-2. The retention times were found to be 1.694minutes and 3.334 minutes for Metformin and sitagliptin respectively. Calibration plots were linear for both the drugs (r2 =0.999) over the concentration range 50-250 μg/ml for Metformin 5-50 μg/ml for sitagliptin. The LOD and LOQ values for Metformin and Sitagliptin were found to be 2.17 µg/ml, 0.0372µg/ml and 6.60 µg/ml and 0.112 µg/ml respectively. The optimized method was validated in accordance with ICH guidelines(IC(R1)) for accuracy, precision, specificity, linearity, and sensitivity. The proposed method was successfully used for quantitative analysis of tablets. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that method is specific, rapid, reliable, and reproducible. As the method shows high recovery and low relative standard deviation which confirms the suitability of the method for routine determination of Metformin and Sitagliptin in bulk drug and tablet dosage forms.