Development and validation of a simple method for simultaneous estimation of metformin hydrochloride and gliclazide in tablets by using reversed phase high performance liquid chromatography

The objective of this study was to develop a simple, efficient, precise and accurate reverse-phase HPLC method for the simultaneous determination of metformin in combination with gliclazide in newly formulated tablets. Chromatographic determination was performed on a reversed phase C18 column (2.6 mm × 250 mm; 5 μm particle size) using a mixture of buffer (1 ml of orthophosphoric acid with 1 ml triethylamine upto 1000 ml with HPLC grade water) and methanol at the ratio of 60:40 as mobile phase at a flow rate of 1ml/min. The UV detection was set at 230 nm. Under the developed conditions, good separation of the analytes was achieved. The calibration curves were linear with coefficient correlation between 0.998 to 1.0 for both drugs over a concentration range of 1 to 50 μg/ml for metformin hydrochloride and 0.16 to 8 μg/ml for gliclazide. The method was also validated in terms of precision (RSD = 0.06 to 3.22%) and accuracy (percent deviation = 0.049 to 2.602%). The proposed method was applied for the analysis of these analytes in newly formulated tablets and potencies were found to be 99.41±0.24% for metformin hydrochloride and 99.77±0.37% for gliclazide which were acceptable.