A Validated Stability Indicating Method for Simultaneous Estimation of Metformin Hcl and Acarbose in Bulk and its Combined Tablet Dosage form by RP-HPLC

The current work explains simple, accurate, rapid and precise isocratic reverse-phase high-performance liquid chromatographicstability indicating method for simultaneous determination of metformin HCl and acarbose in bulk and combined dosage form. The chromatographic separation was carried out on Zorbax C-18 analyticalcolumn (4.6×250 mm; 5 μm) with a mixture of methanol: 0.1% O-phosphoric acid 60:40(v/v) as mobile phase; at a flow rate of 1.2 ml/min. UV detection was performed at 239 nm. The retention times were 2.218 min and 2.972 min for metformin HCl and acarbose respectively. Calibration plots were linear over the concentration range of 400-1200 μg/ml for metformin HCl and 40-120 μg/ml for acarbose. The method was validated for accuracy, precision, 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. Degradation studies were performed by subjecting the sample to various stressed conditions of acid, alkali, peroxide, thermal and photolytic studies.