Development and validation of the liquid chromatographic method for simultaneous estimation of metformin, pioglitazone, and glimepiride in pharmaceutical dosage forms

INTRODUCTION A simple, precise, and accurate HPLC method for simultaneous estimation of metformin hydrochloride (MET), pioglitazone hydrochloride (PIO), and glimepiride (GLIMP) was developed and validated. MATERIALS AND METHODS Chromatographic separation of the drugs was performed by using a Phenomenex-ODS-3 (C-18) column (250 × 4.60 mm, 5 μm) with a mobile phase consisting of methanol:acetonitrile:15 mM potassium dihydrogen phosphate (pH 4) in the proportion of 40:35:25 (v/v) at a flow rate of 1 ml/min. Detection was carried out using a UV-SPD-10AVP detector at 240 nm. RESULTS The retention time for MET, PIO, and GLIMP were 2.85 ± 0.03 min, 4.52 ± 0.03 min, and 7.08 ± 0.02min, respectively. Parameters such as linearity (0.2-50 μg/ ml for MET, 0.2-30 μg/ml for PIO, and GLIMP, respectively), precision (intra-day % RSD was 1.01-3.24 and inter-day % RSD was 1.54-4.09 for MET; intra-day % RSD was 1.03-2.09 and inter-day % RSD was 2.26-3.10 for PIO; and intra-day% RSD was 1.00-3.15 and inter-day % RSD was 1.58-3.07 for GLIMP), accuracy (99.66 ± 0.14 for MET, 98.46 ± 0.40 for PIO, and 98.62 ± 0.39 for GLIMP), specificity and robustness were calculated in accordance with ICH guidelines. CONCLUSIONS The method was proved to be simple, rapid, precise, accurate, and cost effective.