Simultaneous estimation of pioglitazone, glimepiride & metformin hydrochloride in bulk & tablet dosage form by UV, RP-HPLC method

A stability-indicating UV spectroscopic and high-performance liquid chromatography (RP-HPLC) method is developed for the quantification ofPioglitazone, Glimepiride & Metformin Hydrochloride drug substances. UV spectroscopic method was developed and validated, the wavelength selected for simultaneous estimation were 226nm for pioglitazone, 229nm for glimepiride and 232nm for metformin hydrochloride. The isosbestic point found for the analysis was 229nm. Selected mobile phase was a combination of methanol and water with a ratio of 70% Methanol and 30 % HPLC water with the flow rate of 0.85ml/min. The analyte was analysed on the C18 HPLC column having the pore size of 5 microns at room temperature. The method is validated according to ICH guidelines, the retention time of about 4.0min for metformin, 5.5min for Pioglitazone and 6.8min for Glimepiride was observed. The linearity range with regression co-efficient for Pioglitazone, Glimepiride & Metformin Hydrochloride is 3-15 μg/mL,0.4-1.2 μg/mL and 100-500 μg/mL and 0.9998, 0.9991, 0.9991 respectively.