Validated UPLC/Q-TOF-MS Method for Simultaneous Determination of Metformin, Glimepiride and Pioglitazone in Human Plasma and its Application to Pharmacokinetic Study

In the presented work the ultra-performance liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC/Q-TOF-MS) method has been developed for simultaneous determination of metformin, glimepiride and pioglitazone in human plasma. For identification of drugs, the Q-TOF mass spectrometer was operated in positive ionization mode and quantification was done using the MS/MS transitions at m/z 130.0 to 71.0 for metformin, 491.00 to 352.00 for glimepiride and 357.00 to 134.00 for pioglitazone. The chromatographic separation was achieved on Acquity UPLC^TM BEH C₁₈ (100.0 × 2.1 mm, 1.7μm) column using isocratic mobile phase consisting of acetonitrile-2mM ammonium acetate (50:50, v/v) at a flow rate of 0.20 mL/min. The elution of metformin, glimepiride and pioglitazone was occurred at 0.50, 1.40 and 1.22 min, respectively. The calibration curves were linear over the concentration range of 1–1000 ng/mL for all the drugs. The developed method was validated according to ICH guidelines. The method was applied for pharmacokinetic study of drugs in FDC tablets in human plasma.