Abstract
Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is a preeminent analytical tool for rapid biomedical analysis with the objective of reducing analysis time and maintaining good efficiency. In this study a simple, rapid, sensitive and specific ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of the angiotensin II receptor antagonist, irbesartan and hydrochlorthiazide in human plasma. After a simple protein precipitation using methanol and acetonitrile, irbesartan, hydrochlorthiazide and internal standard (IS) telmisartan were separated on Acquity UPLC BEH (TM) C18 column (50 x 2.1 mm, i.d. 1.7 mu m, Waters, USA) using a mobile phase consisting of acetonitrile:10 mM ammonium acetate:formic acid (85:15:0.1 % v/v/v) pumped at a flow rate of 0.3 mL/min and detected by tandem mass spectrometry with negative ion mode. The ion transitions recorded in multiple reaction monitoring mode were m/z 427.2 -> 193.08 for irbesartan, m/z 295.93 -> 268.90 for hydrochlorthiazide and m/z 513.2 -> 287.14 for IS. The assay exhibited a linear dynamic range of 30-500 ng/mL for irbesartan and 1-500 ng/mL in human plasma with good correlation coefficient of (0.996) and (0.997) and with a limit of quantitation of 30 and 1 ng/mL for irbesartan and hydrochlorthiazide, respectively. The intra- and inter-assay precisions were satisfactory; the relative standard deviations did not exceed 10.13 % for irbesartan and 11.14 % for hydrochlorthiazide. The proposed UPLC-MS/MS method is simple, rapid and highly sensitive, and hence it could be reliable for pharmacokinetic and toxicokinetic study in both animals and humans.