Determination and Pharmacokinetic Study of Azilsartan in Rat Plasma by UPLC-MS/MS

A simple, rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of azilsartan in rat plasma. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column and the total run time was 2.5 min while the elution of azilsartan was at 1.10 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 457.2 -> 279.2 for azilsartan and m/z 515.3 -> 305.3 for telmisartan (IS), respectively. The calibration curve was linear over the range of 0.1-2500 ng/mL with a lower limit of quantitation (LLOQ) of 0.1 ng/mL. Mean recovery of azilsartan in plasma was more than 91.3%. Intra-day and inter-day precision were both <5.76%. This method was successfully applied in pharmacokinetic study after oral administration of 1.5 mg/kg azilsartan in rats.