A simple and sensitive ultra‐high performance liquid chromatography tandem mass spectrometry method for the quantitative analysis of VX‐548 in monkey plasma: Method validation and application to pharmacokinetic study

column with 0.1% aqueous formic acid and acetonitrile as mobile phase. The precursor-to-product ion transitions were m/z 474.2 > 165.0 and m/z 441.2 > 138.1 for VX-548 and internal standard, respectively. This developed method was successfully validated in the concentration range of 1-1000 ng/mL. The calibration curve showed excellent linearity with a correlation coefficient of >0.999. The precision expressed as relative standard deviation (RSD) was <8.4%, whereas the accuracy denoted as relative error (RE) ranged from -5.0% to 9.1%. The mean recovery was >84%. VX-548 was stable in monkey plasma after storage under certain conditions. The validated method was successfully applied to the pharmacokinetic study of VX-548 in monkey plasma after single oral (2 mg/kg) and intravenous (1 mg/kg) administrations.