LAUSR

The aim of the present study was to establish an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of orelabrutinib in rat plasma using futibatinib as internal standard (IS), and to apply it for a pharmacokinetic study in rats. Orelabrutinib was extracted from plasma by protein precipitation and quantitatively analyzed by UPLC-MS/MS. An Acquity UPLC BEH C18 column was used for rapid separation by gradient elution using 0.1% formic acid and acetonitrile as mobile phases. The validation results of bioanalytical methodology showed that the linearity of orelabrutinib in plasma samples was good within the concentration range of 1–2000 ng/ml. The lower limit of quantification (LLOQ) was 1 ng/ml. The precision of orelabrutinib ranged from 1.4% to 11.5%, with intra-day and inter-day accuracy ranging from −5.7% to 7.7% and −0.2% to 12.5%, respectively. The selectivity, stability, matrix effect and recovery of the method all met the requirements of quantitative analysis of biological samples. The method was simple, sensitive, accurate and specific, and had high recovery rate. It also could be successfully applied to the pharmacokinetic study of rats.