A validated assay for the quantitative analysis of tranexamic acid in human serum by liquid chromatography coupled with electrospray ionization mass spectrometry

BackgroundTranexamic acid is a synthetic lysine analog used for management of bleeding disorders. The objective of this study was first to develop a method for measurement of tranexamic acid in human serum using liquid chromatography coupled to ion-trap mass spectrometry (LC-MS/MS), and then to validate it throughout a wide range of concentrations allowing quantification in patients receiving tranexamic acid infusion during surgery.MethodsSerum samples (100 µL) were subjected to protein precipitation with perchloric acid, and after pH adjustment, tranexamic acid and internal standard were separated on a C18 column and isocratically eluted using a mobile phase constituted of formate buffer/acetonitrile (95:5, v/v). Tranexamic acid was ionized by electrospray in positive mode. Parent [M + H]+ ions were m/z 158.0 for tranexamic acid and m/z 144.0 for IS. The most intense product ion of tranexamic acid (m/z 122.7) and IS (m/z 126.0) were used for quantification.ResultsThe assay was accurate and precise over the range of 1.0 (lower limit of quantification) to 200.0 µg/mL (upper limit of quantification), and has been successfully applied to study the clinical pharmacokinetics in two volunteers undergoing cardiac surgery.ConclusionA reliable method for quantification of tranexamic acid for analysis in clinical studies was obtained.