Fully validated ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of fimasartan in human plasma

Fimasartan is a novel angiotensin II receptor blocker with strong anti-hypertensive activity. In this study, a more rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine fimasartan in human plasma was developed and fully validated. The quantification of analytes was conducted by MS/MS in a multiple reaction monitoring mode at m/z 502.2 → 207.1 for fimasartan and m/z 526.3 → 207.1 for the internal standard (IS, BR-A-563). The method showed a linear response from 3 to 1000 ng/mL (r > 0.9950). The intra- and interday accuracy values were 86.9 - 98.2 and 93.3 - 100.1%, respectively. The intra- and inter-day precision values were 2.0 - 3.1 and 0.8 - 8.0%, respectively. This UPLC-MS/MS method was validated for specificity, linearity, precision, accuracy, recovery, system suitability, and stability, and was found to be acceptable for bioanalytical applications. Finally, this fully validated method was successfully applied to a pharmacokinetic study of fimasartan in healthy volunteers following oral administration.