A novel, rapid and sensitive UPLC-MS/MS method for the determination of macitentan in patients with pulmonary arterial hypertension.

Macitentan is an endothelin receptor antagonist commonly used in the treatment of pulmonary arterial hypertension (PAH). A novel, rapid, simple and sensitive UPLC-MS/MS method was developed and validated for pharmacokinetic study and the determination of macitentan in PAH patients. Macitentan and bosentan which is used as internal standard were detected using APCI in positive ion and MRM mode by monitoring the mass transitions m/z 589.1→203.3 and 552.6→311.5, respectively. Chromatographic separation was performed on reverse phase C18 column (5 μm, 4.6 *150 mm) with a isocratic mobile phase, which consisted of water containing 0.2% acetic acid:acetonitrile (90:10, v/v) at a flow rate of 1 mL/min. Retention times were 1.97 and 1.72 min. for macitentan and IS, respectively. The calibration curve with high correlation coefficient (0.9996) was linear range 1-500 ng/mL. The LLOQ and average recovery values were determined as 1 ng/mL and 89.8%, respectively. This method is the first UPLC-MS/MS method developed and validated for the determination of macitentan from human plasma. The developed analytical method was fully validated for linearity, selectivity, specificity, accuracy, precision, sensitivity, stability, matrix effect and recovery according to FDA guidelines. The developed method applied successfully for pharmacokinetic study and the determination of macitentan in PAH patients.