Related substances method development and validation of an LCMS/MS method for quantification of selexipag and its related impurities in rat plasma and its application to pharmacokinetic studies

The present application wish to seem at the event of validation of bio analytical method and pharmacokinetic study of selexipag and its related impurities in rat plasma using LC–MS/MS. The optimized method contains gradient elution of selexipag with a flow rate of 1 ml/min and X-Bridge phenyl column (150 × 4.6 mm, 3.5 µ). A buffer of 1 mL formic acid in l liter water and acetonitrile mixture is used as mobile phase. 30 min run time was used for separation of selexipag and its related impurities with Ambrisentan as internal standard and impurity-D as active metabolite. The linearity curves are linear in between the percentages of 10 to 200% of rat plasma and R 2 value of each analyte was observed as 0.999. This application denotes all the parameters like precision, accuracy, recovery and stability were got the results within the limit of USFDA guidelines. This method applies effectively for the investigation of pharmacokinetic studies using rat plasma.