Stability indicating LC-MS/MS method and validation of Selexipag impurities and identification of its force degradation products

Selexipag belongs to a class of medicines known as IP prostacyclin receptor agonists used to treat pulmonary arterial hypertension.A simple and sensitive LC-MS/MS method has been developed for the identification of process related impurities in Selexipag API. The method was developed using a Zorbax C18 15 × 0.46 cm, 5μ column with a gradient program at 35 0C and flow rate of 1.0 mL/min. Detection was carried out by MS/MS with an ESI detector. Stress conditions were established by exposing the drug to acidic, alkaline, oxidative, thermal and photolytic stress condition. Identified and unidentified impurity was found when the fractions of acid and alkaline degradation product was analyzed by LC-MS/MS. The suggested methodology can be used to test the quality of Selexipag and identify the process-related impurities in pharmaceutical products.