Development and validation of a method for studying Relugolix and its impurities by UPLC-MS

In accordance with the International Coordinating Committee's recommendations, an acceptable UPLC-MS method is being developed for analyzing Relugolix stability under various stress scenarios. Stress conditions included exposure to 0.1 and 1 N acid, alkali, hydrolysis, peroxide, light, reduction, and heat. The mobile phase for this analysis was prepared by blending acetonitrile and a 0.1% orthophosphate solution in a 50:50 (v/v) ratio. A C18 Column with dimensions of 100 3 2.1 mm and a particle size of 1.7 [micro]m was employed as the stationary phase. The wavelength at which detection was performed was 247 nm, and the flow rate was maintained stable at 0.5 mL [min.sup.-1]. Strong linearity was shown by this method across a concentration range of 1.25 [micro]g [mL.sup.-1] to 7.5 [micro]g [mL.sup.-1]. The method's reliability was shown by ensuring all of the validation parameters fell within the acceptable range. Furthermore, forced degradation studies were conducted using standard drugs. Different stress conditions led to the formation of degradation products, which were successfully separated from Relugolix using the C18 column in combination with an auto-purification mass spectrometer. Among the stress conditions, alkaline conditions showed a lower degradation rate. Interestingly, seven distinct types of degradation products were identified from the degradation studies under acid, alkali, hydrolysis, hydrogen peroxide, light, reduction, and thermal conditions. Remarkably, these seven degradation products have not been reported in previous literature, making this study the first to document their existence. KEYWORDS Relugolix, UPLC-MS method, acid, base, hydrolysis, hydrogen peroxide, light, reducing, thermal conditions, degradation products, stability-indicating, forced degradation, novel discovery