Developement and Validation of a Stability Indicating RP-HPLC Method for Determination of Macitentan in Bulk Drug

Abstract

RP-HPLC method for determination of Macitentan was developed and process-related impurities were separated and identified. Chromatographic separation was achieved within 75 minutes on Purosphere star RP-8 column (250 x 4.6 mm, 5μm) using mobile phase A- 0.01 M Phosphate buffer, pH 4.5 adjusted with dilute OPA and Acetonitrile (80:20, v/v) and mobile phase B- 0.01 M Phosphate buffer , pH 4.5 adjusted with dilute OPA and Acetonitrile (30:70, v/v) in gradient elution. Flow-rate of mobile phase was set at 1.0 ml/min and column oven temperature was maintained at 30 ºC. Eluted compounds were monitored at 214 nm using PDA detector. Macitentan was subjected to acid-base hydrolytic, oxidative, photolytic and thermal stress conditions and the degraded samples were analyzed using developed method. It was validated as per ICH guidelines. Retention time of KSM-03, MCA-02, MCA-01 and MCA API were found to be 5.90, 13.38, 17.45 and 37.78 min respectively. The drug showed extensive degradation in acidic and basic conditions, slight degradation in oxidative and thermal and highly stable in photolytic conditions. Validation parameters proved the precision, accuracy, specificity and robustness of the method. RP-HPLC method was successfully developed with satisfactory separation of Macitentan and impurities. Degradation products of Macitentan were well resolved from the drug peak and its impurities, proving stability indicating power of the method. Validation parameters showed satisfactory results as per ICH guidelines. The proposed method can be successfully employed in routine analysis of Macitentan.