Degradation Pathway for Rilpinavir Hydrochloride by Validated Stability Indicating UP-LC Method

Abstract

Degradation pathway for Rilpivirine Hydrochoride is established as per ICH recommendations by validated and stability indicating reverse phase liquid chromatographic method. Rilpivirine Hydrochoride is subjected to stress conditions of acid, base, oxidation, thermal and photolysis. Significant degradation is observed in acid and base stress conditions. Six impurities are studied and the major degradant (RRT about 0.52) is identified by LC-MS and spectral analysis. The stress samples are assayed against a qualified reference standard and the mass balance is found close to 99.5 %. Efficient chromatographic separation is achieved on a Shimpack XR –ODS-II stationary phase with simple mobile phase combination delivered in gradient mode and quantification is carried at 295 nm at a flow rate of 1.0 mL min-1.In the developed LC method the resolution between Rilpivirine Hydrochoride and six potential impurities (imp-1, imp-2, imp-3, imp-4, imp-5 and imp-6) is found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) of greater than 0.995 for Rilpivirine Hydrochoride and six potential impurities. This method is capable to detect the impurities of Rilpivirine Hydrochoride at a level of 0.006 % with respect to test concentration of 1.0 mg mL-1 for a 4-µL injection volume. The developed LC method is validated with respect to specificity, linearity & range, accuracy, precision and robustness for impurities and degradant determination.