METHOD DEVELOPMENT AND VALIDATION FOR IMPURITY PROFILING OF BOSENTAN MONOHYDRATE USING A NOVEL RP- HPLC METHOD

A novel liquid chromatographic method has been developed and validated for the determination of Bosentan monohydrate (BOS), together with its four related substances (Styrene, Hydroxy, Bosentan stage-3 and Dimer) in a laboratory mixture as well as in marketed formulation. Efficient chromatographic separation was achieved on an Inertsil ODS-3V (450mm×4.6mm i.d., 5.0 µm particles), containing Mobile phase A – Buffer : Acetonitrile (50:50) and Mobile phase B – Buffer : Acetonitrile (20:80). Mobile phases were used in gradient combination for about 45 min at a flow rate 1.0ml/min and the eluant was monitored at 225nm. Regression analysis gave the correlation coefficient value greater than 0.999 for BOS and its four known impurities. The linearity of the method was determined over the concentration range of LOQ-150% of target concentration. The method has shown good and consistent recoveries for BOS (93.7998.67%) and also for its four known impurities (97.2–101.3%). The proposed analytical method has been validated in accordance with ICH guidelines.