A stability indicating RP-UPLC method for simultaneous estimation of Sildenafil citrate, Bosentan and their impurities in bulk drugs and pharmaceutical dosage forms.

This study is aimed at Developing and validating an UPLC method for Sildenafil citrate, Bosentan and its related substances that might coexist in bulk drugs and its tablet formulations as impurities that may originate from synthesis process or degradation. A chromatographic system consisting Waters Acquity UPLC HSS PFP, 2.1x 50mm (2.5 µm) column, mobile phase of 0.02M KH2PO4with pH 2.0 as Buffer phase and Acetonitrile: Methanol in 1:1 ratio as organic phase, with gradient elution at flow of 0.4 mL/min and UV detector set at 220 nm has shown a good chromatographic separation for sildenafil citrate, Bosentan and its related substances. The developed method was validated as per ICH Guidelines. The developed UPLC method has run time of only 20 minutes making the method productive and may be applied for Quality control Testing.