Estimation of Bosentan Monohydrate in Tablet Dosage Forms by a New RP-HPLC Method

A Simple, Sensitive, and rapid reverse phase high performance liquid chromatographic method has been developed for the determination of Bosentan monohydrate in bulk and tablet Dosage Forms. Chromatographic separation was achieved on a Zorbax SB-Phenyl (150×4.6 mm), 3.5 µm make: Aglient column with a 30:70 mixture of 0.02M sodium dihydrogen phosphate and HPLC grade Methanol as mobile phase, detection was at 225 nm, oven temperature is 30°C, injection volume is 20µL, flow rate is 1.5 mL/min and the expected retention of Bosentan monohydrate peak is about 5.2 minutes. Response was a linear function of concentration in the range 2-0.01 µg/mL for Bosentan monohydrate; correlation coefficiencent was 0.9999, respectively.LOD and LOQ for Bosentan monohydrate were found 0.01 µg/mL and 0.03 µg/mL based on signal to noise ratio(S/N). Accuracy (recoveries 90-98%) and reproducibility were found to satisfactory. Key words: Bosentan monohydrate, S/N ratio, RP-HPLC method and validation.