A simple and sensitive high performance liquid chromatographic method is developed for the estimation of bosentan in pharmaceutical dosage forms. Chromatographic separation of the drug was achieved with an Thermo Scientific C18 column (250 mm × 4.6 mm I.D., 5 μm particle size) analytical column using ammonium bicarbonate (pH was adjusted to 5.0 with phosphoric acid) and acetonitrile (70:30 v/v) as mobile phase. The instrumental settings are flow rate of 1.0 ml/min, column temperature at 25±1°C, detector wavelength of 220 nm and the run time was 5 min. The retention time of the drug was 1.986 min. The developed method shows linearity over a range of 5-100 μg/ml of bosentan with correlation coefficient of 0.9991. The relative standard deviation is less than 1.5%. The proposed method was found to be suitable and accurate for quantitative determination of bosentan in pharmaceutical dosage forms
