A simple, fast, accurate and precise method has been developed for the simultaneous determination of Telmisartan and Clorthalidone from pharmaceutical formulation by reversed-phase high performance liquid chromatography. The separation was carried out on C18 column using mobile phase consisting of a mixture of acetonitrile: methanol and pH adjusted to 3.4 with orthophosphoric acid in the ratio (80:20 v/v). The flow rate was maintained at 1 ml/min. The UV detection was carried out at a wavelength of 225 nm. The retention time for Telmisartan and Clorthalidone was found to be 3.1 min and 4.6 min respectively. Linear response obtained for Telmisartan was in the concentration range 10-60 μg/ml (r2 = 0.999) and Clorthalidone in the range 10-50 μg/ml (r2 = 0.999). The relative standard deviation in the tablets was found less than 2% for six replicates. The method was validated according to the ICH guidelines with respect to linearity, precision, accuracy, ruggedness and robustness. Thus, proposed method can be successfully applicable to the pharmaceutical preparation containing the above mentioned drugs without any interference of excipients.
