Abstract
Novel RP-HPLC method was developed for the simultaneous estimation of chlorthalidone and telmisartanin bulk drug and combined dosage form. The separation was achieved by Grace column (4.6 mm I.D × 250 mm) C18 column with mobile phase consist of acetonitrile and potassium phosphate buffer (pH 2.5) in the ratio 45:55 v/vat 0.7 mL/min flow rate.The detection was carried out at 235 nm. The retention time of chlorthalidone and telmisartanwas found to be 3.41 min and 6.05 min, respectively.Linear response obtained for chlorthalidonewere in the range 10-60 μg/ml (r2 = 0.999) and for telmisartanin 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 for linearity, precision, accuracy, ruggedness and robustness.