A Validated Liquid Chromatographic Method for the Determination of Rifampicin and Isoniazid in Pharmaceutical Formulations

A simple RP-HPLC method with more accuracy and precission was developed for determination of Rifampicin and Isoniazid simultaneously. A mobile phase consisted of methanol, acetonitrile and water in the ratio 60:20:20(v/v) was used, at a flow rate of 1 mL/min. The wavelength of detection was 254 nm and the column used was Kromasil C18, (250 x 4.6 nm, 5 µm). The retention time for rifampicin and isoniazid are 3.42 and 7.43 min respectively. A concentration range of 40-100 µg/mL was studied to test the linearity of the developed method. The correlation coefficient (r2) of regression was found to be 0.998 which is almost equal to 1. The LOQ was 1.75 µg/mL for both rifampicin and isoniazid and the LOD was 0.5 µg/mL for both rifampicin and isoniazid. The mean percentage recovery of rifampicin was 99.56% and 99.83% for isoniazid respectively.