Isocratic High Performance Liquid Chromatographic (HPLC) Determination of Rifampicin in Presence of Isoniazid

Measurement of rifampicin in complex pharmaceutical formulation was accomplished by high-performance liquid chromatography (HPLC). A Shimadzu liquid chromatographic unit equipped with a C18 Grace Vydac analytical column (250 mm x 4.6 mm id., 5 μm particle size) was used. The drug was eluted using a mobile phase consisting of 0.05M Sodium dihydrogen phosphate solution (adjusted to pH 3.1) and Acetonitrile at a ratio of 20:80. The detection was done at wave length 254 nm with flow-rate set at 0.6 ml/min. Peaks were identified using ultra violet (UV) detector. Calibration curves showed good linearity when various concentrations were compared to peak areas (correlation coefficient higher than 0.999). The application of this validation design due to its simplicity, robustness, precision and accuracy offer good opportunity for quality control testing of anti-tuberculosis combination dosage form containing rifampicin.