Optimisation and validation of hplc method for simultaneous quantification of rifampicin, isoniazid, pyrazinamide, and ethambutol hydrochloride in anti-tuberculosis 4-FDC

5 ?m) at 30oC. The mobile phase used was a mixture of acetonitrile and 20 mM phosphate buffer solution (pH 6.8) containing triethylamine and delivered at 1.5 mL/minute using gradient elution. TheUV detector was set at 210 nm. The method was validated in terms of selectivity, linearity, accuracy, precision, detection limit, quantification limit, and robustness according to International Conference on Harmanization (ICH). The optimized method is succcesfully used for quantitative analysis of RIF, INH, PYR and ETM in 4-FDC tablets. The level of these drugs in 4-FDC tablets were in accordance to that specified in Indonesian pharmacopei