Determination of antitubercular drugs by micellar electrokinetic capillary chromatography (MEKC).

A method for the determination of isoniazid (ISO), pyrazinamide (PYR) and rifampicin (RIF) in pharmaceutical products, by micellar electrokinetic capillary chromatography (MEKC) with ultraviolet detection is described. The influence of pH, concentration of surfactants, buffer and organic solvents, over the separation were studied as experimental variables. The optimal separation was carried out at 30 degrees C and 20 kV, using a 40 mM borate buffer and 100 mM sodium dodecylsulphate (SDS) adjusted to pH 8.5. Under these conditions, the analysis is accomplished in about 8 min. The method was applied to the determination of these compounds in different pharmaceuticals with good results when compared with a reference liquid chromatographic (LC) method.