Analysis of cefadroxil by micellar electrokinetic capillary chromatography: Development and validation

A method is developed and validated for analysis of the antibiotic cefadrox il using micellar electrokinetic capillary chromatography. It permits cefad roxil to be completely separated from ten of its known related substances w ithin 15 min (including the washing procedure). The separation is performed in an acetate buffer (50 mM, pH 5.25) containing sodium dodecyl sulfate (S DS; 110 mM). The fused-silica capillary was 44 cm long (36 cm effective len gth), 50 mu m ID; the voltage, 18 kV; temperature, 15 OC; and the detection wavelength; 254 nm. The influence of the type of buffer, buffer pH and con centration, and of the SDS-concentration was investigated. The robustness o f the method was examined by means of a full-fraction factorial. design. Th e parameters for validation such as linearity, precision, limit of detectio n and limit of quantitation are also reported.