Simultaneous determination of econazole nitrate, main impurities and preservatives in cream formulation by high performance liquid chromatography

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for determination of econazole nitrate, preservatives (methylparaben and propylparaben) and its main impurities (4-chlorobenzyl alcohol and alpha-(2,4-dichlorophenyl)-1H-imidazole-1-ethanol) in cream formulations, has been developed and validated. Separation was achieved on a column Bondclone^® C18 (300 mm × 3.9 mm i.d., 10 μm) using a gradient method with mobile phase composed of methanol and water. The flow rate was 1.4 mL min⁻¹, temperature of the column was 25 °C and the detection was made at 220 nm. Miconazole nitrate was used as an internal standard. The total run time was less than 15 min. The analytical curves presented coefficient of correlation upper to 0.99 and detection and quantitation limits were calculated for all molecules. Excellent accuracy and precision were obtained for econazole nitrate. Recoveries varied from 97.9 to 102.3% and intra- and inter-day precisions, calculated as relative standard deviation (R.S.D.), were lower than 2.2%. Specificity, robustness and assay for econazole nitrate were also determined. The method allowed the quantitative determination of econazole nitrate, its impurities and preservatives and could be applied as a stability-indicating method for econazole nitrate in cream formulations.