Fast and simple method for assay of ciclopirox olamine by micellar electrokinetic capillary chromatography

A rapid, simple and specific method has been developed and validated for the assay of ciclopirox olamine in pharmaceutical formulations using micellar electrokinetic capillary chromatography (MEKC). The key factors, including pH, buffer concentration and buffer additive, sodium dodecyl sulfate (SDS) concentration, applied voltage and injection time have been systematically investigated in a fused silica capillary (i.d. 50 microm, total length 45 cm and effective length 38 cm) with UV detection at 298 nm. Optimized conditions have been established on the basis of the experimental results. The buffer contains 200 mM borate, 20 mM SDS and 2 mg mL(-1) EDTA at pH 8.0 and the applied voltage is 20 kV with hydrodynamics sample injection (15 cm high for 5s). The method has been validated with respect to its specificity, linearity, limits of detection, and quantification, precision and accuracy. The total analysis time was less than 10 min with good peak shape for ciclopirox olamine, which eluted at 3.6 min. Degradation of the ciclopirox olamine was forced using different conditions. These were using hydrogen peroxide, acidic and basic conditions, heat and light. The degradation products so produced showed no interference with ciclopirox olamine. A linear standard curve was established over the concentration range 31.3-2.00 x 10(3) microg mL(-1) of ciclopirox olamine in running buffer with a correlation coefficient (r) of 0.9999. The limits of quantification and detection were 31.3 and 9.36 microg mL(-1), respectively. The proposed method has been successfully used for the quantitative determination of ciclopirox olamine in pharmaceutical suppository and cream formulations.