Analysis of active ingredients and preservatives in creams by capillary electrochromatography (CEC)

Capillary electrochromatography (CEC) is an analytical method of growing interest to the pharmaceutical industry. Because CEC is a combination of high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) it has the advantages of the high selectivity of HPLC and the high efficiency of CE. The capillaries can be packed with different packing materials. The mixed-mode phase consisting of a strong cation exchanger and alkyl chains on the silica surface has some advantages over conventional reversed-phase (RP) packing materials. In this article the authors describe the use of CEC to separate the active ingredients and preservatives in creams from different manufacturers. On the basis of the high efficiency of CEC it was possible to develop one isocratic method for all the compounds in the different samples. The method was validated with regard to identification, reproducibility, linearity, limit of detection, and quantitation.