Determination of micelle/water partition coefficients of cosmetic preservatives: Optimisation of the capillary electrophoretic method Original Research Article

The hydrophobicity of a group of molecules used as preservatives for aqueous cosmetics, containing surfactants in the form of micelles, was evaluated by means of micellar electrokinetic capillary chromatography (MECC). Five different preservatives mixtures were examined, with a composition analogous to that employed in the preservation of cosmetic formulations. Sodium dodecyl sulphate and sodium dodecyl(polyoxyethylene)1–4 sulphate were used as model surfactant and surfactant present in real cosmetic samples, respectively. The appropriate choice of the micellar velocity marker turned out to be a crucial point for the application of the MECC approach.