Stabilization of L-ascorbic acid in cosmetic emulsions

The prevention of the oxidation of L-ascorbic acid in cosmetic emulsions was investigated. First, its stability was tested to determine the optimum ratio, and the effects of changes in the pH, color, and concentration of L-ascorbic acid in the emulsions were investigated. The kinetics of L-ascorbic acid in emulsions were studied through HPLC. The inclusion of glycerine in the dispersion was more effective in maintaining the initial L-ascorbic acid content than the inclusion of propylene glycol, butylene glycol or DI water. A zero-order reaction model best fitted the butylene glycol-in-oil emulsion, whereas a first-order model best fitted the water-in-oil emulsion. (c) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.