Effect of P(MAA-co-PEGMA) Hydrogel Compositions and Loading pH on the Loading Efficiency of Cosmetic Active Agents

Abstract

In order to develop an intelligent delivery system for cosmetic active agents (e.g.. arbutin, ascorbic acid, and adenosine), pH-responsive P(MAA-co-PEGMA) hydrogel particles having an average size of approx. 2 mu m and spherical shape were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-PEGMA) hydrogels at a pH 5. which is the pK(a), of the hydrogel. To determine the factors that have an effect on the loading of cosmetic active agents into the hydrogel, the loading efficiency of the active agents was investigated at various MAA and EG compositions of the hydrogel and the loading pH conditions. When the MAA contents in the hydrogel decreased. the loading efficiency of the active agents increased. In loading experiments with different pH conditions, the active agents showed higher loading efficiency into the hydrogel at the pH where the hydrogel was at the swollen state than at the pH where the electrostatic repulsion was minimized.