Smart delivery system for cosmetic ingredients using pH-sensitive polymer hydrogel particles

pH-Sensitive P(MAA-co-EGMA) hydrogel microparticles were prepared and their feasibility as smart delivery carriers for cosmetically active ingredients such as arbutin, adenosine, and niacinamide was evaluated. P(MAAco-EGMA) hydrogel microparticles were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-EGMA) microparticles at a pH of around 5. The loading efficiency of the cosmetic ingredients was affected by the electrostatic interaction between the hydrogel and the cosmetic ingredients. The P(MAAco-EGMA) hydrogel microparticles showed a pH-sensitive release behavior. Thus, at pH 4 almost none of the cosmetic ingredients except adenosine permeated through the skin, while at pH 6 relatively high skin permeability was obtained. These results indicate that the P(MAA-co-EGMA) hydrogel microparticles synthesized in this study have the potential to be used as a smart carrier for cosmetic ingredients triggered by an external pH change for cosmetic applications.