Intercalation assembly of kojic acid into Zn-Ti layered double hydroxide with antibacterial and whitening performances

A melanin synthesis inhibitor and bacteriostatic agent, kojic acid (KA) has been intercalated into Zn-Ti layered double hydroxide (LDH) by an anion-exchange reaction. The structure and the thermal stability of the samples were characterized by XRD, FT-IR, TG-DTA and SEM. The study of KA release from ZnTi-KA-LDH in phosphate buffered solution (pH 5) implies that ZnTi-KA-LDH is a better controlled release system than pure KA. Meanwhile, the mechanisms of slow release were assessed by using four commonly kinetic models. The antimicrobial activity of ZnTi-KA-LDH was tested against three kinds of bacteria. The inhibition of L-dopa oxidation was tested to verify its skin whitening effect. The studies suggest that the kojic acid intercalated LDHs has the potential application as a safely functional composite in cosmetic. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.