Transdermal Kinetics And Whitening Mechanism Of α-Arbutin

This research study mainly includes two parts:Study on the transdermal kinetics of a-arbutin; Study on the whitening mechanism of a-arbutin. Studying on the transdermal kinetics of a-arbutin, has guiding significance for its using in a drug and cosmetic as whitening factor. Studying on the whitening mechanism of a-arbutin provides a theoretical basis for its application in fields of cosmetics and medicine.1. Using YB-P6 intelligent transdermal diffusion device, improved Franz method, a-arbutin transdermal kinetic experiments were performed in vitro. The study results show that:a-arbutin itself has poor permeability, and permeation rate of 8 mg-L"1 a-arbutin solution is only 0.00993 mg·cm-2·h-1; AES, SDS, Tween 80 and glycerol all have promotion effect on permeability of a-arbutin, enhancement ratio of AES reached 3.18 times,6% glycerol reached 5.39 times.2-D,3-D transdermal enhancers all have better promotion effect on the permeability of a-arbutin than that of each of them. The enhancement ratio of 2% propanediol reached 6.18 times; the enhancement ratio of 5% oleic acid, reached 2.98 times; the enhancement ratio of 4% azone reached 8.78 times; the enhancement ratio of 2% propanediol reached 6.18 times; the enhancement ratio of 4% DMSO reached 5.85 times; the enhancement ratio of 4% azone+ 2% propanediol reached 10.57 times; the enhancement ratio of 4% glycerin+ 2% propanediol reached 8.62 times; the enhancement ratio of 2% azone+2% propanediol+4% glycerin reached 11.97 times.2. Study of whitening mechanism of a-arbutin shows that:For monophenolase:a-arbutin can not only inhibit the monophenolase activity, but also can prolong the lag time of reaction of monophenolase. Mechanism:the reason is proposed that a-arbutin acts as three phenolic substrates, makes part of oxidized enzyme inactivation, which accounts for a decrease of the oxidized enzyme concentration.For diphenolase:when the concentration of a-arbutin is in a certain range, with increasing of the concentration of a-arbutin, it has gradually stronger activation on the enzyme, but when concentration of a-arbutin reached 1.75 mmol·L-1, the activation rate remained invariant. Mechanism:the reason is proposed that when the diphenolase reaction system containing a-arbutin, it will interact with the residue around the active center of enzyme, leading to a change of enzyme conformation, such leads to the more effective interaction between the substrate and the active site of the enzyme.