Lin Chih-Chien, Yang Chao-Hsun, Chang Nai-Fang, Wu Pey-Shiuan, Chen Yi-Shyan, Lee Shu-Mei, Chen Chiu-Wen
Department of Cosmetic Science, Providence University, 200 Chung-Chi Road, Shalu, Taichung 43301, Taiwan; E-Mails:
Int J Mol Sci. 2011;12(9):5946-54. doi: 10.3390/ijms12095946. Epub 2011 Sep 15.
The skin-whitening agent, deoxyArbutin, is a potent tyrosinase inhibitor that is safer than hydroquinone and arbutin. However, it is thermolabile in aqueous solutions, where it decomposes to hydroquinone. Pharmaceutical and cosmetic emulsions are normally oil-in-water (o/w) or water-in-oil (w/o) systems; however, emulsions can be formulated with no aqueous phase to produce an anhydrous emulsion system. An anhydrous emulsion system could offer a stable vehicle for compounds that are sensitive to hydrolysis or oxidation. Therefore, to enhance the stability of deoxyArbutin in formulations, we chose the polyol-in-silicone, anhydrous emulsion system as the basic formulation for investigation. The quantity of deoxyArbutin and the accumulation of hydroquinone in both hydrous and anhydrous emulsions at various temperatures were analyzed through an established high performance liquid chromatographic (HPLC) method. The results indicated that water increased the decomposition of deoxyArbutin in the formulations and that the polyol-in-silicone, oil-based, anhydrous emulsion system provided a relatively stable surrounding for the deoxyArbutin that delayed its degradation at 25 °C and 45 °C. Moreover, the composition of the inner hydrophilic phase, containing different amounts of glycerin and propylene glycol, affected the stability of deoxyArbutin. Thus, these results will be beneficial when using deoxyArbutin in cosmetics and medicines in the future.
皮肤美白剂脱氧熊果苷是一种有效的酪氨酸酶抑制剂，比氢醌和熊果苷更安全。然而，它在水溶液中热不稳定，会分解为氢醌。药物和化妆品乳液通常是水包油（o/w）或油包水（w/o）体系；不过，乳液也可以不含有水相来配制，从而产生无水乳液体系。无水乳液体系可以为对水解或氧化敏感的化合物提供稳定的载体。因此，为了提高脱氧熊果苷在制剂中的稳定性，我们选择了聚醇-硅氧烷无水乳液体系作为基础制剂进行研究。通过一种既定的高效液相色谱（HPLC）方法分析了不同温度下含水和无水乳液中脱氧熊果苷的含量以及氢醌的积累情况。结果表明，水会增加制剂中脱氧熊果苷的分解，而聚醇-硅氧烷油基无水乳液体系为脱氧熊果苷提供了相对稳定的环境，在25℃和45℃下延缓了其降解。此外，含有不同量甘油和丙二醇的内亲水相的组成会影响脱氧熊果苷的稳定性。因此这些结果对未来在化妆品和药品中使用脱氧熊果苷将是有益的。
