Study on the preparation and properties of sunscreen O/W/Si multiple emulsion

O/W/Si多重防晒乳液的制备及性能研究

To solve the greasiness and irritation risks brought about by organic sun-screening agents in sunscreen emulsions,in this work,a sunscreen O/W/Si multiple emulsion was prepared by two-step emulsification method,in which the outer oil phase was silicone oil and the inner oil phase was solid lipid nanoparticles coated with organic sun-screening agent.Several influencing factors on the formation and stability of the emulsion were analyzed,including inorganic salts,the volume fraction of outer oil phase(silicone oil),and the dosage of W/O emulsifier.The in vitro sunscreen performance,water resistance and skin permeability of different types of sunscreen emulsions were further studied.The results showed that the sunscreen O/W/Si multiple emulsion containing 22.5%silicone oil,2.5%emulsifier and 0.2%NaCl had the best stability under the experimental conditions.The SPF value and water resistance of sunscreen O/W/Si multiple emulsion were slightly higher than those of sunscreen W/O emulsion,but significantly higher than those of sunscreen O/W emulsion.Compared with sunscreen W/O emulsion,the in vitro transdermal permeability of organic sun-screening agent in sunscreen O/W/Si multiple emulsion was reduced by approximately 60%,indicative of higher safety and good application prospect in sunscreen cosmetics.

为解决防晒乳液中有机防晒剂带来的油腻感和刺激性风险,文章使用包覆了有机防晒剂的固体脂质纳米粒,通过两步乳化法制备了外油相为硅油,内油相为有机防晒剂的O/W/Si多重防晒乳液;分析了外硅油相体积比、W/O乳化剂用量、无机盐对乳液形成及稳定性的影响,深入研究了不同类型防晒乳液的体外防晒性能、抗水性及防晒剂皮肤渗透性能的不同。结果显示,在实验条件下,含有22.5%的外硅油相、2.5%的乳化剂及0.2%的NaCl所制得的O/W/Si多重防晒乳液稳定性最佳;O/W/Si多重防晒乳液的SPF值和抗水性略高于W/O防晒乳液,但显著高于O/W防晒乳液;对比于W/O防晒乳液,O/W/Si多重防晒乳液中有机防晒剂的体外经皮渗透率降低了约60%,具备更高安全性,展现了在防晒化妆品中的良好应用前景。