Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, China.
Int J Cosmet Sci. 2022 Apr;44(2):249-261. doi: 10.1111/ics.12771. Epub 2022 May 4.
In recent years, glycyrrhetinic acid (GA) has been popularly used in cosmetics because of its anti-inflammatory and anti-oxidant effects. However, due to the poor water solubility of GA and the barrier effect of human skin, the penetration of GA through the skin may be hindered. Liposomes are a common delivery system for functional compounds in cosmetics. Nonetheless, the stability and transdermal effect of traditional liposomes are limited. The aim of this work was to prepare a new liposome system that contained glycerol and ethanol to enhance the stability of the vesicles and promote the penetration of GA into the skin.
The glycethosomes were prepared by ethanol injection and sonication method. The effects of different concentrations of glycerol and ethanol on the particle size, polydispersity (PDI), entrapment efficiency (EE), stability and rheological properties of vesicles were evaluated. Lipophilic and hydrophilic fluorescent probes were used to investigate the microviscosity of vesicles. In vitro permeation tests were performed with pig skin in Franz cells and the concentration of GA in different skin layers was determined by high-performance liquid chromatography (HPLC). The ability of different vesicles to induce lipid extraction and fluidization was analysed by using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR).
When glycerol was 50% and ethanol was 25%, the obtained glycethosomes had the smallest particle size and the best stability with a mean particle size of 94.5 nm, PDI 0.216 and 99.8% EE. Fluorescence probe studies indicated that the microviscosity of glycethosomes was the largest when the concentration of glycerol and ethanol was 50% and 25%, which was consistent with the storage stability of glycethosomes. It was found that the glycethosomes had the best transdermal effect and the total skin permeation percentage of GA was 20.67%, while those of ethosomes, glycerosomes, liposomes and dispersion were 10.56%, 9.38%, 7.78% and 5.02%, respectively. And glycethosomes had effectively lipid extraction and fluidization effect on the skin stratum corneum.
Compared with other traditional liposomes, glycethosomes can significantly improve the stability of vesicles and the transdermal effect of GA. Glycethosomes is promising vesicles for the delivery of GA.
近年来，甘草次酸（GA）因其具有抗炎和抗氧化作用而在化妆品中广泛应用。然而，由于 GA 的水溶性差和人体皮肤的屏障作用，GA 通过皮肤的渗透可能会受到阻碍。脂质体是化妆品中功能性化合物的常用递送系统。然而，传统脂质体的稳定性和透皮效果有限。本工作旨在制备一种新的脂质体系统，其中包含甘油和乙醇，以增强囊泡的稳定性并促进 GA 进入皮肤。
采用乙醇注入和超声法制备甘醇脂质体。考察了不同浓度的甘油和乙醇对囊泡粒径、多分散性（PDI）、包封率（EE）、稳定性和流变学性质的影响。使用亲脂性和亲水性荧光探针研究囊泡的微观粘度。采用Franz 细胞进行猪皮体外渗透实验，高效液相色谱法（HPLC）测定不同皮肤层中 GA 的浓度。采用衰减全反射-傅里叶变换红外光谱（ATR-FTIR）分析不同囊泡诱导脂质提取和流态化的能力。
当甘油浓度为 50%，乙醇浓度为 25%时，所得甘醇脂质体的粒径最小，稳定性最好，平均粒径为 94.5nm，PDI 为 0.216，EE 为 99.8%。荧光探针研究表明，当甘油和乙醇浓度分别为 50%和 25%时，甘醇脂质体的微观粘度最大，与甘醇脂质体的储存稳定性一致。结果发现，甘醇脂质体具有最好的透皮效果，GA 的总皮肤渗透百分比为 20.67%，而醇质体、甘油体、脂质体和分散体分别为 10.56%、9.38%、7.78%和 5.02%。并且甘醇脂质体对皮肤角质层具有有效的脂质提取和流态化作用。
与其他传统脂质体相比，甘醇脂质体能显著提高 GA 囊泡的稳定性和透皮效果。甘醇脂质体有望成为 GA 的递送载体。
