Novel transdermal ethosomal gel containing green tea (Camellia sinensis L. Kuntze) leaves extract: Formulation and in vitro penetration study

Background: One of the natural products that have many benefits is green tea (Camellia sinensis L.). It can be used to maintain health because of its high antioxidant activity from epigallocatechin gallate (EGCG). However, EGCG has a low ability to penetrate through the skin due to its hydrophilicity. The aim of this study is to improve the penetration of EGCG through the skin by lipid nanovesicle, namely ethosome. Methods: Ethosomes were made using thin layer hydration method. Ethosomes were formulated with different concentration, equal to 1% (F1), 1.5% (F2), and 2% (F3) of EGCG from green tea leaves extract. They were characterized, then a chosen formula would be formulated into a gel dosage form (ethosomal gel). A gel without ethosome (non-ethosomal gel) was prepared as a control. Both of them were evaluated their penetration enhancement ability using Franz diffusion cells with the abdomen skin of Sprague-Dawley rats. Results and Discussion: Based on the results, F1 had a spherical shape, Dv90 129.00 ± 0.00 nm, polydispersity index 0.05 ± 0.00, zeta potential at -62.6 ± 5.05 mV, and the highest entrapment efficiency of 54.39 ± 0.03 %. The cumulative amount of EGCG penetrated from ethosomal and non-ethosmal gel were 1364.28 ± 56.32 μg/cm2 and 490.17 ± 2.60 μg/cm2, respectively (p<0.05). The flux value of ethosomal and non-ethosomal gel were 56.97 ± 2.06 μg/cm2. hour and 31.09 ± 0.29 μg/cm2. hour, respectively. Conclusion: It can be concluded that ethosomal gel can increase the penetration of EGCG from green tea leaves extract.