Formulation, stability test and in vitro penetration study of transethosomal gel containing green tea (Camellia sinensis L. Kuntze) leaves extract

Objective: The aim of this study was to increase penetration of epigallocatechin gallate (EGCG) from the extract using transethosomal gel. Methods: Transethosomes (TE) formulae were made using thin layer hydration method with different concentration of green tea extract which was equivalent to 1% (F1), 1.5% (F2), and 2% (F3) of EGCG. F1 was the chosen formula to be incorporated into a gel as a transethosomal gel (TEG). A gel containing green tea extract was also made as a control called as non-transethosomal gel (NTEG). A stability test and in vitro penetration study of gels using Franz diffusion cell were performed. Results: F1 was the chosen formula because it had a spherical shape, a particle size of 112.14±2.19 nm, PDI of 0.166±0.03, a zeta potential of- 52.05±1.34 mV, and %EE of 58.06±0.08%. Stability test results showed that TEG more stable than NTEG. The amount of EGCG penetrated from TEG and NTEG were 1391.16±34.89 μg/cm² and 485.29±14.49 μg/cm², respectively (p<0.05). The lag time for TEG was around 0.99±0.2 h, while NTEG was 8.69±0.2 h (p<0.05). Conclusion: It can be concluded that transethosomes can improve gel stability and increase the amount of EGCG penetrated through the skin.