ABSTRACT
Objective: To prepare and optimize the prescription of betulinic acid (BA) ethosomes modified by sodium deoxycholate (SDC) and then to investigate its transdermal penetration as carrier of BA. Methods: The BA ethosomes modified by SDC were prepared by the ethanol injection method. The encapsulation efficiency (EE) was considered as the evaluation index to optimize the prescription of the ethosomes by orthogonal design, and the shape and particle size of the optimized ethosomes were analyzed. The in vitro transdermal absorption of BA was evaluated using Franz diffusion cells. The accumulated permeation amounts and permeation rate of liposomes, ethosomes, and BA ethosomes modified by SDC were compared. Results: The best formulation consisted of soybean lecithin-SDC-BC (18:1:1) and 35% ethanol. The average EE and the particle size were (93.8 ± 1.6)% and (102.3 ± 3.6) nm, respectively. The accumulated permeation amount of BA ethosomes modified by SDC in 12 h was (99.62 ± 9.44) μg/cm2, which was 1.67, 3.85, and 8.33 times of ethosomes, liposomes, and satuated solution containing 10% isopropanol, respectively. Conclusion: The BA ethosomes, modified by SDC with high EE, obviously enhance the percutaneous absorption of BA and might be one of the most perspective percutaneous preparations.