Preparation and in vitro transdermal diffusion characteristics of Centella asiatica total glucosides liposome / 中草药

ABSTRACT

Objective To optimize the preparation technology for Centella asiatica total glucosides (CTG) liposome and to investigate its percutaneous permeability in vitro. Methods Liposomes were prepared by reverse-phase evaporation technique. Taking the entrapment efficiency of madecassoside and asiaticoside as indexes, the preparation of liposome was optimized by using single factor and Box-Behnken response surface method. The properties of liposomes including morphology, entrapment efficiency, mean diameter, Zeta potential, and accumulative release were studied. Results The optimal formulation was lecithin-cholesterol (41), lecithin-CTG (23.221), and organic- aqueous (71). The liposome was smooth and spherieal in appearance, mean diameter, and Zeta potential were 201.7 nm and -15.7 mV, respectively. The entrapment efficiency of madecassoside and asiaticoside were 75.85% and 84.94%. The in vitro 12 h accumulative release was 52.10% and 45.97%. The equations for the permeation rate of madecassoside and asiaticoside in liposomes were Q = 67.93 t1/2-50.34, R2 = 0.988, Q = 139.74 t1/2-241.2, R2 = 0.987, respectively. The retention amount in the skin was 76 μg/cm2 and 48.7 μg/cm2, which were 1.56 and 1.18 times higher than those of solution. Conclusion The optimized process is rational, feasible, and good stability. The CTG liposome prepared in this study have the smaller size, the higher encapsulation efficiency, higher retain in skin and obvious sustained-release effects.