Preparation of colchicine ethosomes containing TPGS and in vitro transdermal permeation / 中草药

ABSTRACT

Objective: To prepare and optimize the prescription of colchicine ethosomes containing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and to investigate its feasibility as a carrier for transdermal drug delivery. Methods: The colchicine ethosomes containing TPGS were prepared by the injection-sonication method. And the encapsulation efficiency (EE) was determined by minicolumn centrifugation method. The prescription of ethosomes was optimized by uniform design with EE as the evaluation index, and the physicochemical properties of the optimized ethosomes were investigated. Characterization of the vesicles was based on particle size, Zeta potential, entrapment efficiency, and transmission electron microscopy (TEM). The transdermal permeation characteristics of ethosomes, colchicine 30% ethanol solution, and colchicine ethosomes containing TPGS were compared by using Franz diffusion cells. Results: The optimized formulation was as follows: The contents of soybean phospholipid and TPGS were 350 and 50 mg, respectively. In addition, the concentration of ethanol was 36.44%. The average EE, particle size, polydispersity index, and Zeta potential were (74.71 ± 2.18)%, (89.6 ± 3.5) nm, 0.201 ± 0.008, and (-34.6 ± 2.7) mV, respectively. The in vitro experiment showed that the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes were (64.49 ± 5.61) μg/cm2, (2.84 ± 0.23) μg/(cm2∙h), (128.22 ± 11.64) μg/cm2, and the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes containing TPGS were (91.36 ± 7.11) μg/cm2, (4.73 ± 0.38) μg/(cm2∙h), and (182.84 ± 14.37) μg/cm2, respectively, which was significantly higher than those in ethosomes. Conclusion: The colchicine ethosomes containing TPGS show high EE and obviously enhance the percutaneous absorption of colchicine, which might be a potential carrier for transdermal drug delivery.