Objective: To study the in vitro percutaneous absorption and in vitro release state of the main effective element colchicine in Fengling gelatin. Method: The Franz diffusion cells were chosen with excised SD rat skin and dialyzer as the in vitro permeability barrier; the content of colchicine was determined by HPLC

the cumulative permeation amount per unit area and release amount of colchicine were calculated

and the percutaneous absorption velocity and release velocity were compared. Result: The in vitro release and penetration process of colchicine in Fengling gelatin conformed to Higuchi kinetic equation process within 8h; the release amount of colchicine in Fengling gelatin was higher than cumulative permeation amount

and the release velocity was higher than percutaneous absorption velocity. Conclusion: Skin was the main percutaneous absorption barrier of colchicine in Fengling gelatin. The active constituent could be released steadily

which showed that Fengling gelatin was a prolonged action lente liberantes praeparatum.