Abstract: AIM: To study the permeation of transdermal progesterone delivery system in vitro.METHODS: The polyacrylic matrix-type transdermal patch of progesterone was prepared.The effect of penetration enhancers and drug content of the patch on the in vitro permeability of progesterone through human skin was examined using Valia-Chien diffusion cell and high performance liquid chromatography.RESULTS: The patch consisting of 23%monolaurin and 15% ethyl palmitate showed the optimal permeation , mean permeation rate being 1.50 ±0.64 μg·cm^-2 ·h^-1 with 21.4-fold enhancement, and permeation rate increased significantly with the increase of progesterone content from 0.75 to1.0 mg·cm^-2 , and did not increase further with the increase of content from 1.0 to 1.25 mg·cm^-2.CONCLUSION: Combination of monolaurin and ethyl palmitate can significantly increase the percutaneous absorption of transdermal progesterone delivery system , whose optimal contents of progesterone was 1.0 mg·cm^-2.

Key words: transdermal delivery system, pressuresensitive adhesive matrix, skin penetration enhancers, polyacrylate, progesterone, high efficiency liquid chromatography