Analysis of in vitro skin permeation of 22-oxacalcitriol having a complicated metabolic pathway.

Purpose: The purpose of this study is to analyze simultaneous skin permeation and metabolism of 22-oxacalcitriol (OCT) having several metabolites in skin by observing skin permeation of only unchanged OCT through excised rat skin.

Methods: A diffusion model including metabolic processes was employed to express simultaneous skin permeation and metabolism of OCT. In vitro permeation experiments of OCT from Oxarol ointment through full-thickness and stripped rat skin were carried out using Franz-type diffusion cells.