SKIN ABSORPTION - FLOW-THROUGH OR STATIC DIFFUSION CELLS

Flow-through diffusion cells for the measurement of skin permeability in vitro are available commercially. We have designed a new system in our laboratory as an improvement on other cells. The CTL system is cap able of running 15 cells simultaneously. In this study the flow-throug h diffusion system was compared with our well-validated and establishe d static cell system, for ability to measure percutaneous absorption. Two hydrophilic chemicals-water and mannitol-were chosen as test penet rants. The permeability of whole skin, epidermis and dermatomed skin f rom humans, pigs, and rats was examined. The effect of tissue culture medium as receptor fluid was assessed in comparison with saline. Absor ption data from the Row-through cells were similar to results from con temporary static cell. Thus, for each species and skin preparation the re was good agreement in the permeability coefficients between the cel l types. The absorption of the hydrophilic test penetrants into saline and tissue culture medium receptor fluid was also very similar. Furth er evaluation of this system, particularly for lipophilic molecules, i s required.