title: Methods for in vitro percutaneous absorption studies IV: The flow-through diffusion cell.
abstract: A flow-through diffusion cell system for percutaneous absorption studies has been developed. The results of initial studies with a limited number of compounds are reported. The cells were constructed from Teflon and contained a glass window in the bottom for viewing the receptor contents. A flow rate of at least 5 mL/h is required through the receptor (volume, 0.4 mL) for accurate results. The skin permeation of water, cortisone, and benzoic acid was determined in the flow-through cell and a standard static-diffusion cell. The absorption profiles and quantitative values obtained were similar for the two types of cells. The permeation of cortisone and benzoic acid applied in a petrolatum vehicle was determined in vivo in rats and with rat skin in the flow-through and static-diffusion cells. Good agreement was obtained between the results of the in vivo and in vitro procedures. The percutaneous absorption of a hydrophobic compound [3-phenyl-2-propenyl 2-aminobenzoate (cinnamyl anthranilate)] was enhanced with normal saline receptor solution in the flow-through cell when compared with results in the static cell. Maximum in vitro absorption was obtained with either cell using a 6% solution in water of the nonionic surfactant polyethylene glycol 20 oleyl ether (PEG-20 oleyl ether).
mesh_terms: D000818:Animals; D001565:Benzoates / Q000378:metabolism; D019817:Benzoic Acid; D003348:Cortisone / Q000378:metabolism; D004058:Diffusion; D066298:In Vitro Techniques; D008722:Methods; D051381:Rats; D012869:Skin Absorption; D012995:Solubility; D013696:Temperature
chemical_list: D001565:Benzoates; D019817:Benzoic Acid; D003348:Cortisone