LABORATORY METHODS FOR STUDYING PERCUTANEOUS ABSORPTION AND THE CHEMICAL EFFECTS OF TOPICAL AGENTS UPON HUMAN SKIN

[摘要] Methods for studying the penetration of topical agents through dead human skin are described. These in vitro tests include spot tests in the corium, sulfhydryl determinations in the isolated epidermis and colorimetric estimations in dermal extracts. Under the experimental conditions salicylic acid was found to penetrate most rapidly from Plastibase, Hydrophilic Plastibase and lanolin. Carbowax was less efficient and petrolatum was slowest in releasing salicylic acid. Sodium salicylate did not penetrate through the epidermis from any of the bases tested. Vitamin A did not penetrate through human skin, unless salicylic acid was also added to the ointment. Phenol penetrated very rapidly into the corium from all vehicles tested. On the basis of sulfhydryl in-activation, it was concluded that ammoniated mercury penetrated better from Hydrophilic Plastibase than from other ointment bases tested. Sulfur decreased sulfhydryl concentrations to the same degree regardless of the ointment base used. An excellent correlation was found between the penetrating ability and sulfhydryl inactivating capacity of potassium bichromate in two different ointments. Advantages of in vitro methods for studying the effects of topical agents are discussed.