Percutaneous penetration through slightly damaged skin

Guidelines for experimental studies of percutaneous penetration prescribe optimal barrier integrity of the skin. The barrier integrity of the skin exposed in occupational or household situations is, however, not always ideal, and skin problems are among the most dominant reasons for absence from work. We have therefore evaluated an experimental model for percutaneous penetration through slightly damaged skin. The influence of a slight damage to the skin was evaluated using five pesticides covering a wide range of solubilities. We used an experimental model with static diffusion cells mounted with human skin. A slight damage to the barrier integrity was induced by pre-treatment of the skin with sodium lauryl sulphate (SLS) before pesticide exposure. The experimental model with 3 h pre-treatment with SLS (0.1% or 0.3%) assured a significant but controlled damage to the barrier integrity, a damage that remained unchanged for an experimental period of 48 h. Based on the percutaneous penetration of five pesticides, we conclude that a slightly damaged skin may significantly affect the rate, lag-time as well as total penetration of chemicals covering a wide range of solubilities. The percutaneous penetration of the most hydrophilic compounds will be those most affected. These findings should be considered when setting standards for dermal exposure to chemicals.