In vitro evaluation of the efficacy of skin barrier creams and protective gloves on percutaneous absorption of industrial solvents.

The aim of the experiments was to evaluate the efficacy of skin barrier creams (SBCs) and protective gloves and its potential for reduction of percutaneous absorption of industrial solvents. We assessed percutaneous absorption of ethylene glycol (EG), isopropyl alcohol (IA) and 1,2,4-trimethylbenzene (TMB), using static diffusion cells. These solvents were applied neat (EG, TMB) as well as in 10% and 50% aqueous solution (EG, IA) or in 10% and 50% ethanol-diluted solution (TMB). Furthermore, we tested the percutaneous absorption of IA mixed in one cleaning agent (CA), used in newspaper printing shops to clean the rollers of printing machines. Additionally, the penetration behaviour of 10% and 50% solutions of EG, IA and TMB was tested. The experiments were carried out on untreated and on SBC-treated excised human skin from one donor, and on protective gloves. Saline was used as receptor fluid for EG and IA, and neat ethanol for TMB. The penetration of 50% EG, IA and TMB solutions through SBC-treated skin was higher than in untreated skin (factor 3.9 for EG, 0.32 for IA and 0.06 for TMB). The penetration of IA in the IA-CA mixture was five-times higher through untreated skin as for the single compound in 10% aqueous solution. In skin, treated with SBC, we found a 17-fold penetration enhancement of IA in the IA-CA mixture. No appreciable penetration of EG and IA was observed through nitrile rubber gloves. Our in vitro experiments could not demonstrate an efficacy of SBC to protect skin penetration for the tested solvents. The percutaneous absorption of all solvents in 50% solution was increased through skin treated with SBCs. Furthermore, SBCs enhance the penetration rates of solvents from complex mixtures compared with the single solvents. The tested gloves showed sufficient protection for the hydrophilic solvents, but not for TMB.