Irritancy of antiseptics tested by repeated open exposures on the human skin, evaluated by non-invasive methods

The aim of the study was to test the irritancy of 6 antiseptics in an open exposure model. The following agents were tested in their normal use concentrations using open exposures, 2x daily for 4 days in 20 subjects: chlorhexidine 4% (CH), chlorhexidine 0.5% in ethanol 70% (CE), ethanol 70% (ET), iodine 1% in ethanol 70% (IE), povidone-iodine 10% (PI) and sodium hypochlorite 0.25% (SH). Responses were evaluated by visual scoring, subjective irritancy scoring, stratum corneum hydration (Corneometer), transepidermal water loss and laser Doppler flowmetry. Exposure to SH had to be discontinued after 4 applications because of severe subjective irritation. The same held true for IE (7 applications), whereas the other agents were exposed 8x. All evaluation methods showed SH to be significantly more irritating than IE, which was in turn more irritating than CH, CE, ET and PI. Thus, it can be concluded that CH, CE, ET and PI were non-irritating in this open exposure model.