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Int Arch Occup Environ Health (2010) 83:683690 DOI 10.1007/s00420-010-0546-y
ORIGINAL ARTICLE
Efcacy of skin wash on dermal absorption: an in vitro study on four model compounds of varying solubility
Jesper Bo Nielsen
Received: 20 July 2009 / Accepted: 11 May 2010 / Published online: 26 May 2010 Springer-Verlag 2010
AbstractPurpose Following dermal exposure to chemicals causing systemic toxicity, the general advice to avoid further systemic exposure is to wash the skin. The present study uses four model compounds (benzoic acid, glyphosat, caffeine, malathion) with varying size and solubility to substantiate this advice and quantify the effect of skin wash following 6 h dermal exposure on subsequent extent of skin penetration and deposition within the skin compartment.
Method Percutaneous penetration through human skin is studied in an in vitro model with static diffusion cells. Results The study demonstrates that percutaneous penetration continues after end of exposure due to the reservoir present in the skin. However, penetration rate will decrease signicantly, and it is evident that simple hand-wash after end of exposure not only reduces the amount of residue present in the upper skin compartment but also signicantly reduces the total absorption of test substance, most so for the hydrophilic compounds.
Conclusion Our observations support the continuing initiatives from occupational hygienists to urge people with dermal exposure hazards to wash potentially exposed skin areas.
Keywords Percutaneous penetration In vitro
Skin wash Lipophilicity Skin deposition
Introduction
When a substance stays and accumulates in the skin instead of passing directly through to the bloodstream it is described as a reservoir. A reservoir can be present in the stratum corneum, the viable epidermis or in the dermis (Roberts et al. 2004). The substance staying in the reservoir will often be released with a certain delay to the blood stream or possibly back to the skin surface. The absorption of the substance into the blood stream continues from the application site at a gradually declining pace reecting the decreasing concentration gradient between skin and receptor compartment of diffusion cells, giving the appearance of prolonged elimination (Cnubben et al. 2002). Another possibility is that the substances remaining in the upper layers of the skin are removed by washing the skin or by desquamation after end of exposure. Studies have shown that absorption...