The Study of Irritancy of Surfactants with Low Concentrations by Non-invasive Bioengineering Methods

Lee, Ha Rin; Choi, Sung Woo; Kim, Dai Ho; Kim, Hyung Ok

Abstract

BACKGROUND: The bioengineering methods for investigating irritant skin reaction have been developed for several decades to evaluate the irritation potential more objectively and quantitatively and obtain the information which is not obvious by the visual examination.
OBJECTIVE
The purpose of this study was to compare the irritant skin reaction of three kinds of surfactants with various low concentrations which produce little reaction visually and investigative the threshold concentration that is reliable for a patch test. Also we investigated the sensitivity and the correlation between visual examination and bioengineering methods in four different concentrations of surfactants
METHODS
Twenty healthy volunteers were patch tested with 0.01%, 0.05%, 0.1%, 1.0% of sodium lauryl sulfate(SLS), cetyl trimethyl ammonium chloride(CETAC), POE(20) sorbitan monolaurate (Tween-20) on the flexor side of the Lt. forearm. The result of patch test was evaluated by visual scoring, evaporimeter, colorimeter, and corneometer until 72 hours.
RESULTS
1. SLS, anionic surfactant, showed the highest irritation potential in visual scoring, TEWL, and skin color measurement. And CETAC, cationic surfactant, showed the greatest irritation in corneometer measurements than other surfactants. 2. TEWL was the most sensitive method for evaluation of skin irritation and correlated most closely with visual examination. 3. Concentration of surfactant higher than 0.1% showed to produce reliable and constant result of skin irritation as the experimental primary irritant.
CONCLUSION
SLS is proved to be the most appropriate primary irritant for studying irritant contact dermatitis, and the degree and mode of skin irritation is different according to the concentration and kinds of surfactants. TEWL measurement is the most sensitive bioengineering method, which could detect early stages of irritation and correlate well with visual examination.