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Influence des ions sur le pouvoir hydratant de I'urée: étude sur peau de porc ex vivo
Author(s) -
DUPUIS L.,
MANFAIT M.,
SERPIER H.,
CAPON F.,
KALIS B.
Publication year - 1997
Publication title -
international journal of cosmetic science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 62
eISSN - 1468-2494
pISSN - 0142-5463
DOI - 10.1111/j.1467-2494.1997.tb00164.x
Subject(s) - urea , chemistry , aqueous solution , sodium , penetration (warfare) , ex vivo , crystallization , hydrate , peg ratio , nuclear chemistry , chromatography , biochemistry , in vitro , organic chemistry , operations research , engineering , finance , economics
Synopsis This study deals with the influence of ions (NaCl and MgSO 4 ) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.