In dermatology and cosmetics, moisturizers are used to soften skin. The objectives of this study were to compare the influence of three different moisturizers on skin hydration and skin mechanics by various non-invasive test methods and to determine the relationship between the methods used.
In 27 test subjects, four test areas in each were treated over 3 days, three times a day. An oil-in-water (o/w) emulsion was applied without moisturizer, the same with 10% glycerol, with 10% urea, or with 10% propylene glycol, respectively. Three hours after the last treatment results were measured by using the following instruments: Corneometer CM 820, Skicon 200, Frictionmeter, and Cutometer.
In all procedures a significant effect, in the sense of an increase in the data recorded, could be demonstrated by glycerol-treatment. During Corneometer, Frictionmeter, and Cutometer measurements, an additional unidirectional effect caused by the basic emulsion was seen. With all test methods, the influence of urea and propylene glycol was not significant compared to the basic emulsion. For all pretreatments there was a correlation between Corneometer data and Skicon data. Because of the low correlation coefficients between hydration parameters and mechanical parameters, it is to be assumed that other effects of glycerol- and basic-emulsion-treatment-independent from the hydration effect – have an additional influence on the data obtained by using the Frictionmeter and the Cutometer. This indicates that the clinical effect of emulsions should not be evaluated exclusively on the basis of electrical measurements of hydration.