INFLUENCE OF EMULSIONS WITH AND WITHOUT UREA ON WATER-BINDING CAPACITY OF THE STRATUM-CORNEUM

This study was undertaken to delineate the effects of emulsions with a nd without urea on the water-binding behavior of the stratum corneum a t different relative humidities (RH). The heels of 54 human volunteers were treated with water-in-oil (w/o), and oil-in-water (o/w) emulsion s with and without urea (urea content 10%). After treatment the water content was determined by measuring the weight of the callus. The resu lts show that urea increases the amount of free water at high RH. Both types of emulsions led to a significant reduction in the water conten t of the stratum corneum at 60%-70% RH, suggesting an effect on the se condary, weakly bound water.