Use Ano Efficacy of Urea in Dermatological Preparations

The bas is of the effects of urea on the human skin is its penetration kinetics into different skin layers. A strong vehicle dependence can be estabilished. Therefore wide differences are found in the duration and intensity of increased water-binding capacity after application of different urea containing emulsions. For therapy to increase the hydration and water-binding capacity in the homy layer of diseased skin preparations with IO% urea are more suitable than those containing 2% or 5% urea. For cosmetic preparations, the higher concentrations of urea are inappropriate, lower ones are sufficient. By altering the functional structure of the homy layer and increasing of drug liberation from ointment bases, urea is one of the most effective penetration promoters. An increased penetration rate of some corticostero ids, dithranol and other drugs in human skin. The resulting penetration has two possible implications for topica! therapy: an increased therapeutic effect for any given concentration of an active constituent the attainment of a g iven therapeutic effect with a reduced concentration of the active ingredient.