[Penetration and effectiveness of hydrocortisone in reduced concentration in vehicles].
Several attempts have been made to optimize the efficiency of topical glucocorticoids (GC) and, at the same time, to minimize their side effects. In this respect, we should first consider attenuated GC. Dependent on the urea concentration, hydrocortisone (HC) in combination with urea results in both a considerable increase of the HC liberation from the ointment base, as well as an increased penetration rate of HC into the individual skin layers. If we apply these mechanisms to a preparation containing low HC concentrations, a given therapeutic effect can be obtained with definitely reduced HC concentrations. On the other hand, the therapeutic efficiency or the penetration rate of GC can not be deduced from the galenic formulation, the drug concentration, or the amount of urea.