[Experimental results of the optimization of external prednisolone therapy]

The initial steps of any topical therapy are characterized by the degree of liberation of the agent from the ointment base and their penetration into different skin layers. A high percentage of the topically applied prednisolone does not penetrate into the skin and may be removed from the skin surface even after some time. By altering the functional structure of the horny layer and considerably increase of prednisolone liberation from ointment bases urea is a effective penetration promotor also for prednisolone. The increased prednisolone penetration into human skin from urea containing ointment correspond with the degree of blanching results by vasoconstriction test under in vivo conditions. The resulting penetration optimation of prednisolone has two possible applications in topical therapy: an increased therapeutic effect for a given prednisolone concentration and a given therapeutic effect could be obtained with a reduced prednisolone concentration.