[Transdermal salicylate absorption and behavior of corticosteroid plasma levels during epidermal administration of an antiphlogistic ointment].

After repeated epidermal application of an ointment containing salicylic acid, mucopolysaccharidepolysulfate and suprarenal extract (Mobilat) the transdermal absorption of salicylate was determined in seven healthy volunteers by measuring the renal excretion of salicylate as well as the plasma level. The determination of the corticosteroid plasma level was to elucidate a possible effect caused by the suprarenal extract contained in Mobilat ointment. By means of high pressure liquid chromatography the concentrations of salicylic acid and salicyluric acid in the collected urine and in the plasma were established. The quantitative determination of hydrocortisone, 11-desoxycortisol and 17 alpha-hydroxyprogesterone, selected as indicator steroids, was performed by radioimmuno assay. After repeated application of Mobilat ointment a constant level of salicylic acid in plasma of approximately 0.2 microgram/ml was observed. The total excretion of salicylate reaches a constant level of approximately 12 mg/day. About 6.9% of the amount of salicylate was renally excreted after 7 days. The corticosteroid plasma level showed no significant change.