THE PENETRATION AND DISTRIBUTION OF C-14 HYDROCORTISONE IN HUMAN SKIN AFTER ITS TOPICAL APPLICATION

[摘要] C14-tagged hydrocortisone was used as a tracer incorporated into an ointment base containing 1% stable hydrocortisone, applied to the normal skin of human volunteers, following which biopsies were performed at varying time intervals. After 1 hour, radioactive material was visualized in the epidermis, by 2 hours the tracer material had concentrated in the basal layer. After 6 hours the C14 was identified in the cutis about blood vessels, while it had disappeared entirely from the skin after 16 hours. Experiments done to compare the penetration of the C14-hydro-cortisone through normal skin with that through hyperkeratotic, lichenified areas showed that the material failed to enter the epidermis of the latter by 2 hours, but had done so after 6 hours. Its penetration appeared to be much retarded by this alteration. Application of the tagged hormones to irradiated (Grenz or UV) skin resulted in more rapid penetration before and during the early erythema, but no difference from normal during the late erythema was noted. Comparison of the rate of penetration of the radioactive material if applied in 4 different vehicles failed to reveal any major difference dependent on the base used. Despite the relatively small numbers of biopsies taken it is believed that 2 features were definitely shown[long dash]1st, the epidermal penetration of hydrocortisone was illustrated, and 2nd, its temporary concentration in the basal layer of the epidermis was shown. A suggestion was made on the basis of this latter finding, as to the function of the basal layer in inflammation. The assumption of a preferential penetration of topically applied hydrocortisone through follicular structures is not substantiated by these experiments.