Differential rates of percutaneous absorption through the eczematous and normal skin of a monkey

A monkey (Macaca fascicularis), diagnosed as having eczematous dermatitis on the basis of histopathology of a skin biopsy, was used to study the percutaneous absorption of 2 anti-inflammatory steroids. Absorption was measured through involved and uninvolved skin by using in vitro diffusion cell techniques. Hydrocortisone (0.5%) and triamcinolone acetonide (0.1%) were applied to the skin in a petrolatum vehicle. After application for 24 h, the permeation of hydrocortisone was approximately doubled (from 2.6 to 5.5% of the applied dose) when diseased skin was used. The absorption of triamcinolone acetonide was enhanced through the eczematous skin during the initial 12 h. At 24 h, however, no significant difference in total absorption was obtained.