Quantitative evaluation of glucocorticosteroid permeation in the stratum corneum based on the sequential application of both glucocorticosteroid ointment and moisturizing ointment

Abstract

We investigated the combination of dexamethasone valerate ointment (Voalla® ointment) and water-in-oil-based moisturizing ointment (Hirudoid® soft ointment) to determine whether the topical drug application sequence (moisturizing ointment on glucocorticosteroid ointment or glucocorticosteroid ointment on moisturizing ointment) influences percutaneous absorption of dexamethasone valerate in isolated pig ear skin and in living human skin. The dose was administered with glucocorticosteroid ointment alone (group A). Then the dose was initially administered with glucocorticosteroid ointment preceding moisturizing ointment (group B). And finally, the dose was administered with moisturizing ointment preceding glucocorticosteroid ointment (group C). This study evaluated the skin penetration of dexamethasone valerate from glucocorticosteroid ointment, using non-viable excised pig ear skin samples (n = 8). We measured the concentration of dexamethasone valerate in isolated pig ear skin by HPLC. We obtained information on the depth profiles of dexamethasone valerate in living human skin (n = 2) by confocal Raman spectrometer. The permeability of dexamethasone valerate of pig ear skin was compared among groups A, B and C. Group A demonstrated the highest concentration of dexamethasone valerate penetrating the skin. The permeability of dexamethasone valerate when moisturizing ointment was applied on glucocorticosteroid ointment (group B) was greater than that when glucocorticosteroid ointment was applied on moisturizing ointment (group C) (P<0.01 ; t-test). Our findings were similar in both isolated pig ear skin and in living human skin.