Hydrocortisone (HC) penetration into excised human skin from 1% (w/w)
HC containing formulations with white petrolatum, an o/w cream and an
aqueous polyacrylate gel is described. The experiments were performed
with pure HC and the inclusion compounds with beta-cyclodextrin and hy
droxypropyl-beta-cyclodextrin. The smallest HC amounts in the skin wer
e found with the petrolatum preparations. No differences between the i
ncorporation of free HC and the inclusion compounds was found, The hig
hest HC amounts in the skin are found with the o/w cream and hydrogel
formulation containing nonincluded HC. Incorporation of both inclusion
compounds into these vehicles diminishes the HC concentration in the
upper skin layers but not in the dermis, It is assumed that the prefer
red penetration route for the easily soluble inclusion compounds is a
transappendageal diffusion rather than a transdermal one. A comparison
with release results by using an ointment liberation model gives a go
od correlation with the penetration results in the dermis but not in t
he other skin layers.