Abstract
Hairless animals have been frequently used for in vivo and in vitro skin penetration experiments. The flux and enzymatic activity are obviously influenced by the species of animal used. In this paper, we have investigated the penetration and metabolism of prednisolone(PN) and prednisolone 21-acetate (PNA) in the skin using two different strains of hairless mouse. The abdominal skin of hairless mouse, inbred (HOS : HR-1 and Hr/Kud) and closed-colony (BALB/cA hr/hr) mice, was mounted between in vitro side-by-side penetration systems or homogenized by Polytrone® and Potter-Elvehjim type homogenizer. The thickness of whole skin (227 μm) and stratum corneum(29 μm) of HOS : HR-1 mouse was same as that of Hr-/Kud mouse. The diffusion and partition coefficients in stratum corneum of PN for Hr-/Kud mouse were 0.45 and 2.80 times as these for HOS : HR-1 mouse, respectively. The kinetic constants, Vmax and Km, for skin enzyme also differ between HOS : HR-1 and Hr-/Kud mice.
