ANIMAL-MODELS FOR TRANSDERMAL DRUG-DELIVERY

The purpose of this investigation was to compare the permeation charac teristics of two different compounds (extremely polar and nonpolar) i. e. tritium-labeled water (W) and C-14-labeled 7-hydroxycoumarin (7-OHC ), among 16 different species, including human skin. Snake skin exhibi ted highest permeability for both W and 7-OHC. Permeability and lag ti me values of W and 7-OHC. Permeability and lag time values of W and 7- OHC across Brattleboro rat and hairless guinea pig are very close to h uman skin. Skin thickness in micrometers (full thickness, epidermis an d stratum corneum, and stratum corneum), and number of hair follicles present in each cm(2) were determined for each species. There was no r elationship between number of hair follicles and permeability values f or both W and 7-OHC. The skin thickness (full) was related to the rela tive permeability values of W, whereas for 7-OHC it was not.