Ex vivo Skin model Advantages Disadvantage
Human excerpts
Gold-standard model
Ethical permission High inter- and intra-variability than with porcine ear skin Storage stability lack
Pig (ear)
No ethical restrictions Availability (waste from slaughter) Similarity with human skin Age of animal influences skin thickness Hair follicles (removal may conduce to skin damage) Storage stability lack
Newborn pig
Similar thickness of the SC
Higher number of hairs than in humans Variability due to the use of different anatomical sites Storage stability lack
Mouse / Rat
Small size Uncomplicated handling Hairless species available Ethical restrictions Lower thickness High permeability High density of hair follicles Removal of hairs (skin damage)
Guinea pig
Similar permeability to human skin Hairless species available Ethical restrictions High density of hair follicles Removal of (skin damage)
Rabbit
Ears as waste from slaughter Similar permeability to guinea pig Ethical restrictions High density of hair follicles Hair follicles (removal may conduce to skin damage)
Shed snake
Single animal provides repeated sheds Multiple samples from one animal Storage at room temperature Absence of hair follicles Different skin metabolism Absence of living epidermis and dermis
Bovine udders
Availability (easily obtained waste from slaughter) Multiple samples from one animal Weaker barrier to some drugs than pig skin Storage stability lack