Twenty-four hours after treatment, animals were humanely euthanized under anesthesia (urethane 1 g/kg and α-chloralose 50 mg/kg). In order to evaluate the histology of the skin at the site of application, the skin was dissected and fixed with buffered 10% formalin solution for 48 h. Tissue samples were embedded in paraffin following a routine protocol. Subsequently, sections 5 µm thick were stained with hematoxylin and eosin (H&E). The slides were examined using a light microscopy (Olympus BH-2, Tokyo, Japan) and the histopathological appearance of tissues in the different groups were compared. Possible structure changes and cell infiltration were evaluated by two analyzers blinded to the treatments.