2.9. Histopathology study of skin
According to established method, the skin histopathological examination was carried out to detect the topical effect of RPV- LNCs on skins (Fang et al., 2008). RPV-LNCs and RPV propylene glycol were applied to the hair-removed mice for 12 h, respectively. Afterwards, the treated skin pieces were washed twice with physiological saline and collected into formalin for tissue fixation. Then the specimen was embedded in paraffin wax, followed by subjected to hematoxylin/eosin staining. Paraffin tissue sections of 3–4 mm were cut and examined under light microscopy