Study on reflection of human skin with liquid paraffin as the penetration enhancer by spectroscopy.

Optical clearing agents can improve tissue optical transmittance by reducing the diffuse reflection. The reflection on in vivo human skin before and after applying anhydrous glycerol and 30 to 50% liquid paraffin glycerol mixed solution are investigated in this paper. From their visible and near-infrared reflection spectroscopy, all of their diffuse reflections are reduced after applying the agents. It is found that the three mixed solutions show stronger effect than that of anhydrous glycerol. These results further prove liquid paraffin can enhance the percutaneous penetration of glycerol and take synergistically optical clearing effect with glycerol over visible and near-infrared wave bands.