An increase of skin penetration was reported for coenzyme Q10-loaded SLN and NLC compared to nanoemulsion and liquid paraffin or isopropanol respectively, performing a tape stripping test. Using the fluorescence dye Nile red as a marker, it could be shown by Teeranachaideekul et al. that the penetration depth and the amount penetrated into the skin depends on the oil content used in NLC. It was found that the degree of epidermal targeting depends on the oil content, and associated with the oil content, the occlusive factor.