We applied essential oil creams– nano-emulsions, conventional o/w emulsions, and conventional w/o emulsions –to the forearms of volunteers and then used a high performance liquid chromatograph with a fluorometric detector to evaluate serum levels of eugenol. Six volunteers were investigated before and after treatment with different formulations of clove essential oil. Blood samples were collected over 4 h. We conclude that nano-emulsion formulations may be used to permit the permeation of essential oil creams into the skin or to increase their rate of permeation.
