Transdermal permeation of Zanthoxylum bungeanum essential oil on TCM components with different lipophilicity

Z. bungeanum oil facilitated transdermal permeation of drugs with different lipophilicity, including the extremely hydrophilic and lipophilic drugs, whereas it exhibited greater enhancement activity for strongly hydrophilic drugs. The mechanisms of transdermal permeation enhancement by the oil could be explained with SC/vehicle partition coefficient, saturation solubility, and the interactions with SC lipids.