Transdermal permeation of geniposide in the herbal complex liniment in vivo and in vitro

Zhongtong Caji, a kind of liniment, is a traditional Chinese medicinal formula that is widely used for clinical treatment of inflammation and sprains. In this study, the principal effective compound of this formula, geniposide, was used as a criterion to represent the transdermal permeability of the whole formula. A passive diffusion of Zhongtong Caji through the stratum corneum was discovered by an in vitro experiment. The dosage–content relationship detected in subcutaneous tissue after in vivo drug administration was further evidence of its permeation. Blood analysis after different dosages showed that the geniposide could be absorbed and accumulated by subcutaneous tissue within 1 h after drug administration, and it would be eliminated by blood circulation 1 h after drug treatment.