[In vivo transdermal penetration enhancing activity of essential oil from Zanthoxyli Pericarpium by using...

The aim of this paper is to investigate the topical pharmacodynamics behavior of different lipophilic model drugs after treatment with essential oil from Zanthoxyli Pericarpium by using the cutaneous microdialysis technique, and then evaluate its in vivo transdermal penetration enhancing properties. Two traditional Chinese medicine active components, namely tetramethylpyrazine and puerarin, were chosen as lipophilic and hydrophilic model drugs, respectively. Firstly, the concentration difference method was employed to measure the in vitro recovery rate and loss of the microdialysis probe, and the in vivo recoveries of two model drugs were determined by using the retrodialysis method. Secondly, the skin pharmacodynamics behaviors of two model drugs were studied after treatment with different concentrations of the essential oil, and the well-established and standard penetration enhancer Azone was selected as a positive control. It was found that the recovery of microdialysis probe was equal to its loss for two model drugs, with no interaction between drugs in dialysis membranes. The retrodialysis studies revealed that the in vivo recovery of tetramethylpyrazine and puerarin were 59.17%, 19.85%, respectively. The skin pharmacodynamics studies showed that the essential oil could facilitate the transdermal absorption of tetramethylpyrazine in a concentration-dependent manner, and the enhancement ratio (ER) for 5% essential oil was 98.64, which was higher than that of the optimum concentration of Azone (3% Azone, ER=89.11). Meanwhile, the Zanthoxyli Pericarpium could effectively promote the transdermal permeation of the puerarin in a concentration-dependent manner. Hence, this study further confirmed that the Zanthoxyli Pericarpium had excellent penetration-enhancing activity as a natural transdermal penetration enhancer, providing data support for its application in traditional Chinese medicine external preparations.