Comparison on Skin Permeability of Corydalis Rhizoma Total Alkaloid Patches at Shenque Acupoint and Non-acupoint Administration / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo compare the differences in resistance and structure of skin between acupoints and non-acupoints， and to study the difference in skin permeability characteristics of Corydalis Rhizoma total alkaloid patches （CTTP） after administration at Shenque acupoint and non-acupoint， so as to provide experimental support for its clinical acupoint application to prevent and treat chronic pain. MethodTaking corydaline （CD）， tetrahydropalmatine （THP） and corydalis L （CDL） as evaluation indexes， and the quantitative analysis was carried out by high performance liquid chromatography （HPLC）. The mobile phase was methanol-0.04 mol·L-1 phosphoric acid aqueous solution （70∶30， pH 6.0 adjusted with triethylamine）， the detection wavelength was 281 nm. In vitro transdermal test in Franz diffusion cell and in vivo transdermal test were used to study the skin permeability characteristics of CTTP through Shenque acupoint and non-acupoint administration. At the same time， the skin resistance between Shenque acupoint and non-acupoint was measured before and after the administration， and the distribution of the drug in each layer of the skin was compared by freezing sectioning， and visual verification was performed with fluorescence inverted microscope. ResultAfter 24 h of administration， the results of in vivo and in vitro experiments showed that the cumulative permeation and retention of CD， THP and CDL at Shenque acupoint skin were higher than those at non-acupoint skin （P<0.05， P<0.01）， the skin resistance of Shenque acupoint was lower than that of non-acupoint at all time points. The fluorescence microscopic observation results showed that the drug content of each layer of the skin was all Shenque acupoint>non-acupoint， indicating that the skin of Shenque acupoint had better effect on drug penetration and storage than non-acupoint. ConclusionThe 24 h cumulative permeation and retention of CTTP in Shenque acupoint skin are higher than those in non-acupoint skin， and the mechanism may be related to the thin skin， low electrical resistance and large number of hair follicle bodies at Shenque acupoint.