Preparation of 3,5,4′-trimethoxy-trans-stilbene and its transdermal absorption ex vivo

Objective To prepare 3,5,4′-trimethoxy-trans-stilbene(BTM) emulsion-gel and investigate the effect of dosage,different penetration enhancers and their combinations on percutaneous absorption of BTM and discuss the feasibility of transdermal administration of BTM.Methods BTM emulsion-gel was prepared with carbopol 940 as the base material.The percutaneous permeation experiment was carried out with modified Franz-type diffusion cell with isolated piglets skin as the barrier and the concentration of each sample in the reception room was determined by HPLC-UV to calculate the parameters.Results The cumulative permeation quantity of BTM at 24 h doubled as the dosage increased from 1% to 2%,but showed no significant difference(P0.1) between 2% and 4%.Enhancers obviously promoted the percutaneous absorption of BTM with the effect of enhancers as follows: 2% geraniol2% isopropyl myristate2% oliec acid2% azone2% nerolidolcontrol,but no difference in permeation quantity(P0.05) was observed when the concentration of geraniol in BTM emulsion-gel increased,as well as enhancers combined(2% geraniol+2% isopropyl myristate,2% geraniol+2% propylene glycol).There was a weak antagonistic effect of penetration when 2% geraniol combining 2% isopropanol.Conclusion The percutaneous absorption of BTM significantly increases with the enhancers and reaches its biggest absorption when 2% dosage and 2% geraniol are used.The transdermal penetration of BTM can be saturated,which provides a basis for futher transdermal delivery study.