Résumé
Objective To compare the improvement effect of three physical techniques on the transdermal absorption of sinapine thiocyanate(ST)in vitro, including microneedles, sonophoresis and iontophoresis, and to evaluate the mechanism and rules of physcial techniques on the transdermal absorption of poorly transdermal absorbed drugs. Methods In vitro transdermal experiment was carried out under the circumstances of microneedles, sonophoresis or iontophoresis, using the modified Franz diffusion pool. The 2 mg/ml ST solution was adopted as the donor solution, and the SD rats′ abdomen skin was used as the model skin. Sampling was carried out at the predetermined time points and each sample was analyzed by HPLC. Cumulative transdermal amount and steady transdermal absorption rate were calculated. Pathological slides were made after the skins were treated with microneedles, sonophoresis and iontophoresis for 12 h. The structure changes were observed to evaluate the transdermal improvement mechanism of different technologies. Results Accumulated transdermal amount of ST was little without any techniques. The transdermal improvement effect of different technologies was as follows: Microneedles>sonophoresis>iontophoresis. A substantial hole formed on the skin by microneedles to promote ST transdermal absorption obviously. Sonophoresis disrupted the tight structure of skin and improved the transdermal absorption of drugs easily. The effect of iontophresis on skin structure was little. Conclusion This study provides experimental evidence for choice of different techniques to improve transdermal absorption.
Résumé
Objective To compare the improvement effect of three physical techniques on the transdermal absorption of sinap?ine thiocyanate(ST)in vitro,including microneedles,sonophoresis and iontophoresis,and to evaluate the mechanism and rules of physcial techniques on the transdermal absorption of poorly transdermal absorbed drugs. Methods In vitro transdermal experiment was carried out under the circumstances of microneedles,sonophoresis or iontophoresis,using the modified Franz diffusion pool. The 2 mg/ml ST solution was adopted as the donor solution, and the SD rats′abdomen skin was used as the model skin. Sampling was car?ried out at the predetermined time points and each sample was analyzed by HPLC. Cumulative transdermal amount and steady transder?mal absorption rate were calculated. Pathological slides were made after the skins were treated with microneedles ,sonophoresis and iontophoresis for 12 h. The structure changes were observed to evaluate the transdermal improvement mechanism of different technolo?gies. Results Accumulated transdermal amount of ST was little without any techniques. The transdermal improvement effect of differ?ent technologies was as follows:microneedles>sonophoresis>iontophoresis. A substantial hole formed on the skin by microneedles to promote ST transdermal absorption obviously. Sonophoresis disrupted the tight structure of skin and improved the transdermal absorp?tion of drugs easily. The effect of iontophresis on skin structure was little. Conclusion This study provides experimental evidence for choice of different techniques to improve transdermal absorption.