Effect of Electroporation on Percutaneous Permeation of Sinomenine Hydrochloride / 中国实验方剂学杂志

Objective:To investigate the percutaneous permeability of sinomenine hydrochloride （SNH） and optimize the parameters of electroporation to achieve the best permeation enhancing effect on SNH. Method:The percutaneous permeability of SNH and the enhancement effect of electroporation were studied by <italic>in vitro</italic> diffusion cell method， and the enhancement effect of electroporation was further evaluated by <italic>in vivo</italic> study in mice. Result:Under steady-state condition， the permeation rates of SNH in stripped skin and intact skin of hairless mice were （385.81±12.88）， （0.88±0.20） μg·cm^-2·h^-1， respectively. The permeation rate in stripped skin was 438 times higher than that in intact skin. The results of percutaneous permeation kinetics analysis showed that the solubility and diffusion coefficient of SNH in stratum corneum were relatively low， which were （70.82±9.63）×10³ g·m^-3 and （3.07±1.52）×10^-14 cm²·s^-1， respectively. Under the optimized electroporation conditions （voltage of 72 V， time of 60 min）， the 24 h cumulative permeation amount of SNH through skin of mice was （10 008.39±1 961.57） μg·cm^-2， and the steady-state permeation rate was （456.01±51.26） μg·cm^-2·h^-1， which were 5.4 times and 5.1 times higher than those of blank group， respectively. <italic>In vivo</italic> studies in mice showed that the contents of SNH in skin and muscle of electroporation group were 2.0 times and 1.5 times higher than those of blank group. Conclusion:The low solubility and low diffusion coefficient of SNH in the stratum corneum are the main factors hindering the percutaneous permeation of SNH. Electroporation can significantly increase the percutaneous permeation of SNH and its retention in skin and muscle of mice.

Effect of skin condition on the permeability of theophylline via rat skin / 中国药理学通报

Aim To investigate the influence of skin layers ( st ratum corneum and viable layer) on the percutaneous absorption of drug with or w ithout isopropyl myristate (IPM). Methods We chose theophylline (TP ) as a model drug. Patches containing saturated concentration of TP were prepare d. The in vitrotransdermal permeation experiment via different rat skin lay ers was carried out. Results The Kp of TP via stripped skin was 2.1 times larger than that via intact skin. The permea bility was en hanced when coexisted with IPM either via intact skin or via stripped skin. Conclusion IPM can significantly enhance the percutaneous absorption of TP via different skin layers. And these data and methods represent a novel appr oach to evaluate the effects of skin damage and skin disease on drug percutaneou s absorption.