Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio 45267, USA.
J Pharm Sci. 2010 Jan;99(1):107-18. doi: 10.1002/jps.21800.
The objectives of this study were to investigate the effects of hydration and solution ion concentration on the electrical properties of human nail in vivo and compare these in vivo results with those in vitro. In vivo electrical resistance measurements on the nail were conducted with a three-electrode system in phosphate buffered saline of 0.01-0.6 M. The effect of electric current on nail resistance and possible adverse effects were studied under 1.5- and 9-V iontophoresis in vivo. The electrical resistance of the nail plate was measured in vitro in side-by-side diffusion cells under the same conditions and compared with those in vivo. The in vivo electrical resistance decreased significantly upon 2-h nail hydration and then slowly decreased to a constant value, showing the same pattern as that in vitro. No significant effect of the applied voltage upon the nail electrical resistance was observed. Higher current densities caused moderate sensation and slight changes in nail appearance after iontophoresis. The observed decrease in nail resistance demonstrates the significance of nail hydration in transungual iontophoresis. The in vitro and in vivo correlation suggests that the in vitro nail plate can be a model in the research and development of transungual iontophoretic delivery.
本研究旨在探讨水合作用和溶液离子浓度对活体人指甲电特性的影响，并将体内结果与体外结果进行比较。在 0.01-0.6 M 的磷酸盐缓冲盐溶液中，采用三电极系统对指甲进行体内电阻测量。在 1.5 和 9 V 电渗析条件下，研究电流对指甲电阻和可能产生的不良反应的影响。在相同条件下，通过并排扩散池测量体外指甲板的电阻，并与体内电阻进行比较。指甲水合作用 2 小时后，体内电阻显著下降，然后缓慢下降至恒定值，与体外结果一致。施加电压对指甲电阻没有显著影响。较高的电流密度导致电渗析后中等程度的感觉和指甲外观的轻微变化。观察到的指甲电阻降低表明指甲水合作用在透皮离子导入中的重要性。体外和体内相关性表明，体外指甲板可以作为透皮离子导入传递研究和开发的模型。
