Studies on Transdermal Therapeutic System using pulse iontophoresis

点击翻译按钮获取中文摘要

Iontophoretic penetration of model drugs was investigated in vitro using the excised nude mouse skin. 1. In the preliminary study using sodium salicylate as a low-molecular model compound (research plan (1) for 1988), it was found that the flux of drug was proportional to the current density at direct current iontophoresis and to both the "on" time and current density at pulse iontophoresis. 2. The impedance change and histological alteration of the excised skin after the application of various modes of iontophoresis revealed that (1) the cathodic current had more marked effects on the skin than the anodic current, (2) the pulse current induced a milder tissue damage than the direct current when compared at the same effective applied time of iontophoresis. Therefore, a higher current density and a longer net period of iontophoresis could be applied to the skin with the use of pulse current.3. The iontophoretic study on SOD as a model polypeptide-drug, showed that a very small amount of SOD was transported through the excised skin owing to its high-molecular-weight properties (research plan (1) for 1989). 4. The enhancing effect of cetyl lactate and oleic acid on the percutaneous absorption of indomethacin through the abdominal skin of rats was suggested (research plan (4) for 1988 and 1989). However, some problems such as water solubility must be solved to apply these enhancers to the iontophoretic system.The development of a iontophoretic device and more extensive investigations in vivo are necessary.