Vutla N B, Betageri G V, Banga A K
Department of Pharmacal Sciences, Auburn University, AL 36849-5503, USA.
J Pharm Sci. 1996 Jan;85(1):5-8. doi: 10.1021/js950349y.
Transdermal iontophoretic transport of a liposomal formulation of [Leu5]enkephalin, across human cadaver skin, was investigated. Franz (vertical) cells were supplied with 0.5 mA/cm2 current density via silver/silver chloride electrodes from a Scepter power supply. Enkephalin spiked with [3H]enkephalin was transported across skin from anode or cathode, depending on the charge on the molecule. Liposomes or their constituents were shown to penetrate into the skin. Enkephalin, when delivered iontophoretically at its isoelectric point, from liposomes carrying positive or negative charge on their surface, resulted in permeation of radioactivity which was same or less than that of the controls when analyzed by liquid scintillation counting. When analyzed by radiochromatography detector on HPLC, degradation of enkephalin during transport was observed, with several degradation peaks in the chromatogram. The degradation was less in liposome formulations, as compared to controls. This is the first report of the combined use of liposomes and iontophoresis for transdermal delivery.
研究了[亮氨酸5]脑啡肽脂质体制剂经皮离子电渗转运穿过人体尸体皮肤的情况。使用Scepter电源通过银/氯化银电极向Franz（垂直）扩散池提供0.5 mA/cm²的电流密度。掺入[³H]脑啡肽的脑啡肽从阳极或阴极穿过皮肤，这取决于分子上的电荷。脂质体或其成分显示可渗透进入皮肤。当脑啡肽在其等电点通过离子电渗法从表面带有正电荷或负电荷的脂质体中递送时，通过液体闪烁计数分析，放射性物质的渗透量与对照相同或低于对照。当通过HPLC上的放射色谱检测器分析时，观察到脑啡肽在转运过程中发生降解，色谱图中有几个降解峰。与对照相比，脂质体制剂中的降解较少。这是脂质体与离子电渗法联合用于透皮给药的首次报道。
