School of Pharmacy, Shaheed Beheshti Medical University, Valiasr Ave., Niayesh Junction, P.O. Box 14155-6153, Tehran, Iran.
Int J Pharm. 2010 Nov 30;401(1-2):47-50. doi: 10.1016/j.ijpharm.2010.09.008. Epub 2010 Sep 18.
Microwaves (MW), a part of the electromagnetic spectrum at 0.3-300GHz, affect human body in different ways through its thermal and athermal effects, including fluidization of cell membranes and liquid crystalline systems. Due to presence of such structures in skin barrier, it was decided here to investigate the potential of athermal MW as skin penetration enhancer. In this investigation, nitrofurazone was chosen as the model penetrant and its permeation through rat skin was studied in vitro at 45 and 90min exposure intervals using MW intensities of 3, 15, 30, 60, 120W at 2450MHz. Results revealed that at 30°C and 45min exposure, 3W MW does not affect permeation of nitrofurazone (P=0.148), while higher intensities increased its flux significantly (P<0.05) in a intensity-dependent manner up to 2.7 times. When the duration of exposure increased to 90min, the enhancement ratio also increased to reach a maximum of 3.3. Applying 60W MW at 25, 30, 37 and 42°C resulted in a parabolic relationship between temperature and enhancement ratio. The present results reveal that microwave can act as a skin penetration enhancement method and that its effect depends on applied intensities, exposure time and temperature.
微波（MW）是电磁频谱的一部分，频率在 0.3-300GHz 之间，通过其热效应和非热效应以不同的方式影响人体，包括细胞膜和液晶系统的流化。由于皮肤屏障中存在这样的结构，因此决定研究非热 MW 作为皮肤渗透增强剂的潜力。在这项研究中，选择呋喃妥因作为模型渗透物，并在 2450MHz 下使用 3、15、30、60 和 120W 的微波强度，在 45 和 90min 的暴露间隔时间内，在体外研究其通过大鼠皮肤的渗透情况。结果表明，在 30°C 和 45min 暴露下，3W MW 不会影响呋喃妥因的渗透（P=0.148），而较高的强度以强度依赖性方式显著增加其通量（P<0.05），最高可达 2.7 倍。当暴露时间延长至 90min 时，增强比也增加到 3.3 倍。在 25、30、37 和 42°C 下应用 60W MW 时，温度与增强比之间呈抛物线关系。本研究结果表明，微波可以作为一种皮肤渗透增强方法，其作用取决于施加的强度、暴露时间和温度。
