Application of Ultrasound to Drug Therapy ; Transdermal Therapeutic System Using Pulsed Ultrasound

研究了开关比为1:2、1:4和1:9的脉冲超声（1 MHz）对大鼠吲哚美辛及软膏透皮吸收的影响。在强度范围（0.5-2.5 W cm^<-2>）下提供10至19分钟的超声能量，通常用于治疗目的的能量水平。研究发现，开/关脉冲比、脉冲强度和给药时间对吲哚美辛经皮传音系统有重要影响；1:2脉冲输出超声对改善吲哚美辛的透皮吸收效果最好。最强穿透强度为1.0 W cm^<-2>，施加时间为15min。脉冲输出可以在不增加皮肤温度的情况下使用更高强度的超声波。随着超声强度和应用时间的增加，皮肤损伤逐渐增加。当在适当的强度和时间使用时，脉冲超声似乎是一种安全的技术，可以增强各种药物分子通过人体皮肤的通道。

The effect of pulsed ultrasound (1 MHz) with on/off ratios of 1 : 2,1 : 4 and 1 : 9 on transdermal absorption of indomethacin from and ointment was studied in rats. Ultrasound energy was supplied for between 10 and 19 min at a range of intensities (0.5-2.5 W cm^<-2>), energy levels commonly used for therapeutic purposes.The on/off pulsed ratio, intensity and the time of application were found to play an important role in the transdermal phonophoretic delivery system of indomethacin ; 1 : 2 pulsed output ultrasound appeared to be the most effective in improving the transdermal absorption of indomethacin. The highest penetration was observed at an intensity of 1.0 W cm^<-2> and time of application of 15min. With pulsed output it is possible to use higher intensities of ultrasound without increasing skin temperature. Progressively more skin damage was noted as the intensity and the time o application of ultrasound increased.When used at a proper intensity and time of application, pulsed ultrasound appears to be a safe technique for enhancing the passage of various drug molecules through human skin.