Hikima T, Hirai Y, Tojo K
Department of Biochemical Science and Engineering, College of Computer Science and Biosystems Engineering, Kyushu Institute of Technology, Iizuka, Fukuoka, Japan.
Pharm Res. 1998 Nov;15(11):1680-3. doi: 10.1023/a:1011944209274.
The effect of ultrasound on skin penetration and metabolism of prednisolone (PN) and prednisolone 21-acetate (PNA) was investigated in the hairless mouse skin in vitro.
The abdominal skin excised freshly was pretreated under different ultrasound intensities (4.32, 2.88, and 1.50 W/cm2) for 10, 30, and 60 min. The penetration/metabolism rate of PNA and its metabolite (PN) was then measured using a side-by-side diffusion cell.
The skin penetration of PN was enhanced by the ultrasound pretreatment. This enhancement was attributed to the decrease in the stratum corneum barrier capacity by ultrasound energy. The steady-state appearance rate of PN following the skin bioconversion of PNA decreased appreciably with increasing the product of the duration of pretreatment (Dp, min) and the intensity of ultrasound applied (Iu, W/cm2). When the product value was less than 40 W/cm2 . min, the steady-state appearance rate of the PN hardly increased in spite of the penetration enhancement of PNA.
These findings indicated a possible deactivation of the skin enzymes by ultrasound energy.
在体外无毛小鼠皮肤中研究超声对泼尼松龙（PN）和泼尼松龙21 - 乙酸酯（PNA）经皮渗透及代谢的影响。
将新鲜切除的腹部皮肤在不同超声强度（4.32、2.88和1.50 W/cm²）下预处理10、30和60分钟。然后使用并列扩散池测量PNA及其代谢产物（PN）的渗透/代谢速率。
超声预处理可增强PN的经皮渗透。这种增强归因于超声能量使角质层屏障能力降低。随着预处理持续时间（Dp，分钟）与施加的超声强度（Iu，W/cm²）乘积的增加，PNA经皮肤生物转化后PN的稳态出现率明显降低。当乘积值小于40 W/cm²·分钟时，尽管PNA的渗透增强，但PN的稳态出现率几乎没有增加。
这些发现表明超声能量可能使皮肤酶失活。
