Abstract: “Transdermal drug delivery has a critical contribution to medical practice and some advantages over conventional oral administration and hypodermic injection. Enhancement of percutaneous absorption or penetration of a therapeutic agent by ultrasound (sonophoresis) has been applied and studied for decades. In this study, the penetration percentage through the porcine ear skin specimen was determined quantitatively by measuring the fluorescence from nanoparticles in the size of 60 nm, 220 nm, and 840 nm in the receptor chamber at different sonication parameters. It is found that the sonophoresis efficiency increased with the acoustic intensity, duty cycle, and sonication duration, but decreased with the particle size (62.65.4% for 60 nm vs. 11.91.1% for 840 nm polystyrene nanospheres after 30 min sonication at 0.5 W/cm2 and 100% duty cycle, p 0.05). Although the pore size kept almost the same in scanning electron microscopy, more flakes were observed at the entry site with the progress”

Keywords: transdermal drug delivery, sonophoresis, fluorescent nanoparticles, quantitative drug penetration, cavitation