Low frequency sonophoresis

Mitragotri S, Kost J. Low-frequency sonophoresis—a review. Adv Drug Delivery Rev 2004 56 589-601. 

Mitragotri, S., and J. Kost. 2004. Low-frequency sonophoresis A review. Adv Drug Deliv Rev 56,... 

Mitragotri, S., D. Blanckschtein, and R. Langer. 1996. Transdermal drug delivery using low-frequency sonophoresis. Pharm Res 13 411. 

Tezel, A., A. Sens, and S. Mitragotri 2003. A theoretical description of transdermal transport of hydrophilic solutes induced by low-frequency sonophoresis. J Pharm Sci 92 381. 

Tezel, A., and S. Mitragotri. 2003. Interactions of inertial cavitation bubbles with stratum corneum lipid bilayers during low-frequency sonophoresis. Biophys J 85 3502. 

Kushner, J. IV, D. Blankschtein, and R. Langer. 2004. Experimental demonstration of the existence of highly permeable localized transport regions in low-frequency sonophoresis. J Pharm Sci 93 2733. 

Since cavitational effects in fluids vary inversely with ultrasound frequency, it is likely that cavitational effects should play an even more important role in low-frequency sonophoresis. Tachibana et al. hypothesized that application of low-frequency ultrasound results into acoustic streaming in the hair follicles and sweat ducts of the skin, thus leading to enhanced transdermal transport. Mitragotri et al. hypohesized that transdermal transport during low-frequency sonophoresis occurs across the keratinocytes rather than hair follicles. They provided the following hypothesis for the higher efficacy of low-frequency sonophoresis. 

Fig. 5 Transdermal transport through the stratum corneum. (A) Passive and (B) during low-frequency sonophoresis.

Tezel A, Dokka S, Kelly S, Hardee G E, Mitragotri S (2004). Topical delivery of anti-sense oligonucleotides using low-frequency sonophoresis. Pharm. Res. 21 2219-2225. 

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