Ultrasound, transdermal penetration

A recent work by Lavon et al. [74] suggests that the synergistic effect of SLS and ultrasound when applied simultaneously can also be attributed to the modification of the stratum corneum pH profile when exposed to ultrasound. The altered pH profile that results in improved SLS lipophylic solubility, together with improved SLS penetration and dispersion, can explain the synergistic enhancing effect on transdermal transport (see Figure 16.4). 

The use of ultrasound (US) to enhance percutaneous absorption (so-called sonophoresis or phonophoresis) has been studied over many years, and is the basis of US propagation and US effects on tissue, and the use of US in transdermal delivery have been reviewed in detail. The proposed mechanisms by which US enhances skin penetration include cavitation, thermal effects and mechanical perturbation of the SC that is, US acts on the barrier function of the membrane. ... 

Kost, J. Langer, R. Ultrasound-mediated transdermal drug delivery. In Topical Drug Bioavailability, Bioequivalence, and Penetration Shah, V.P., Maibach, H.I. Eds. Plennum New York, 1993 91-103. 

Miyzaki, S. Mizuoka, O. Takada, M. External control of drug release and penetration enhancement of the transdermal absorption of indomethacin by ultrasound irradiation. J. Pharm. Pharmacol. 1990, 43, 115-116. 

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