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Application of ultrasound enhances skin permeability to a variety of molecules (sonophoresis). The enhancement induced by ultrasound is particularly significant at low-frequencies (f<100 kHz, low-frequency sonophoresis). This review summarizes mechanisms and applications of low-frequency sonophoresis. In vitro, in vivo, as well as clinical studies(More)
This paper discusses the state of the art in a relatively new approach in the field of controlled drug delivery-responsive polymeric drug delivery systems. Such systems are capable of adjusting drug release rates in response to a physiological need. The fundamental principles of externally and self-regulated delivery systems are examined. Special attention(More)
Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Application of ultrasound to the skin increases its permeability (sonophoresis) and enables the delivery of(More)
Ultrasound is used in many medical applications, such as imaging, blood flow analysis, dentistry, liposuction, tumor and fibroid ablation, and kidney stone disruption. In the past, low frequency ultrasound (LFUS) was the main method to downsize multilamellar (micron range) vesicles into small (nano scale) unilamellar vesicles. Recently, the ability of(More)
The effect of ultrasound on the degradation of polymers and the release rate of incorporated molecules within those polymers was examined. Up to 5-fold reversible increases in degradation rate and up to 20-fold reversible increases in release rate of incorporated molecules were observed with biodegradable polyanhydrides, polyglycolides, and polylactides. Up(More)
The reproducible regulation of release of a macromolecule (bovine serum albumin) from biocompatible polymer systems has been demonstrated. Small magnetic spheres or cylindrical magnets were embedded within the polymer matrix which was then subjected to an oscillating magnetic field. In this fashion baseline release rates could be increased 5- to 10-fold(More)
The effect of therapeutic range ultrasound (1 MHz) on skin permeation of D-mannitol, a highly polar sugar alcohol, inulin, a high molecular weight polysaccharide and physostigmine, a lipophilic anticholinesterase drug was studied in rats and guinea pigs. D-Mannitol and inulin are totally and rapidly excreted, once they have penetrated through the skin into(More)
Application of low-frequency ultrasound has been shown to enhance transdermal transport of drugs (low-frequency sonophoresis). In this paper, we show that the efficacy of low-frequency ultrasound in enhancing transdermal transport can be further increased by its combination with sodium lauryl sulfate (SLS), a well-known surfactant. The dependence of the(More)