Quantitative Evaluation of Sonophoresis Efficiency and Its Dependence on Sonication Parameters and Particle Size

Abstract

ral administration and hypodermic injection are routine approaches for drug delivery to the circulation. However, they are associated with some shortcomings, such as premature drug metabolization by the first-pass effect of the liver and gut wall, degradation of drugs by the digestive tract, unstable plasma levels, difficulty of immediate termination, pain, dangerous medical waste, and risk of disease transmission by needle reuse. 1 Transporting therapeutic agents through the wide epidermis, known as transdermal drug delivery, is an attractive alternative to conventional approaches. Transdermal drug delivery is noninvasive in nature, and the systems can be self-administered, released over a long period, and inexpensive. Three generations of development have been undergone in transdermal drug delivery, such as chemical enhancers, 2 iontophoresis, 3 biochemical enhancers, 4 electroporation, 5 and microneedles. 6 These techniques are mostly reversible except microneedles. The skin structure and elasticity can be altered to enable increased permeation of compounds temporarily and resumed a few hours after termination without permanent damage. Kun Loong Lee, BS, Yufeng Zhou, PhDReceived January 14, 2014, Transdermal drug delivery makes a critical contribution to medical practice and some advantages over conventional oral administration and hypodermic injection. Enhancement of percutaneous absorption or penetration of therapeutic agents (ie, drugs and macromolecules) by ultrasound, termed sonophoresis, has been applied and studied for decades. In this study, the penetration percentage through porcine ear skin specimens was determined quantitatively by measuring the fluorescence from nanoparticles of 60, 220, and 840 nm in size in a receptor chamber at different sonication parameters (ie, duty cycle, 20%-100%; acoustic intensity, 0.3-1.0 W/cm 2 ; duration, 7-30 minutes; and frequency, 1 MHz). In general, the sonophoresis efficiency increased with the acoustic intensity, duty cycle, and sonication duration but decreased with the particle size (mean ± SD, 62.6% ± 5.4% for 60-nm versus 11.9% ± 1.1% for 840-nm polystyrene nanospheres after 30 minutes of sonication at 0.5 W/cm 2 and a 100% duty cycle; P < .05). On scanning electron microscopy the pore size remained the same (≈100 μm), but more flakes were observed with the progress of sonication. In summary, sonophoresis efficiency is dependent on the ultrasound parameters and particle size. Sufficient sonication would lead to satisfactory penetration of even submicrometer objects through the pores.

Dexamethasone Sodium Phosphate Penetration During Phonophoresis at 2 Ultrasound Frequencies

“…Various frequencies have been examined in phonophoresis laboratory experiments, 23,24 but this has not altered phonophoresis factors in randomized clinical trials in humans. In most randomized clinical trials, 1 MHz has been used as the phonophoresis frequency of choice.…”

Effect of silicone gel versus Contractubex or corticosteroid phonophoresis for post-burn hypertrophic scars: a single-blind randomized controlled trial

“…it combines ultrasound therapy with topical drug therapy to gain therapeutic drug concentrations at selected sites within the skin. in this technique, the drug is combined with a coupling agent, commonly a gel [15].…”

“…Application of low-frequency ultrasound (20-100 kHz) enhances skin permeability more efficiently than high-frequency ultrasound (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). The mechanism of transdermal permeation involves a breakdown of the stratum corneum lipids, therefore allowing the drug to pass via the skin.…”

“…Previous studies have focused only on the efficacy of silicon alone, Contractubex, or corticosteroids, but no research has been conducted to compare those different methods and apply ultrasound waves to improve the skin absorption of the medications [15,17,18].…”

Histological and immunohistochemical profile of bone tissue regenera tion under ultrafonophoresis of hyaluronic acid

“…В последнее время особое значение приобретает методика ульрафонофореза, при которой в качестве контактной среды применяют лекарственные вещества. Эта методика значительно расширяет возможности трансдермального введения лекарственных веществ [15,16], тем более, что в данном случае лечебное воздействие одномоментно осуществляется двумя факторами -ультразвуковой волной и введенным с ее помощью веществом, под действием которых улучшается обмен веществ, усиливается репарация и регенерация костной ткани [17,18].…”