Enhanced Transdermal Drug Delivery by Sonophoresis and Simultaneous Application of Sonophoresis and Iontophoresis

Transdermal drug delivery has advantages of topical drug administration compared to the other conventional administration methods. However, the skin penetration of drugs is limited by the barrier properties of stratum corneum. The combinational strategy has been investigated to improve the skin permeability of the drug. For this study, we devised an improved device that can perform not only the single application of sonophoresis or iontophoresis but also the simultaneous application. The enhancement effect of sonophoresis was evaluated for various cosmeceutical drugs using a Franz diffusion cell. The enhancement ratio of niacinamide and retinol with sonophoresis was increased to 402% and 292%, respectively. The relationship was found between the enhancement effect of sonophoresis and the physicochemical properties of drugs. In particular, the simultaneous treatment of sonophoresis and iontophoresis enhanced skin penetration of glutamic acid to 240% using the fabricated device. The simultaneous application showed significantly higher enhancement ratio than application of sonophoresis or iontophoresis alone. Moreover, the improved device achieved skin penetration enhancement of various cosmeceutical drugs with lower intensity and a short application time. This combined strategy of transdermal physical enhancement methods is advantageous in terms of decline in energy density, thereby reducing the skin irritation. The miniaturized device with sonophoresis and iontophoresis is a promising approach due to enhanced transdermal drug delivery and feasibility of self-administration in cosmetic and therapeutic fields.