Experimental Study Of Transdermal Iontophoresis Of Vancomycin

Objective: To apply transdermal iontophoresis of vancomycin to infectious disease in orthopedics. To study the feasibility of transdermal iontophoresis of vancomycin. To research the antibacterial stability of vanconmycin after transdermal iontophoresis and the toxicity of vanconmycin to dermal cell. And to investigate the effect of background ion and current on iontophoresis.Methods: calculate the regressive equation based on the standard curve of vancomycin. Divide 78 Sprague-Dawley (SD) rats into 3 groups at random. 18 rats are in vancomycin-normal saline group (V-NS group);30 rats in vancomycin-distilled water group (V-DW group);and 30 rats in contrast group (C group). Divide V-NS group into 3 sub-groups on average. Apply 0.5mA/cm~2 and 1.0 mA/cm~2 direct current (DC) for one hour to two sub-groups for vancomycin-normal saline solution transdermal iontophoresis respectively. However, passive transdermal diffusion was carried out in another sub-group. Then gain the tissue under the skin from diffusion site, and measure the concentration of vancomycin quantitatively. Divide the V-DW group into 5 sub-groups in the same way. Apply 0.3mA/cm~2, 0.5mA/cm~2, 1.0mA/cm~2 and 1.5mA/cm~2 DC to 4 sub-groups for vancomycin-distilled water solution transdermal iontophoresis respectively, and passive diffusion was carried out in another sub-group as the V-NS group. Measure the concentration of vancomycin quantitatively, and observe the structure and ultrastructure of skins gained from diffusion site with microscope and transmission electron microscope. Divide the C group into 5 sub-groups. The transdermal diffusion without drug was carried out under 0.3mA/cm~2, 0.5mA/cm~2, l.OmA/cm~2 and 1.5mA/cm~2 DC respectively in 4 subgroups, and any intervention would not be done in another sub-group. Observe the structure and ultrastructure of skins in thesame way.Results: Circle of repressing bacteria was not found in V-NS group. In V-DW group, vancomycin can not transport across the skin under passive diffusion, but it can do under electric field. The flux of vancomycin become greater along with increasing intensity of current (PO.Ol) . There is a relation of linear regression between flux and current (f=8.1158+12.\7%1X). The observations of structure and ultrastructure of skins shows that the skins were injured under 1.0mA/cm2 and 1.5mA/cm2 DC, while they were intact under 0.3mA/cm2 and 0.5mA/cm2 DC. The gaps between epidermal cells get greater under 0.5mA/cm2 DC, but the desmosome are intact. Conclusions: The transdermal iontophoresis of vancomycin can be carried out under lower DC, and it will not result in injury to skin. The repressing bacteria effect of vancomycin will not be changed by iontophoresis, so transdermal iontophoresis has the potential to be a noninvasive method for delivering vancomycin. The transdermal flux of vancomycin is affected by current and competitive background ions, transdermal iontophoresis of vancomycin is a promising method for treating local infection, especially in orthopedics disease.