Iontophoretic delivery of dexamethasone-loaded nanoparticles to the anterior segment of the eye

Eye drops are often prescribed for the treatment of inflammatory diseases in the anterior segment of the eye; however, owing to rapid preocular drug clearance, frequent administration is required. In this study, we propose the noninvasive iontophoretic delivery of poly (lactic-co-glycolic acid) nanoparticles loaded with the anti-inflammatory drug dexamethasone (DXT). After topical administration of DXT-loaded nanoparticles (DXT-NP) to the eye, we applied iontophoresis with electrodes attached to the skin of the forehead and eyelid. Iontophoresis increased the amount of DXT-NP permeated into the eye tissues of rabbits by ten folds compared to that without iontophoresis. One-time iontophoretic delivery of DXT-NP released the drug, in a sustained manner, in the aqueous humor of the eye for more than 10 days. In contrast, the drug was cleared rapidly in hours with Maxidex®, a commercially available eye drop of DXT. Therefore, iontophoretic delivery of DXT-loaded nanoparticles is a promising strategy to enhance drug bioavailability and reduce the frequency of topical drug administration to the eye.