Delivery of Hydrophobic Drugs to the Posterior Ocular Region by Gel-in-Water Nanoemulsion

PURPOSE: The aim of this study was to develop a nanogel emulsion as a minimally invasive, safe, and effective treatment alternative for posterior ocular diseases. METHODS: A gel-in-water (G/W) nanoemulsion was developed by ultrasonication using beeswax as an organogelator. Different physicochemical properties were evaluated along with particle size analysis by dynamic light scattering. In vitro biocompatibility of G/W nanoemulsion using rat hepatocytes and human umbilical vein endothelial cells (HUVECs) and in vivo corneal permeability as eye drops were investigated. RESULTS: The nanogel emulsion was monodispersed with a polydispersity index and particle diameter of approximately 0.2 and 200 nm, respectively. The zeta potential value of −8.1 mV suggested enhanced stability and improved retinal permeability of nanoparticles. The prepared nanoemulsion was found to be biocompatible with hepatocytes and HUVECs in vitro. Moreover, in vivo study demonstrated high permeability of G/W nanoemulsion to the retinal layer with no ocular irritation. CONCLUSIONS: G/W nanoemulsions have the potential for topical drug delivery in the posterior eye segment with maximum therapeutic efficacy. TRANSLATIONAL RELEVANCE: Organogel nanodispersion is a new concept to deliver hydrophobic drugs to the posterior segment of eyes as a novel drug delivery system.