Enhanced Everolimus Delivery: Development and Evaluation of a Nanosuspension Formulation

To develop everolimus-loaded nanosuspensions (EV-sus) for the in vitro and in vivo corneal neovascularization (CNV) treatment.

Everolimus was encapsulated into nanosuspensions using a solvent volatilization technique. The developed nanosuspensions exhibited a drug concentration of 0.96 mg·mL^-1, an average particle size of 141.0 ± 1.0 nm, and a zeta potential of -12.2 ± 0.4 mV. C6-labeled EV-sus uptake by Human Corneal Epithelial Cells-Transformed (HCE-T) was time-dependent, energy-dependent, and involved multiple endocytic pathways, including caveolae- and lipid raft-mediated endocytosis, clathrin-mediated endocytosis, and caveolae-mediated endocytosis. The nanosuspensions exhibited efficacy in inhibiting VEGF-induced proliferation, migration, and tube formation in Human Umbilical Vein Endothelial Cells (HUVECs). According to RT-qPCR, the in vivo CNV model showed that EV-sus effectively reduced neovascularization, decreased vascular length and area, and diminished the expression of IL-1, IL-6, MMP-9, VEGF, and TNF-α. Additionally, the rabbit eye irritation test confirmed the safety and tolerability of the formulation.

These findings indicate that EV-sus might be an effective therapy for corneal neovascularization. The formulation exhibits excellent biocompatibility, efficient cellular uptake, and robust anti-angiogenic activity, suggesting its suitability for ocular administration and the potential to mitigate CNV progression with minimal irritation.