2023 Volume 46 Issue 7 Pages 921-928
Intravitreal injection therapy of anti-vascular endothelial growth factor (VEGF) antibody or steroids is the mainstream for patients with age-related macular degeneration (AMD). However, since intravitreal injection is invasive administration, side effects such as endophthalmitis are major problems. In this study, we selected eye drops as a non-invasive treatment method, and aimed to develop eye drops that can deliver TAK-593 (VEGF receptor tyrosine kinase inhibitor) to the posterior segment of the eye. Since TAK-593 is a poorly water-soluble drug, the TAK-593 emulsion was formulated. The solubility of TAK-593 in various oils was measured, and the oil used for the emulsion was selected. Furthermore, viscosity enhancers were added to the emulsion in order to improve the drug delivery into the eye. As viscosity enhancer, xanthan gum was selected based on the properties and the viscosity of the emulsion. The delivery of TAK-593 to the posterior eye was increased by the formulation concentration and the addition of viscosity enhancers. In the laser-induced choroidal neovascularization model, TAK-593 emulsion eye drops showed the same angiogenesis-suppression efficacy as anti-VEGF antibody intravitreal injection. From these results, it was revealed that TAK-593 with an effective drug concentration can be delivered to the posterior eye by non-invasive eye drop administration.
