An eye on metformin: Applications and drug delivery strategies for ocular conditions.

Metformin, a widely recognized anti-hyperglycaemic agent, shows pleiotropic effects across various disease states. Recent research has highlighted its potential therapeutic applications in ocular conditions, including inflammation, oxidative stress, burns, conjunctivitis, and neovascularization. Although the high-water solubility of metformin is considered advantageous, it may pose challenges for conventional eye drops due to the potential for rapid solubilization in aqueous-based lacrimal fluid and removal via tear turnover. To address this limitation, innovative ocular delivery systems, such as in situ gels, polymeric films, and nanoparticles, have been developed and shown efficacy in treating ocular diseases. However, further exploration and optimization of these delivery strategies are essential to enhance clinical outcomes. Moreover, the role of organic cation transporters in facilitating metformin's trans-barrier movement within ocular tissues offers a promising avenue for non-invasive drug delivery. This review outlines current ocular applications of metformin, evaluates emerging delivery technologies, and discusses future perspectives to overcome existing therapeutic barriers.