Long acting injectables & implants: advances in intraocular drug delivery.

The treatment of posterior segment ocular diseases, such as age-related macular degeneration and diabetic retinopathy, poses a significant challenge for ophthalmologists due to the eye's complex anatomy and physiological barriers. To overcome these challenges, intravitreal drug delivery offers a promising solution by enabling direct administration of therapeutic agents into the pathological area through an injection. However, these injections are highly invasive and carry several risks, including infection, retinal detachment, and increased intraocular pressure. As a result, considerable efforts have been directed toward developing drug delivery platforms (implants, nano- and microparticles, and hydrogels) capable of providing sustained drug release over extended periods. These long-acting systems aim to reduce the frequency of injections, thereby improving patient quality of life and decreasing the overall economic burden of treatment. This review provides an overview of intravitreal drug delivery systems, evaluating their clinical applicability and the potential challenges that must be addressed before they can be successfully translated into marketed drug products.