Ocular Drug Delivery System: A Review

The ocular drug delivery system is designed to deliver medications directly to the eye for the prevention, treatment, and management of various eye disorders. Conventional dosage forms such as eye drops are simple to use but often show poor drug absorption because of rapid tear drainage, blinking, and limited contact time with the eye surface. To overcome these challenges, researchers have developed advanced ocular drug delivery approaches, including in situ gels, nanoparticles, liposomes, ocular inserts, contact lens-based systems, and biodegradable implants. These novel systems improve drug retention, enhance bioavailability, provide sustained drug release, and reduce the frequency of administration, thereby improving patient compliance. The selection of an appropriate delivery system depends on the target tissue, drug properties, and the nature of the ocular disease. Continuous advancements in pharmaceutical technology are contributing to safer, more effective, and patient-friendly ocular therapies. This review highlights the anatomy-related barriers to ocular drug delivery, the limitations of conventional formulations, recent technological developments, and future perspectives in the field.