Emerging Nanoformulations in Targeted Drug Delivery for Ocular Applications

Abstract: Effectively administering ocular drugs while preserving patient compliance, improving efficacy, and achieving greater bioavailability presents several challenges. This is due to the eye’s defensive systems, physico-biological barriers, and structural obstacles. To overcome these limitations, numerous investigations on nanotherapeutic treatments have been conducted in recent years. To increase the efficacy of drug delivery, several novel medications with unique formulations have been developed for targeted distribution through modified drug administration techniques and routes. Novel drug carrier systems in nanoformulations have demonstrated potential in enhancing medication release and retention in ocular tissue. To boost therapeutic outcomes, biodegradable polymers have been investigated as fundamental materials for developing nanocarriers to encapsulate currently available medications due to their improved bioavailability, extended drug action, enhanced tissue adhesion, reduced toxicity, and targeted administration in the eye. Chitosan-based systems are biodegradable, mucoadhesive, and enhance drug permeation across ocular barriers, but may have limited mechanical strength and faster degradation in retinal environments. PLGA-based systems provide robust structural stability and prolonged, controlled drug release for retinal delivery, although they may cause localized acidity upon degradation and have less inherent mucoadhesion. The nanoformulations developed for the diagnosis and treatment of different eye conditions are the main topic of the current review.