Revolutionizing Conjunctivitis Treatment: Nanotechnology Advances and Innovative Drug Delivery Strategies

This comprehensive review outlines the challenges and advancements in the treatment of conjunctivitis, emphasizing the limitations of conventional therapies and the promise of nano-technology-based solutions. Conjunctivitis, one of the common external eye diseases, is a tissue inflammation that affects people of all ages. Redness, irritation, tearing, and increased secretions are the primary symptoms of conjunctivitis. This review highlights the eye's complex anatomy and physiological barriers, i.e., corneal, pre-corneal, and blood-corneal barriers, which signifi-cantly limit drug penetration and bioavailability within ocular tissues. Antibacterial and anti-inflammatory drugs are prescribed to treat conjunctivitis. Conventional eye drops, the primary treatment, are convenient but their effectiveness is limited, delivering less than 5% of the drug to the intended site due to tear drainage, enzymatic degradation and short residence time. Nanotech-nology-based drug delivery like nanoemulsions, liposomes, nanosuspensions, polymeric nanopar-ticles, niosomes and nanofibers provide drug stability, prolong ocular residence time, reduce side effects and improve drug permeability across ocular barriers, yet each faces distinct challenges that hinder their broader application. For instance, liposomes and niosomes are prone to stability issues, hydrogels lack mechanical strength, nanofibers struggle with constant drug release, and microemulsions are challenging to scale up. Nanomicelles, however, show significant potential in ocular therapy. These systems, with particle sizes ranging from 10 to 100 nm, are easily scalable, exhibit high encapsulation efficiency, and effectively enhance the solubility and stability of hy-drophobic drugs. Their small size and distinct properties enable targeted delivery to both anterior and posterior eye tissues, minimizing systemic side effects, improving cell bioavailability, and fa-cilitating focused drug deposition in affected tissues. Thus, nanotechnology offers a transforma-tive approach to overcoming the limitations of traditional ocular drug delivery systems. Among these, nanomicelles stand out due to their unique therapeutic potential. However, addressing the challenges of scalability, stability, and long-term efficacy remains crucial for the widespread ap-plication of these technologies.