Emerging Trends in Ophthalmic Drug Delivery: Focus on NSAIDs and Corticosteroids

Ocular drug delivery is severely affected by anatomical and physiological ocular barriers, preventing drug permeation and therapeutic effects. Uveitis, keratitis, and inflammatory postoperative ocular complications demand accurate, sustained, and localized therapy. Nonsteroidal Anti-inflammatory Drugs (NSAIDs) and Steroidal Anti-inflammatory Drugs (Corticosteroids) are cornerstones for managing anterior and posterior ocular inflammation. Their traditional formulations, however, are flawed, with compromised bioavailability, tear clearance, and systemic toxicity. Nano-formulations prepared using the latest breakthroughs in nanotechnology have transformed ophthalmic drug delivery by offering enhanced solubility, prolonged retention time, and extended drug release. Liposomes, nanoemulsions, dendrimers, and polymeric nanoparticle-based nanocarriers enhance the therapeutic index of Corticosteroids and NSAIDs by improving penetration across ocular barriers and reducing dosing intervals at the systemic level. Of particular interest, prodrug medications, such as nepafenac, are metabolized intraocularly and provide greater inhibition of cyclooxygenase-2 (COX-2). To this end, biopharmaceutical drug evaluation tools, e.g., in vitro models of the cornea, pharmacokinetic profiling, and ocular imaging, are of utmost significance for determining the drug's efficacy and safety. Immunopharmacology, by the design of immunosuppressive drugs such as cyclosporine A, is also another branch of anti-inflammatory therapies, such as for chronic ocular surface diseases, such as dry eye. Nano-based and combination corticosteroids have been effective methods for controlled inflammation and synergy. Together with nanotechnology and the incorporation of biopharmaceutical screening, the era is opening to a new generation of ophthalmic anti-inflammatory therapy with lower risk, greater efficacy, and a patient-centered approach.