Abstract

SMART HYDROGELS IN OCULAR DRUG DELIVERY: MECHANISMS, MATERIALS, AND THERAPEUTIC APPLICATIONS

*Santhiya P., Arun S., Anumanth K., Chandru K., Danisam A., Dr. V. Ganesan

ABSTRACT

Smart hydrogels represent a rapidly evolving class of stimuliresponsivebiomaterials with transformative potential in oculardrug delivery. Unlike conventional ophthalmic formulations,smart hydrogels are designed to undergo controlledphysicochemical transitions in response to physiological orexternal stimuli, including temperature, pH, ionic strength,enzymatic activity, light, and electric fields. These intelligentsystems significantly improve precorneal residence time,enhance drug bioavailability, and enable sustained and sitespecificdrug release in both anterior and posterior ocularsegments. This review presents a comprehensive analysis ofsmart hydrogel systems, encompassing their fundamentalmechanisms, polymer classifications, stimuli-responsivebehaviour, and therapeutic applications across a broad spectrumof ocular diseases. Key polymer matrices including chitosan,alginate, poly(N-isopropylacrylamide) (PNIPAAm),polyethylene glycol (PEG), and natural polysaccharides are critically evaluated. Specialemphasis is placed on recent formulation advances, literature evidence from 2019–2026, andthe challenges surrounding clinical translation such as biocompatibility, sterilisation,regulatory compliance, and scalable manufacturing. The review concludes with a forwardlookingperspective on multi-stimuli-responsive systems, regenerative ophthalmic applications, and the integration of nanotechnology with smart hydrogel platforms as future directions for precision ocular therapeutics.

Keywords: Smart hydrogels, ocular drug delivery, stimuli-responsive, in situ gel, thermoresponsive, pH-sensitive, chitosan, alginate, PNIPAAm, glaucoma, ocular bioavailability.