In situ Ophthalmic Gels Meet Nanotechnology: Nanoparticle-laden Smart Hydrogels for Precision Ocular Drug Delivery
Shraddha Pravin Vashikar *
Dr J.J. Magdum Pharmacy College, Jaysingpur, Kolhapur, Maharashtra, India.
Satvik Rahul Chavan
Dr J.J. Magdum Pharmacy College, Jaysingpur, Kolhapur, Maharashtra, India.
Shubham Bhauso Patil
Dr J.J. Magdum Pharmacy College, Jaysingpur, Kolhapur, Maharashtra, India.
Pranil Balasaheb Toraskar
Dr J.J. Magdum Pharmacy College, Jaysingpur, Kolhapur, Maharashtra, India.
Vrushabh Sunil Patil
Dr J.J. Magdum Pharmacy College, Jaysingpur, Kolhapur, Maharashtra, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Topical ocular therapy is dominated by eye drops, yet drug delivery to ocular tissues is frequently inefficient because of rapid tear dilution, blinking, nasolacrimal drainage, and layered anatomical barriers. These limitations can lead to low bioavailability, frequent dosing, variable clinical response, and avoidable systemic exposure. Stimuli-responsive in situ gels and drug nanocarriers have each been developed to address parts of this problem, motivating integrated “nano-in-gel” systems.
Objective: To summarize and critically analyze nanoparticle-laden in situ ophthalmic gels as precision drug-delivery platforms for anterior and posterior segment diseases, focusing on design rationale, materials, performance outcomes, and translational barriers.
Method: This narrative review synthesizes peer-reviewed research on ophthalmic in situ gelling systems (thermo-, pH-, and ion-activated) and nanocarriers (polymeric nanoparticles, lipid nanoparticles, liposomes, micelles, dendrimers, and nanogels), with emphasis on hybrid formulations in which nanoparticles are dispersed within an in situ gelling matrix. Key formulation variables, characterization methods, and in vitro/ex vivo/in vivo evaluation approaches are summarized.
Results: Across reported studies, nanoparticle-laden in situ gels consistently improve precorneal residence time and enable sustained drug release, often translating into higher corneal permeation and enhanced pharmacodynamic effects in models of glaucoma, keratitis, dry eye disease, and ocular inflammation. Performance is driven by dual mechanisms: gel-mediated retention and nanoparticle-mediated protection, solubilization, and controlled release. However, clinical translation is constrained by sterilization compatibility, long-term stability, scalable manufacturing, and regulatory complexity for combination products.
Conclusion: Nanoparticle-laden in situ gels are promising, adaptable platforms that can reduce dosing burden and improve ocular exposure, but progress to routine clinical use will depend on robust quality-by-design development, standardized characterization, and clinically relevant safety and efficacy validation.
Keywords: In situ gel, ophthalmic drug delivery, nanoparticle-laden in situ gel, stimuli-responsive hydrogel, thermos-responsive gel, pH-sensitive gel