Hyaluronic acid nanoparticle as drug delivery carrier for the treatment of allergic conjunctivitis.

BackgroundAllergic conjunctivitis is an inflammatory disorder of the conjunctiva triggered by allergens. Although topical eye drops are widely used, their efficacy is limited by rapid precorneal clearance and low ocular bioavailability. Hyaluronic acid (HA)-based nanoparticles may prolong ocular residence time and improve drug delivery.ObjectiveThis study aimed to develop and evaluate chitosan- and polyethylenimine (PEI)-cross-linked HA nanoparticles to improve drug encapsulation efficiency and achieve sustained release of diclofenac sodium for allergic conjunctivitis.MethodsHA nanoparticles were prepared by EDC/sulfo-NHS-mediated cross-linking with chitosan or PEI. Nanoparticle properties were characterized by FTIR, 1H-NMR, DLS, and HRTEM. Encapsulation efficiency, in vitro drug release, and cytocompatibility in SIRC cells were evaluated.ResultsFTIR and 1H-NMR analyses confirmed successful nanoparticle formation, cross-linking, and drug incorporation. H1P1-01DS exhibited a particle size of approximately 170 nm and a significantly higher encapsulation efficiency (82.0%) than the HA-chitosan formulations. Drug release followed a biphasic profile, with H1P1-01DS achieving approximately 90% cumulative release within 180 min, compared with 68-83% for HA-chitosan formulations. WST-1 assays demonstrated favorable cytocompatibility across all formulations, although cell viability decreased in a dose-dependent manner at higher concentrations.ConclusionThe HA-PEI nanoparticle formulation (H1P1-01DS) demonstrated sustained drug release, high encapsulation efficiency, and favorable biocompatibility, indicating its potential as a long-acting ocular drug delivery system for allergic conjunctivitis.