DEVELOPMENT AND EVALUATION OF A PH-RESPONSIVE OFLOXACIN-LOADED NANOPARTICLE IN-SITU GEL FOR SUSTAINED OCULAR DELIVERY

Objective: This study aims to develop an in-situ gel formulation incorporating Ofloxacin-loaded nanoparticles to enhance ocular residence time and therapeutic efficacy of drug. Methods: The formulation process included pre-formulation studies such as solubility and UV analysis of Ofloxacin. A pH-triggered in-situ gel was prepared using Poloxamer 407, chitosan, and Eudragit L-100. Various post-formulation parameters were evaluated, including pH, viscosity, drug content, and in-vitro drug release kinetics. Results: Nanoparticles were confirmed using DLS with a particle size of 688 nm. The viscosity of in-situ gel formulations followed a shear thinning process before contact with simulated tear fluid (STF). The viscosity reduced significantly (p<0.05, two-way ANOVA) for the in-situ formulations after contact with STF. the formulation containing 4% Poloxamer 407 and 0.8% Gellan Gum (OFX3) demonstrated acceptable viscosity behavior and sustained drug release. OFX3 achieved a drug release of 97.81% over 6 h, adhering to Higuchi release models and expressing quasi-Fickian diffusion. The HET-CAM test confirmed the formulation non-irritant nature, while stability studies demonstrated no significant changes over a 3-month period. Conclusion: The developed pH-sensitive in-situ gel effectively enhances the solubility of Ofloxacin, providing a promising treatment option for bacterial conjunctivitis. The developed ofloxacin-loaded nanoparticulate in-situ gel successfully integrates controlled release through prolonged ocular residence. Future in-vivo studies will further consolidate its potential as a pioneering candidate for translational ophthalmic applications.