Copyright © 2026 Authors retain the copyright of this article. This article is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

@article{205236,
        author = {Mr. Amit Anil Jawadwar and Dr. Kavaljit Satish Birajdar and Mr. Dasrao Ashok Patil},
        title = {Formulation and Evaluation of Norfloxacin-Loaded In Situ Ophthalmic Gel for Sustained Antibacterial Action},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {1},
        pages = {6136-6141},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=205236},
        abstract = {Conventional ophthalmic solutions suffer from poor bioavailability because the instilled dose is rapidly lost from the precorneal area through tear turnover and nasolacrimal drainage, necessitating frequent dosing. In situ gelling systems overcome this limitation by being instilled as a free-flowing liquid that undergoes a sol-to-gel transition in the conjunctival cul-de-sac, thereby prolonging ocular residence time. In this work, a pH-triggered in situ gel of norfloxacin (0.3% w/v), a broad-spectrum fluoroquinolone, was developed for the treatment of bacterial conjunctivitis, corneal ulcer and blepharitis using Carbopol 940 as the gelling polymer and hydroxypropyl methylcellulose (HPMC K15M) as a viscosity enhancer, with mannitol and benzalkonium chloride as the tonicity-adjusting agent and preservative, respectively. Five formulations (F1–F5) were prepared and evaluated for clarity, pH, gelling capacity, viscosity, drug content, in vitro diffusion, antibacterial activity and accelerated stability; drug–excipient compatibility was confirmed by FTIR and DSC. All formulations showed an ocular-compatible pH (5.9–6.9), instantaneous gelation on contact with simulated tear fluid and a drug content of 79.56–85.23%. The optimized formulation, F5, exhibited the highest viscosity (1456 cP) and gelling capacity, released 81.43% of norfloxacin over 8 h following a non-Fickian (Korsmeyer–Peppas) mechanism, retained antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa comparable to the pure drug, and remained stable under accelerated storage conditions. The developed in situ gel therefore represents a promising, patient-compliant alternative to conventional norfloxacin eye drops.},
        keywords = {Carbopol 940; HPMC K15M; in situ gel; norfloxacin; ocular drug delivery; sustained release.},
        month = {June},
        }