LABORATORY-SCALE DEVELOPMENT AND IN-VITRO EVALUATION OF NORFLOXACIN-LOADED POLYMERIC OCUSERTS PREPARED BY SOLVENT CASTING METHOD

Background: Conventional ophthalmic dosage forms are associated with rapid precorneal clearance, tear dilution, blinking, nasolacrimal drainage, and short ocular residence time, which may reduce ocular drug bioavailability. Polymeric ocuserts are laboratory-scale ocular inserts designed to provide comparatively prolonged residence and controlled drug release under in-vitro conditions. Objective: The present study aimed to formulate and evaluate Norfloxacin-loaded polymeric ocuserts using HPMC, PVP K30, and sodium alginate by the solvent casting method. Materials and Methods: Nine formulations, F1–F9, were prepared by varying polymer concentrations. Ocuserts were evaluated for preformulation properties, thickness, weight variation, folding endurance, surface pH, drug content, moisture absorption, moisture loss, in-vitro drug release, release kinetics, sterility observation, and accelerated stability. Norfloxacin showed λmax at 269.6 nm. The UV calibration curve was linear in the concentration range of 2–12 µg/mL, with equation y = 0.078x + 0.006 and R² = 0.9991. FTIR analysis showed retention of major characteristic peaks of Norfloxacin in the drug–polymer mixture. Results: Thickness ranged from 0.21 ± 0.01 to 0.27 ± 0.01 mm, surface pH from 7.0 ± 0.06 to 7.2 ± 0.09, drug content from 96.2 ± 0.8% to 99.1 ± 0.4%, weight variation from 42.6 ± 1.2 to 52.4 ± 1.2 mg, folding endurance from 145 ± 5 to 212 ± 9, moisture absorption from 5.82 ± 0.21% to 7.28 ± 0.26%, and moisture loss from 4.71 ± 0.18% to 5.76 ± 0.18%. F7 showed the most balanced laboratory profile, with 43.62 ± 1.15% drug release at 150 minutes and best fit to the Higuchi model with R² = 0.991. Sterility observation showed no visible microbial growth. Accelerated stability testing of F7 for three months showed no major change in physical appearance, drug content, or release behaviour. Conclusion: Norfloxacin-loaded polymeric ocuserts were successfully prepared by solvent casting. F7 was identified as the most suitable laboratory-scale formulation based on physicochemical characteristics and comparatively slower in-vitro release. However, further extended release, ex-vivo permeation, ocular irritation, antimicrobial, in-vivo, packaging, and long-term stability studies are required.