In Vitro and In Vivo Assessment of Levofloxacin Ocular Films for Enhanced Management of Bacterial Eye Infections

Introduction: Ocular infections such as conjunctivitis and keratitis present significant challenges due to rapid tear turnover, poor corneal permeability, and low patient compliance with frequent eye-drop dosing. Levofloxacin (LFX), a broad-spectrum fluoroquinolone, is widely used for ocular infections; however, its therapeutic effect is limited by poor ocular bioavailability. This study aimed to formulate and evaluate sustained-release LFX ocular films using biocompatible polymers HPMC K4M, gelatin, and Aloe barbadensis leaf mucilage (ABLM) to enhance retention, penetration, and antibacterial performance. Methodology: Ocular films were prepared using the solvent casting method and further optimized through Box–Behnken Design. Physicochemical evaluations included drug content, thickness, weight uniformity, moisture absorption/loss, and in vitro permeation. Antibacterial activity was assessed by agar-well diffusion, disc diffusion, and an in vivo Staphylococcus aureus conjunctivitis model in rabbits. Sterility testing and UV-based sterilization ensured safety. Results: All formulations showed uniform thickness (0.15–0.19 mm), consistent weight (61.85–65.54 mg), and high LFX content (88–97%). Moisture studies confirmed stability, with gelatin-rich films absorbing more moisture without structural damage. The optimized formulation, LF-6, exhibited the strongest antibacterial activity, producing inhibition zones of 21 mm (S. aureus) and 19 mm (E. coli). In vivo, LF-6 reduced conjunctival redness by day 4 and maintained antimicrobial action for 12 hours, with tear samples showing inhibition up to 23 mm². Permeation followed non-Fickian and Higuchi models. Discussion & Conclusion: The optimized LFX film (LF-6) demonstrated sustained release, prolonged ocular residence, and enhanced antibacterial efficacy compared with conventional eye drops. The polymer blend of gelatin, ABLM, and HPMC K4M was identified as optimal for stable, effective ocular inserts for bacterial conjunctivitis, highlighting their promise as superior alternatives to traditional ophthalmic solutions.