Design and Evaluation of Fluconazole loaded In-Situ Gel for Ocular Keratitis

Ocular keratitis, particularly fungal keratitis, remains a significant cause of visual impairment globally, especially in tropical and subtropical regions. Conventional ophthalmic formulations like eye drops often suffer from poor ocular bioavailability due to rapid precorneal elimination, tear turnover, and blinking. To address these limitations, the present research aimed to develop a fluconazole-loaded in-situ gel (ISG) using temperature-sensitive polymers for sustained ocular drug delivery. The study utilized Poloxamer 407, in combination with mucoadhesive agents such as xanthan gum and carbopol 934, to formulate a sol-to-gel system that undergoes gelation upon contact with physiological temperature. A 3² factorial design was employed to optimize the formulation based on critical parameters including gelation temperature, viscosity, and drug release profile. The optimized ISG formulation was characterized for clarity, pH, viscosity, gelation time and temperature, mucoadhesive strength, in vitro diffusion, and release kinetics. The antifungal efficacy of the optimized formulation was tested against Candida albicans and confirmed via agar diffusion studies. Additionally, the formulation exhibited sustained drug release, improved ocular residence time, and was found to be non-irritating in the HET-CAM test. Stability studies further validated the physical and chemical integrity of the formulation over a defined period. This study successfully demonstrates the potential of fluconazole-loaded thermosensitive ISGs as an effective, patient-compliant strategy for the targeted treatment of fungal keratitis, enhancing both therapeutic efficacy and drug bioavailability.