Abstract
Rapid precorneal clearance and nasolacrimal drainage often result in low bioavailability (typically less than 5%) for conventional ophthalmic therapies. To improve the ocular administration of ciprofloxacin hydrochloride, this project will construct and assess an ion-activated in situ gelling system using a synergistic matrix of natural polymers: sodium alginate and Locust Bean Gum (LBG). By changing the sodium alginate concentrations while keeping the percentage of LBG constant, formulations (IG-1 to IG-4) were created. Clarity, pH, drug concentration, and in vitro gelling capacity in simulated tear fluid were all evaluated as part of the thorough characterisation of the produced formulations. Using FT-IR spectroscopy, drug-polymer compatibility was examined. Additionally, the study assessed the formulations' antibacterial activity against S. aureus and P. aeruginosa, rheological behaviour, and in vitro drug release kinetics. The compatibility of ciprofloxacin with the natural polymers was demonstrated by FT-IR spectra, which verified the lack of notable chemical interactions. When the optimised formulation (IG-3) encountered physiological ions, it showed an adequate pH of 6.29, a high drug content of 96.6%, and rapid, extended gelation. According to rheological analyses, the addition of LBG greatly strengthened the alginate matrix, producing a shear-thinning (pseudoplastic) profile that protects against erosion caused by blinking while guaranteeing patient comfort. IG-3 followed Zero-Order kinetics (R2 = 0.9999) with an anomalous (non-Fickian) diffusion mechanism, according to in vitro release tests. This resulted in a controlled and sustained drug release of roughly 85% over eight hours. After autoclaving, the formulation retained its stability and sterility while demonstrating outstanding antibacterial activity.