Smart gel system of Linum usitatissimum mucilage as a vehicle of an ophthalmic drug

Smart gel systems involve the utilization of the rapid sol-gel phase transition of an ocular solution in the cul-de-sac of eye in response to physicochemical stimuli. The current investigative scheme has been designed to formulate and assess a smart in situ gelling system of a quinolone antibiotic (ofloxacin) in combination with biodegradable polymers: Linum usitatissimum mucilage (LUM) and sodium alginate. The medicated formulations were clear and isotonic in the pH range 5.57-6.23 and converted into gel in the presence of simulated lachrymal fluid. The formulations were scrutinized through content uniformity, gelling capacity and rheological parameters and in vitro diffusion studies. The formulations were characterized by ultraviolet-visible and Fourier transform infrared spectroscopy for unveiling of the chemical interactions and preliminary structural elucidation. Sterility and stability, antibacterial and eye safety tests using in vitro and in vivo models proved that the optimized formulation (F2) is stable, therapeutically efficacious and non-irritant and provides complete and sustained release of the drug over a 12 h period in a predetermined manner. The data obtained thus suggest that a novel in situ gel system can be successfully designed by using biodegradable polymers for sustained ofloxacin delivery, leading toward the goal of a viable alternate ophthalmic medicine.