Development and evaluation of locust bean gum based in situ gel for ocular delivery of ofloxacin for treatment of bacterial keratitis.

One of the drawbacks of conventional ocular dosage forms is their short residence time in the eye. To address this, we propose an ocular in situ gel that adheres to the eye surface for a prolonged period. Locust bean gum (LBG), a galactomannan polysaccharide, exhibits the desired characteristics to serve as a drug carrier for ocular application. However, the gum has not yet been investigated for ocular drug delivery. In this work, we have developed an LBG based in situ gel loaded with ofloxacin and evaluated its drug delivery efficacy through in vitro and ex vivo tests. To confer temperature sensitivity, LBG was grafted with N-isopropyl acrylamide (NIPAAm), and a series of solutions were made with ofloxacin (0.03 % w/v). The solution turned into a gel when the temperature was raised to 37 °C. The safety and efficacy of the developed in situ gels were validated through experiments on rat eyes infected with clinical strains of bacteria. The developed keratitis was completely healed indicating that the grafted LBG can be used as a potential candidate for the development of ocular in situ gel.