Preparation of levofloxacin loaded in situ gel for sustained ocular delivery: in vitro and ex vivo evaluations

The major drawback of the eye drops is rapid elimination of drug from the precorneal region, thus ensuing poor bioavailability as well as therapeutic efficacy. To conquer these limitations, a pH triggered in situ gel was developed for sustained delivery of levofloxacin. Two polymers namely hydroxypropyl methylcellulose (HPMC) and sodium alginate along with the boric acid buffer were used to formulate the in situ gel. Based on the various physicochemical evaluation parameters like pH, clarity and gelling capacity placebo formulations were selected and further characterized for viscosity, in vitro release, ex vivo corneal permeation, and histopathological studies. The optimized in situ gel (F28) showed sustained release of 93 +/- 4.23% for 24 h and cumulative drug permeation of 71.81 +/- 4.7% for 72 h. Additionally, ocular irritation study and histopathology of the formulation treated cornea confirm the non-irritancy of the optimized formulation. Based on all the above performed studies, it can be concluded that the in situ gel would present a fruitful alternative for the ocular infections.