Formulation and evaluation of an in situ gel-forming ophthalmic formulation of moxifloxacin hydrochloride

Background/Aim: The aim of the present investigation is to prepare and evaluate in situ gel-forming ophthalmic drug delivery system of moxifloxacin hydrochloride. Materials and Methods: Sodium alginate, a novel ophthalmic gel-forming mucoadhesive polymer, which gets converted to gel in the presence of divalent-cations (calcium ion) present in the lachrymal fluid, was used as the gelling agent. Hydroxy propyl methyl cellulose (HPMC) is a mucoadhesive polymer used as viscosity enhancer. Suitable concentrations of buffering agents were used to adjust the pH to 6.5. All the formulations were sterilized in an autoclave at 121 degrees C for 15 minutes. The formulations were evaluated for clarity, pH measurement, gelling capacity, drug content estimation, rheological study, in vitro diffusion study, antibacterial activity, isotonicity, and eye irritation study. Results: The developed formulations exhibited sustained release of drug from formulation over a period of 10 hours thus increasing residence time of the drug. The optimized formulations were tested for eye irritation on albino rabbit (male). The formulations were found to be non-irritating with no ocular damage or abnormal clinical signs to the cornea, iris or conjunctiva observed. Conclusion: These in situ gelling systems containing gums may be a valuable alternative to the conventional systems.