One among many strategies to prolong ocular residence time and enhance local effect of antibiotics/antimicrobials in eye to eradicate bacterial infections was in situ ocular gels particularly thermoresponsive ocular in situ gels. The objective of present work was to develop and optimize thermoresponsive Gatifloxacin ocular in situ gels using Pluronic F127 and Hydroxyl ethyl cellulose as gelator and mucoadhesive agent, respectively to improve the local availability of gatifloxacin to eradicate bacterial infections in the eye. Thermoresponsive ocular gels were optimized using 32 factorial design. The selected independent variables were percentage of Pluronic F127(X1) and percentage of Hydroxy ethyl cellulose (X2) and dependent variables were % cumulative drug release (% CDR) at 3rd h (YQ3), % CDR at 10th h (YQ10) and mucoadhesive strength (YMAS). Physical properties, pH, Gelation temperature, Gelling capacity, Viscosity studies were conducted for all the formulations. Antimicrobial assay and in vivo ocular irritation study on rabbit eye were also conducted for optimized formulation. Mucoadhesive strength of the formulations gave good results with sheep corneal membrane. All the formulations have shown Newtonian nature in the sol state and pseudoplastic behavior in the gel state. Antimicrobial studies indicated efficacy comparable that of marketed formulation. No ocular irritation was observed in rabbits following Draize technique. These results demonstrate that pluronic F127 and HEC can be used for the preparation of Gatifloxacin in situ gel for improving ocular bioavailability.
