G.P Senthil Kumar

The aim of the present study was an attempt to formulate and evaluate Levofloxacin loaded chitosan nanoparticles (CS-NP) by Emulsion solvent diffusion method using poloxamer 188 as surfactant; about eight different formulations (F1-F8) were prepared by changing the ratios of drug and excipients . Among all the formulations F3 was selected as optimized formulations  based on the physico chemical parameters and drug release studies and  it was incorporated in to 1% W/W of Carbopol gel (GF3) to obtained ophthalmic gel ,further, it was evaluated for antimicrobial activity against S. aureus and Bacillus subtilis. Compatibility studies by FT-IR showed no significant interactions between drug and excipients. The prepared Chitosan nanoparticle were characterized for different parameters like particle size analysis, zeta measurement, SEM, % drug content, entrapment efficiency, FT-IR, DSC, In-vitro release. The Gel containing chitosan nanoparticles (GF3)  were evaluated for different parameters like physical examination, pH, spread ability, viscosity, reological property, % drug content and  In-vitro release. The in vitro dug release and antimicrobial efficacy of GF3 formulation was compared with marketed product. From the results it was observed that the formulation controlled the drug release over a period of 24 hrs following Higuchi model and nonfickian diffusion mechanism with better antimicrobial action than the marketed product. The ocular irritancy study confirmed that ther is no irritation to the eye. From the above study we can conclude that the Levofloxacin loaded CS-NP were successfully prepared by emulsion solvent diffusion method and it is found to be  suitable for sustained ocular drug delivery having improved antibacterial action.