Coloaded Surface–Modified PLGA Nanoparticles for Sustained Ocular Delivery of Levofloxacin and Flurbiprofen

Purpose The purpose of the present work was to develop levofloxacin-flurbiprofen coloaded PLGA (LEV-FLU-PLGA) nanoparticles with surface modification using chitosan to attain mucoadhesion for the treatment of bacterial conjunctivitis. Method Polymeric nanoparticles were prepared by nanoprecipitation method and evaluated for parameters like particle size, PDI, zeta potential, entrapment efficiency (%), in vitro drug release, ex vivo permeation studies, microbial assay against Staphylococcus aureus and ocular tolerance using Hen’s egg test-chorioallantoic membrane (HET-CAM). Furthermore, surface of optimized PLGA nanoparticle formulation was modified by coating with chitosan. Results LEV-FLU-PLGA nanoparticles demonstrated particle size of 166.1 nm with PDI of 0.137 and zeta potential of − 16.8 mV. The entrapment efficiency was found to be 39.37% for levofloxacin (LEV) and 48.33% for flurbiprofen (FLU), whereas for surface-modified nanoparticles, it was found to be 42.05% for LEV and 45.26% for FLU. LEV-FLU chitosan-coated PLGA nanoparticles showed an increase in particle size, i.e., 333.6 nm with PDI of 0.319 and an inversion of zeta potential to 37.67 mV. The developed nanosystems showed sustained release and improved eye permeability. Microbiological studies showed equivalent zone of inhibition to that of marketed formulation. HET-CAM assay revealed the non-irritant nature of drug-loaded PLGA nanoparticles; however, chitosan-coated PLGA nanoparticles were found to be moderately irritating owing to the acidic nature of formulation. Conclusion The nanoparticulate system provides prolonged drug release making it a promising alternative to conventional dosage forms. It reduces systemic effects of locally acting drugs, improving therapeutic efficacy and patient compliance.