Abstract:
Gatifloxacin is one of the main fluoroquinolone antibiotics used to treat various ocular related diseases and infections. Nanoparticle formulations intended for ocular delivery bring many benefits and advantages, helps produce the desired drug effect at the most appropriate site for the period required and can add delayed action to counteract the fast elimination process and tear reflux in the eye. The aim of this study was to develop chitosan and carbopol coated polymeric nanoparticles for ocular delivery of gatifloxacin. Gatifloxacin nanoparticles were fabricated by the solvent evaporation technique using two different polymers, Eudragit and poly lactic-co-glycolic acid (PLGA), each with their desired characteristics and ability to encapsulate drug particles and provide protection and controlled release. Each of these systems were investigated and characterized for the polymers, Eudragit and PLGA and the two different coating materials, carbopol and chitosan. The nanoparticles formulated from Eudragit and PLGA with and without coating with carbopol or chitosan were characterized for their particle size and zeta potential and their yield was established. The formed nanoparticles were all in a nano size range and therefore suitable for their intended purpose. Their zeta potential which reflects particle stability was dependant on the drug-loading for the Eudragit polymer based nanoparticles, while the coating materials seemed to have a more pronounced effect in PLGA based nanoparticles. The Eudragit and PLGA based nanoparticles were smooth and spherically shaped and generally showed sustained drug release. However carbopol coated nanoparticles of either polymer showed a much more abrupt and fast drug content release. The fabricated nanoparticles were also tested for their cytotoxicity using a corneal epithelial cell line as different polymers and materials could be irritating or lethal to these cells. The Eudragit based nanoparticles resulted in a very low cytotoxic effect and may therefore be considered safe for ocular use. However, the cytotoxic effect of the PLGA based nanoparticles was concentration dependent with higher concentration reducing the cell viability. Coating materials seemed to have no or little effect on the cell viability compared to polymers for particles preparation.