Carboxymethyl gum kondagogu-chitosan polyelectrolyte complex nanoparticles: Preparation and characterization

The interaction between carboxymethyl gum kondagogu and chitosan was optimized to prepare polyelectrolyte complex nanoparticles using ofloxacin as the model drug. The effect of concentrations of carboxymethyl gum kondagogu and chitosan on the particle size and % drug entrapment was screened using 2-factor, 3-level central composite experimental design. The results revealed that the concentration of carboxymethyl gum kondagogu has a pronounced effect on the particle size while the concentration of chitosan affected the drug entrapment prominently. The optimized concentrations of carboxymethyl gum kondagogu and chitosan were 0.031% (w/v) and 0.059% (w/v) respectively. The optimized batch of nanoparticles had a particle size of 285.9 nm, entrapment efficiency of 63% and was observed to be ovoid in shape. Screening of ofloxacin-loaded nanoparticles for antibacterial activity with aqueous ofloxacin solution revealed no significant difference between the two formulations. Nanoparticles provided a sustained release with 50% of the drug getting released in 24 h following Higuchi's square-root kinetics. (C) 2013 Elsevier B.V. All rights reserved.