Preparation, evaluation, and in vitro release study of O‐carboxymethyl chitosan nanoparticles loaded with gentamicin and salicylic acid

Abstract To inhibit the ototoxicity of gentamicin (GM) and overcome the drawback related to chitosan (CS) nanoparticles preparation in acid solution, O ‐carboxymethyl chitosan ( O ‐CMC) nanoparticles loaded with GM and salicylic acid (SA) were prepared by ionic cross‐linking method using calcium chloride as crosslinking agent. The Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD) were used to analyze the reaction of O ‐CMC and crosslinking agent. The parameters of preparation of the compound nanoparticles including the concentration of O ‐CMC, the mass ratio of O ‐CMC to calcium chloride, and the feed ratio of SA to GM were investigated. The results showed that the obtained nanoparticles had a high zeta potential and drug‐loading capacity. The nanoparticles were characterized by a spherical morphology, with average size ranging from 148 to 345 nm and a narrow particle size distribution. In vitro release studies in phosphate buffer saline (pH 7.4) evidenced a burst release in the first 1 h, followed by a sustained release in the residual time. The release amount of SA and GM were approximately equal in 24 h, which indicated that the SA‐ and GM‐loaded O ‐CMC nanoparticles are a promising carrier system for inhibiting the ototoxicity of GM. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012