Preparation, characterization and in vitro release of chitosan nanoparticles loaded with gentamicin and salicylic acid

Salicylic acid (SA) and gentamicin (GM) loaded nanoparticles of chitosan (CS) cross-linked with tripolyphosphate (TPP) were prepared and used to inhibit the ototoxicity of GM. The prepared nanoparticles were characterized by FT-IR spectroscopy to confirm the cross-linking reaction between CS and cross-linking agent. X-ray diffraction (XRD) was performed to reveal the crystalline nature of the drug after encapsulation. Up to 24.67 +/- 2.06% of SA and 26.64 +/- 3.92% of GM were loaded into the nanoparticles and the average size of nanoparticles ranged from 148 +/- 8.6 to 345.0 +/- 12.9 nm. The nanoparticles formed were spherical in shape with high zeta potentials (higher than +30 mV). In vitro release studies in phosphate buffer saline (pH 7.4) showed an initial burst effect and followed by a slow drug release. The drug release followed Weibull equation and a non-Fickian transport. The amounts of SA and GM released from the nanoparticles met the dosage ratio requirement for inhibiting ototoxicity of GM by SA. (C) 2011 Elsevier Ltd. All rights reserved.