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.