N-Benzyl-O-carboxymethyl chitosan (OCChB) was synthesized through a reaction of O-carboxymethylchitosan (OCCh) and benzaldehyde by the reductive amination method. The chemical structures and physical properties of the derivatives were confirmed by Fourier transform infrared spectroscopy and 1H-NMR. The cytotoxicity of the polymers was tested by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay at concentrations ranging from 0.01 to 1000 mu g/mL. The substitution degrees of the derivatives, calculated by 1H-NMR, were 12 and 53% for OCChB1 and OCChB2, respectively. The results show that the derivatives were not toxic at 1000 mu g/mL and could decrease the surface tension by concentration on the system surface compared with OCCh. Because of this property, OCChB was applied as a solubility enhancer for triamcinolone (TC), a poorly water-soluble drug. The polymer solutions at 1.0 mg/mL increased the TC solubility up to 3.5 times for OCChB1 and 5.0 times for OCChB2 compared with its solubility in water. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012