Polyelectrolyte complex nanoparticles based on chitosan and methoxy poly(ethylene glycol) methacrylate-co-poly(methylacrylic acid) for oral delivery of ibuprofen.

In this study, the copolymer of methoxy poly(ethylene glycol) methacrylate-co-poly(methylacrylic acid) [poly(mPEGMA-co-MAA)] was synthesized via radical polymerization. Based on this copolymer, novel chitosan-modified poly(mPEGMA-co-MAA) nanoparticles (CS/NPs) were developed to improve the bio-availability of ibuprofen (IBU). Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectra were used to confirm the synthesis of the copolymers. The morphology of CS/NPs was investigated with transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) was used to reveal the thermodynamic properties of the CS/NPs. The cytotoxicity of CS/NPs was assessed by the cell viability of 293T cells. FTIR and 1H NMR spectra confirmed the synthesis of the novel copolymer. TEM photographs showed that the CS/NPs had a core-shell structure. High cell viability indicated that the CS/NPs were nontoxic. The in vitro release profiles suggested that the CS/NPs released IBU in pH 7.4 buffer in a continuous manner. Furthermore, the IBU-CS/NPs showed a long antifebrile effect. Animal experiments showed that the IBU-CS/NPs had obvious antifebrile effects. Therefore, CS/NPs could reduce the dosing frequency of IBU, and improve its bio-availability.