Self-assembled nanoparticles of glycol chitosan – Ergocalciferol succinate conjugate, for controlled release

Glycol chitosan was linked to vitamin D2 hemisuccinate (ergocalciferol hemisuccinate) for controlled release through water-soluble carbodiimide activation. The resulting conjugate formed self-assembled nanoparticles in aqueous solution with particle size of 279 nm and ergocalciferol hemisuccinate content of 8.4% (w/w). Almost spherical 50–90 nm nanoparticles were observed by scanning and transmission electron microscopy upon drying. Drug linking to glycol chitosan was confirmed by FTIR spectroscopy and proton NMR. Particles were also characterized by differential scanning calorimetry and wide-angle X-ray diffraction studies. In vitro vitamin D2 release studies performed in water at acid pH indicated a drug release dependence on the solution acidity. Almost constant release rate was observed during the first 8 h. These results indicate that the obtained nanoparticles could be good candidates for vitamin D2 release to animals and humans.