Magnetic targeted nanoparticles double coated with β-cyclodextrin (β-CD) and chitosan (CS) were formed using a layer-by-layer model and their potential for hydrophobic drug delivery was evaluated in the study reported here. The resulting nanoparticles (NPs) had an average size of 102 nm and were spherical in shape. The double polymer layers ensured the colloidal stability and biocompatibility of the nanocarriers. Ibuprofen was chosen as the model drug. The nanocarriers possessed good magnetic properties and exhibited a high loading capacity that depended on the hybrid effects of electrostatic interaction and inclusion provided by the CS layer and the β-CD layer, respectively, which was confirmed using zeta potential analysis and a molecular modeling study. The in vitro release results revealed that the two-step release process consisted of an initial fast release and then a slower sustained release. Based on the Korsmeyer–Peppas model, the release mechanism was attributed to a mixed effect of swelling and a diffusion controlled release, which could be affected by pH, temperature and magnetic field. It is anticipated that the CS–CD–silica coated magnetic nanoparticles (SMNPs) will be a promising candidate as a nanocarrier for hydrophobic drugs.

Chitosan and β-cyclodextrin doubly coated with Fe₃O₄ nanoparticles was prepared and applied as magnetic solid-phase extraction adsorbent to separate ibuprofen.