Synthesis, Characterization, and Magnetically Controlled Release Behavior of Novel Core−Shell Structural Magnetic Ibuprofen-Intercalated LDH Nanohybrids

Abstract

LDH (layered double hydroxides)-based magnetic-sensitive drug−inorganic nanohybrids were assembled by a one-step co-precipitation method. The effect of a magnetic substance on the microstructure and drug release behavior of ibuprofen (IBU)-intercalated Mg−Al−LDH in magnetic nanohybrids was systematically studied via XRD, TEM, XPS, and VSM methods and in vitro release with and without an external magnetic field (MF). The results reveal a well-defined core−shell structure with a gray IBU−LDH shell coated onto the surface of a dark magnetic core and superior magnetic sensitivity of the magnetic nanohybrids. Compared with the clear platelets of the pure IBU−LDH, the IBU−LDH coatings in magnetic nanohybrids exhibit more like a compact stacking film fully covering the magnetic core and their particle sizes and thickness decrease with increasing core contents, explaining an enhanced release rate under no MF. While under a 1500 G MF, the release rate is greatly reduced with increasing core content due to the instant aggregation of the magnetic nanohybrid particles induced by the external MF. The release mechanism was discussed, and a primarily pulsatile drug release upon a consecutive MF “on−off” operation was also achieved.