Abstract:

The drug emodin was first intercalated into the layers of Mg-Zn-Al layered double hydroxides (Mg-Zn-Al-LDHs) by the re-assemble method. The emodin／LDHs nanohybrids could be used to extend the action duration and reduce the side effect of emodin. Then the effect of the temperature T and the mass ratio R of emodin to LDHs on drug loading were discussed. The XRD spectra indicated that the interlayer distance of Mg-Zn-Al-LDHs increased from 0.48 nm to 3.42 nm with the increase of drug loading. The determination results of the drug release showed that the drug release rate from the emodin／LDHs nanohybrids was much slower than that of the corresponding physical mixture with the pH of solution of either 4.8 or 7.5. Analysis showed that the mechanism of the pH 7.5 release was primarily through ion-exchange with the ions in the buffer solution, while that of the pH4.8 release was primarily through the dissolution of LDHs.

Key words: emodin, layered double hydroxides (LDHs), re-assemble method, mass ratio, drug loading, nanohybrids, controlled release