Facile synthesis of camptothecin intercalated layered double hydroxide nanohybrids via a coassembly route

A method has been developed for the synthesis of intercalated layered double hydroxide (LDH) nanohybrids of the charge-neutral and poorly water-soluble anticancer drug camptothecin (CPT) using a coassembly route. For this route, CPT molecules were initially incorporated into the micelles of a biocompatible surfactant, such as sodium cholate (SCh) or sodium deoxycholate (SDC). The resulting negatively charged CPT-loaded micelles and the positively charged LDH nanosheets were then coassembled together into the CPT intercalated LDH nanohybrids. The resulting nanohybrids were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and elemental analyses. The results revealed that the loading of CPT in the nanohybrids could reach as high as 13%, indicating that this route could be used to achieve the effective intercalation of charge-neutral and poorly water-soluble drugs into the LDH gallery. The in vitro release of CPT from the nanohybrids was examined, and the results showed that the release was a diffusion-controlled process and that the diffusion process through the LDH particles was the rate-limiting step. The parabolic diffusion equation effectively described the kinetic process associated with the release of CPT from the nanohybrids.