A hybrid of montmorillonite (Mnt) and rifampicin (RIF) was synthesized and the structure and stability of the drug carrier system clarified. Density functional theory calculations involving dispersion corrections (DFT-D3) were performed to characterize interactions acting in the interlayer space of montmorillonite intercalated with rifampicin. The structure and stability of the RIF-Mnt intercalated complex were determined. Calculations revealed the deformation of the molecular structure of rifampicin after intercalation into the Mnt interlayer space due to the clay environment. The ansa chain of RIF was bent in the interlayer space compared with the structure of the RIF molecule in the monocrystal. RIF was keyed into the Mnt surface by means of numerous hydrogen bonds of weak to moderate strength. The calculated vibrational spectrum from ab initio molecular dynamics (AIMD) was in good agreement with the FTIR measured spectra and helped to analyze the overlapped vibrational bands. Based on analysis of structural stability, theoretical calculations revealed that Mnt is a suitable drug carrier for delayed release of the RIF drug. Batch adsorption experiments showed the large adsorption capacity of montmorillonite for RIF.

This investigation was carried out to determine whether the adsorptive and ion-exchange properties of faujasite (FAU) could be used to delivery locally the anticancer drugs gemcitanine hydrochloride (dFdU.HCl) and oxaliplatin (DACH-Pt). A soaking procedure was used for the determination of the maximum adsorption capacity of FAU and the mechanism described here was achieved. 274 mg dFdU.HCl/g FAU were adsorbed in 16 h, while 48 h were needed for the adsorption of 79.7 mg DACH-Pt/g FAU. Drug release studies were carried out by soaking the samples of loaded FAU in simulation body fluids (SBF). After only one hour 76% of dFdU.HCl was released while the release of DACH-Pt from the FAU was more normal since 38% of DACH-Pt was released in the first 24 h.