Synthesis and characterization of maleated cyclodextrin-grafted-silylated montmorillonite for the controlled release and colon specific delivery of tetracycline hydrochloride

In order to exploit the potential of host-guest interaction of cyclodextrin molecules and the controlled release properties of sodium montmorillonite, we have developed a novel composite hydrogel (CH), namely maleated cyclodextrin-grafted-silylated montmorillonite (MACD-g-MPTMS/MMT) for colon specific tetracycline hydrochloride (TCH) drug delivery. The CH was characterized by using techniques such as FTIR, SEM and XRD. The effect of the pH on the encapsulation of TCH was studied and found to be maximum at pH 3.0. The study of the surface morphology of CH using SEM showed an irregular and rough surface morphology, which favors TCH drug loading. In TCH loaded CH, the shift of the FTIR bands of amide I and II in comparison to crystalline TCH suggested a strong interaction between the amide groups and the clay surfaces. The swelling behavior of CH was measured in different media and found to be a maximum at pH 7.4. The drug delivery results demonstrated that CH could successfully deliver TCH to the colon without losing the drug in the stomach, and could be a good candidate for an orally administered drug delivery system. Results showed that the prepared CH showed good biocompatibility in the range 10-75 mu g ml(-1), being also able to effectively stimulate cell proliferation.