Characterization and Application of Intercalated Montmorillonite with Verapamil and its Polymethyl Methacrylate Nanocomposite in Drug Delivery

This work examined two drug delivery systems: the first system studied the adsorption of Verapamil hydrochloride drug into montmorillonite clay (MMT) by intercalation process to prepare MMT-Verapamil hybrid at different intercalating time, temperatures, pH values and initial drug concentrations. The second system includes the preparation of MMT-Verapamil hybrid combined with polymethyl methacrylate via an emulsion polymerization process to produce a novel nanocomposite material to be used in drug delivery. The polymerization process was carried out using an ultrasonic technique to achieve a biologically safe drug delivery system. Best conditions for the intercalation of verapamil hydrochloride drug into the interlayer of MMT clay were found to be at 50 degrees C and 1 hr using pH ranges of 4-6. The prepared MMT-Verapamil hybrid and the produced MMT-verapamil-MMA nanocomposite material were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermal gravimetric analysis (TGA). The in-vitro release profile of Verapamil in the case of a drug hybrid is faster than the release in the case of a drug nanocomposite in both gastric and intestinal fluids where, in the case of gastric fluid (pH 1.2), about 40% of the loaded drug was released from the drug hybrid in the first 4 h against only 37% in 5 h in the case of drug nanocomposite. Also in the intestinal fluid (pH 7.4), the verapamil release from drug hybrid reached 68% in 5 h against only 57% was released from drug nanocomposites in 7 h.