Complex Material Using β-Cyclodextrins and Nickel-Zinc Ferrite to Obtain a Magnetically Targetable Drug Carrier Alberto Bocanegra, Nelcy D. S. Mohallem and Rubén D. Sinisterra Universidade Federal de Minas Gerais, ICEx, Dept. of Chemistry, Avenida Antônio Carlos 6627, CEP 31270-901, Belo Horizonte, BRAZIL nelcy@dedalus.lcc.ufmg.br ABSTRACT In this study we describe the preparation and the characterization of a complex material using β-cyclodextrin covalently bound to Ni-Zn ferrite to obtain a magnetically targetable drug carrier. The physical-chemical characterization was performed through Fourier transformed infrared spectroscopy, X-ray diffraction, XRD, thermal analysis (TG/DTA), and atomic absorption spectroscopy. The results pointed out that β-cyclodextrin is externally covalently bound to Ni-Zn ferrite. However it was also verified that the β-cyclodextrin cavity is free and can include bioactive agents. The most interesting feature of this approach is the combination of magnetic properties and the host:guest technology to obtain an efficient targetable drug carrier system. INTRODUCTION In order to design drug delivery systems, various kinds of high-performance carrier materials are being developed to deliver the necessary amount of drug to the targeted site in the necessary period of time, both efficiently and precisely. Cyclodextrins, CDs, are potential candidates to play such a role, because of their ability to alter physical, chemical and biological properties of guest molecules through the formation of inclusion compounds in both solution and solid state, or as functional carrier materials in pharmaceutical formulations [1]. The physical-chemical properties of CDs [2], together with other technologies such as magnetic targeting substances, could bring an interesting, new and effective strategy to deliver and transport drugs to specific sites of choice in chemotherapy [3]. The main application of magnetic carriers has been derived from the fact that specific ligands can be covalently or ionically bound to the magnetic particles [4]. The strong binding makes desorption process of these ligands a difficult task and sometimes this approach changes the biological activity of the bioactive agents [5]. This major clinical limitation has generated interest in site-specific drug delivery systems. Magnetite (Fe 3 O 4 ) has been the material most often used in the laboratory to establish magnetic susceptibility for drug carrying particles because it is inexpensive, readily commercially available, and safe. However, to date, small magnetite particles have not shown clinical utility for several reasons, such as low magnetic susceptibility at the distances human solid tumors are usually encountered, and the tendency to agglomerate in the magnetic field [3]. Accordingly, the aim of the current work is to use NiZn ferrites as a magnetic moiety because of the ease of variation of their magnetic properties with their composition, thus allowing the development of design materials for specific applications [6]. In this work, a complex system HH3.30.1 Mat. Res. Soc. Symp. Proc. Vol. 711 © 2002 Materials Research Society