[en] Full text: The study of processes involving clay minerals has been growing due to its high availability, besides physical and chemical properties. Among these clay minerals, montmorillonite was extensively used in modification with organosilanes, since its expansive nature allows the incorporation of the organic groups without a step of pre-intercalation [1. The study of drug release based on clay minerals systems has been outstanding, where high cation exchange capacity and the possibility of interlayer expansion provide versatility for the interaction and intercalation of bulky molecules, such as drugs [2]. In this work KSF-montmorillonite was firstly modified with aminopropyltriethoxysilane (KSF-1N) and it loaded with thiabendazole, being subsequently used as a system release in the simulated gastric (SGF), body (SBF) and intestinal (SIF) fluids. The pristine and modified montmorillonites were characterized before and after interaction with thiabendazole by CHN elemental analysis, XRD and FTIR. The amount of drug loaded into KSF-1N was 38.3 mg/g. The release profiles in simulated fluids showed maximum release quantities of 25% and 11% in SIF and SBF, respectively, with saturation times of 27 and 55 h. The drug does not release in SGF fluid. References: [1] H. He, Q. Tao, J. Zhu, P.Yuan, W.Shen, S. Yang. Silylation of clay mineral surfaces. Applied Clay Science 71 (2013) 15-20. [2] G.V. Joshi, B.D. Kevadiya, H.A. Patel, H.C. Bajaj, R.V. Jasra, Montmorillonite as a drug delivery system: Intercalation and in vitro release of timolol maleate, Int. J. of Pharm. 374 (2009) 53-57. (author)