Zeolites: promising candidates for drug delivery systems (DDSs)

Abstract

[Excerpt] The aim of controlled drug delivery systems (DDSs) is to administer the necessary amount of drug safely and effectively to specific sites in the human body and to regulate the temporal drug profile for maximum therapeutic benefits.[1] Zeolites are crystalline aluminosilicates solids with very regular microporous structures and they have been recently considered for medical use due to their biological properties and stability in biological environments.[1,2] The large variety in pore structures and morphologies provided by different types of molecular sieves offers unique possibilities for the design of host-guest systems with particular properties.[3] One of the many potentially medicinal applications of zeolites is the encapsulation of different drug molecules into them so as to obtain subsequent DDSs. 5-fluoro-1H-pyrimidine-2,4-dione (5-FU), a drug traditionally used in anticancer treatment of colorectal carcinoma (CRC)[4] was chosen as a guest in zeolite structure for DDS. The zeolite in sodium form (NaY) was used for encapsulation of 5-FU as a guest, by diffusion in liquid phase in the void space of the host zeolite. The new DDS, 5-FU@zeolite, was evaluated by several techniques (FTIR, UV-vis, XRD, SEM and chemical analysis). The cytotoxic effect of the zeolite and 5-FU@zeolite on RKO and HCT-15 human colon carcinoma cell line viability was evaluated. The results show that 5-FU@zeolite has a significantly higher inhibitory effect on the viability of both cell lines (assessed by Sulforhodamine B assay), as compared to 5-FU alone. [...]