CLAY ENCLOSED TRANSITION AND RARE EARTH METAL IONS AS CONTRAST AGENTS FOR THE GASTROINTESTINAL TRACT.

摘要

The invention relates to compositions and methods of using clay-enclosed paramagnetic ions as image brightening or image contrast agents. In particular, T1 relaxivity measurements on Hectorite and mortmorillonite clay-enclosed trivalent gadolinium suggest improved imaging over zeolite-enclosed paramagnetic species. Clay-enclosed gadolinium complexes are amenable to convenient administration in oral preparations and are readily formulated in stable aqueous suspensions. Other transition metal ions, including divalent manganese, may be enclosed in the clay structures, either as free metals or in the forms of chelated complexes. Alternatively, improved relaxivities are envisioned for clays incorporating a paramagnetic metal ion as part of the frameword structure.