The invention relates to novel complexes and complex salts, agents containing these compounds, their use in diagnostics and therapy, as well as processes for preparing these compounds and agents.
Metallic complexes have been scrutinized as early as at the beginning of the fifties as contrast media for radiology. The compounds then employed were, however, of such toxicity that utilization on human patients could not be considered. It was, therefore, entirely surprising to find that certain complex salts exhibit adequate compatibility for considering routine administration to human patients for diagnostic purposes. The first representative of this class of compounds was the dimeglumine salt of Gd DTPA [gadolinium(III) complex of diethylenetriaminepentaacetic acid] described in the European Patent Application, Publication No. 71564, which proved itself very well in the form of a contrast medium for nuclear spin tomography. This compound has been registered, under the name of "Magnevist", worldwide as the first NMR diagnostic agent.
Contrast media exhibiting an at least partial extrarenal excretion would be desirable, in particular for patients with limited kidney function.
Consequently, there is a need for NMR contrast media exhibiting various pharmacokinetic behaviors.