| abstract |
The invention relates to a condensation product obtainable by reacting a1) at least one bicyclic or polycyclic aromatic or heteroaromatic compound, wherein the bicyclic or polycyclic aromatic or heteroaromatic compound is substituted with at least one carboxy group (-COOH), and wherein the carboxy group can be present in salt form, a2) at least one carbonyl compound, a3) optionally at least one sulfonation agent, a4) at least one urea derivative, and a5) optionally at least one further aromatic or heteroaromatic compound, or a physiologically compatible salt thereof. |