Patent ID: 6312664
Filing Date: 2001-11-06
Classification: A61K,G01R

Abstract:
A pharmaceutical agent having the formula:R.sup.1 {--R.sup.2 (--R.sup.3).sub.m }.sub.nin which:R.sup.1 is a polysaccharide group which is non-toxic and non-antigenic;R.sup.2 is a group which includes at least four atoms bonded together and adjoining R.sup.1 to R.sup.3 and is a member selected from the group consisting ofX--R.sup.4 --Y--R.sup.5 --Z, X--R.sup.5 --Y--R.sup.4 --Z and X--(CH.sub.2).sub.t --R.sup.5 --(CH.sub.2).sub.u Z in which:R.sup.4 is polyethylene glycol having a formula weight of from about 100 to about 20,000 daltons;R.sup.5 is a member selected from the group consisting of C(O)--O and O--C(O), such that at least 10% of all R.sup.5 groups are degraded in plasma after 24 hours;X, Y and Z are inert linking groups and are members selected from the group consisting of (CH.sub.2).sub.q --NH, NH--(CH.sub.2).sub.q, NH--C(O)--O, O--C(O)--NH, (CH.sub.2).sub.q --NH--C(O)--O, O--C(O)--NH--(CH.sub.2).sub.q, NH--C(S), and C(S)NH;R.sup.3 is a complex of a ligand and a paramagnetic metal cation capable of altering contrast in magnetic resonance imaging;m is at least 1;n is at least 3;q is a number from 1 to 10; andt+u is at least 2.