Radiopaque polymers
A liquid composition comprising a polymer having pendant groups of the formula I: (I) Wherein X is either a bond or is a linking group having 1 to 8 carbons and optionally 1 to 4 heteroatoms selected from O, N and S; and n is 1 to 4.
1. A liquid embolic composition suitable for therapeutic embolization, the composition comprising a polymer in solution in an organic solvent, the polymer comprising units of the formula 1:
wherein X is either a bond or is a linking group having 1 to 8 carbons and optionally 1 to 4 heteroatoms selected from O, N and S;
wherein n is 1 to 4;
wherein the polymer precipitates on contact with normal saline at 20° C.;
wherein the precipitate has a radiodensity of at least 1000HU; and
wherein the polymer is biodegradable.
2. A liquid embolic composition according to claim 1 wherein n is 1, 2 or 3.
3. A liquid embolic composition according to claim 1 wherein the polymer comprises units selected from
4. A liquid embolic composition according to claim 1 where X is selected from a bond, (C 1-4 )alkylene, (C 1-4 )oxyalkylene and amino(C 1-4 )alkylene.
5. A liquid embolic composition according to claim 1 where X is a bond.
6. A liquid embolic composition according to claim 1 wherein the polymer comprises units of the formula 3
7. A liquid embolic composition according to claim 1 comprising the polymer and a water-miscible solvent.
8. A liquid embolic composition according to claim 7 comprising between 3% and 70% wt/wt of the polymer dissolved in the water-miscible solvent.
9. A liquid embolic composition according to claim 7 wherein the water-miscible solvent is a polar aprotic solvent.
10. A liquid embolic composition according to claim 7 wherein the water-miscible solvent is selected from dimethylsulphoxide, dimethylformamide, N, N′-dimethylpropyleneurea, 1,3-dimethyl-2-imidazolidinone, glycerol, ethyl lactate, N-Methyl-2-pyrrolidone and 2-(Oxolan-2-ylmethoxy)ethanol.
11. A liquid embolic composition according to claim 1 wherein n is 2 or 3.
12. A liquid embolic composition according to claim 1 wherein the polymer comprises a polyvinyl alcohol copolymer.
13. A liquid embolic composition according to claim 1 wherein the polymer is non cross linked.
14. A liquid embolic composition according to claim 1 wherein the polymer comprises iodine in an amount of 10% or greater (w/w) based on a dried weight of the polymer.