# US 5,702,682 A · Methods for preparing radiopaque medical devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,682 A - Document ID: US5702682A - Status: Granted - Kind: A - Application number: 08/566,452 - Filed: 1995-12-01 - Granted: 1997-12-30 - Earliest claimed: 1995-12-01 - Assignees: Hercules Incorporated - Inventors: Samuel Anthony Thompson - Web page: https://patentgrep.com/patent/US5702682A ## CPC - A61K 49/0409: {Physical forms of mixtures of two different X-ray contrast-enhancing agents, containing at least one X-ray contrast-enhancing agent which is not a halogenated organic compound} - Y10S 424/90: In vivo diagnostic or in vivo test agent which contains an additional ingredient to reduce the toxicity or side effects of the active ingredient - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Disclosed is a method for providing radiopacity to a medical device comprising incorporating in said medical device metal-cation salt of anionic polymer, wherein the metal has atomic weight greater than about 40; radiopaque medical devices comprising the essentially water-insoluble metal-cation salts of anionic polymers; and a method for carrying out x-ray diagnostic procedures comprising administering to a subject a contrast agent comprised of the essentially water-insoluble metal-cation salts of anionic polymer. ## Claims ### Claim 1 A method for increasing the radiopacity of a medical device comprising: (a) providing: (i) a medical device comprising a cation salt of an anionic polymer and (ii) an aqueous solution of a water-soluble composition containing metal-cations of atomic weight greater than about 40; and (b) soaking said medical device in said aqueous solution for a time effective to replace at least a portion of the cations in the medical device with said metal-cations to form an essentially water-insoluble metal-cation salt of anionic polymer dispersed within said medical device, thereby obtaining a medical device with increased radiopacity. ### Claim 2 (depends on 1) The method of claim 1 wherein said medical device is selected from the group consisting of catheters, stents, cannulas, plugs and constrictors. ### Claim 3 (depends on 1) The method of claim 1 wherein said medical device is degradable in vivo. ### Claim 4 (depends on 1) The method of claim 1 wherein said medical device is non-degradable in vivo. ### Claim 5 (depends on 1) The method of claim 1 wherein the essentially water-insoluble metal-cation salt of anionic polymer is present at a minimum level of about 1% by weight on a dry basis based on the dry weight of the medical device. ### Claim 6 (depends on 5) The method of claim 5 wherein the essentially water-insoluble metal-cation salt of anionic polymer is present at a minimum level of about 10% by weight on a dry basis based on the dry weight of the medical device. ### Claim 7 (depends on 6) The method of claim 6 wherein the essentially water-insoluble metal-cation salt of artionic polymer is present at a minimum level of about 50% by weight on a dry basis based on the dry weight of the medical device. ### Claim 8 (depends on 1) The method of claim 1 wherein said anionic polymer comprises polysaccharide. ### Claim 9 (depends on 1) The method of claim 1 wherein the anionic polymer comprises at least one polymer from the group consisting of carboxylate and sulfate functionalized polymers. ### Claim 10 (depends on 6) The method of claim 6 wherein the anionic polymer comprises at least one polymer selected from the group consisting of polyacrylic acid, polymethacrylic acid, alginic acid, pectinic acid, carboxymethyl cellulose, carboxymethyl dextran, carboxymethyl starch, carboxymethyl chitosan, hyaluronic acid, heparin, heparin sulfate and chondroitin sulfate. ### Claim 11 (depends on 1) The method of claim 1 wherein said metal-cation has an atomic weight equal to or greater than about 87. ### Claim 12 (depends on 1) The method of claim 1 wherein said metal-cation has an atomic weight equal to or greater than about 137. ### Claim 13 (depends on 1) The method of claim 1 wherein the essentially water-insoluble metal-cation salt is at least one member selected from the group consisting of salts of barium, strontium, iron, copper, lead, tin, iron, gold and silver. ### Claim 14 (depends on 13) The method of claim 13 wherein said essentially water-insoluble metal-cation salt comprises a salt of barium. ### Claim 15 (depends on 13) The method of claim 13 wherein said essentially water-insoluble metal-cation salt comprises a salt of strontium. ### Claim 16 (depends on 1) The method of claim 1 wherein the essentially water-insoluble metal-cation salt of anionic polymer comprises a salt of alginic acid and at least one metal cation selected from the group consisting of cations of barium, strontium, iron, copper, lead, tin, iron, gold and silver. ### Claim 17 (depends on 16) The method of claim 16 wherein the essentially water-insoluble metal-cation salt of anionic polymer comprises barium alginate. ### Claim 18 (depends on 16) The method of claim 16 wherein the essentially water-insoluble metal-cation salt of anionic polymer comprises lead alginate. ### Claim 19 (depends on 1) The method of claim 1 wherein the minimum level of radiopacity of the medical device is about 100 hounsfield units. ### Claim 20 (depends on 19) The method of claim 19 wherein the minimum level of radiopacity of the medical device is about 300 hounsfield units. ### Claim 21 (depends on 20) The method of claim 20 wherein the minimum level of radiopacity of the medical device is about 500 hounsfield units. ### Claim 22 (depends on 21) The method of claim 21 wherein the minimum level of radiopacity of the medical device is about 700 hounsfield units. ### Claim 23 (depends on 1) The method of claim 1 wherein the anionic polymer is ionically crosslinked. ### Claim 24 (depends on 1) A medical device prepared by the method of claim 1.