Antimicrobial coatings for medical devices and processes for preparing such coatings

• US 9,789,228 B2
• Filed: 12/11/2014
• Issued: 10/17/2017
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: Mozarc Medical US LLC
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Tramontano, Valentino J., Marsden, Brent, Almeida, Robert F., Dahl, Eric W., Rawlins, James W., Mendon, Sharathkumar K.
• Primary Examiner(s): Kwon, Brian-Yong
• Assistant Examiner(s): PHAN, DOAN THI-THUC
• Application Number:
  US14/567,183
• Publication Number:
  US 20160166738A1
• Time in Patent Office: 1,041 Days
• CPC Class Codes: A61L 17/145 Coating
• CPC Class Codes: A61L 2300/104 Silver, e.g. silver sulfadiazine
• CPC Class Codes: A61L 2300/206 Biguanides, e.g. chlorohexidine
• CPC Class Codes: A61L 2300/224 containing metals, e.g. porphyrins, vitamin B12
• CPC Class Codes: A61L 2300/404 Biocides, antimicrobial agents, antiseptic agents
• CPC Class Codes: A61L 2300/45 Mixtures of two or more drugs, e.g. synergistic mixtures
• CPC Class Codes: A61L 2300/602 Type of release, e.g. controlled, sustained, slow
• CPC Class Codes: A61L 2420/02 Methods for coating medical devices
• CPC Class Codes: A61L 2420/06 Coatings containing a mixture of two or more compounds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence

Abstract

Antimicrobial formulations and coatings for medical devices and processes therefor are disclosed. The formulations include at least one water permeable polymer with at least one antimicrobial agent in a liquid medium and are prepared by wet milling the components and can form antimicrobial coatings having uniformly dispersed particles having an average size of no greater than 50 microns.

Claims

1. A process of forming an antimicrobial formulation for coating a medical device, the process comprising milling at least one water permeable polymer which is dissolved in a liquid medium with at least one antimicrobial agent which is insoluble in the liquid medium to form the antimicrobial formulation in which the at least one water permeable polymer encapsulates the at least one antimicrobial agent;

and adding a primary C_1-6 alcohol to the antimicrobial formulation;

wherein the at least one antimicrobial agent includes a silver-based antimicrobial agent and wherein the at least one water permeable polymer includes at least one of a polyurethane or a thermoplastic polyurethane elastomer.

2. The process of claim 1, wherein the at least one water permeable polymer has a weight average molecular weight of from about 70,000 to about 120,000 Daltons.

3. The process of claim 1, wherein the at least one antimicrobial agent includes the silver-based antimicrobial agent and a second antimicrobial agent which is a polybiguanide or salt thereof.

4. The process of claim 1, wherein the at least one antimicrobial agent includes silver sulfadiazine, as the silver-based antimicrobial agent, and a second antimicrobial agent which is chlorhexidine diacetate.

5. The process of claim 1, wherein the liquid medium includes one or more of an alcohol;

an ether;

a ketone;

an organic acid;

an organic ester;

an amide;

a hydrocarbon;

or a halogenated solvent or liquid.

6. The process of claim 1, wherein the liquid medium includes an ether and a primary C_1-6 alcohol.

7. The process of claim 1, wherein the at least one antimicrobial agent is insoluble in the formulation and the formulation is milled until the insoluble antimicrobial agent has a mean particle size of no greater than 50 microns.

8. The process of claim 1, comprising initially preparing a polymer solution having a viscosity of from about 100 centipoise (cP) to about 1000 cP by dissolving the at least one water permeable polymer in the liquid medium and then adding the antimicrobial agent to the solution followed by milling the formulation.

9. The process of claim 8, further comprising adding a second antimicrobial agent to the formulation after milling, and further milling the formulation with the second antimicrobial agent.

10. The process of claim 9, wherein the primary C_1-6 alcohol is methanol, ethanol, n-propanol, n-butanol, n-pentanol, and/or n-hexanol.

11. A process of forming an antimicrobial coating on a medical device, the process comprising:

applying the antimicrobial formulation of claim 1 on a medical device to form an antimicrobial coating on the medical device.

12. The process of claim 11, wherein the medical device is selected from the group consisting of a dialysis catheter, a urological catheter, an enteral feeding tube, a surgical staple, a trocar, an implant, suture, a respiratory tube, a surgical plate, a surgical screw, a wire, and a hernia mesh.

13. The process of claim 11, wherein the coating has a thickness of between about 20 microns to about 80 microns.

14. The process of claim 11, wherein applying the formulation on the medical device comprises dip-coating the medical device in the formulation and then drying the antimicrobial formulation by driving off the liquid medium to form the antimicrobial coating on the medical device.

15. The process of claim 11, wherein the at least one antimicrobial agent includes a combination of silver sulfadiazine and chlorhexidine diacetate.