Antimicrobial elastomer composition and method for making

• US 7,393,547 B2
• Filed: 08/19/2004
• Issued: 07/01/2008
• Est. Priority Date: 04/11/2001
• Status: Expired due to Term

• Current Assignee: Freudenberg Medical, LLC (Freudenberg & Company KG)
• Original Assignee: Helix Medical LLC (Freudenberg & Company KG)
• Inventors: Nelson, Jesse N.
• Primary Examiner(s): Richter; Johann
• Assistant Examiner(s): Arnold; Ernst V
• Application Number:
  US10/923,138
• Publication Number:
  US 20050020844A1
• Time in Patent Office: 1,412 Days
• Field of Search: None
• US Class Current: 424/618
• CPC Class Codes: A61F 2/203 comprising an air passage from trachea to oesophagus or to pharynx; Artificial epiglottis
• CPC Class Codes: A61K 31/28 Compounds containing heavy metals
• CPC Class Codes: A61L 2300/104 Silver, e.g. silver sulfadiazine
• CPC Class Codes: A61L 2300/404 Biocides, antimicrobial agents, antiseptic agents
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G
• CPC Class Codes: C08G 77/04 Polysiloxanes
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

A method for making an elastomeric material containing an antimicrobial composition such as a dispersion of silver oxide that is suitable for implantation within the body. The elastomer made in accordance with this method extends the amount of work-time available for processing the elastomer into an article as compared with the work-time available when using prior art compounding methods.

Claims

1. A method for making an antimicrobial elastomeric composition comprising the steps of:

(a) presenting Part A and Part B of a silicone elastomer wherein at least one of Part A and Part B includes a first amount of a first inhibitor, and wherein when Part A and Part B are mixed together, a curable silicone elastomer is formed;

(b) mixing part A, part B, a second amount of a second inhibitor that increases a cure time of the curable silicone elastomer, and an antimicrobial work-time altering agent comprising silver oxide to form a curable silicone elastomer dispersion, said second amount is about 0.05 to about 0.40 weight % of said dispersion and relates to an amount of said antimicrobial work-time altering agent present in said dispersion.

2. The method for making an antimicrobial elastomeric composition in accordance with claim 1 wherein the inhibitor of said second amount of inhibitor is 2-methyl-3-butyn-2-ol.

5. The method for making an antimicrobial elastomeric composition in accordance with claim 1 wherein said antimicrobial work-time altering agent is 5-50% w/w silver oxide and the inhibitor of said second amount of an inhibitor is 2-methyl-3-butyn-2-ol and wherein the mole ratio of said second amount of an inhibitor to silver oxide in the curable silicone elastomer is about 1:

40.

7. A method for making an antimicrobial elastomer composition in accordance with claim 1 wherein said curable silicone elastomer is an addition cure silicone elastomer.

9. The method according to claim 1, wherein said mixing further comprises combining said Part A with said Part B, then adding said second amount of said second inhibitor, followed by adding said antimicrobial work-time altering agent.

10. The method according to claim 1, wherein said mixing further comprises first adding said second amount of said second inhibitor into either of said Part A or said Part B prior to combining said Part A with said Part B.

11. The method according to claim 10, wherein said mixing further comprises adding said antimicrobial work-time altering agent into either of said Part A or said Part B, and then combining said Part A with said Part B.

12. The method according to claim 10, wherein said mixing further comprises adding said antimicrobial work-time altering agent into both said Part A and said Part B, and then combining said Part A with said Part B.

13. The method according to claim 1, wherein said mixing further comprises adding said second amount of said second inhibitor to both said Part A and said Part B prior to adding said antimicrobial work-time altering agent to either of said Part A or said Part B, prior to combining said Part A with said Part B.

3. A method for making an antimicrobial elastomeric composition comprising the steps of:

(a) presenting Part A and Part B of a curable silicone elastomer wherein at least one of Part A and Part B includes a first amount of an inhibitor, and wherein when Part A and Part B are mixed together, the curable silicone elastomer is formed;

(b) adding a second amount of an inhibitor to either Part A or Part B wherein the second inhibitor is any agent that increases the cure time of the curable silicone elastomer;

(c) dispersing particles of an antimicrobial work-time altering agent comprising silver oxide into at least one of Part A and Part B; and

(d) mixing Part A with Part B, wherein the second amount of an inhibitor added to either Part A or Part B prior to said mixing is present at a mole ratio of about 1;

40 of said second inhibitor to said antimicrobial work-altering agent, wherein said second amount of inhibitor is effective to increase a work-time of the curable silicone elastomer comprising the antimicrobial work-altering agent prior to curing.

4. The method for making an antimicrobial elastomeric composition in accordance with claim 3 wherein the inhibitor of said second amount of an inhibitor is 2-methyl-3-butyn-2-ol.

6. The method for making an antimicrobial elastomeric composition in accordance with claim 3 wherein said antimicrobial work-time altering agent is 5-50% w/w silver oxide and the inhibitor of said second amount of an inhibitor is 2-methyl-3-butyn-2-ol and wherein the mole ratio of said second amount of an inhibitor to silver oxide when Part A and Part B are mixed is about 1:

40.

8. A method for making an antimicrobial elastomer composition in accordance with claim 3 wherein said curable silicone elastomer is an addition cure silicone elastomer.

14. A method for injection molding an antimicrobial elastomeric composition, the method comprising:

presenting Part A and Part B of a curable silicone elastomer wherein at least one of Part A and Part B includes a first amount of a first inhibitor;

mixing said Part A, said Part B, a second amount of a second inhibitor, and an antimicrobial work-time altering agent comprising silver oxide, to form a curable and flowable silicone elastomer dispersion for injection molding, wherein said second amount of said second inhibitor is related to an amount of said antimicrobial work-time altering agent present in said dispersion and is effective to increase a work-time for injecting said dispersion, wherein in the absence of said second amount of inhibitor, a comparative mixture of said Part A, said Part B, and said antimicrobial work-time altering agent comprising silver oxide has a comparative work-time that is less than said work-time;

injecting said dispersion into a mold, wherein said dispersion conforms to a contour of said mold during said injecting; and

curing said curable silicone elastomer dispersion to form the antimicrobial elastomeric composition.

15. The method according to claim 14, wherein a mole ratio of said second amount of said second inhibitor to said amount of antimicrobial work-time altering agent in said dispersion is about 1:

40.

16. The method according to claim 14, wherein said second amount of said inhibitor in said dispersion is about 0.05 to about 0.40 weight % of said total dispersion.