Antimicrobial composition for medical articles
View Patent ↗An antimicrobial composition is formed from about 5 to about 25 wt % of an antimicrobial formulation and about 75 to about 95 wt % of a silicone resin. The antimicrobial formulation is formed from about 60 to about 95 wt % of an antimicrobial material, about 1 to about 30 wt % calcium chelator, about 0.001 to about 0.25 wt % pigment, and about 0.5 to about 3.5 wt % lubricant. The silicone resin may be a dispersion of about 40 to about 60 w/v % of an RTV silicone resin in a solvent, a liquid silicone resin, or a solid silicone resin. An antimicrobial coating may be formed on the surface of an article by applying an antimicrobial composition to the article and permitting the solvent to evaporate. It may also be formed by making a mixture of about 5 to about 12 wt % of an antimicrobial formulation and about 88 to about 95 wt % of a liquid or solid silicone resin and molding, overmolding, or extruding the article from the compounded mixture.
1. An article having an antimicrobial coating made by
(A) applying to an uncoated article an antimicrobial composition that comprises
(1) about 5 to about 25 wt % of an antimicrobial formulation that comprises
(a) about 40 to about 65 wt % of an antimicrobial material;
(b) about 1 to about 55 wt % calcium chelator;
(c) about 0.00 1 to about 0.25 wt % pigment; and
(d) about 0.5 to about 5 wt % polyethylene oxide; and
(2) about 75 to about 95 wt % of a silicone resin; and
(3) an optional non-toxic organic solvent; and
(B) permitting said coating to form on said uncoated article, whereby said antimicrobial material leaches from said antimicrobial formulation, keeping the surface of said coating free of live bacteria, yeasts, and molds.
2. An article according to claim 1 wherein said antimicrobial material is selected from the group consisting of silver, silver-copper, partially water soluble compounds of silver, silver pyrithione, zinc pyrithione, bismuth pyrithione, parabenzoic acid esters, and mixtures thereof.
3. An article according to claim 1 wherein said antimicrobial material contains silver and copper particles that are less than about 100 nm in size.
4. An article according to claim 1 wherein said antimicrobial material includes silver, copper, and parabenzoic acid esters.
5. An article according to claim 1 wherein said antimicrobial material is silver-copper nanoparticles.
6. An article according to claim 1 wherein said calcium chelator is citric acid, ethylene diamine tetraacetic acid, or a mixture thereof.
7. An article according to claim 1 wherein said pigment is copper phthalocyanine.
8. An article according to claim 1 that includes about 0.5 to about 4 wt % titanium dioxide.
9. An article according to claim 1 wherein said silicone resin is dispersed ma solvent at about 40 to about 60 w/v %.
10. An article according to claim 9 wherein said solvent is hexane.
11. An article according to claim 1 wherein said article is a Foley catheter.
12. An article according to claim 11 wherein said Foley catheter is made of silicone.
13. An article according to claim 1 wherein said silicone resin is a liquid silicone resin.
14. An article according to claim 1 wherein said silicone resin is a solid silicone resin.
15. An article according to claim 1 wherein said silicone resin is an RTV silicone resin.
16. An article according to claim 1 wherein said antimicrobial coating is formed on the surface of said uncoated article by molding, overmolding, or extruding.
17. A Foley catheter having an antimicrobial coating made by
(A) applying to an uncoated catheter an antimicrobial composition that comprises
(1) about 5 to about 1 wt % of an antimicrobial formulation that comprises
(a) about 15 to about 1 wt % of an antimicrobial material that includes silver, copper, and parabenzoic acid esters;
(b) about 20 to about 1 wt % citric acid and about 20 to about 1 wt % ethylene diamine tetraacetic acid;
(c) about 0.1 to about 0.1 wt % pigment;
(d) about 4 to about 5 wt % polyethylene oxide; and
(e) about 0 to about 4 wt % titanium dioxide; and
(2) about 88 to about 95 wt % of a dispersion of about 40 to about 60 w/v % of an RTV silicone in a solvent selected from the group consisting of hexanes, methyl ethyl ketone, and xylenes whereby said antimicrobial material slowly leaches from said antimicrobial formulation, keeping the surface of said coating free of live bacteria, yeasts, and molds.
18. A catheter according to claim 15 wherein said antimicrobial material has a particle size of less than 100 nm.
19. A catheter according to claim 15 wherein said solvent is hexane.
20. A Foley catheter having an antimicrobial coating made by applying to an uncoated catheter an antimicrobial composition that comprises
(1) about 5 to about 12 wt % of an antimicrobial formulation that comprises
(a) about 15 to about 1 wt % of an antimicrobial material that includes silver, copper, and parabenzoic acid esters;
(b) about 20 to about 1 wt % citric acid and about 20 to about 1 wt % ethylene diamine tetraacetic acid;
(c) about 0.005 to about 0.01 wt % pigment;
(d) about 2 to about 5 wt % polyethylene oxide; and
(e) about 0 to about 4 wt % titanium dioxide; and
(2) about 88 to about 95 wt % of a liquid silicone resin whereby said antimicrobial material leaches from said antimicrobial formulation, keeping the surface of said coating free of live bacteria, yeasts, and molds.
21. A catheter according to claim 20 wherein said antimicrobial material has a particle size of less than 100 nm.
22. A catheter according to claim 20 wherein said solvent is hexane.