Water-based sterilization indicator composition
View Patent ↗Water-based formulations comprising an indicating composition dispersed in water are described. The water-based indicating compositions include an organic Bi(III) compound, a sulfur source, a carbonate salt, and strontium hydroxide. Formulations further including a resin and/or an acidic additive are also described.
1. An indicator formulation comprising an indicating composition dispersed in water, wherein the indicating composition comprises
(a) an organic Bi(III) compound;
(b) a sulfur source;
(c) a carbonate salt; and
(d) strontium hydroxide;
wherein at least one of the organic Bi(III) compound and the sulfur source has solubility in water at 20° C. of less than 5 grams/100 ml.
2. The indicator formulation of claim 1 , further comprising water.
3. The indicator formulation of claim 1 , wherein the indicating composition comprises bismuth subcarbonate formed in situ.
4. The indicator formulation according to claim 1 , wherein both the organic Bi(III) compound and the sulfur source have solubility in water at 20° C. of less than 5 grams/100 ml.
5. The indicator formulation of claim 4 , wherein at least one of the organic Bi(III) compound and the sulfur source have solubility in water at 20° C. of less than 1 gram/100 ml.
6. The indicator formulation according to claim 1 , wherein the organic Bi(III) is selected from the group consisting of bismuth subsalicylate, bismuth citrate, bismuth tartrate, and combinations thereof.
7. The indicator formulation according to claim 1 , wherein the sulfur source is selected from the group consisting of sulfur, 1,3-diphenylthiourea, sodium thiosulfate, and combinations thereof.
8. The indicator formulation according to claim 1 , wherein the carbonate salt is selected from the group consisting of lithium carbonate, magnesium carbonate, sodium carbonate, sodium bicarbonate, and combinations thereof.
9. The indicator formulation according to claim 1 , further comprising an acidic compound.
10. The indicator formulation of claim 9 , wherein the acidic compound is non-polymeric.
11. The indicator formulation of claim 10 , wherein the acidic compound is selected from the group consisting of citric acid, gallic acid, oxalic acid, and combinations thereof.
12. The indicator formulation according to claim 1 , further comprising a resin.
13. The indicator formulation of claim 12 , wherein the resin comprises an acrylic resin.
14. A method of preparing an indicator formulation comprising combining an organic Bi(III) compound; a sulfur source; a carbonate salt in water; and strontium hydroxide; wherein at least one of the organic Bi(III) compound and the sulfur source has solubility in water at 20° C. of less than 5 grams/100 ml, and reacting the organic Bi(III) compound with the carbonate salt to form bismuth subcarbonate.