ENZYMATIC REAGENT INKS FOR USE IN TEST STRIPS HAVING A PREDETERMINED CALIBRATION CODE

• US 20120043204A1
• Filed: 08/23/2010
• Published: 02/23/2012
• Est. Priority Date: 08/23/2010
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: LifeScan Scotland Limited (Johnson & Johnson)
• Inventors: O'Connell, Michael, McNeilage, Alan, Alvarez-Icaza, Manuel, YOUNG, Gary, McArthur, Ian, Phippen, Nick
• Granted Patent: US 8,409,412 B2
• Time in Patent Office: Days
• US Class Current: 204/403.14
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

The invention provides an enzyme ink useful in test strips that provides a test strip bias, at the low and high glucose ends, falling within a desired target range. The ink of the invention permits an improved method for the production of single calibration code strip lots with good yields.

Claims

1. An enzyme ink composition, comprising an enzyme capable of selectively recognizing glucose in a blood sample, a mediator, and one or more materials capable of regulating the mass transport of the mediator so that biases in response to one or more of a low glucose value and a high glucose value falls within a predetermined target for a predetermined calibration code.

2. The enzyme ink of claim 1, wherein the one or more materials comprises a first and a second fumed silica.

3. The enzyme ink of claim 2, wherein the first fumed silicas comprises a BET measured surface area of about 130 to 170 m²/g and a carbon content of about 0.8 to about 1.23 weight percent and the second of the second fumed silica comprises a BET measured surface area of about 270 to 330 m²/g and a carbon content of about 1.4 to about 2.6 weight percent.

4. The enzyme ink of claim 3, wherein the first fumed silica is present in an amount of about 99 to about 1 weight percent of the total amount of the fumed silicas and the second fumed silica is present in amount of about 1 to about 99 weight percent.

5. The enzyme ink of claim 3, wherein the first fumed silica is present in an amount of about 75 to about 45 weight percent of the total amount of the fumed silicas and the second fumed silica is present in amount of about 25 to about 55 weight percent.

6. The enzyme ink of claim 3, wherein the enzyme is elected from the group consisting of glucose oxidase, glucose dehdryogenase, glucose dehydrogenase with a pyrrolo-quinolone co-factor, and glucose dehydrogenase with a flavin adenine dinucleotide co-factor and the mediator is elected from the group consisting of ferricyanide and ruthenium hexamine trichloride.

7. The enzyme ink of claim 3, wherein the enzyme is glucose oxidase mediator is ferricyanide.

8. An enzyme ink, comprising about 0.3 percent by mass of an antifoam compound, about 0.6 percent by mass of polyvinyl alcohol, about 0.6 percent by mass citric acid, about 1.9 percent by mass trisodium citrate, about 0.6 percent by mass polyvinylpyrrolidone-vinyl acetate copolymer, about 3.27 percent by mass hydroxyethyl cellulose, about 3.6 percent by mass of a first fumed silica with a BET measured surface area of about 130 to 170 m²/g and a carbon content of about 0.8 to about 1.23 weight percent, about 1.3 percent by mass of a second fumed silica with a BET measured surface area of about 270 to 330 m²/g and a carbon content of about 1.4 to about 2.6 weight percent, about 0.03 percent by mass potassium hexacynaoferrate III, about 23 percent by mass of potassium ferricyanide;

about 2.1 percent by mass glucose oxidase and about 62.4 percent by mass water

9. A test strip, comprising at least two co-planar electrodes, wherein at least one of the electrodes comprises an enzyme ink composition comprising an enzyme capable of selectively recognizing glucose in a blood sample, a mediator, and one or more materials capable of regulating the mass transport of the mediator so that biases in response to one or more of a low glucose value and a high glucose value falls within a predetermined target.

10. The test strip of claim 9, wherein the one or more materials comprises a first and a second fumed silica.

11. The test strip of claim 10, wherein the first fumed silicas comprises a BET measured surface area of about 130 to 170 m²/g and a carbon content of about 0.8 to about 1.23 weight percent and the second of the second fumed silica comprises a BET measured surface area of about 270 to 330 m²/g and a carbon content of about 1.4 to about 2.6 weight percent.

12. The test strip of claim 11, wherein the first fumed silica is present in an amount of about 99 to about 1 weight percent of the total amount of the fumed silicas and the second fumed silica is present in amount of about 1 to about 99 weight percent.

13. The test strip of claim 11, wherein the first fumed silica is present in an amount of about 75 to about 45 weight percent of the total amount of the fumed silicas and the second fumed silica is present in amount of about 25 to about 55 weight percent.

14. The test strip of claim 11, wherein the enzyme is elected from the group consisting of glucose oxidase, glucose dehdryogenase, glucose dehydrogenase with a pyrrolo-quinolone co-factor, and glucose dehydrogenase with a flavin adenine dinucleotide co-factor and the mediator is elected from the group consisting of ferricyanide and ruthenium hexamine trichloride.

15. The test strip of claim 11, wherein the enzyme is glucose oxidase mediator is ferricyanide.

16. The test strip of claim 11, wherein the enzyme ink comprises about 0.3 percent by mass of an antifoam compound, about 0.6 percent by mass of polyvinyl alcohol, about 0.6 percent by mass citric acid, about 1.9 percent by mass trisodium citrate, about 0.6 percent by mass polyvinylpyrrolidone-vinyl acetate copolymer, about 3.27 percent by mass hydroxyethyl cellulose, about 3.6 percent by mass of a first fumed silica with a BET measured surface area of about 130 to 170 m²/g and a carbon content of about 0.8 to about 1.23 weight percent, about 1.3 percent by mass of a second fumed silica with a BET measured surface area of about 270 to 330 m²/g and a carbon content of about 1.4 to about 2.6 weight percent, about 0.03 percent by mass potassium hexacynaoferrate III, about 23 percent by mass of potassium ferricyanide;

about 2.1 percent by mass glucose oxidase and about 62.4 percent by mass water.