Sterilization indicator test packs

• US 7,045,343 B2
• Filed: 02/24/2003
• Issued: 05/16/2006
• Est. Priority Date: 06/02/1998
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Foltz, William E., Asmus, Robert A., Witcher, Kelvin J., Chandrapati, Sailaja, Lulich, Ronald G., Rosenlund, Thomas T.
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US10/372,993
• Publication Number:
  US 20030215923A1
• Time in Patent Office: 1,177 Days
• Field of Search: 435/287.4, 435/31, 435/287.6, 435/287.8, 435/288.1, 435/288.2, 435/288.5, 435/288.7, 422/58, 436/1
• US Class Current: 435/287.6
• CPC Class Codes: A61L 2/28 Devices for testing the effectiveness or completeness of sterilisation, e.g. indicators which change colour apparatus involving enzymes or microorganisms C12M1/34; methods involving enzymes or microorganisms C12Q1/00
• CPC Class Codes: C12Q 1/22 Testing for sterility conditions
• CPC Class Codes: G01N 31/226 for investigating the degree of sterilisation

Abstract

Sterilization indicator test packs for testing the effectiveness of a sterilization procedure are provided. Both non-challenge and challenge-type test packs are disclosed. The non-challenge test packs include generally comprise a tray for holding a sterilization indicator the tray containing an elevated rim surface defining the perimeter of the tray and a recessed trough for receiving a sterilization indicator. The rim surface includes a plurality of spaced-apart grooves along its length extending through the rim to the recessed trough; a sterilization indicator within the recessed trough of the tray; and a lid that forms a plurality of channels with the grooves in the tray such that sterilant can enter the tray through the channels and contact the sterilization indicator.

The challenge-type test packs generally include a tray for holding a sterilization indicator, the tray comprising a substantially planar surface, a recessed trough for receiving a sterilization indicator, and a recessed groove of a defined length and cross-sectional area extending through the recessed trough and penetrating the edge of the tray; a sterilization indicator within the recessed trough of the tray; and a lid forming a substantially sterilant-impermeable seal with the planar surface of the tray and forming a lumen path with the recessed groove in the tray.

Claims

1. A sterilization test pack, comprising:

(a) a tray for holding a sterilization indicator, said tray comprising an elevated rim surface defining the perimeter of the tray and a recessed trough for receiving a sterilization indicator, said rim surface including a groove of a defined length and cross-sectional area extending through the rim to the recessed trough;

(b) a sterilization indicator within the recessed trough of the tray, for testing the effectiveness of a sterilization procedure; and

(c) a lid associated with the rim surface of the tray, said lid forming a substantially sterilant-impermeable seal with the rim surface, and said lid forming a channel with the groove in the tray, such that sterilant may enter the tray through the channel and contact the sterilization indicator.

2. The sterilization test pack according to claim 1 wherein the sterilization indicator comprises a source of an active enzyme.

3. The sterilization test pack according to claim 2 wherein the source of an active enzyme is a microorganism.

4. The sterilization test pack according to claim 3 wherein the microorganism is Bacillus subtilis spores.

5. The sterilization test pack according to claim 3 wherein the microorganism is Bacillus stearothermophilus spores.

6. The sterilization test pack according to claim 2 wherein the source of an active enzyme is a purified enzyme.

7. The sterilization test pack according to claim 1 wherein the sterilization indicator comprises:

(i) a compressible outer container having at least one opening to allow sterilant to enter the compressible outer container during the sterilization procedure;

(ii) a source of an active enzyme contained within the outer container, the enzyme having an enzyme activity that is correlated with the survival of at least one test microorganism commonly used to monitor the effectiveness of a sterilization procedure, wherein the enzyme is substantially inactivated by a sterilization procedure that is lethal to the test microorganism, but wherein the enzyme may not be substantially inactivated by a sterilization procedure that is sublethal to the test microorganism; and

(iii) a breakable inner container within the outer container that is impermeable to the sterilant used in the sterilization procedure and that contains a substrate, wherein the inner container is breakable to allow the substrate to contact the enzyme, to form a detectable enzyme-modified product when the sterilization procedure is sublethal to the test organism.

8. The sterilization test pack according to claim 1 wherein said sterilization procedure employs one or more of sterilants selected from the group consisting of steam, hydrogen peroxide, hydrogen peroxide plasma, ethylene oxide gas, dry heat, propylene oxide gas, methyl bromide, chlorine dioxide, formaldehyde and peracetic acid.

9. A sterilization test pack according to claim 1 wherein the source of active enzyme comprises an interactive enzyme system and wherein said sterilization indicator further comprises one or more enzyme indicator reagents contained in a chamber which is in fluid communication with the source of active enzyme and which is initially sealed but when unsealed allows the enzyme indicator reagents to contact the source of active enzyme to provide an indication of sterilization.

10. A sterilization test pack according to claim 1 wherein the rim surface further includes a plurality of grooves, each groove of a defined length and cross-sectional area extending through the rim to the recessed trough;

the lid forming a plurality of channels with the grooves in the tray, such that sterilant may enter the tray through the channels and contact the sterilization indicator.

11. A sterilization test pack according to claim 1 wherein the sterilization test pack is a non-challenge test pack for testing the effectiveness of a hydrogen peroxide plasma sterilization procedure, the sterilization indicator comprising:

(a) a source of active enzyme having an enzyme activity that is correlated with the survival of at least one test microorganism commonly used to monitor the effectiveness of a sterilization procedure, wherein the enzyme is substantially inactivated by a sterilization procedure that is lethal to the test microorganism, but wherein the enzyme may not be substantially inactivated by a sterilization procedure that is sublethal to the test microorganism;

(b) a sterilant-resistant chemical associated with the source of active enzyme in such a manner that the active enzyme is more resistant to inactivation by a hydrogen peroxide plasma sterilization procedure than it would be if it were not associated with the sterilant resistant chemical; and

(c) a substrate that reacts with the active enzyme to form an enzyme-modified product that provides a detectable indication of the failure of the sterilization procedure.

12. A sterilization test pack according to claim 11, wherein the sterilant-resistant chemical is a compound selected from the group consisting of decaglyceryl decaoleate, decaglycerol pentaoleate, tetraglycerol monooleate, decagLyceryl tri-oleate, decaglycerol hexaoleate, hexaglycerol dioleate, polyoxyethylene (60) glycerol monostearate, polyoxyethylene (20) sorbiatan monostearate, and hexaglyn di-stearate, and mixtures of two or more members of the group.

13. A sterilization test pack according to claim 11 wherein the sterilization test pack is a non-challenge test pack for testing the effectiveness of a hydrogen peroxide plasma sterilization procedure, the sterilization indicator further comprising:

(a) a compressible outer container having at least one opening to allow sterilant to enter the outer container during the sterilization procedure, the source of active enzyme contained within the outer container; and

(b) a breakable inner container within the outer container that is impermeable to the sterilant used in the sterilization procedure and that contains the substrate, wherein the inner container is adapted so that it may be broken by compressing the outer container to allow the substrate to contact and react with the active enzyme to form the enzyme-modified product.

14. A sterilization test pack according to claim 13, wherein the sterilant-resistant chemical is a compound selected from the group consisting of decaglyceryl decaoleate, decaglycerol pentaoleate, tetraglycerol monooleate, decaglyceryl tri-oleate, decaglycerol hexaoleate, hexaglycerol dioleate, polyoxyethylene (60) glycerol monostearate, polyoxyethylene (20) sorbiatan monostearate, and hexaglyn di-stearate, and mixtures of two or more members of the group.

15. A sterilization test pack according to claim 11 wherein the channel is a lumen path and the sterilization test pack is a lumen-challenge test pack for testing the effectiveness of a hydrogen peroxide plasma sterilization procedure.

16. A sterilization test pack according to claim 15, wherein the sterilant-resistant chemical is a compound selected from the group consisting of decaglyceryl decaoleate, decaglycerol pentaoleate, tetraglycerol monooleate, decaglyceryl tri-oleate, decaglycerol hexaoleate, hexaglycerol dioleate, polyoxyethylene (60) glycerol monostearate, polyoxyethylene (20) sorbitan monostearate, and hexaglyn di-stearate, and mixtures of two or more members of the group.

17. A sterilization test pack according to claim 16, further comprising a sterilant barrier positioned within the recessed trough over the sterilization indicator.

18. A sterilization test pack according to claim 16, wherein the defined length of the lumen path is approximately 12 inches (30.48 cm) and the defined cross-sectional area of the lumen path is approximately the cross-sectional area of a circle having a diameter of 0.25 inches (0.635 cm).

19. A sterilization test pack according to claim 16, wherein the lumen path is generally in a “

Z”

—

type configuration.

20. A sterilization test pack according to claim 19, wherein the defined length of the lumen path is approximately 59 inches (150 cm) and the defined cross-sectional area of the lumen path is approximately the cross-sectional area of a circle having a diameter of about 0.2 inch (5 mm).

21. A sterilization test pack according to claim 19, further comprising a sterilant barrier in the recessed trough over the sterilization indicator.

22. A sterilization test pack, comprising:

(a) a first chamber;

(b) an enzymatic indicator within the first chamber;

(c) a lumen in fluid communication with the chamber and the enzymatic indicator within the chamber, the lumen comprising a hollow tube of predetermined length and cross-sectional area;

(d) a second chamber and an indicator reagent mixture, the second chamber in fluid communication with the first chamber so that the indicator reagent mixture may be brought into contact with the enzymatic indicator after a sterilization cycle is complete.

23. A sterilization test pack, comprising:

(a) a tray for holding a sterilization indicator, said tray comprising a recessed trough for receiving a sterilization indicator;

(b) a sterilization indicator within the recessed trough of the tray, for testing the effectiveness of a sterilization procedure;

(c) a lid associated with the rim surface of the tray covering the recessed trough and the sterilization indicator, said lid comprising a material that is penetrable by a sterilant, such that sterilant may enter the recessed trough through the lid; and

(d) A sterilant barrier within the recessed trough.