U.S. patent application number 10/067809 was filed with the patent office on 2002-10-03 for hydrogen peroxide disinfectant with increased activity.
Invention is credited to Rochon, Michael J..
Application Number | 20020142051 10/067809 |
Document ID | / |
Family ID | 26809541 |
Filed Date | 2002-10-03 |
United States Patent
Application |
20020142051 |
Kind Code |
A1 |
Rochon, Michael J. |
October 3, 2002 |
Hydrogen peroxide disinfectant with increased activity
Abstract
An acidic aqueous hydrogen peroxide solution is provided with
improved disinfectant activity. Concentrated solutions preferably
contain up to about 8 wt./wt. % H2O2 and as-used concentrations
contain about 0.5% wt./wt. % H2O2. The solution also contains from
0.05 to 8.0 wt./wt. % of at least one phosphorous-based acid, e.g.
phosphoric acid and/or a phosphonic acid with from 1 to 5
phosphonic acid groups, and from 0.02 to 5 wt./wt. % of at least
one anionic surfactant. The surfactant is selected from C8 to C16
alkyl aryl sulfonic acids, sulfonated C12 to C22 carboxylic acids,
C8 to C22 alkyl diphenyl oxide sulfonic acids, naphthalene sulfonic
acids, C8 to C22 alkyl sulfonic acids, and alkali metal and
ammonium salts thereof, and alkali metal C8 to C18 alkyl sulfates,
and mixtures thereof. Most preferably the solution has an
emulsifier, e.g. a polyoxyethylene surfactant. The solution also
preferably contains a hydrotrope, e.g. an alkylated sulfonated
diphenyl oxide salt. The solution may also contain corrosion
inhibitors and/or lower alcohols.
Inventors: |
Rochon, Michael J.;
(Caledon, CA) |
Correspondence
Address: |
Clark & Brody
Suite 600
1750 K Street, NW
Washington
DC
20006
US
|
Family ID: |
26809541 |
Appl. No.: |
10/067809 |
Filed: |
February 8, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10067809 |
Feb 8, 2002 |
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09356345 |
Jul 19, 1999 |
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6346279 |
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60112047 |
Dec 14, 1998 |
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Current U.S.
Class: |
424/616 |
Current CPC
Class: |
A01N 59/00 20130101;
A01N 59/00 20130101; Y10S 424/06 20130101; A01N 59/00 20130101;
Y10S 514/973 20130101; A61P 31/02 20180101; A01N 2300/00 20130101;
A01N 25/22 20130101; A01N 25/30 20130101; Y10S 514/97 20130101 |
Class at
Publication: |
424/616 |
International
Class: |
A01N 039/00 |
Claims
1. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to 20 wt./wt. % of the solution; ii)
at least one phosphorus-based acid in a concentration range of from
0.05 to 8.0 wt./wt. % of the solution; iii) at least one anionic
surfactant selected from the group consisting of C8 to C16 alkyl
aryl sulfonic acids and alkali metal and ammonium salts thereof,
sulfonated C12 to C22 carboxylic acids and alkali metal and
ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; and iv) the remainder to 100 wt./wt. % water.
2. A solution according to claim 1 wherein the pH is from 1 to
3.
3. A solution according to claim 2 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 8.0 wt./wt. % of
the solution.
4. A solution according to claim 3 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 1.0 wt./wt. % of
the solution.
5. A solution according to claim 2 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
phosphonic acids having 1 to 5 phosphonic acid groups, and mixtures
thereof.
6. A solution according to claim 5 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
amino tri(methylene phosphonic acid),
1-hydroxyethylidene-1,1,-diphosphonic acid,
diethylenetriaminepenta(methylene phosphonic acid),
2-hydroxyethylimino bis(methylene phosphonic acid), ethylene
diamine tetra(methylene phosphonic acid), and mixtures thereof.
7. A solution according to claim 6 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
1-hydroxyethylidene-1,1,-diphosphonic acid, and mixtures
thereof.
8. A solution according to claim 2 containing dodecyl benzene
sulfonic acid or an alkali metal salt or ammonium salt thereof.
9. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to 20 wt./wt. % of the solution; ii)
at least one phosphorus-based acid in a concentration range of from
0.05 to 8.0 wt./wt. % of the solution iii) at least one anionic
surfactant selected from the group consisting of C8 to C16 alkyl
aryl sulfonic acids and alkali metal and ammonium salts thereof,
sulfonated C12 to C22 carboxylic acids and alkali metal and
ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) up to about 3 wt./wt. % of an additional
component selected from the group consisting of emulsifiers,
hydrotropes, and mixtures thereof; and v) the remainder to 100
wt./wt. % water.
10. A solution according to claim 9 wherein the pH is from 1 to
3.
11. A solution according to claim 10 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 8.0 wt./wt. % of
the solution.
12. A solution according to claim 11 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 1.0 wt./wt. % of
the solution.
13. A solution according to claim 10 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
phosphonic acids having 1 to 5 phosphonic acid groups, and mixtures
thereof.
14. A solution according to claim 13 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
amino tri(methylene phosphonic acid),
1-hydroxyethylidene-1,1,-diphosphonic acid,
diethylenetriaminepenta(methylene phosphonic acid),
2-hydroxyethylimino bis(methylene phosphonic acid), ethylene
diamine tetra(methylene phosphonic acid), and mixtures thereof.
15. A solution according to claim 14 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
1-hydroxyethylidene-1,1,-diphosphonic acid, and mixtures
thereof.
16. A solution according to claim 10 containing dodecyl benzene
sulfonic acid or an alkali metal salt or ammonium salt thereof.
17. A solution according to claim 10 wherein the emulsifier is a
polyoxyethylene surfactant.
18. A solution according to claim 10 wherein the hydrotrope is
selected from an alkylated sulfonated diphenyl oxide and an
alkylated sulfonated diphenyl oxide salt.
19. A solution according to claim 18 containing a C6 alkylated
sulfonated diphenyl oxide disodium salt.
20. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to 20 wt./wt. % of the solution; ii)
at least one phosphorus-based acid in a concentration range of from
0.05 to 8.0 wt./wt. % of the solution; iii) at least one anionic
surfactant selected from the group consisting of C8 to C16 alkyl
aryl sulfonic acids and alkali metal and ammonium salts thereof,
sulfonated C12 to C22 carboxylic acids and alkali metal and
ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) a corrosion inhibitor in a concentration of from
0.05 to 10.0 wt./wt % of the solution; and v) the remainder to 100
wt./wt. % water.
21. A solution according to claim 20 wherein the pH is from 1 to
3.
22. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to 20 wt./wt. % of the solution; ii)
at least one phosphorus-based acid in a concentration range of from
0.05 to 8.0 wt./wt. % of the solution; iii) at least one anionic
surfactant selected from the group consisting of C8 to C16 alkyl
aryl sulfonic acids and alkali metal and ammonium salts thereof,
sulfonated C12 to C22 carboxylic acids and alkali metal and
ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) from 0.1 to 10 wt./wt. % of an alcohol comprising
one to six carbon atoms; and v) the remainder to 100 wt./wt. %
water.
23. A solution according to claim 22 wherein the pH is from 1 to
3.
24. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to 20 wt./wt. % of the solution; ii)
at least one phosphorus-based acid in a concentration range of from
0.05 to 8.0 wt./wt. % of the solution; iii) at least one anionic
surfactant selected from the group consisting of C8 to C16 alkyl
aryl sulfonic acids and alkali metal and ammonium salts thereof,
sulfonated C12 to C22 carboxylic acids and alkali metal and
ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) a monocarboxylic acid or polycarboxylic acid in a
concentration of from about 0.05 to about 4.0 wt./wt. %; and v) the
remainder to 100 wt./wt. % water.
25. A solution according to claim 24 wherein the pH is from 1 to
3.
26. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to about 20 wt./wt. % of the solution;
ii) at least one phosphorus-based acid in a concentration range of
from 0.05 to 8.0 wt./wt. % of the solution; and iii) at least one
anionic surfactant selected from the group consisting of C8 to C16
alkyl aryl sulfonic acids and alkali metal and ammonium salts
thereof, sulfonated C12 to C22 carboxylic acids and alkali metal
and ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) up to about 3 wt./wt. % of an additional
component selected from the group consisting of emulsifiers,
hydrotropes, and mixtures thereof; v) a corrosion inhibitor in a
concentration of from 0.05 to 10.0 wt./wt % of the solution; and
vi) the remainder to 100 wt./wt. % water.
27. A solution according to claim 26 wherein the pH is from 1 to
3.
28. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to about 20 wt./wt. % of the solution;
ii) at least one phosphorus-based acid in a concentration range of
from 0.05 to 8.0 wt./wt. % of the solution; and iii) at least one
anionic surfactant selected from the group consisting of C8 to C16
alkyl aryl sulfonic acids and alkali metal and ammonium salts
thereof, sulfonated C12 to C22 carboxylic acids and alkali metal
and ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) up to about 3 wt./wt. % of an additional
component selected from the group consisting of emulsifiers,
hydrotropes, and mixtures thereof; v) a monocarboxylic acid or
polycarboxylic acid in a concentration of from about 0.05 to about
4.0 wt./wt. %; vi) the remainder to 100 wt./wt. % water.
29. A solution according to claim 28 wherein said pH is from 1 to
3.
30. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and consisting essentially of: i) hydrogen peroxide in
a concentration of from 0.01 to about 20 wt./wt. % of the solution;
ii) at least one phosphorus-based acid in a concentration range of
from 0.05 to 8.0 wt./wt. % of the solution; and iii) at least one
anionic surfactant selected from the group consisting of C8 to C16
alkyl aryl sulfonic acids and alkali metal and ammonium salts
thereof, sulfonated C12 to C22 carboxylic acids and alkali metal
and ammonium salts thereof, C8 to C22 alkyl diphenyl oxide sulfonic
acids and alkali metal and ammonium salts thereof, naphthalene
sulfonic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl sulfonic acids and alkali metal and ammonium salts
thereof, alkali metal C8 to C18 alkyl sulfates, and mixtures
thereof, in a concentration range of from 0.02 to 5 wt./wt. % of
the solution; iv) up to about 3 wt./wt. % of an additional
component selected from the group consisting of emulsifiers,
hydrotropes, and mixtures thereof; v) a corrosion inhibitor in a
concentration of from 0.05 to 10.0 wt./wt % of the solution; vi) a
monocarboxylic acid or polycarboxylic acid in a concentration of
from about 0.05 to about 4.0 wt./wt. %; and vii) the remainder to
100 wt./wt. % water.
31. A solution according to claim 30 wherein the pH is from 1 to
3.
32. An aqueous disinfecting or sanitizing solution having a pH of
from 1 to 7 and comprising: i) hydrogen peroxide in a concentration
of from 0.01 to 20 wt./wt. % of the solution; ii) at least one
phosphorus-based acid in a concentration range of from 0.05 to 8.0
wt./wt. % of the solution; iii) at least one anionic surfactant
selected from the group consisting of C8 to C16 alkyl aryl sulfonic
acids and alkali metal and ammonium salts thereof, sulfonated C12
to C22 carboxylic acids and alkali metal and ammonium salts
thereof, C8 to C22 alkyl diphenyl oxide sulfonic acids and alkali
metal and ammonium salts thereof, naphthalene sulfonic acids and
alkali metal and ammonium salts thereof, C8 to C22 alkyl sulfonic
acids and alkali metal and ammonium salts thereof, alkali metal C8
to C 18 alkyl sulfates, and mixtures thereof, in a concentration
range of from 0.02 to 5 wt./wt. % of the solution; and iv) a
hydrotrope selected from an alkylated sulfonated diphenyl oxide and
an alkylated sulfonated diphenyl oxide salt.
33. A solution according to claim 32 wherein the pH is from 1 to
3.
34. A solution according to claim 33 wherein said hydrotrope is a
C6 alkylated sulfonated diphenyl oxide disodium salt.
35. A solution according to claim 33 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
phosphonic acids having 1 to 5 phosphonic acid groups, and mixtures
thereof.
36. A solution according to claim 35 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
amino tri(methylene phosphonic acid),
1-hydroxyethylidene-1,1,-diphosphonic acid,
diethylenetriaminepenta(methylene phosphonic acid),
2-hydroxyethylimino bis(methylene phosphonic acid), ethylene
diamine tetra(methylene phosphonic acid), and mixtures thereof.
37. A solution according to claim 36 wherein the phosphorus-based
acid is selected from the group consisting of phosphoric acid,
1-hydroxyethylidene-1,1,-diphosphonic acid, and mixtures
thereof.
38. A solution according to claim 33 containing dodecyl benzene
sulfonic acid or an alkali metal salt or ammonium salt thereof.
39. A solution according to claim 33 further comprising an
emulsifier.
40. A solution according to claim 39 wherein the emulsifier is a
polyoxyethylene surfactant.
41. A solution according to claim 33 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 8.0 wt./wt. % of
the solution.
42. A solution according to claim 41 wherein the solution has a
hydrogen peroxide concentration of from 0.05 to 1.0 wt./wt. % of
the solution.
43. A solution according to claim 33 containing a corrosion
inhibitor in a concentration of from 0.05 to 10.0 wt./wt % of the
solution.
44. A solution according to claim 33 containing from 0.1 to 10
wt./wt. % of an alcohol comprising one to six carbon atoms.
45. A solution according to claim 33 containing a monocarboxylic
acid or polycarboxylic acid in a concentration of from about 0.05
to about 4.0 wt./wt. %.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/356,345 filed Jul. 19, 1999 which claims
the benefit of U.S. provisional patent application No. 60/112,047
filed Dec. 14, 1998.
Field of the Invention
[0002] The present invention relates to disinfectants and, in
particular, it relates to hydrogen peroxide solutions with improved
disinfectant and antimicrobial properties.
Background to the Invention
[0003] A wide range of disinfectants is known, as discussed for
example in Disinfection, Sterilization, and Preservation, edited
and partially written by Professor Seymour S. Block, Fourth
Edition, published 1991 by Lea & Febiger, Pennsylvania. Certain
peroxygen compounds, chlorine compounds, phenolics, quaternary
ammonium compounds and surface active agents are known for their
germicidal properties. The rate of disinfection is relatively slow
in many cases, and some compounds emit volatile organic compounds
or leave a persistent residue in the environment.
[0004] Hydrogen peroxide is finding favour in many applications
because its breakdown products, water and oxygen, are innocuous,
and it tends to have broad spectrum antimicrobial activity. Broad
spectrum activity is important in situations where harmful
organisms are present but their identity is not known.
[0005] As hydrogen peroxide tends to be unstable and decomposes
over time, steps must be taken to stabilize the hydrogen peroxide
solutions for storage purposes. All commercially available aqueous
hydrogen peroxide contains added stabilizers in small amounts, i.e.
measured in parts per million, and have an excellent shelf life.
For example, see Kirk-Othmer et al, "Encyclopaedia of Chemical
Technology", vol. 13 (New York: Wiley-Interscience, 1991) at page
965 which discusses the requirement to add stabilizers to
commercial hydrogen peroxide solutions. Hence, all references
herein to hydrogen peroxide are references to commercially
available hydrogen peroxide containing small amounts of
stabilizers. Known hydrogen peroxide stabilizers include organic
sequestering agents, i.e. stannates and phosphates, and
combinations of organic compounds and organometallic salts with or
without stannates and phosphates. An exemplary stannate is sodium
stannate trihydrate and an exemplary phosphate is sodium
pyrophosphate.
[0006] A major drawback of most disinfectants used heretofore has
been the length of time needed to reduce the bacterial count after
the disinfectant has been applied to a bacterially contaminated
material. For example, it may take 30 minutes or more after
application of the disinfectant to disinfect a treated surface. In
many circumstances this rate of disinfection is far from
satisfactory.
[0007] Combinations of hydrogen peroxide with various surfactants
are known. For example, Winterton et al. discloses, in U.S. Pat.
No. 5,523,012, a buffered disinfecting solution for contact lenses,
which has from about 0.1% to about 1.0% of an ocularly compatible
surfactant. Winterton discloses that, in one experiment, addition
of about 0.4% anionic sulfosuccinate surfactant improved the
killing time for aspergillus fumigatus to 6.9 minutes, compared to
9.4 minutes for a solution containing 0.1% nonionic surfactants.
However, even 6.9 minutes is far too long for many
applications.
[0008] The present invention is directed to improving the efficacy
of hydrogen peroxide based solutions.
Summary of the Invention
[0009] Accordingly, the invention provides an aqueous solution
having a pH of from 1 to 7, and preferably 1 to 3, and comprising
i) hydrogen peroxide in a concentration of from 0.01 to about 20
wt./wt. % of the solution, ii) at least one phosphorus-based acid
in a concentration range of from 0.05 to 8.0 wt./wt. % of the
solution, and iii) at least one anionic surfactant selected from
the group consisting of C8 to C16 alkyl aryl sulfonic acids and
alkali metal and ammonium salts thereof, sulfonated C12 to C22
carboxylic acids and alkali metal and ammonium salts thereof, C8 to
C22 alkyl diphenyl oxide sulfonic acids and alkali metal and
ammonium salts thereof, naphthalene sulfonic acids and alkali metal
and ammonium salts thereof, C8 to C22 alkyl sulfonic acids and
alkali metal and ammonium salts thereof, alkali metal C8 to C18
alkyl sulfates, and mixtures thereof, in a concentration range of
from 0.02 to 5 wt./wt. % of the solution.
[0010] Preferably, the phosphorus-based acid is selected from the
group consisting of phosphoric acid, phosphonic acids having 1 to 5
phosphonic acid groups, and mixtures thereof. Of the phosphonic
acids having 1 to 5 phosphonic acid groups,
1-hydroxyethylidene-1,1,-diphosphonic acid is most preferred.
However, also preferred are amino tri(methylene phosphonic acid),
diethylenetriaminepenta(methylene phosphonic acid),
2-hydroxyethylimino bis(methylene phosphonic acid), ethylene
diamine tetra(methylene phosphonic acid).
[0011] Preferred anionic surfactants are anionic alkyl aryl
sulfonic acids and alkali metal and ammonium salts thereof,
preferably dodecyl benzene sulfonic acid, and alkali metal and
ammonium salts thereof.
[0012] The solution may contain up to about 3 wt./wt. % of an
additional component selected from the group consisting of
emulsifiers, hydrotropes, and mixtures thereof. Preferred
emulsifiers are polyoxyethylene surfactants, preferably alkyl
polyoxyethylene surfactants and alkyl aryl polyoxyethylene
surfactants. An example of an alkyl aryl polyoxyethylene surfactant
is C8 to C16 alkyl phenoxypolyethoxy ethanol.
[0013] Preferred hydrotropes are alkylated sulfonated diphenyl
oxides, alkylated sulfonated diphenyl oxide salts, and mixtures
thereof. Even more preferred is a C6 alkylated sulfonated diphenyl
oxide disodium salt.
[0014] The solution may contain hydrogen peroxide in a
concentration of from 0.05 to 8.0 wt./wt. % of the solution, 0.05
to 1.0 wt./wt. % of the solution, and from 3.0 to 8.0 wt./wt. % of
the solution.
[0015] The solution may also contain a corrosion inhibitor in a
concentration of from 0.05 to 10.0 wt./wt % of the solution, and
from 0.1 to 10 wt./wt. % of an alcohol comprising one to six carbon
atoms. Furthermore, the solution may contain a monocarboxylic acid,
a polycarboxylic acid, or mixtures thereof, in a concentration of
from about 0.05 to about 4.0 wt./wt. % of the solution.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] In the past few years, efforts have been concentrated on
developing chemicals that will be highly effective against
microorganisms when highly diluted, will be low in toxicity to
humans and other animals, and will not injure the environment. Of
all the known disinfectants and antimicrobials, hydrogen peroxide
appears to have exceptional potential, especially in terms of
toxicity and injury to the environment because the decomposition
products are benign. For example, at concentrations of 1-3 wt./wt.
% aqueous solution, hydrogen peroxide is considered non-corrosive
and non-irritating; at concentrations of 3-7 wt./wt. % aqueous
solution, hydrogen peroxide is considered non-corrosive but an eye
irritant; and at concentrations of above about 8 wt./wt. % aqueous
solution, hydrogen peroxide is considered corrosive, more so at
higher concentrations, and also a strong oxidizing agent.
[0017] The higher concentration levels of hydrogen peroxide
solutions required to provide fast, effective action are not
practical or economically viable, and may be subject to hazardous
goods regulations and require special precautions for handling and
use. Heretofore, one of the major drawbacks of hydrogen peroxide,
in low concentrations, is that its antimicrobial action is too
slow. A second major drawback is that it has not been considered
possible to stabilize the peroxide sufficiently to make the
solution commercially acceptable. For example, prior references
indicate that a 0.1 wt./wt. % aqueous solution of hydrogen peroxide
requires 60 minutes to disinfect surfaces contaminated with
staphylococcus aureus, whereas a 25.8 wt./wt. % aqueous solution of
hydrogen peroxide requires only 20 seconds to disinfect surfaces
contaminated with staphylococcus aureus. The latter solution is
clearly unacceptable for commercial use, both from a safety
standpoint and an economic standpoint.
[0018] It has now been found that addition of phosphorus-based
acids and anionic surfactants greatly enhance the activity of
aqueous hydrogen peroxide solutions. The phosphorus-based acids are
inorganic acids or organic acids. Especially preferred are
phosphoric acid (H.sub.3PO.sub.4) and phosphonic acids having 1 to
5 phosphonic acid groups. Particularly preferred phosphonic acids
are amino tri(methylene phosphonic acid),
1-hydroxyethylidene-1,1,-diphosphonic acid,
diethylenetriaminepenta-(meth- ylene phosphonic acid),
2-hydroxyethylimino bis(methylene phosphonic acid), and ethylene
diamine tetra(methylene phosphonic acid). Each may be used alone,
but mixtures of phosphoric acid and at least one of the phosphonic
acids are preferred. Some of these phosphonic acids are available
from Albright & Wilson under the trade mark BRIQUEST and some
from Solutia Inc. under the trade mark DEQUEST. The concentration
of the phosphorus-based acids is from 0.05 to 8.0 wt./wt. % of the
solution. The lower concentrations are preferable for solutions
with lower concentrations of hydrogen peroxide. The pH of the
solutions are from 1 to 7, and even more particularly from about 1
to about 3.
[0019] The anionic surfactant is selected from the group consisting
of C8 to C16 alkyl aryl sulfonic acids and alkali metal and
ammonium salts thereof, sulfonated C12 to C22 carboxylic acids and
alkali metal and ammonium salts thereof, C8 to C22 alkyl diphenyl
oxide sulfonic acids and alkali metal and ammonium salts thereof,
naphthalene sulfonic acids and alkali metal and ammonium salts
thereof, C8 to C22 alkyl sulfonic acids and alkali metal and
ammonium salts thereof, alkali metal C8 to C18 alkyl sulfates, and
mixtures thereof, in a concentration range of from 0.02 to 5
wt./wt. % of the solution. Preferably, the anionic surfactant is an
alkyl aryl sulfonic acid or a salt thereof, especially a C8 to C16
alkyl benzene sulfonic acid or a salt thereof, or mixtures thereof.
Preferred anionic surfactants are dodecyl benzene sulfonic acid and
tridecyl benzene sulfonic acid and their salts, e.g. sodium,
potassium, ammonium salts.
[0020] Of the sulfonated C12 to C22 carboxylic acids, sulfonated
9-octadecanoic acid is preferred. Of the C8 to C22 alkyl diphenyl
oxide sulfonic acids and salts, dodecyl diphenyl oxide disulfonic
acid and disodium 4-dodecylated diphenyloxide sulfonate, alkylated
sulfonated diphenyl oxide disodium salt are preferred. Of the C8 to
C22 alkyl sulfonic acids, the sodium salts of 1-octane sulfonic
acid, 1-decane sulfonic acid and tridecane sulfonic acid are
preferred. Of the alkali metal C8 to C18 alkyl sulfates, sodium
lauryl sulfate is preferred.
[0021] The hydrogen peroxide solution may be prepared as a
concentrated aqueous solution, e.g. up to 20 wt./wt. % hydrogen
peroxide, preferably up to 8 wt./wt. %, which then may be diluted
by the end user, or the solution may be prepared in a dilute form,
e.g. from 0.05 to 1.0 wt./wt. %. As will be illustrated by the
examples which follow, solutions of about 0.5 wt./wt. % are
effective in substantially reducing bacterial and viral
activity.
[0022] Solutions having about from 0.05 to 1.0 wt./wt %, especially
about 0.5 wt./wt. % hydrogen peroxide are suitable for use as
household and commercial disinfectants, bactericides, virucides,
sanitizers and cleaners. Solutions having about 3-4 wt./wt. % are
suitable for use as multi-purpose cleaners and bleach alternatives
in healthcare facilities, households and commercial facilities.
Solutions having about 6-8 wt./wt. % hydrogen peroxide are suitable
for use as a sporicides, fungicides, virucides, bactericides, broad
spectrum sanitizers, general purpose cleaners and bleach
alternatives, particularly in institutional, healthcare and food
applications.
[0023] Other surfactants may be present as emulsifiers and/or
hydrotropes in the solutions. For example, certain emulsifiers
and/or hydrotropes are beneficial for cleaning surfaces with
organic matter or grease and for providing stability to the
solution. Typically, the emulsifiers and/or hydrotropes are present
in a concentration of about 10 to 30 parts emulsifier per hundred
parts of hydrogen peroxide or up to about 3.0. wt./wt. % of the
solution. Preferably, they are present in a concentration of about
0.1 to 0.2 wt./wt. % of the solution.
[0024] Preferred emulsifiers are non-ionic alkylated alkoxylate
surfactants. More preferred are alkylated polyoxyethylene
surfactants, including aryl polyoxyethylene surfactants such as C8
to C16 alkylphenol ethoxylates (e.g. octyl phenol ethoxylate).
[0025] A short-chain alcohol, e.g. a C1-C6 alcohol, especially
methanol, ethanol or iso-propanol, may be added to provide
additional cleaning ability for organic contaminants. Preferred
concentrations of the short chain alcohol are from about 0.1 to
about 10 wt./wt. % of the solution. Addition of the alcohol is
believed to provide better germicidal activity.
[0026] Because hydrogen peroxide has a broad spectrum of activity,
it is useful in many different applications. In the healthcare
field, the solution may be used in hospitals, clinics,
laboratories, dental offices, home care and chronic care
facilities. It may also be used in food and beverage processing and
preparation, animal husbandry, the hospitality industry and for
general sanitation, e.g. janitorial services.
[0027] The solutions of the present invention have a long shelf
life, e.g. up to a year or more.
[0028] A preferred method for preparing the solutions of the
present invention comprises adding the phosphorus-based acid(s) and
the anionic surfactant(s) and optionally the emulsifiers and/or
hydrotropes to distilled or otherwise purified water prior to the
addition of hydrogen peroxide. If there are any other ingredients,
e.g. alcohols, scents, colouring agents, dyes, corrosion inhibitors
these are preferably added before the hydrogen peroxide.
[0029] The invention may also be better understood by reference to
the following examples:
EXAMPLE I
[0030] A solution of the present invention (Solution A) was
prepared with 695 parts by weight distilled water, 20 parts by
weight 75% phosphoric acid (H.sub.3PO.sub.4), 75 parts by weight
50% Briquest 301-50A (trade mark) amino tri(methylene phosphonic
acid), 25 parts by weight 45% hydrotrope Dowfax (trade mark) C6
alkylated sulfonated diphenyl oxide disodium salt, 25 parts by
weight 98% Biosoft S-100 (trade mark) dodecyl benzene sulfonic
acid, 10 parts by weight Triton X-405 70% (trade mark) octyl phenol
ethoxylate emulsifier and 150 parts by weight 50% hydrogen
peroxide. The ingredients were mixed in a passivated vessel, with
hydrogen peroxide being the last ingredient added to the solution.
The pH of the solution was 1.27.
[0031] Aliquots of this solution were tested for mycobacterial,
sporicidal, fungicidal, bactericidal and virucidal activity and
compared against commercially available disinfectants. For testing
for bactericidal and virucidal activity, aliquots were diluted with
water, with 1 part solution to 15 parts water.
[0032] Quantitative carrier tests were conducted on the samples.
The test methods incorporated the essential requirements of the
Canadian General Standards Boards' standard entitled "Assessment of
Efficacy of Antimicrobial Agents for Use on Environmental Surfaces
and Medical Devices" (CGSB 1997), and also conform to the ASTM
requirements for evaluating virucidal activity of liquid germicides
to be used on non-porous surfaces.
[0033] The inside bottom surface of glass vials was used as the
carrier surface for mycobacterial, sporicidal, fungicidal,
bactericidal tests. Stainless steel disks were used as the carrier
surface for virucidal tests. Silk suture loops were not used
because of the extreme difficulty in using them for standardized
tests.
[0034] All test organisms were first suspended in bovine serum at a
final concentration of 5 wt./wt. % of the solution. When the
product was to be tested after dilution, water with a standard
hardness of 200 ppm as calcium carbonate was used as the diluent.
The water was prepared according to the formula in AOAC
International (1990).
[0035] Phosphate buffer, at pH 7.2, was used to make dilutions of
spores and vegetative bacterial cells and to rinse membrane filters
in tests for sporicidal and bactericidal tests. The diluent and
filter rinse used for mycobacterial and fungicidal tests was
sterile normal saline (0.85% sodium chloride). Earle's balance salt
solution was used to prepare dilutions of the virus prior to
infectivity assays.
[0036] The general steps for quantitative analysis of
mycobacterial, sporicidal, fungicidal and bactericidal activities
of the test disinfectant involved i) inoculating carriers with
inserts centred in vials, ii) dyeing the inoculated carriers, iii)
removing the inserts, iv) adding a test disinfectant to the
inoculated carrier, v) diluting the test disinfectant at the
completion of a known exposure time at a known temperature, vi)
filtering and vii) placing the filters onto a medium, followed by
incubating. The colony forming units (CFU) were then
determined.
[0037] Control carriers were used in the same manner as test
carriers, except that phosphate buffer was applied to the dried
inoculum instead of disinfectant in the case of sporicidal and
bacterial tests, and sterile saline was applied in the case of
mycobactericidal and fungicidal tests. In the tests, there were
three control carriers to every seven test carriers.
[0038] For virucidal activity, each stainless steel disk received
test virus in bovine serum. After the inoculum had dried, it was
exposed either to Earle's buffer solution or the test disinfectant
for the required contact time and temperature. Each disk was placed
in a vial with eluent/diluent and vortexed to recover the inoculum.
The control and test eluates were inoculated into cell cultures for
virus plaque assays. The plaque forming units (PFU) were then
determined. To avoid false positive results, further controls were
carried out by exposing the cell monolayers to a non-virucidal and
non-cytotoxic dilution of the test products and then using the same
monolayers for plaque assays. If the number of plaques on such
pre-exposed monolayers was the same as those exposed to Earle's
solution, the product was regarded as free from interference. In
the tests, there were three control carriers to every five test
carriers.
[0039] The test results are shown in Tables I and II
1 TABLE I Organism Contact time CFU** Control Solution A ATCC
19659* 6 hours 1.96 .times. 10.sup.8 0 ATCC 7955* 6 hours 3.12
.times. 10.sup.7 0 ATCC 15442* 10 minutes 1.79 .times. 10.sup.6 0
ATCC 15442* 3 minutes 1.25 .times. 10.sup.6 0 ATCC 15442* 1 minute
1.45 .times. 10.sup.6 0 ATCC 6538* 1 minute 1.40 .times. 10.sup.6 0
ATCC 10708* 1 minute 1.16 .times. 10.sup.6 0 ATCC 15755* 20 minutes
1.8610.sup.6 0 ATCC 9533* 5 minutes 4.0 .times. 10.sup.5 0
[0040]
2 TABLE II Organism Contact time PFU** Control Solution A ATCC
VR-192* 5 minutes 8.7 .times. 10.sup.4 1 ATCC VR-192* 5 minutes 8.7
.times. 10.sup.4 10 *ATCC 19659 Bacillus subtilis; *ATCC 7955
Clostridium sporogenes; *ATCC 15442 Pseudomonas aeruginosa; *ATCC
6538 Staphylococcus aureus; *ATCC 10708 Salmonella chloreraesuis;
*ATCC 15755 Mycobacterium terrae; *ATCC 9533 Trichophyton
mentagrophytes; *ATCC VR-192* Sabin vaccine strain of polio virus
Type I **CFU = colony forming units; PFU = plaque forming units
EXAMPLE II
[0041] Solution A of Example I was tested further, according to the
method of Germicidal and Detergent Sanitizing Action of
Disinfectants, Final Action AOAC XV, 1995, Part 6.3.03.
[0042] Samples of the organism being tested were mixed with 5%
bovine serum. 56 mL portions of Solution A were diluted with 4
liters of 200 ppm synthetic hard water. Each dilute solution was
applied to an organism at 20.degree. C. and the organism count per
milliliter was determined before application of the solution, and
30 seconds and 60 seconds after application of the solution. The
results are shown in Table III.
3 TABLE III Count Count Organism Initial Count 30 sec 60 sec ATCC
15442 94.5 .times. 10.sup.6 <10 <10 ATCC 6538 44.5 .times.
10.sup.6 218 75 ATCC 33592* 32.3 .times. 10.sup.6 <10 <10
ATCC 51575* 94.5 .times. 10.sup.6 <10 <10 *ATCC 33592
Staphylococcus aureus (methicillin resistant); ATCC 51575
Enterococcus faecalis (vancomycin resistant)
EXAMPLE III
[0043] Solution A of Example I was tested further, according to the
method of Germicidal and Detergent Sanitizing Action of
Disinfectants, Final Action AOAC XV, 1995, Part 6.3.03.
[0044] Samples of the organism being tested were mixed with 5%
bovine serum. The undiluted Solution A was applied to the organisms
at 20.degree. C. and the organism count per milliliter was
determined before application of the solution, and 30 seconds and
60 seconds after application of the solution. The results are shown
in Table IV.
4 TABLE IV Count Count Organism Initial Count 30 sec 60 sec ATCC
10708 117 .times. 10.sup.6 <10 <10 ATCC 15442 94.5 .times.
10.sup.6 <10 <10 ATCC 6538 44.5 .times. 10.sup.6 <10
<10 ATCC 33592 79.5 .times. 10.sup.6 <10 <10 ATCC 51575
32.3 .times. 10.sup.6 <10 <10
EXAMPLE IV
[0045] The test according to Example II was modified, using 50%
bovine serum which was added to the organism. 56 mL portions of
Solution A were diluted with 4 liters of 200 ppm synthetic hard
water. Each dilute solution was applied to an organism at
20.degree. C. and the organism count per milliliter was determined
before and application of the solution, and 30 seconds and 60
seconds after application of the solution. The results are shown in
Table V.
5 TABLE V Count Count Organism Initial Count 30 sec 60 sec ATCC
15442 235 .times. 10.sup.6 <10 <10 ATCC 6358 115 .times.
10.sup.6 <10 <10 ATCC 10708 81.3 .times. 10.sup.6 <10
<10
EXAMPLE V
[0046] Tests were carried out to determine the cleaning efficiency
of diluted solutions of Solution A compared to commercially
available cleaners. Test Procedure CAN/CGSB 2.1, Method 20.3 was
used, in which synthetic soil, of brown iron oxide pigment,
kerosene, Stoddard solvent, white petroleum jelly, lubricating oil
and shortening, was applied to white vinyl tiles. As a control, a
1% CGSB standard detergent in 125 ppm hard water, was used.
[0047] One portion of Solution A was diluted in 125 ppm hard water
to form Solution B, which contained about 0.06% hydrogen peroxide.
Another portion of Solution A was diluted in 125 ppm hard water to
form Solution C, which contained about 0.01% hydrogen peroxide. A
sample of commercial sodium hypochlorite bleach was diluted 1:20 to
form Solution D.
[0048] The contaminated tiles were cleaned with 50 mL of each
solution being tested and cleaning efficiency values were based on
reflectance measurements. The results are shown in Table VI.
6 TABLE VI Solution Efficiency (%) Solution B (0.06%
H.sub.2O.sub.2) 94.6 Solution C (0.01% H.sub.2O.sub.2) 93.7
Solution D (Na hypochlorite) 11.3 Standard Detergent 77.2 Distilled
water 11.4
* * * * *