U.S. patent application number 10/566542 was filed with the patent office on 2007-08-16 for disinfection of a contaminated environment.
This patent application is currently assigned to BIOTAL LIMITED. Invention is credited to Philip Caunt, Deborah Williams.
Application Number | 20070187404 10/566542 |
Document ID | / |
Family ID | 27799497 |
Filed Date | 2007-08-16 |
United States Patent
Application |
20070187404 |
Kind Code |
A1 |
Caunt; Philip ; et
al. |
August 16, 2007 |
Disinfection of a contaminated environment
Abstract
A formulation to reduce the numbers of bacteria, particularly
Gram positive bacteria, in a space such as a waste disposal bin,
via the vapour phase, and active over a long period, typically
several weeks. The product comprises one or more essential oils or
essential oil components plus a mixture of volatile and
non-volatile solvents, on a carrier such as a non-woven, sintered
plastic or cardboard.
Inventors: |
Caunt; Philip; (Cardiff,
GB) ; Williams; Deborah; (Cardiff, GB) |
Correspondence
Address: |
THELEN REID & PRIEST LLP;LESLIE G. RESTAINO
200 CAMPUS DRIVE
SUITE 210
FLORHAM PARK
NJ
07932
US
|
Assignee: |
BIOTAL LIMITED
Cardiff
GB
|
Family ID: |
27799497 |
Appl. No.: |
10/566542 |
Filed: |
July 29, 2004 |
PCT Filed: |
July 29, 2004 |
PCT NO: |
PCT/GB04/03289 |
371 Date: |
December 18, 2006 |
Current U.S.
Class: |
220/62.11 ;
220/694; 424/725; 424/739; 428/195.1; 428/497 |
Current CPC
Class: |
A01N 2300/00 20130101;
A01N 25/02 20130101; A01N 35/02 20130101; A01N 65/24 20130101; A01N
25/02 20130101; A01N 65/00 20130101; A01N 31/16 20130101; A01N
31/02 20130101; A01N 25/34 20130101; A01N 31/16 20130101; A01N
35/02 20130101; A01N 31/02 20130101; A01N 65/24 20130101; A01N
35/02 20130101; A01N 31/02 20130101; A01N 25/34 20130101; A01N
25/02 20130101; A01N 31/16 20130101; A01N 25/34 20130101; A01N
65/28 20130101; A61L 9/048 20130101; A61L 9/012 20130101; A61L 2/16
20130101; A61L 9/046 20130101; B65F 1/0026 20130101; A61K 8/922
20130101; A01N 65/00 20130101; A61L 9/04 20130101; A61Q 17/00
20130101; A01N 35/02 20130101; A01N 65/24 20130101; A61L 9/013
20130101; A01N 65/24 20130101; A01N 35/02 20130101; A61L 9/12
20130101; Y10T 428/31844 20150401; A61L 9/044 20130101; Y10T
428/24802 20150115; A01N 65/28 20130101; A01N 65/00 20130101; A01N
65/28 20130101; A61K 8/0208 20130101; A61L 9/015 20130101 |
Class at
Publication: |
220/062.11 ;
424/725; 424/739; 428/195.1; 428/497; 220/694 |
International
Class: |
B32B 9/04 20060101
B32B009/04; B65D 1/40 20060101 B65D001/40 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 30, 2003 |
GB |
0317862.1 |
Claims
1. A vapor-producing composition for disinfecting a space
comprising one or more essential oils or essential oil components,
and a mixture of volatile and non-volatile solvents absorbed on a
carrier.
2. The composition of claim 1, wherein the essential oil component
is cinnamic aldehyde.
3. The composition of claim 1, wherein the essential oil component
is cinnamic alcohol.
4. The composition of claim 1, wherein the essential oil component
is eugenol.
5. The composition of claim 1, wherein the essential oil is a tea
tree oil.
6. The composition of claim 1, wherein the essential oil is
cinnamon oil.
7. The composition of claim 1, wherein the volatile solvent is an
alcohol.
8. The composition of claim 7, wherein the alcohol is
isopropanol.
9. The composition of claim 1, wherein the non-volatile solvent is
water.
10. The composition of claim 9, wherein the non-volatile solvent is
a glycol.
11. The composition of claim 10, wherein the glycol is
monopropylene glycol.
12. The composition of claim 1, wherein the ratio of volatile to
non-volatile solvents is in the ratio 10:1 to 1:10.
13. The composition of claim 1, wherein carrier is a non-woven
material.
14. The composition of claim 13, wherein the non-woven carrier is a
combination of cellulose and polypropylene.
15. The composition of claim 1, wherein the carrier is
cardboard.
16. The composition of claim 1, wherein the carrier is sintered
plastic.
17. The composition of claim 1, wherein the carrier is amorphous
silicon dioxide.
18. The composition of claim 1, wherein the cardboard carrier has
one dimension of at least 200 mm.
19. The composition of claim 1, wherein the carrier is a
self-adhesive item or label.
20. A vapor-producing formulation comprising one or more essential
oils or essential oil components and a mixture of volatile and
non-volatile solvents in a viscous liquid.
21. The formulation of claim 20, wherein the essential oil
component is cinnamic aldehyde.
22. The formulation of claim 20, wherein the essential oil
component is cinnamic alcohol.
23. The formulation of claim 20, wherein the essential oil
component is eugenol.
24. The formulation of claim 20, wherein the essential oil is a tea
tree oil.
25. The formulation of claim 20, wherein the essential oil is
cinnamon oil.
26. The formulation of claim 20, wherein the volatile solvent is an
alcohol.
27. The formulation of claim 26, wherein the alcohol is
isopropanol.
28. The formulation of claim 20, wherein the non-volatile solvent
is water.
29. The formulation of claim 20, wherein the non-volatile solvent
is a glycol.
30. The formulation of claim 29, wherein the glycol is
monopropylene glycol.
31. The formulation of claim 20, wherein the ratio of volatile to
non-volatile solvents is in the ratio 10:1 to 1:10.
32. A formulation according to claim 20, wherein the viscosity is
modified by addition of silicon dioxide.
33. A carrier material, comprising one or more essential oil or
essential oil components impregnated thereon, wherein the carrier
is a resilient or rigid material having a length of at least 200
mm.
34. A carrier material according to claim 33, wherein the material
is cardboard.
35. A carrier material according to claim 33, comprising a length
of about 300 mm and a width of no more than about 50 mm.
36. A carrier material according to claim 33, wherein the carrier
material comprises an elongated substantially flat card for
insertion into a waste bin.
37. Use of a composition of claim 1, to sanitize and deodorize a
waste disposal bin.
38. Use of a formulation of claim 20, to sanitize and deodorize a
waste disposal bin.
39. Use of a carrier material of claim 33, to sanitize and
deodorize a waste disposal bin.
40. A waste disposal bin comprising the composition of claim 1.
41. A waste disposal bin comprising the formulation of claim
20.
42. A waste disposal bin comprising a carrier of claim 33.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a product which prevents
proliferation of microorganisms, particularly Gram-positive
bacteria such as Staphylococcus aureus, within a space, via a
vapour action, and which is active for long periods, typically
several weeks.
BACKGROUND OF THE INVENTION
[0002] In the field of disinfection and sanitisation, there is a
general move away from chemical agents, due to concerns regarding
the safety and effects of these chemical compounds, or their
residues, on the environment. This has led to increased interest in
the use of natural compounds as disinfectants in many sectors.
[0003] The anti-microbial nature of essential oils is well
documented. For example, EP 1146111 discloses a hard surface
disinfecting formulation based on cinnamon oil or it's actives. The
compositions are tested according to European Standard EN1276,
which measures anti-microbial performance on a single occasion, and
over a contact time of 5 minutes. In addition, as the application
is for hard surface disinfection, the anti-microbial activity is by
direct contact of the active molecules with the microbes. The use
of a wipe is discussed, but no details of other carriers, or the
effects of different chemistries of the wipe on anti-microbial
performance are given.
[0004] WO 96/39826 describes the use of essential oil components
such as cinnamic aldehyde and coniferyl aldehyde to disinfect
contaminated environments, although no useful performance data for
the formulations is provided in the specification.
[0005] A number of patent publications have also proposed essential
oils and essential oil components as a replacement for the fumigant
methyl bromide, for the control of plant pathogens. WO200021364
examines the activity of essential oils from plants native to
Turkey, such as Thymbra spicata, and although the primary targets
are insects and fungi, some anti-bacterial activity is claimed, and
methods for small scale, short term assessment of vapour activity
of the oils are also described. Of the 70 essential oil components
listed in the patent publication, the compound anethole was
selected for further studies as a fumigant. In addition, no
attempts to control the activity over a time period are
described.
[0006] Feminine hygiene waste, such as used sanitary towels and
tampons, and soiled nappies and incontinence pads, are often
disposed of in specialist bins, and several companies offer a
service relating to these bins. Typically, the bins remain in
service at the customers premises for between 2 and 8 weeks. This
represents a particular challenge to a disinfectant or sanitizing
system, as waste contaminated with potentially pathogenic organisms
is constantly being placed into the bins over a long period,
steadily increasing the organic matter loading and constantly
adding new pathogenic bacteria, requiring disinfection. Thus,
feminine hygiene waste bins provide both an application for the
technology, and an ideal demonstration of the advantages and
features of the invention.
[0007] There is concern about the proliferation of microbes within
the bin, and it is felt that this may present a hazard to the
customers and operatives of the service companies, and may also
lead to the development of unpleasant odours. To combat this, a
biocidal system is often used in the bin. Traditionally, this has
involved use of a large volume of liquid disinfectant, but this
leads to an increased weight of material requiring disposal, and
there are also concerns regarding the long-term effectiveness of a
liquid system throughout the bin once the material has been
absorbed into the sanitary waste at the base. Other systems are
based on gas-generating systems which produce, for example, sulphur
dioxide which can then penetrate and disinfect waste throughout the
bin. There is some doubt about the control of release of the gas,
as well as health and safety concerns about sulphur dioxide, which
has lead to this technology being banned in a number of
countries.
[0008] As mentioned above, in the field of disinfection, there is a
general move away from chemical agents. Simple low volume
disinfectant systems for use in bins, based on essential oils and
plant extracts is the subject of EP 0 965 541.
[0009] The bacteria used to test the performance of the vapour
based products disclosed in EP 0 965 541 were Gram-negative
bacteria such as Salmonella, Pseudomonas and Escherichia coli.
Gram-positive bacteria seem generally more resistant to natural
plant extracts and essential oils. However, many Gram-positive
bacteria are pathogenic. Staphylococcus aureus for example, can
cause a number of common skin infections, and if ingested, can also
cause food poisoning. In addition, the experiments reported in EP 0
965 541 did not reflect the time interval of a bin service, and in
particular, did not involve repeated experiments in the same
receptacle over an extended time. A truly effective natural product
for use in a feminine hygiene waste bin will need to be active
against all types of bacteria, and over a time frame which
accurately represents the service life of the bin, both to fulfill
the role of consumer and operator protection, and to achieve
regulatory approval in certain markets. Thus, improving the
performance of a product against Gram-positive bacteria and
controlling the activity of the product to match the service
interval of the bin are major features of the present
invention.
SUMMARY OF THE INVENTION
[0010] According to one aspect of the present invention a
vapour-based product for sanitising and deodorising a space such as
waste disposal bin over several weeks, comprises a combination of
one or more essential oils or essential oil components, and a
combination of volatile and non-volatile solvents, absorbed onto a
carrier.
[0011] According to a second aspect of the present invention, a
vapour-producing formulation comprises a combination of one or more
essential oils or essential oil components, and a combination of
volatile and non-volatile solvents, in a viscous liquid.
[0012] According to a third aspect of the present invention, a
formulation as defined above is used to sanitse and deodorise a
waste disposal bin.
[0013] According to a fourth aspect of the present invention, a
waste disposal bin comprises a product or formulation as defined
above.
[0014] According to a fifth aspect of the present invention, a
carrier material has one or more essential oil or essential oil
components impregnated thereon, the carrier is a resilient or rigid
material having a length of at least 200 mm.
DESCRIPTION OF THE INVENTION
[0015] The present invention provides formulations and products for
sanitising and deodorising a space, for example a waste disposal
bin. The invention makes use of an identified synergy between an
essential oil or essential oil component and a mixture of volatile
or non-volatile solvents.
[0016] Preferred essential oil components for use in this
invention, which can be used singly, or in combination, are
selected from the group consisting of cinnamaldehyde, cinnamic
alcohol, geraniol, linalool, benzaldehyde, anisaldehyde,
terpinen-4-ol, amyl-cinnamic aldehyde, hexyl-cinnamic aldehyde and
eugenol. Preferred essential oils, which again can be used singly
and in combination include tea tree oil, clove leaf oil, clove bud
oil, cinnamon leaf oil, cinnamon bark oil, spearmint oil (whether
of US or Chinese origin), bergamot oil, marjoram oil, bitter almond
oil, lemon tea tree oil, bay oil, origanum oil, lemon oil, pimento
berry oil, orange oil, cassia oil and cumin oil.
[0017] Such essential oil components and/or essential oils can be
absorbed onto certain carriers, such as paper, cardboard, etc., so
that the vapour action of the product is controlled over a
specified time period.
[0018] An important aspect of the present invention is the
combination of the active ingredient(s) with a blend of at least
two solvents. The solvents in the mixture comprise volatile
solvents, particularly lower alcohols, and most preferably
iso-propanol, and non-volatile solvents such as water, or glycols,
most preferably monopropylene glycol. The solvent mixture has two
purposes. Firstly by changing the ratio of volatile to non-volatile
solvents, the active life of the product can be manipulated. Higher
levels of volatile solvents tend to lead to a large initial burst
of anti-microbial activity, but a short active life, whilst
increasing the levels of non-volatile solvents tends to slow down
the rate of release of the anti-microbial vapour, and increase the
active life of the product. The ratio of solvents in the current
invention can vary between 10:1 and 1:10 volatile to non-volatile
solvents, and more preferably between 3:1 and 1:3.
[0019] The solvents have a second effect in terms of a synergistic
improvement in the anti-microbial activity of the invention.
Although both alcohols such as iso-propanol and ethanol, as well as
glycols such as monopropylene glycol are all reported as having
anti-bacterial or anti-fungal activities, this is normally in
relatively high concentrations in a liquid system. In the present
invention, a few grams of each solvent are used, which would not be
expected to have a disinfecting effect in a bin of up to 50 litre
volume over a 6 to 8 week period. However, when used in combination
with the oils and oil fractions, unexpected synergistic effects are
found, with the combination having a much larger and longer lasting
anti-microbial vapour effect than the components alone.
[0020] The present invention has also identified synergistic
combinations of essential oils and essential oil components.
Certain combinations of an essential oil and an essential oil
component have a much greater anti-microbial effect than either
component demonstrates when used alone. An example of such a
mixture is the combination of cinnamon leaf oil and cinnamic
alcohol. Although cinnamic alcohol is present in cinnamon leaf oil,
it is not the main fraction of the oil, and is not reported to be
anti-microbial. Thus increasing it's concentration in a mixture
would not be expected to result in any particular increase in
anti-microbial activity of the cinnamon leaf oil.
[0021] The active material may be impregnated onto a carrier
material to permit release of the antimicrobial vapour over an
extended period.
[0022] A number of carriers can be used to deliver the active
ingredient/solvent mixture. A preferred embodiment is the use of a
cellulosic fibre/plastic non-woven sheet. Changing the ratio of
cellulosic fibre (a polar material) and plastic (non-polar
material) can have an effect on the release rate and release
characteristics of the active ingredients, in that the
polypropylene will have an attraction for non-polar molecules in
the active mixture, and will tend to retain them more strongly,
whilst the viscose will tend to attract non-polar materials and
hold onto them more strongly. A preferred embodiment of the
invention is a cellulose (wood pulp fibre)/polypropylene non-woven
material of approximately 60 g/m.sup.2 weight, manufactured by a
hydro-entanglement process, known commercially as Ahlstrom A4459.
Other suitable non-woven materials from other sources will be
obvious to those skilled in the art.
[0023] A further embodiment of the invention is the use of a
resilient or rigid material, e.g. cardboard, as the carrier. In one
embodiment, the cardboard is in the form of a corrugated or solid
card, and has a length at least 200 mm, preferably at least 300 mm
and most preferably no more than 1000 mm (e.g. up to 400 mm). The
width may be at least 10 mm, more preferably 20 mm, and most
preferably less than 50 mm. The dimensions have been chosen so that
the cardboard can be used as an insert in a waste bin, with the
cardboard standing up within the bin, preventing it from being
buried by the waste entering the bin. The cardboard may be placed
substantially upright or placed across the diagonal of the bin.
[0024] The active ingredient mixture can be placed at one end of
the cardboard during the manufacturing process, and if this end was
then placed uppermost in the bin, it would further resist being
buried by the incoming waste. The cardboard, or other resilient or
rigid material, may therefore be in the form of a stick. Other
shapes and materials which would achieve these objectives will be
apparent to those skilled in the art.
[0025] The carrier can also consist of a piece of sintered plastic,
for example polyethylene or polypropylene. This material can be
manufactured in such a way that it consists of an approximately 50%
void volume, and this can be filled with the active mixture, either
by passive adsorption or by vacuum techniques. The shape of the
material can be a sheet, or a more sophisticated moulding,
machining or lamination so that in some way it can be attached to
inside the bin or on the lid of the bin.
[0026] A further embodiment of the carrier is the use of amorphous
silicon dioxide, which can absorb over 50% by weight of the active
mixture, and due to the fine particle size, can deliver
vapour-releasing particles, each producing the active ingredient
throughout the bin.
[0027] Any suitable solid carrier, either organic, or inorganic,
may also be used as a delivery system for the active/solvent
mixture. This can include but is not limited to powders, granules,
pellets, blocks, pads, sheets, self adhesive materials or labels,
etc.
[0028] A further embodiment of the invention involves delivery of
the active mixture as a viscous gel. The viscosity of the active
mixture can be modified by the addition of viscosity-modifying
agents such as cellulose gums, anionic co-polymers etc. A preferred
method for increasing the viscosity is the use of amorphous silicon
dioxide, for example Aerosil 200 from Degussa AG, which can be
added to the liquid in the range 1-9%, and more preferably in the
range 6.5-8.5% (w/w). Other suitable viscosity modifying systems
will be familiar to those skilled in the art.
[0029] The following Examples illustrate the invention.
EXAMPLE 1
[0030] This Example illustrates the fact that cinnamic aldehyde on
a carrier can have relatively long lasting anti-microbial
properties, as described in WO96/39826, but the addition of the
solvent mixture increases the initial activity of the formulation,
and also significantly improves the effectiveness in the long term.
The solvent mixture alone starts off being very effective, but
fades rapidly, and at end of the experiment, it is little better
than the untreated control.
[0031] The test system consisted of a common type of feminine
hygiene waste bin. One bin received 2 g of monopropylene glycol and
6 g of iso-propanol, the second 0.5 g of cinnamic aldehyde, the
third 0.75 g of cinnamic aldehyde, the fourth 0.5 g of cinnamic
aldehyde, plus 2 g of monopropylene glycol and 6 g of iso-propanol,
the fifth 0.75 g of cinnamic aldehyde, plus 2 g of monopropylene
glycol and 6 g of iso-propanol. All test solutions were absorbed
onto a 20 cm.times.20 cm piece of a cellulose/polypropylene non
woven, namely Ahistrom AH4559. A final bin received no treatment
and served as a control.
[0032] To begin the experiment, 1 ml of sterile horse serum was
added to 9 ml of an overnight culture of the Gram-positive organism
Staphylococcus aureus NCTC 4163, and 20 .mu.l of this mixture was
then pipetted onto 40 sterile Whatman antibiotic discs for each
bin. The inoculated discs were placed in individual compartments of
Sterilin 25 compartment square Petri dishes, (Sterilin part code
103), and the lids were turned so that they were propped open. The
plates were then placed in baskets approximately 15 cm above the
base of the bin, and the lid placed on the bin. Following either
24, 48 or 72 hours of exposure to the product vapour (see Table 1),
discs were removed from the trays and surviving bacteria counted by
decimal dilutions in maximum recovery diluent and plating onto
solidified Baird-Parker medium, which is selective for
Staphylococcus strains, using the Miles and Misra technique. The
plates were incubated overnight at 37.degree. C., and then colonies
counted on the appropriate dilution. Discs were placed into the
units at time zero, after 14 days, 20 days and 35 days, and the
number of surviving bacteria on each disc on each occasion was
calculated, and the results for the test formulations are shown
below: TABLE-US-00001 TABLE 1 Surviving bacteria on disc when discs
placed in bin After 14 After 20 After After 0 days days days 35
days (72 hr (72 hr (24 hr (24 hr exposure) exposure) exposure)
exposure) Control 4.0 .times. 10.sup.7 2.4 .times. 10.sup.6 1.4
.times. 10.sup.7 5.8 .times. 10.sup.7 Solvent mixture <6.6
.times. 10.sup.1 1.3 .times. 10.sup.2 3.8 .times. 10.sup.6 3.1
.times. 10.sup.7 0.5 g cinnamic 1.9 .times. 10.sup.3 <6.6
.times. 10.sup.1 3.2 .times. 10.sup.6 7.3 .times. 10.sup.5 aldehyde
0.75 g cinnamic 5.0 .times. 10.sup.2 <6.6 .times. 10.sup.1 1.7
.times. 10.sup.5 6.5 .times. 10.sup.4 aldehyde 0.5 g cinnamic
<6.6 .times. 10.sup.1 <6.6 .times. 10.sup.1 7.1 .times.
10.sup.5 5.3 .times. 10.sup.4 aldehyde plus solvent mixture 0.75 g
cinnamic <6.6 .times. 10.sup.1 <6.6 .times. 10.sup.1 1.3
.times. 10.sup.4 3.3 .times. 10.sup.2 aldehyde plus solvent
mixture
EXAMPLE 2
[0033] To further illustrate the synergistic effects of mixtures of
essential oils and essential oil components, three formulations
were prepared, one containing 2 g of cinnamon leaf oil, the second
1 g of cinnamic alcohol and the third both 2 g of cinnamon leaf oil
and 1 g of cinnamic alcohol.
[0034] The method used was the disc method described in Example 1,
except that Escherichia coil NCTC8196 was used as the test
organism, the discs were placed into the units at time zero, and
they were exposed to the product vapour for 72 hours, and MacConkey
agar No. 3 was used for enumeration of surviving bacteria. The
results for the three test formulations are shown below:
TABLE-US-00002 TABLE 2 2 g 1 g cinnamon leaf cinnamic 1 g cinnamic
alcohol plus oil alcohol 2 g cinnamon leaf oil Number of 4.9
.times. 10.sup.5 1.1 .times. 10.sup.5 <6.6 .times. 10.sup.1
bacteria surviving on the disc
[0035] This experiment clearly illustrates that a combination of
the essential oil and the essential oil component is considerably
more effective than either constituent alone.
EXAMPLE 3
[0036] A further experiment was conducted to study the effect of
varying the solvent ratio in relation to the longevity of the
action of the product. Various formulations were prepared, each
containing 2 g of cinnamon leaf oil and 1 g of cinnamic alcohol.
Each formulation also contained 10 g of the solvent mixture, at
varying ratios of iso-propanol to monopropylene glycol.
[0037] The test system described in Example 2 was used, in that the
organism used was Escherichia coli NCTC8196, and the agar used for
growth of the organisms was MacConkey agar No. 3. In this example,
following 24, 48 and 72 hours of exposure to the product vapour, 5
discs were removed from the trays and placed into 9 ml of nutrient
broth. These broths were incubated at 37.degree. C., and then
examined for growth after 24 hours. Any broths showing growth were
subsequently streaked onto MacConkey agar No. 3, to test for the
presence of E. coli. Growth on the streak was scored as a positive
(i.e. surviving E. coil were present on the disc) and no growth as
a negative (100% kill of E. coli on the disc). The experiment was
repeated, in that fresh inoculated discs were placed into the bins
at 0, 2, 4, 6 and 8 weeks after the addition of the test
formulation, and the results for the varying solvent ratios are
shown below: TABLE-US-00003 TABLE 3 Ratio IPA:MPG code 0 weeks 2
weeks 4 weeks 6 weeks 8 weeks 1:3 H All All All Not Not tested
negative positive positive tested 48 hours 72 hours 72 hours 1:1 K
All All All Not Not tested negative positive positive tested 48
hours 72 hours 72 hours 3:1 V All All All All All negative negative
negative negative negative 48 hours 24 hours 48 hours 48 hours 72
hours 5:1 R All All All Two Two negative negative negative positive
positive 24 hours 48 hours 48 hours 72 hours 72 hours
[0038] The results show that in mixtures containing predominantly
monopropylene glycol, the initial performance of the product is
acceptable, but the performance rapidly fades over the longer term.
Increasing the proportion of iso-propanol to make an equal mixture,
shows no improvement, but increasing it again to 3:1 iso-propanol
to monopropylene glycol, significantly improves the long term
performance of the product, so that it remains active for the
desired 8 weeks in the unit. By increasing the amount of
iso-propanol even further, to 5:1, the initial performance is
improved slightly, but the long term performance is again less
acceptable. Thus, the effect of manipulating the ratio on the long
term activity of the formulation is demonstrated. A 3:1 ratio is
the correct combination for a product active against this bacterium
and utilizing these oils, but other oils and other active mixtures
may require different proportions of volatile and non-volatile
solvents, depending on the characteristics of the active mixture
itself.
EXAMPLE 4
[0039] A further illustration of the value of this invention over
the prior art is provided in the following Example. A combination
of tea tree oil and silicon dioxide was described in EP 0 965 541.
This prior art formulation, consisting of 1.2 g of tea tree oil
absorbed onto 3.8 g of Sipernat 22 silicon dioxide, was tested
against a formulation consisting of 1.2 g of tea tree oil, 4.2 g of
monopropylene glycol, 1.8 g of iso-propanol, absorbed onto 5.4 g of
Sipernat 22 silicon dioxide in a jar experiment. Three jars were
used for each of the two trial formulations and three jars for the
control. The two products were each placed into the bottom of three
jars, and sanitary towels inoculated with three test bacteria,
Salmonella typhimurium, Staphylococcus aureus and Escherichia coli,
suspended above the products in separate jars, and the jars sealed.
Surviving bacteria in the towels were counted using standard
microbiological methods. TABLE-US-00004 TABLE 4 Organism Formula 1
day contact 2 day contact 7 day contact Staphylococcus Prior art
2.7 .times. 10.sup.8 4.7 .times. 10.sup.8 <3 .times. 10.sup.3
aureus Solvent <3 .times. 10.sup.3 NT NT formulation Salmonella
Prior art 3.6e8.sup.8 3.7 .times. 10.sup.8 <3 .times. 10.sup.3
typhimurium Solvent <3 .times. 10.sup.3 NT NT formulation
Escherichia Prior art 4.5 .times. 10.sup.8 2.9 .times. 10.sup.8
<3 .times. 10.sup.3 coli Solvent <3 .times. 10.sup.3 NT NT
formulation
[0040] The data from the prior art formulation is similar to that
reported in EP 0 965 541, in that bacteria numbers were reduced in
around 7 days exposure to the product vapour. The increased
activity of the new formulation, including solvents, is clearly
shown, in that bacteria levels are reduced to below detection
limits in just one day.
EXAMPLE 5
[0041] One particular embodiment of the present invention involves
delivering the active ingredient mixture on a sheet of non-woven
fabric. Not only does this make the manufacturing process economic,
and the product easy for the end user to dispense, it also improves
the anti-microbial performance of the product. An active ingredient
mixture, consisting of 2 g of cinnamic aldehyde and 1 g of cinnamon
leaf oil, plus a solvent mix of 6 g of monopropylene glycol and of
2 g iso-propanol, was tested in a number of delivery systems. In
one sanitary disposal unit, the liquid active itself was placed in
a small glass beaker placed in the base of the unit, in a second
unit, the active mixture was absorbed onto a 85 mm.times.55
mm.times.4 mm thick pure cellulose pad, and in a third, the active
was absorbed onto the preferred embodiment, a 20 cm.times.20 cm
piece of a cellulose/polypropylene non-woven, namely Ahlstrom
AH4559. A fourth unit had no treatment and thus served as the
control.
[0042] The test system described in Example 1 was used, i.e.
Staphylococcus aureus bacteria on discs. In this Example, the
inoculated discs were placed into the units after 10 days, and
exposed to the product for 48 hours before the discs were removed
and surviving bacteria on each disc were enumerated. The results
are shown in the following table 5: TABLE-US-00005 TABLE 5
Surviving bacteria per disc after Treatment 48 hours exposure None
(control) 3.0 .times. 10.sup.7 Active mix + solvents in glass
beaker 6.2 .times. 10.sup.6 Active mix + solvents of cellulose pad
2.5 .times. 10.sup.5 Active mix + solvents on non-woven sheet 7.2
.times. 10.sup.3
EXAMPLE 6
[0043] A further embodiment of the present invention involves
delivering the active ingredient mixture on a piece of cardboard.
The active mixture consisted of 0.75 g of cinnamic aldehyde, and
the cardboard was a B flute corrugated board, and of dimensions 400
mm.times.20 mm.times.3 mm. The active mixture was absorbed onto one
end of the cardboard, and this end was then placed uppermost in the
unit. One sanitary disposal unit received the test system, and a
second had no treatment and thus served as the control. The test
system described in Example 1 was used, i.e. Staphylococcus aureus
bacteria on discs. In this example, the inoculated discs were
placed into the units at time zero and after 14 days, and exposed
to the product for 72 hours before the discs were removed and
surviving bacteria on each disc were enumerated. The results are
shown in the following table 6: TABLE-US-00006 TABLE 6 Surviving
bacteria per disc after 72 hours exposure Treatment Time zero 14
days None (control) 2.3 .times. 10.sup.7 3.1 .times. 10.sup.7
Active mix on cardboard 1.3 .times. 10.sup.3 3.2 .times.
10.sup.4
[0044] The results show that cardboard is a further suitable
material to deliver the technology.
EXAMPLE 7
[0045] Further embodiments of the present invention involve
delivering the active ingredient mixture on a piece of sintered
polyethylene, or in a viscous gel, formed by the addition of
silicon dioxide. In each case, the active mixture consisted of 1 g
of cinnamic aldehyde plus a solvent mix of 6 g of monopropylene
glycol and of 2 g iso-propanol. The sintered polyethylene was of
dimensions 100 mm.times.80 mm.times.3 mm, and had an average pore
size of 100 .mu.m and a void volume of approximately 40%. The gel
was created by adding 6.5% Aerosil 200, a fumed silicon dioxide
produced by Degussa, to the liquid preparation. One sanitary
disposal unit received the sintered plastic system, one the gel,
and the third unit had no treatment and thus served as the
control.
[0046] The test system described in Example 1 was used, i.e.
Staphylococcus aureus bacteria on discs. In this example, the
inoculated discs were placed into the units at time zero and after
14 days, and exposed to the product for 72 hours before the discs
were removed and surviving bacteria on each disc were enumerated.
The results are shown in the following table 7: TABLE-US-00007
TABLE 7 Surviving bacteria per disc after 72 hours exposure
Treatment Time zero 14 days None (control) 2.3 .times. 10.sup.7 3.1
.times. 10.sup.7 Active mix in sintered plastic <6.6 .times.
10.sup.1 <6.6 .times. 10.sup.1 Active mix in viscous gel <6.6
.times. 10.sup.1 1.5 .times. 10.sup.5
[0047] The results show that both embodiments are suitable ways of
delivering the technology. Indications from these un-optimised
systems are that the sintered plastic is slightly more effective
than the viscous gel.
EXAMPLE 8
[0048] A further illustration of the value of the current invention
over the prior art is provided below. An active ingredient mixture,
consisting of 4 g of cinnamic aldehyde and a solvent mix of 6 g of
monopropylene glycol and of 2 g iso-propanol, absorbed onto a 20
cm.times.20 cm piece of Ahistrom AH4559 was tested against a
formulation containing 1.2 g of tea tree oil absorbed onto 3.8 g of
Sipernat 22 silicon dioxide, as described in EP 0 965 541.
[0049] The test system described in Examples 1 and 5 was used, i.e.
Staphylococcus aureus NCTC 4196 bacteria on discs. In this Example,
inoculated discs were placed into the units at time zero, and after
4 and 8 weeks, and exposed to the product vapour for 72 hours on
each occasion, before the discs were removed and the number of
surviving bacteria per disc enumerated. The results are shown in
the following table 8: TABLE-US-00008 TABLE 8 Surviving bacteria
per disc after 72 hours exposure Treatment Time zero 4 weeks 8
weeks Prior art 3.6 .times. 10.sup.5 1.6 .times. 10.sup.7 4.1
.times. 10.sup.7 (tea tree oil and silicon dioxide) Present
invention <6.6 .times. 10.sup.1 <6.6 .times. 10.sup.1 <6.6
.times. 10.sup.1 (cinnamic aldehyde + solvents on a non-woven
sheet)
[0050] The fact that significant anti-microbial results, were
obtained, against a Gram positive bacterium over an 8 week period,
clearly illustrates the value of the invention over the prior
art.
EXAMPLE 9
[0051] A further experiment was conducted to illustrate the effect
of using different volatile solvents in place of iso-propanol. An
active ingredient mixture, consisting of 1.5 g of cinnamic
aldehyde, 0.25 g cinnamon leaf oil and a solvent mix of 3 g of
monopropylene glycol and 9 g of each alcohol was used. Five
alcohols were tested in total, namely iso-propanol, n-propanol,
methanol, ethanol and n-butanol. Each active and solvent mixture
was absorbed onto a 20 cm.times.20 cm piece of Ahlstrom AH4559.
[0052] The test system described in Example 1 was used, i.e.
Staphylococcus aureus NCTC 4196 bacteria on discs. In this Example,
inoculated discs were placed into the units at time zero, and after
2, 4 and 6 weeks. Samples were removed from each bin following
exposure to the product vapour for 72 hours on each occasion. The
discs were removed and placed into 9 ml of nutrient broth. These
broths were incubated at 37.degree. C., and then examined for
growth after 24 hours. Any broths showing growth were subsequently
streaked onto Baird Parker agar, to confirm the presence of
Staphylococcus aureus. Growth on the streak was scored as a
positive (i.e. surviving Staphylococcus aureus were present on the
disc) and no growth as a negative (100% kill of Staphylococcus
aureus on the disc). The results are shown in the following table
9: TABLE-US-00009 TABLE 9 Presence of surviving bacteria following
72 hours exposure Treatment Week 0 Week 2 Week 4 Week 6 Control + +
+ + + + + + Iso-propanol - - - - - - - - Methanol - - - - - - - -
Ethanol - - - - - - - - N-Butanol - - - - - - - - N-Propanol - - -
- - - - -
[0053] These results clearly show that a wide range of alcohols can
be used in the present invention.
EXAMPLE 10
[0054] A further experiment was conducted to illustrate the effect
of using different glycols in place of mono propylene glycol. An
active ingredient mixture, consisting of 1.5 g of cinnamic
aldehyde, 0.25 g cinnamon leaf oil and a solvent mix of 3 g of
glycol and of 9 g isopropanol was used as standard. Five glycols
were tested in total. Each active mixture was absorbed onto a 20
cm.times.20 cm piece of Ahlstrom AH4559.
[0055] The test system described in Examples 1 was used, i.e.
Staphylococcus aureus NCTC 4196 bacteria on discs. In this Example,
inoculated discs were placed into the units at week 1 and removed
from each bin following exposure to the product vapour for 24 and
48 hours. The discs were removed and placed into 9 ml of nutrient
broth. These broths were incubated at 37.degree. C., and then
examined for growth after 24 hours. Any broths showing growth were
subsequently streaked onto Baird Parker agar, to test for the
presence of Staphylococcus aureus. Growth on the streak was scored
as a positive (i.e. surviving Staphylococcus aureus were present on
the disc) and no growth as a negative (100% kill of Staphylococcus
aureus on the disc). The results are shown in the following table
10: TABLE-US-00010 TABLE 10 Presence of surviving bacteria
Treatment T = 24 hours T = 48 hours Control + + + + Diethylene
glycol - - - - Hexylene glycol - - - - Butyl glycol - - - -
Monoethylene glycol - - - - Dipropylene glycol - - - -
[0056] These results clearly show that a wide range of glycols can
serve as the non-volatile solvent in the present invention.
EXAMPLE 11
[0057] A further illustration of the range of non-volatile solvents
useable in the current invention is provided below. An active
ingredient mixture, consisting of 2 g of cinnamic aldehyde, 0.25 g
cinnamon leaf oil, plus a solvent mix of 3.5 g of water and of 6.5
g iso-propanol, absorbed onto a 22 cm.times.25 cm piece of Ahlstrom
AH4559 was tested using the method described in Examples 1 and 5,
i.e. Staphylococcus aureus NCTC 4196 bacteria on discs. In this
example, inoculated discs were placed into the units at time zero,
and after 2, 4, 6 and 8 weeks. Samples were removed from each bin
following exposure to the product vapour for 72 hours on each
occasion. The discs were removed and surviving bacteria enumerated
(Table 11). TABLE-US-00011 TABLE 11 Surviving bacteria on the discs
after 72 hours exposure at: Time Treatment: zero 2 weeks 4 weeks 6
weeks 8 weeks none 4.72e7 5.95e7 5.0e7 5.4e7 6.4e7 Active mix
<67 <67 <67 <67 <67
[0058] The fact that significant anti-microbial results, were
obtained, against a Gram-positive bacterium over an 8 week period,
clearly illustrates the value of this particular embodiment of the
invention.
* * * * *