Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02368284 2001-08-16
Applicant: Dr. Schumacher, Henning
Our file: 80166
Agents for disinfecting and cleaning surfaces
The present invention relates to agents for disinfecting and cleaning
surfaces, wherein an
invert soap having at least one branched alkyl chain, is utilized. In
particular, the invention
pertains to agents for disinfecting and cleaning surfaces, wherein the invert
soap utilized has two
short-chain alkyl groups and two long-chain alkyl groups.
Surfaces are constantly contaminated with micro-organisms due to exposure to
the
environment. The presence of such micro-organisms on floors or other surfaces
is not desired in
particular areas, such as e.g, sanitations, hospitals or swimming pools, or
may even be partially
hazardous, since there is a danger of an infection and a transmission of
germs, respectively, to
persons present there. Consequently, such surfaces are treated with
disinfectants, which are
added to a conventional detergent, which is used for cleaning surfaces. A
disadvantage of the
known disinfectants resides in that even though a variety of bacteria are
killed, but however the
efficacy towards viruses is often inadequate.
The requirements for decontamination of surfaces of medical devices, such as
dental
suction devices, endoscopes or other hollow bodies, which are introduced into
living organisms
during surgery are even higher. Therefore, these devices have to be cleaned
from contaminating
material, such as body fluids, e.g. blood or secretory fluid, each time when
used. In order to
prevent a transmission of pathogenic micro-organisms, such as bacteria, funghi
and/or viruses to
patients, treated subsequently, these agents have to be removed, killed or at
least inactivated.
During the last few years specific processing devices, such as specific
"washing
maschines" for endoscopes, have been utilized for cleansing and disinfecting
such devices, so as
to avoid a direct contact of the devices with the personnel during the entire
process.
These apparatuses are run in a two step process at ambient temperature. In a
first step the
devices charged thereto are subjected to a treatment with known detergents,
such as anionic or
non-ionic surfactants and enzymes, respectively, to degrade biological
contaminations. In a
second step they are contacted with disinfectants on the basis of aldehydes.
However, it has been shown that the time required for cleansing and
decontaminating the
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devices by these apparatuses took too long, in order to have a cleaned and
disinfected device
available during clinical tests whenever required. In addition, the devices
could have been
contaminated with germs present in the water utilized for rinsing, which the
germs could have
multiplied during inappropriate storage of the devices and therefore could
render it infectious for
a patient.
Due to these problems, the two-step process for cleaning and decontaminating
medical
devices is run at elevated temperatures up to 60 °C maximum. To this
end, the goods charged are
introduced into a washing department within the apparatus, the temperature of
the cleansing bath
is raised and, during step one, a detergent is dosed into the cleansing bath
at a particular
temperature. After finalizing the cleaning step, the cleansing bath is
discharged and in a second
step fresh water supplemented with a disinfectant is added such that after a
certain processing
time period at a chosen temperature the devices should be free of pathogenic
agents and should
be degerminated. After discharging the apparatus the devices are rinsed with
water once or twice,
whereupon the devices are ready to use them again.
The agents used for this type of processing are variants of the products used
for the
processing at ambient temperature.
Normally, combinations of non-ionic surfactants together with complexing
agents and
enzymes are used as cleansing agents. All of those cleansing agents strive to
improve the
moistening of the devices' hydrophobic surfaces and thus to increase the
volume of the water that
passes through the occasionally existing narrow or confined lamina of such
devices during
processing.
The disinfectants utilized in this process are all based on aldehydes.
Aldehydes are of low
corrosive nature and enable inactivation of a variety of micro-organisms.
However, the efficacy
of aldehydes towards spores is extremely low.
Even though particular viruses, such as picorna-viruses, as well as myco-
bacteria may be
inactivated simply by choosing temperatures of up to 60 °C during the
known processes, an
inactivation of other viruses, such as Hepatitis B viruses, is not
sufficiently possible by applying
the presently known disinfecting methods.
Further, the known processes suffer from the disadvantage that the aldehydes
utilized fix
blood or proteins that had not been entirely removed during the first
cleansing step onto the
surface of the devices. Thus, it has been found that such a fixation often
occurs on the surfaces of
the confined lamina so that the residual contamination is not noticed upon an
unspecific visual
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inspection or by rinsing through a wide lumen of the devices. As is known,
pathogenic germs
may survive such processing in such residual contaminations and may represent
an infectious
agent during subsequent use of the device for the patient. Additionally it has
been found that in
spite of decontaminating the devices according to the process illustrated
above a transmission of
germs derived from a patient that had been treated with that device to a
subsequent patient may
occur.
An additional shortcomings of conventional methods resides in that the
personnel is
confronted with aldehyde containing products. For example, in case the
apparatus is untimely
opened due to malfunctions or in case the aeration of the apparatus is not
sufficiently ensured,
aldehyde containing vapors may get to the ambient air. In addition, during
charging the apparatus
with fresh disinfectants the personnel may come into contact with concentrated
aldehydes.
An object of the present invention resides in reducing the processing time of
medical
devices as well as reducing the risk the personnel is subjected when dealing
with disinfectants
utilized.
This objective has been achieved by providing an agent for disinfecting
decontaminated
surfaces, which contains an invert soap having at least one branched alkyl
chain.
According to a preferred embodiment said at least one branched alkyl chain has
between
4 and 20 carbon atoms, preferably 6 to 16, more preferably between 8 and 14
carbon atoms. Most
preferred the branched alkyl chain is a branched C8-C1z-alkyl chain.
According to another preferred embodiment the invert soap contains at least
another long-
chain alkyl group having 4 to 20 carbon atoms, and exhibits furthermore two
short-chained alkyl
groups, which preferably are 2 methyl groups.
It has been found that such invert soaps particularly are suitable for
cleansing surfaces.
The disinfectants produced therewith are non-toxic and exhibit an extremely
high microbicide
activity against bacteria, funghi and all known species of viruses.
Surprisingly, also spores may
be inactivated using these agents.
Due to the strongly microbicide activity, the processing time for the devices
may
substantially be reduced. This is due to - inter alia - the bivalent
properties of the agents
according to the present invention. Accordingly, a one step processing of the
devices may be
carried out, since the agents used exhibit cleansing as well as excellent
microbicide properties. A
fixation of contaminations in narrow and confined lamina of the devices does
not occur either,
with the effect that the danger of transmitting an infection from one patient
to subsequent
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patients is minimized.
Moreover, the disinfectants of the present invention may generally be applied
for the
disinfective cleansing of all types of surfaces, such as floors, in particular
floors of hospitals or
swimming pools, or for combating fungal infection on the skin, such as
athlete's foot, due to the
tolerance of the skin. Thus, the health risk of the personnel or the person
using the agent may be
minimized.
The disinfectants of the present invention may be used in the processing
apparatuses
commonly put to use or even in open containers at temperatures of from ambient
temperature to
about 75 °C. Having a view to the medical device to be handled treating
temperatures of from
about 40°C to 65°C or about 50°C to 60°C are
preferred.
During a processing of devices using the agents of the present invention
sterilized water is
introduced into the processing apparatus if necessary, optionally after a pre-
cleansing step. In
order to improve the efficacy of the process a disinfectant may be used during
the pre-cleansing
step, which needs, however, not to be identical to the agent of the present
invention.
The water utilized during processing may have any hardness, which does not
negatively
affect the efficacy of the agents of the present invention. Having a view to
the formation of a
deposit onto the devices or in the apparatus it is possible to adapt the
recipe of the applied agents
of the present invention such that a calcification does not occur. The agents
suitable for this
purpose are well known to the skilled person. The use of desalted water may
likewise be
envisaged.
The agent of the present invention is dosed into the cold or already heated
processing
bath, which may be effected manually or by means of a automatic control
system. Depending on
the situation of the apparatus put to use and based on his common technical
skill the skilled
person will decide on the appropriate dosage of the agent of the present
invention to be utilized
as well as adapt the temperature accordingly and determine, whether the
temperature of the bath
shall be raised immediately after dosing or whether it shall be maintained for
a predetermined
period of time.
In carrying out the process for processing medical devices it is preferred
that the
temperature of the bath is raised to the temperature for disinfecting without
changing the bath,
while maintaining it by agitation of the water and cleansing and by
disinfecting the devices for a
particular period of time. After discharging the cleansing and disinfecting
bath the device is then
rinsed with clear and preferably conditioned water, i.e. water having a
reduced number of germs
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or being essentially aseptic, so as to be ready for further use. A subsequent
drying of the medical
device after rinsing may be effected without being necessary.
The specific conduct of the process of the present invention is determined by
the
assembly of the processing apparatus used and by the type of devices to be
processed. In theory a
processing at elevated temperature of the processing bath may also be
performed manually.
For disinfecting and cleaning of surfaces, such as floors, the agent may
simply be added
to the washing fluid, wherein the agent will enable a high cleaning and
degerminating activity. It
has been shown that the agent of the present invention is well accepted by the
skin and does not
tend to foam.
The agent of the present invention contains an invert soap, which has at least
one
branched alkyl group having 4 to 20 carbon atoms. The branchings may be at any
position of the
alkyl chain and comprise methyl, ethyl, propyl or butyl branches,
respectively, on the main chain.
In addition, more than only one branching may also be present, such as e.g.
two or more of
methyl, ethyl or propyl branches or mixtures thereof, wherein the branches may
be present on the
same or on different carbon atoms on the main chain. In particular preferred
branched chains
comprise Cg-CIZ-alkyl groups, that contain methyl and/or ethyl branches. A
most preferred
example of a branched alkyl group is isononyl, which may be obtained from
LONZA under the
product name "Bardac 2170".
The other residues of the positively charged nitrogen atom may be branched or
also linear
alkyl groups containing from 1 to about 20 carbon atoms, e.g. methyl, ethyl,
propyl, butyl, pentyl,
hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,
pentadecyl, hexadecyl,
heptadecyl, octadecyl, nonadecyl and dodecaacyl groups. In addition aryl
groups and aralkyl
groups, respectively, such as benzyl or phenyl groups, or oxyalkyl groups may
be bound to the
nitrogen atom.
Invert soaps are preferred, wherein the branched but also the linear alkyl
groups contain
independently of from 4 to 20 carbon atoms, preferably between 6 to 16,
particularly preferred
between 8 and 14, more particularly preferred between 8 and 12 carbon atoms. A
combination of
branched and linear C8-C12-alkyl chains has been shown to be particularly
effective. The alkyl
groups may be unsaturated, with saturated alkyl groups being preferred.
According to a preferred embodiment the invert soaps comprise two long-chain
alkyl
groups each with more than 4 carbon atoms, with at least one of them being
branched, and two
short-chain alkyl groups each with 1 to 3 carbon atoms, i.e. methyl, ethyl
and/or propyl. The
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long-chain and short-chain, respectively, alkyl groups on the nitrogen atom
may be identical or
different, with the proviso that at least one branched alkyl group is bound to
the nitrogen atom.
The synthesis of such invert soaps is known in the art and may be carned out
by any
person skilled in the field of organic chemistry.
As the counter-ions inorganic ions may be used, such as fluoride, chloride,
bromide or
iodide, as well as organic anions, such as e.g. citrate, propionate and ethyl
sulfate or methyl sul-
fate, respectively. During processing the ion is considered as the counter-ion
that is present
during application of the agent of the present invention in a large excess or
alone and affects the
properties of the product and not the ion that saturates the positive charge
of the nitrogen atom
upon addition of the microbicide agent. However, on the basis of his own
technical knowledge
and by considering the circumstances and objectives the skilled person will
use the appropriate
counter-ion.
The invert soap is solved in a solvent to improve application, e.g. water,
with additional
surfactants, anti-corrosive agents, foam-reducing agents, acids and bases,
respectively, for
adjusting the desired pH, colourants and/or fragrances may be present as well.
Apart from using the above mentioned invert soaps the additional use of other,
commonly
known microbicide substances is likewise possible, such as e.g. aldehydes, in
particular glutar-
aldehyde, benzalkoniumchloride, didecylmethyloxethylammonium propionate,
polyhexa-
methylene biguanide and its salts, chlorhexidine and its salts, chlorine and
chlorine generating
agents, such as chloramine T, and/or per-compounds, such as e.g. potassium-
monopersulfate or
peracetic acid, azine derivates, such as e.g. hexahydrotriazine, microbicide
organic acids, such as
e.g. apple acid, sorbic acid, salicylic acid or benzoic acid.
The variety or the single microbicide agents are/is formulated into the
product in an
amount such that by using a conventional dosage of the product a disinfection
of the medical
device during the processing in the processing apparatus is ensured. This may
be determined first
of all by using contaminated screws or pieces of rubber-tubes.
During processing of medical devices the commonly used dosage regimen of the
agents
of the present invention are usually about 100 to 1000 ppm, preferably 200 to
600 ppm, most
preferred 300 to 500 ppm, based on the entire bath, with the temperature of
the bath being at
ambient temperature, preferably at elevated temperatures of up to 75 °C
and with the time being
maintained between 5 minutes and 10 minutes. With such a dosage regime about
50 to 400 ppm
of non-ionic surfactants, 50 to 800 ppm of inorganic or organic acids and
small amounts of
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corrosion inhibitors, foam-reducing agents, parfume oils or dyes may be dosed.
Advantageously, the surfactants used in the product of the present invention
are selected
such that the cloud temperature of the agent in an aqueous medium is at the
concentration of use
at about the dosage temperature, at which the agent is added to the bath. This
may be easily
determined by the person skilled in the art on the basis of his general
knowledge.
For treating surfaces, such as floors in hospitals and the like, the
concentration of the
agent of the present invention in the washing fluid may be appropriately
increased and is in the
range of up to 1-2 %. Due to the low steam pressure of the agent high
concentrations thereof in
the washing fluid is not detrimental for the personnel, since essentially no
transfer in the ambient
air occurs. Also a contact of diluted solutions with the skin is essentially
not detrimental. The
washing fluid for disinfecting and cleansing (degerminating cleansing) may
easily be prepared by
dosing the agent from a concentrated solution. Even applying a spray is
possible, which may be
used in particular for the treatment of athlete's foot. However, sprays may
likewise be applied for
the treatment of tables and the like.
The following examples illustrate the invention and are not to be construed to
limit the
invention. Examples 2 to 5 are for comparative purposes and show the superior
properties of the
products of the present invention during processing of devices.
Example 1
The disinfectant formulations 1 to 9, listed in the Table 1 as shown below,
have been
prepared. In the formulations 2 to 5 no invert soap has been added.
Table 1
Disinfectant fomulations
formulation 1 2 3 4 5 6 7 8 9
decylisononyldimethyl-3,00 4,00 8,00 2,00
ammoniumchloride
decylisononyhnethyloxethyl- 4,00
ammoniumproprionate
didec ldimeth lammoniumchloride 2,00 4,00
dioc ldimeth lammoniumchloride2,003,00 4,00
ethylhexylisotridecyldimethyl- 5,00
ammoniumchloride
lutaraldeh de 50% 10,00
hexah drotriazine 8,00
citric acid 1_0,0010,0010,0010,00 10,00
acetic acid 5,00 5,00 5,00
1,2- ro anediol 30,0030,0030,0030,0030,0030,0030,003 30,00
0,00
isotricec 1 alcohol 2,002,00 2,00 2,00 2,00 2,00 _ 2,00
EO-PO 2,00
~ anti-foaming agent ~ 0,10 ~ 0,10 0 0 0
3471 ~ ~ 0 10 10 10
10
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g
sodiumh droxide solution18,0036,0036,0036,0036,00 18,0036,0010,00
25%
benzotriazole 0,20 0,200,20 0,20 0,20 2,00 2,00 0,20
butindiole 0,50 0,500,50 0,50 0,50 0,50 0,50 0,50
water to 100
The products are all clear and stable for at least one week even at elevated
temperature of
50°C.
S The capacity of the formulations to disintegrate blood has been examined on
rubber tubes
with wether blood that had been made coagulable and was heparinized. A thin
blood layer has
been deposited onto the tube pieces and left to dry for one hour.
The tube pieces were then immersed at a processing temperature of 60°C
for 10 minutes
in the disinfectant solution, taken after expiry of the time period and
assessed after drying.
A relative scale of 1 to 5, taking water as a reference, has been drawn up.
Table II
As may be derived from Table II, above, the cleaning activity of the exemplary
agents is
improved as compared to the comparative formulations.
Example 2
The formulations shown in Table I have been examined for their efficacy in a
Germ-
Carrier-Assay using screws contaminated by Streptococcus faecium as the
testing germ.
The assay has been performed at 50°C with the contamination being
according to CEN.
After incubation it was assessed, whether there were germs being capable to
survive in the
contamination on the screws after treatment or not. The number indicated shows
the period of
treatment required in minutes, after which no growth was detectable.
Table 3
The obvious superiority of the agent of the present invention as compared to
the agents
according to the prior art becomes evident.
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Example 3
50 processing experiments have been carned out with different flexible
endoscopes.
During processing cleansing and disinfection has been carried out
simultaneously in one bath.
After processing the endoscopes have been analyzed for contaminations using
swabs for
preparing smears. The swabs were transferred to a culture medium which were
incubated at 37°C
for 24 h. The formulations according to the present invention did not show any
residual
contamination.
