DISINFECTANT COMPOSITION COMPRISING A BIGUANIDE COMPOUND
Field of the invention
The invention relates to a disinfectant composition which demonstrates efficacy
against some bacteria such as Clostridium Difficile and to its use in a method to for
disinfecting surfaces and/or for preventing infection.
Background to the invention
Nosocomial infections have always been a major issue in hospitals, nursing homes or
similar institutions where residents are at an elevated risk of infection due to their
failing health, their compromised immune system etc.
Antibiotics are used to kill or inhibit the growth of infectious organisms such as
pathogenic bacteria. Unfortunately, the increased use of antibiotics has been
accompanied by an alarming spread of antibiotic-resistant or opportunistic bacteria.
Clostridium difficile, for example, are now a common cause of infections in hospitals.
Clostridia are motile bacteria that are ubiquitous in nature and are especially
prevalent in soil.
When stressed, certain bacteria and fungi produce spores, which tolerate extreme
conditions that the active bacteria cannot tolerate. For example, C. difficile is a strain
which is present in the human intestine in 2-5% of the population. In small numbers,

C. difficile does not result in significant disease. However antibiotics, especially those
with a broad spectrum of activity, cause disruption of normal intestinal flora, leading
to an overgrowth of C. difficile, which flourishes under these conditions. This can lead
to various inflammatory diseases.
Antibiotic treatment of C. difficile infections can be difficult, due both to antibiotic
resistance as well as physiological factors of the bacteria itself (spore formation,
protective effects of the pseudomembrane). As the organism forms spores which are
heat resistant and not destroyed by conventional biocidal agents, C. difficile spores
can survive normal hospital cleaning procedures and can remain in the hospital or
nursing home environment for long periods of time, able to germinate when
conditions are favourable, resulting in C. difficile infection even after deep cleaning.
Furthermore, C. difficile can be cultured from almost any surface in the hospital.
Additionally, the spores themselves may be picked up from surfaces and ingested or
transferred to other surfaces. Once spores are ingested, they pass through the
stomach unscathed because of their acid-resistance. They change to their active
form in the colon and multiply. Pseudomembranous colitis caused by C. difficile is
treated with specific antibiotics, for example, vancomycin, metronidazole, bacitracin
orfusidicacid.
Several disinfectants commonly used in hospitals may be ineffective against
organisms which form spores, such as C. difficile, and may in some cases actually
promote spore formation. There is therefore a strong need for the development of
novel disinfectant compositions which exhibit efficacy against spore forming
organisms such as C. difficile.
Sporicidal agents are known. However, conventional sporicidal agents such as
hydrogen peroxide, formaldehyde and peracetic acid are highly toxic and thus not
suitable for frequent use. Furthermore, the sporicidal activity of such agents require
specific conditions and are intolerant of "dirty" conditions, i.e. exposure to organic
matter, and thus remain effective for a short time only. Accordingly, these agents are
unsuitable for use to pre-treat materials (such as fabrics or plastics) in order to
provide them with inherent long term resistance to sporicidal contamination.
Biguanide polymers such as polyaminopropyl biguanide (PAPB) or
polyhexamethylene biguanide (PHMB) are a preservative and a disinfectant used for
disinfection on skin and in cleaning solutions for contact lenses. PHMB is a polymer

which comprises biguanide functional groups which are connected by hexyl
hydrocarbon chains, with varying chain lengths. It can be represented by the general
structure:
It is usually used as a heterodisperse mixture of PHMB polymer hydrochlorides of
different lengths with an average molecular weight of approximately 3,000 Da, which
can be represented by the general formula:

PHMB polymer hydrochloride is sold under various trade names such as Vantocil IB.
(Vantocil and Vantocil IB are Trade Marks of Arch chemicals, Inc.) PAPB is
specifically bactericidal at very low concentrations (typically of the order of 10 mg/l).
Furthermore, at low concentrations, PABC is non-toxic and non-irritant.
Polymeric biguanides have found use as general disinfecting agents in the food
industry and, very successfully, for the disinfection of swimming pools. PHMB is a
membrane-active agent that also impairs the integrity of the outer membrane of
gram-negative bacteria, although the membrane may also act as a permeability
barrier. Activity of PHMB increases on a weight basis with increasing levels of
polymerization, which has been linked to enhanced inner membrane perturbation. It
has very low toxicity to higher organisms such as human cells, which have more
complex and protective membranes. However, no activity against spores has been
identified.
Biocidal formulations comprising polymeric biguanides are known and are used, for
example, in contact lens solutions and in compositions applied to surface wipes and
sprays.

Compositions comprising polymeric biguanides have also been associated with
sporicidal activity against bacterial endospores, for example in US 2004/02044956.
However, polymeric biguanides when taken alone, in any concentration, or in any
composition comprising no other active agents, have been shown not to be
sporicidally active.
Accordingly, the previously disclosed compositions comprising polymeric biguanides
as sporicides require the presence of further sporicidally active agents. For example,
all of the compositions disclosed in US 2004/02044956 contain a bis-biguanide such
as alexidine and/or a chlorhexidine compound. Bis-biguanides have previously been
associated with spodicidal activity (e.g. Jones et al., International Journal of
Pharmaceutics Volume 119(2), 1995, 247-250) and, as with other known sporicides,
bis-biguanides are associated with higher toxicity and higher levels of irritation, than
other biocides. Furthermore, bis-biguanides are biocidally active within a
comparatively narrow pH range and are thus unsuitable for certain applications, for
example for use in fungicidal compositions, which are typically alkaline solutions.
Thus, there remains a need for a low toxicity sporicidal composition, and a
composition which provides a long lasting sporicidal effect when applied to a surface.
Summary of the Invention
According to a first aspect of the present invention, there is provided the use of a
composition comprising one or more biguanide polymers, and one or more further
active agents, as a sporicide, characterised in that the or each further active agent is,
when taken alone, sporicidally inactive.
By the sporicidal or biocidal activity of an active agent, when taken alone, we mean
the activity of the active agent in biocidal compositions lacking a biguanide polymer
(which may be compositions having a single active agent or several active agents).
Preferably the one or more further active agents are sporicidally inactive at the
concentration of the or each said active agent in non-toxic compositions. Preferably
the one or more further active agents are sporicidally inactive at much greater
concentrations (such as ten times, or greater than ten times the concentration of the
active agent in biocidal and/or non-toxic compositions), or at any concentration.

Preferably the one or more further active agents are sporicidally inactive in their pure
form.
By sporicide and sporicidally active, and related terms, we mean active against
spores, including spores of bacteria, fungi, molds, algae, plants or other organisms,
including in particular bacterial endospores. Accordingly, a sporicidally active agent
may active against spores including endospores. Additionally, an active agent which
is, when taken alone, sporicidally inactive may be endosporicidally inactive (for
example inactive against bacterial endospores) but may (or may not) be active
against other types of spores.
The composition may be used to kill the spores of C. difficile, and the one or more
further active agents may be inactive against the spores of C. difficile, except in the
presence of the one or more biguanide polymers.
It has now been surprisingly found that compositions comprising polymeric
biguanides and one or more further biocidal agents and, optionally, with a
polyorganosiloxane, are effective as a sporicidal agent and are particularly effective
against the spores of C. difficile.
Thus there is provided a biocidal composition which can be used in hospital due to its
low toxicity, in particular compositions comprising one or more further active agents
which are not in themselves sporicidally active which are also known to produce less
irritation and/or are of lower toxicity than active agents which are sporicidal, when
taken alone, and which composition can effectively diminish the risks of infections
resulting from exposure to bacterial or fungal spores.
Biguanide polymers are known to be sporicidally inactive, when taken alone, or in
any concentration in a solution or composition comprising no other active agents.
Furthermore, we have observed that there is substantially less, or no, sporicidal
activity observed in relation to compositions lacking one or more of the further active
agents and, in particular, lacking a further active agent or a polymeric biguanide.
Accordingly, the sporicidal activity may be regarded as arising from a synergistic
effect between polymeric biguanides and the one or more further active agents.
Thus, although not wishing to be bound by theory, is it postulated that the polymeric
biguanide interacts synergistically with the one or more further active agents to

produce a composition having a surprisingly enhanced level of sporicidal activity, or,
in compositions wherein the one or more further active agents are not, when taken
alone, sporicidally active, to produce a composition having surprising sporicidal
activity.
By synergistic effect, between a first and at least one second constituent, in relation
to the present invention, we mean that the sporicidal (or biocidal) activity in relation to
compositions lacking the first constituent, and in relation to compositions lacking the
at least one second constituent, is greater (in terms of efficacy or durability, or the
range of organisms against which activity is observed) than either of the
compositions lacking the first or at least one second constituent, or which might be
expected from a combination of the sporicidal or biocidal activities of the
compositions lacking the first or at least one second constituent.
Preferably, the composition does not comprise bis-biguanides, and in particular
chlorhexidine compounds (e.g. chlorhexidine or chlorhexidine glutonates) or alexidine
compounds. Bis-biguanide compounds are known irritants and are known to produce
irritation, for example eye irritation, even at very low concentrations (such as the
concentrations required for biocidal compositions). For example, chlorhexidine is
known to cause greater irritation, or to cause irritation at lower concentrations, than
polymeric biguanides such as PHMB. Furthermore, bis-biguanides are biocidally
active within a comparatively narrow pH range. For example, chlorhexidine
compounds are known to hydrolyze at high pH and are thus unsuitable for use in
compositions above approximately pH 7 or 8. Polymeric biguanides and various other
active agents are more stable and, for example, may be less prone to hydrolysis at
higher or lower pH.
Compositions comprising polyorganosiloxanes but lacking bis-biguanides are
therefore sporicidally and/or biocidally active in a wider range of conditions than
compositions comprising bis-biguanides. This is particularly advantageous for high
pH compositions also having fungicidal further active agents. In addition, since pH
can change when a composition is allowed to dry on a surface (for example when
sprayed onto a surface and allowed to dry, or when fixed to a surface by drying or
otherwise removing a solvent or carrier), compositions of the invention lacking bis-
biguanides are particularly suitable for use in treating surfaces.
Preferably, the composition further comprises a suitable excipient, diluent or carrier.

According to a second aspect of the present invention, there is provided a method for
killing spores (and typically in particular, the spores of C. difficile), from a surface or a
material which comprises the step of providing or applying an effective amount of a
biocidal composition which comprises one or more biguanide polymers, and one or
more further active agents on said surface or material, characterised in that the or
each further active agent is, when taken alone, sporicidally inactive.
The biguanide polymer is preferably a biguanide polymer hydrochloride. Preferably it
comprises a mixture a PHMB molecules having a molecular weight ranging from 500
to 20,000 and having preferably an average molecular weight of about 3,000 such as
the biguanide polymer marketed under the Trade Name Vantocil IB.
Herein, the unit of concentration % w/w means percentage by weight. For example, if
a composition comprises a gram of a first compound and 99 g of a second
compound, the first compound has a concentration of 1% w/w and the second
compound has a concentration of 99% w/w.
Herein, the unit of concentration ppm means parts per million, by mass. For example,
if 100 g of a composition comprises a gram of a first compound, the first compound is
present in a concentration of 10,000 ppm, and therefore a concentration of 1% w/w
corresponds to a concentration of 10,000 ppm.
The concentration of the biguanide polymer is advantageously lower than 10% w/w,
preferably lower than 5% w/w and more preferably lower than 3%. The minimum
concentration of the biguanide polymer is preferably at least 0.1% w/w (i.e.
1000 ppm) and preferably ranges between 2 to 5% w/w.
The composition may comprise a diluent, excipient or carrier, which, in some
embodiments, is a non-volatile diluent, excipient or carrier. Such carrier is preferably
water as a water-based composition is both safe and environmentally friendly. The
carrier may be a glycol, an ester derivative of a glycol or an ether derivative of a
glycol.
The one or more further active agents complement and preferably synergistically
enhance the biocidal activity of the composition. The one or more further active
agents selected may further depend on the intended use of the composition, in

particular may be based on the ranges of micro organisms that are required to be
killed by treatment of the surface or implement with the composition and method of
the invention.
The one or more further active agents may be selected from the group consisting of a
biocidal, anti-microbial, bactericidal, fungicidal, germicidal, yeasticidal, moldicidal,
algicidal, virucidal agent, or a mixture thereof.
The one or more further active agents may be selected from cationic, amphoteric,
amino, phenolic and halogen containing biocides. Examples of the biocides which
may be used include:
Cationic biocides such as:
quaternary monoammonium salts, for example
cocoalkyibenzyldimethylammonium, C12-C14 alkylbenzyldimethylammonium,
cocoalkyldichlorobenzyldimethylammonium,
tetradecylbenzyldimethylammonium, didecyldimethylammonium and
dioctyldimethylammonium chlorides,
Myristyltrimethylammonium and cetyltrimethylammonium bromides,
Monoquaternary heterocyclic amine salts such as laurylpyridinium,
cetylpyridinium and C12 -C14 alkylbenzyldimethylammonium chlorides,
Triphenylphosphonium fatty alkyl salts such as myristyltriphenyiphosphonium
bromide;
Polymeric biocides such as those derived from the reactions:
Of epichlorohydrin and dimethylamine or diethylamine,
Of epichlorohydrin and imidazole, Of 1, 3-dichloro-2-propanol and
dimethylamine,
Of 1, 3-dichloro-2-propanol and 1, 3-bis (dimethylamino)-2 propanol,
Of ethylene dichloride and 1, 3-bis(dimethylamino)-2-propanol, and
Of bis (2-chloroethyl) ether and of N, N'-bis (dimethylaminopropyl)urea or
thiourea.
Amphoteric biocides such as derivatives of N-(N'- C8 - C18 alkyl-3-
aminopropyl)glycine, of N-(N'-(N"- C8 - C18 alkyl-2-aminoethyl)-2- aminoethyl)

glycine, of N,N-bis(N'- C8 - C18 alkyl-2-aminoethyl)glycine, such as (dodecyle)
(aminopropyl) glycine and (dodecyl) (diethylenediamine) glycine;
Amines such as N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine;
Phenolic biocides such as para-chloro-meta-xylenol, dichloro-metaxylenol, phenol,
cresols, resorcinol, resorcinol monoacetate, and their derivatives or water-soluble
salts;
Halogenated biocides such as iodophores and hypochiorite salts, for example sodium
dichloroisocyanurate;
5-chloro-2-methyl-4-isothiazolin-3-one; 1,2 benzisothiazol-3(2H)-one; and 2-methyl-
4-isothiazolin-3-one.
The one or more further active agents in the composition may be present in an
amount of from 0.01% to 20% w/w. In some embodiments, each said further active
agent is present in an amount of from 0.01 % to 11 % w/w, or from 0.02% to 11 % w/w.
The one or more further active agents may comprise one, or a combination of, di-
decyl-dimethyl ammonium chloride, alkylbenzyl-di-methyl ammonium chloride, 1,2
benzisothiazol-3(2H)-one, 2-methyl-4-isothiazolin-3-one, or other biocides, for
example one or a combination of the cationic, polymeric, amphoteric, amine or
phenolic biocides set out above.
In some embodiments, the composition comprises two further active agents. In some
embodiments, the composition comprises three, or four further active agents.
The further active agent or agents is preferably one or more of;
- one or more isothiazolone compounds, such as benzisothiazolone or
methylisothiazolone;
one or more cationic biocides, for example C12-C14
alkylbenzyldimethylammonium chloride, didecyldimethylammonium chloride,
or other quaternary monoammonium salts.

We have observed a particularly strong effect (which we postulate to be a synergistic
effect) from the inclusion of one or more quaternary ammonium salts in compositions
comprising one or more polymeric biguanides.
One or more of the one or more further active agents may be contained in a non
volatile carrier. Accordingly, the composition may further comprise one or more non-
volatile carriers. The or each non-volatile carrier may be water, a glycol, an ester
derivative of a glycol or an ether derivative of a glycol. In particular, alkylene glycols
and poly alkylene glycols such as diethylene glycol and polyethylene glycol may be
used. Alternatively, the or each carrier may be an alcohol having from 3 to 30 carbon
atoms, preferably at least 10 carbon atoms.
The composition may further comprise other ingredients, such as surfactants,
chelating agents (such as aminocarboxylates, (ethylenediaminetetra-acetates,
nitrilotriacetates, N,N-bis(carboxymethyl)-glutamates, citrates), alcohols (ethanol,
isopropanol, glycols) detergency adjuvants (phosphates, silicates), dyes, and
fragrances.
The surfactants which may be present in the composition of the invention may
include: non-ionic surfactants such as ethylene oxide/propylene oxide block
polymers, polyethoxylated sorbitan esters, fatty esters of sorbitan, ethoxylated fatty
esters (containing from 1 to 25 units of ethylene oxide) polyethoxylated C8-C22
alcohols (containing from 1 to 25 units of ethylene oxide), polyethoxylated C8-C22
alkylphenols (containing from 5 to 25 units of ethylene oxide), alkylpolyglycosides,
amine oxides (such as C10-C18) alkyldimethylamine oxides, C8-C22
alkoxyethyldihydroxyethylamine oxides) amphoteric or zwitterionic surfactants such
as C6-C20 alkylamphoacetates or amphodiacetates (such as cocoamphoacetates),
C 10 - C18 alkyldimethylbetaines, C10 -C18 alkylamidopropyldimethylbetaines,
C10-C18 alkyldimethylsulphobetaines, C10-C18 alkyl
amidopropyldimethylsulphobetaines.
Preferably, the composition further comprises a polyorganosiloxane or a mixture
thereof. One or more, or all of the or each polyorganosiloxane may be a
functionalised polyorganosiloxane, comprising polar functional groups or more
preferably ionic, or cationic, functional groups. One or more, or all of the or each
polyorganosiloxane may be a functionally terminated polyorganosiloxane (i.e. a
polyorganosiloxane wherein polymer chains are terminated at one or both ends by a

functional group, which may be a polar or, more preferably an ionic, or cationic,
functional group).
Polyorganosiloxanes are known surface wetting agents.
Functionalised polyorganosiloxanes and in particular functionally terminated
polyorganosiloxanes (such as cationic functionally terminated polyorganosiloxanes)
interact strongly with surfaces (which are typically negatively charged) and
compositions comprising such polyorganosiloxanes are particularly suitable for the
treatment of materials and surfaces. Functionalised polyorganosiloxanes, and in
particular functionally terminated polyorganosiloxanes (such as cationic functionally
terminated polyorganosiloxanes) may similarly have strong interactions with other
polar molecules in the composition, which may be polymeric biguanides and further
active agents, and thereby retain such polar molecules to any material or surface to
which the composition is applied.
Polyorganosiloxanes are also known as silicone polymers.
Polyorganosiloxanes which can be used in the invention are of the type having the
formula A:

wherein the symbols R1, R2, R3, R4, R5, R6 and R7, which are identical or different,
represent a hydrogen, phenyl or a C1 - C6 alkyl radical, and the symbols T1, T2 and
T3, which are identical or different, represent a hydrogen, phenyl, a C1-C6 alkyl
radical, or an alkyl group of the form

wherein R8 and R9, which are identical or different, represent a C1 to C6 alkyl radical
containing none, one or more secondary alcohol groups, and X represents a primary
alcohol or a quaternary amine of the form


wherein R10, R11, and R12, which are identical or different, represent C1 -C19 alkyl or
alkene groups, either linear or branched chain, and Z represents an acetate anion.
r is an average value ranging from 1 to 500;
s is an average value ranging from 1 to 10;
It is preferred to use a composition, wherein the polyorganosiloxane is a polymer of
formula B:

Wherein
r is an average value ranging from 1 to 100, preferably 80,
s is an average value ranging from 1 to 10, preferably 2, 15
T represents a group of the formula:

Wherein X represents a primary alcohol, or an amine of the form:

wherein Y represents a C11-C13 alkyl.
Such a mixture is marketed under the reference BC2211 by the company Basildon
Chemical Company Ltd (Kimber road, Abingdon, Oxon).
The composition may comprise a polyorganosiloxane, and may comprise a blend of
polyorganosiloxanes. The polyorganosiloxane or the blend of polyorganosiloxanes
may be present in the composition in an amount of 0% to 10% w/w. In some
embodiments, the polyorganosiloxane or the blend of polyorganosiloxanes is present
in an amount of from 10% to 50% w/w and may be present in the amount of from
30% to 40% w/w. For example, the polyorganosiloxane or the blend of
polyorganosiloxanes may be present in an amount from 0% to 10% w/w in a
composition comprising water as a diluent, the said composition being then applied to
a surface (such as the surface of a fabric) and being fixed thereto by drying so as to
remove all or a substantial part of the water, the resulting composition comprising an

amount from 10% to 50% w/w of the polyorganosiloxane or the blend of
polyorganosiloxanes.
Advantageously, the polyorganosiloxane or the blend of polyorganosiloxanes acts as
a carrier to introduce the active agent to the surface, implement or the like to be
treated by the composition of the invention. The amino and/or polyether (or other)
functions of polyorganosiloxanes interact with the biguanide polymer (or polymers)
and the further active agent (or agents) and also interact with the surface to which the
composition is applied, thereby retaining the said biguanide polymer or polymers and
the said further active agent or agents on the surface.
The composition of the invention provides disinfection of surfaces for a considerable
time after application and will remain active after washing and/or abrading (polishing).
This is advantageous over conventional biocides which quickly lose their efficacy
after application particularly when the treated surface is washed or abraded.
We have observed that surfaces treated with compositions comprising polymeric
biguanides and polyorganosiloxanes remain sporicidally and biocidally active for a
longer period of time after application to a surface, and are particularly sporicidally
and biocidally active, as compared to compositions lacking a polyorganosiloxane. We
have further observed that the effect of the addition of polyorganosiloxanes to
biocidal compositions comprising only monomeric, dimeric or other small molecule
biocidal agents, is less pronounced.
The interaction between polyorganosiloxanes, and in particular functionally
terminated polyorganosiloxanes such as those of formula A and formula B, and other
active agents (including polymeric biguanides) is predominantly an electrostatic
interaction between polar chemical functionalities. Although not wishing to be bound
by theory, it is postulated that higher molecular weight polymeric units of polymeric
biguanides comprise a large number of such functional units thereby providing an
enhanced electrostatic interaction. It is also proposed that polymeric biguanide
species are more strongly physically bound to other polymeric species, such as
polyorganosiloxanes (which may be due, for example, to entanglement of polymer
chains).
Accordingly, the polymeric biguanides and the one or more further active agents
(which may also bind electrostatically and/or physically to the polymeric biguanide,

some or all of which may be polymeric further active agents), and are thus more
strongly physically bound to the polyoranosiloxane or blend thereof than the active
agents of compositions comprising only small molecule active agents. Thus,
polyoranosiloxanes have a more pronounced effect on the retention of polymeric
biguanides and any further active agents interacting therewith, than compositions
comprising only small molecule active agents (for example compositions comprising
biguanides, bis-biguanides and/or additional small molecule active agents).
When the composition is applied to a surface, material or instrument, it may form a
coating layer thereon which contains said polymeric biguanide or biguanides and the
said one or more further active agents, so that any spores, endospores or other micro
organisms present on or subsequently contacting the surface or instrument are killed.
If the composition further comprises a surfactant, this may enhance the spreading
ability of the composition over substantially the entire surface whilst imparting
cleaning and detergent properties to the composition.
The composition or the method according to the invention is effective at killing
spores, endospores or other micro organisms under dry or wet conditions.
Advantageously, the composition or method may be used in different environments,
e.g. in the medical or health care industry, for example in hospitals, in the food
industry, for example in manufacturing plants and restaurants or in domestic
environments.
The composition may be provided in concentrated form and may diluted before
applying it to a surface or implement, such as by 1 to 100 fold or 1 to 1000 fold, for
example by adding water. Alternatively the composition may be provided at a
concentration ready-to-use.
In some embodiments, the composition may be provided in a first concentration in a
diluent, excipient or carrier, for use in applying to a surface or impregnating a surface
such as a fabric surface, and some or all of the diluent or excipient may subsequently
be removed so as to increase the concentration of the composition. In some
embodiments, the composition may be fixed to a surface by removing all or a
substantial part of the composition, for example by applying heat or otherwise drying
the surface so as to cause some or all of the diluent, excipient or carrier to evaporate.

Thus, the method may comprise diluting the composition. Alternatively, or in addition,
the method may comprise drying the composition, or otherwise removing (e.g. by
evaporation) some or all of the diluent, excipient or carrier
The method may comprise fixing the composition to a surface, or to a material
impregnated with the composition, by drying or otherwise removing some or all of the
diluent, excipient or carrier, or by curing.
The composition may be effective at controlling not only spores and more particularly
spores of Clostridia such as Clostridium Difficile, but is further effective in controlling
the proliferation and/or elimination of many types of micro organisms, including gram-
positive and gram- negative bacteria, such as at least one, and preferably several, of:
Bacillus cereus, Bacillus subtilis, Brevibacterium ammoniagenes, Brucella abortus,
Klebsiella pneumonia, Lactobacillus casei, Proteus vulgaris, Listeria monocytogenes,
Pseudomonas aeruginosa, Salmonella gallinarum, Salmonella typhosa,
Staphylococcus aureus, Steptococcus faecalis, Flavobacterium species, Bacillus
species, Escherichia species, Aeromonas species, Anchromobacter species and
Alcaligenes species, fungi such as: Cephalosporium species, Cladosporium species,
Fusarium species, Paecilomyces species, Penicillium species, Streptomyces
species, Trichophyton interdigitale, Chaetorarium globesom, Aspergillus niger, and
Ceniphora puteana, Cornyebacterium species, Proteus penneri, Enterobacter
aerogenes, Salmonella enteritidis; yeasts such as Monilia albicans and
Saccharomyces cerevisiae, Candida albicans; algae such as Chlorella pyrenoidosa
Chlorella vulgaris, Nostoc commune, Scenedesmus vacuolates /and Anabaena
cylindrical; and moulds such as Epidermophyton floccosum, Microsporum canis,
Tricophyton mentagrophytes and Candida albicans.
According to a third aspect of the invention, there is provided a composition for use in
providing a material (such a textile or a plastics material) with a sporicidal property,
the composition comprising one or more biguanide polymers, one or more further
active agents, and a polyorganosiloxane or a blend of polyorganosiloxanes,
characterised in that the or each further active agent is, when taken alone,
sporicidally inactive.

We have observed that surfaces treated with compositions comprising polymeric
biguanides and polyorganosiloxanes remain sporicidally and/or biocidally active for a
longer period of time after application to a surface, and are particularly sporicidally
and/or biocidally active, as compared to compositions compring a small molecule
active agent and one or more polyorganosiloxanes. Although not wishing to be bound
by theory, it is proposed that the persistence and efficacy of the compositions of the
present invention derive from unexpectedly strong interaction (including electrostatic
interactions) between the polymeric species.
Accordingly, the invention extends in a further aspect to a composition for use in
providing a textile with a biocidal property, the composition comprising a biguanide
polymer or a mixture of biguanide polymers, or a polymeric biocide or mixture
thereof, and a polyorganosiloxane or a mixture of polyorganosiloxanes. The invention
also extends to a material (such as a textile or a plastics material) impregnated or
treated with a composition comprising a biguanide polymer or a mixture of biguanide
polymers, or a polymeric biocide or mixture thereof, and a polyorganosiloxane or a
mixture of polyorganosiloxanes.
The composition of the invention may be incorporated into a material such as a textile
material (which may be a woven or a non-woven textile material and which is
preferably a non-woven fabric material) or a plastics material.
Preferably the composition is for use in providing a material such as a textile with a
sporicidal activity. Advantageously, the material is provided with a sporicidal activity
when the composition thereon is wet (such that the material is wet), or dry, such that
the material is dry (for example the material may be sporicidal after the composition
has been fixed to the material, for example following a drying step).
We have observed that the textiles of the invention are sporicidally active when dry,
i.e. during normal use, and that the active agents of the composition thereon need not
be mobile in solution in order to convey a sporicidal effect. Therefore, sporicidal
contamination of the textiles of the invention is prevented.
The composition preferably comprises at least two different polyorganosiloxanes.
Further preferred and optional features of the composition of the third aspect
correspond to preferred and optional features of the first and second aspects.

According to a fourth aspect of the invention, there is provided a material (such as a
textile) treated with a composition according to the invention for killing spores and/or
the prevention of sporicidal contamination, in particular C. Difficile spores.
Advantageously the treated textile requires biocidal activity, such as a sporicidal
activity, which is durable to repeated laundering.
Preferred and optional features of the composition of the material of the fourth aspect
correspond to preferred and optional features of the first, second and third aspects.
According to a fifth aspect of the present invention there is provided a method of
providing a material (such as a textile) with a sporicidal activity comprising the steps
of impregnating the material with a biocidal composition; and fixing the impregnated
composition to the material.
The step of fixing the impregnated composition may comprise drying, or heating (so
as to remove some or substantially all of a diluent or excipient), or curing the
composition and/or the material.
Preferably, the material is a textile, which may be woven or non-woven and may, in
some embodiments be a non-woven fabric. The material may be a plastics material.
The method may comprise the step of drying the textile to remove excess
composition following the impregnation step. The drying step may comprise a heating
step.
The impregnation step may comprise applying composition to the textile and passing
it through a mangle. The mangle may be a pad mangle.
The textile may be soaked with composition as part of the impregnation process.
The fixing step may comprise a baking step and may comprise causing cross-linking
between chemical species (and in particular between polymeric chemical species) of
the composition to the textile (or the material, as the case may be), or may comprise
causing cross-linking between chemical species (and in particular between polymeric
chemical species) of the composition.

The properties of durable biocidal or sporicidal activity regardless of repeated
laundering, or durable biocidal or sporicidal activity regardless of prolonged exposure
of a material to the environment (for example a hospital environment) are particularly
advantageous.
The method of the present invention may therefore render the composition resistant
to being washed out of the textile, or leached out of the impregnated material, as the
case may be.
The composition is preferably non-flammable and/or a non-irritant.
A textile formed in accordance with the present invention may be used to make
articles such as bed sheets, mattress covers, pillowcases, clothing and domestic
furnishings like curtains and tablecloths.
According to a further aspect of the invention there is provided a textile having a
sporicidal activity made according to the method herein described.
The textile may be woven or non-woven but is preferably non-woven, and can be
made of synthetic fibers such as polyester, vegetal fibers, such as cotton, or animal
fibres such as wool, or be a mixtures of these fibres. In some embodiments, the
textile is non-woven polypropylene.
Advantageously the concentration of biguanide polymers contains in said textile may
range from 100 ppm to up to 10,000 ppm, and more preferably from 3,000 ppm to
6,000 ppm.

Detailed Description of an Example Embodiment
Embodiments of the present invention will now be described by way of non- limiting
example only:
Formulations 1-4 were prepared having the following compositions:
Formulation 1 - "Endurocide CD": composition with polyorganosiloxanes
A biocidal composition was made by mixing 8% Endurocide Plus B/N E-154 plus 3%
Vantocil IB in water. Source raw materials were Acticide MBS (comprising 2.5% w/w
benzisothiazolone and 2.5% w/w methylisothiazolone), Acticide BAC 50M
(comprising a 70:30 ratio of, respectively, C12 and C14
alkyldimethylbenzylammonium chloride at a total concentration of 50% w/w, in
water), Acticide DDQ 50 (comprising 50% w/w di-n-decyldimethylammonium chloride
and 20% w/w propan-2-ol co-solvent, in water), BC2211 (comprising 20% w/w
cationic silicone polymer according to formula B, above and <15% w/w alcohol
ethoxylates, in water) and Vantocil IB (comprising 20% w/w PHMB, in water). The
chemical formulation was as follows in ppm by mass:


Formulation 2 - "Endurocide SW1": composition without cationic silicone polymers
A biocidal composition was prepared having a similar composition to Formulation 1,
but without BC2211 (i.e. cationic silicone polymer or alcohol ethoxylates), the
balance of the composition being made up by water such that the concentrations of
remaining compounds were the same as Formulation 1.
The chemical formulation was as follows in ppm by mass:

Formulation 3- "Endurocide SW2": concentrated composition without cationic
silicone polymers
A biocidal composition was made by mixing 10 % of an Endurocide Plus (the
Endurocide Plus formulation lacking BC2211) with 5% Vantocil IB in water.
This sample is a hazardous material, Xi irritant and may cause sensitisation by skin
contact.
The chemical formulation is as follows in ppm by mass:

Example 1: Biocidai Activity
Biocidal activity of Formulations 1-3 were tested according to the standard
suspension test EN 13704 for bacterial C. difficile and were found effective at 30
minutes.
Example 2: Sporicidal activity
Sporicidal activity is shown by testing Formulation 4 according to the EN 13704
standard at 20°C shows an in vitro Log 2.4 reduction in C. difficile spores.

N = Neutralisation M = Membrane filtration
Example 3: Manufacture of a textile according to the invention and testing of
sporicidal activity.
A biocidal textile according to the invention was manufactured according to the
following method:
A piece of textile was dipped into a volume of Formulation 4 and mixed with the
solution so as to saturate the textile with said composition.
The textile was then passed through a pad mangle to impregnate the composition
into the fibres of the textile and remove excess composition.
The impregnated textile was dried in a Stentor heating machine. The drying step may
be carried out, for example, by a temperature of between 50°C and 200°C. A
temperature of 200°C is preferred in some cases. However the fabric in this example
was dried at a temperature of 70°C.

It should be noted that the composition can advantageously be fixed within the textile,
if required, for example by baking in a baker. The baking temperature may be in the
range of 100°to300°C.
The fabric sample, once dried as described above, was independently analyzed
using the standard AATCC147-1998 following the following process:
Method of Analysis Used - AATCC 147-1998 - Clostridium difficile spores
1. Two CBA plates were streaked with five parallel lines of Clostridium difficile spores
ATCC 9689 and allowed to dry.
2. A 20 x 50 mm rectangle of each fabric was placed on each of the two plates from
the previous step.
3. The plates were incubated for 72 hours and examined for bacterial growth on the
surface of the fabric and for bacterial growth on the agar under the fabric.

Liquid agar was inoculated with C. difficile spores (NCTC 11209) and overlaid onto a
pre-prepared (and not inoculated) thinly poured agar plate. The resulting plates were
then allowed to solidify.
A 1 cm x 1 cm square of fabric was then placed at the centre of each plate and the
plate incubated for 24 hours.
Results
Results of the tests are set out in the table below:

* -ve = no growth
+/- = moderate growth
The fire retardant is not an active agent and, accordingly, halo test results of test
fabrics A and B were similar.
Sample C, lacking Acticide MBS, which is present in the undried composition A at
only 0.64%, never the less shows a small reduction in the halo diameter (compared
to test fabric A), indicating that the isothiazolone active agents present in Acticide
MBS contribute to the observed sporicidal effect of the impregnated fabrics.

Sample D, lacking Acticide BAC 50, which is present in the undried composition A at
0.4% shows very little halo, indicating that the active ingredient benzalkonium
chloride (which, when taken alone is sporicidally inactive) makes a significant
contribution to the observed sporicidal activity of test fabric A.
Sample E, lacking Acticide DDQ 50, present in the undried composition A at 0.88%
also shows very little halo, indicating that the active ingredient dimethylammonoim
chloride chloride (which, when taken alone is sporicidally inactive) makes a
significant contribution to the observed sporicidal activity of test fabric A.
Sample F, lacking BC2211, present in the undried composition A at 2.4% shows a
slight reduction in halo diameter very little halo, indicating that the cationic silicone
polymer (which, when taken alone is not known to be biocidally active) makes a
contribution to the observed sporicidal activity of test fabric A.
Sample G, lacking Vantocil IB, present in the undried composition A at 2% also
shows no halo and moderate grown is observed under the fabric sample, indicating
that the active ingredient PAMB (which, when taken alone is sporicidally inactive)
makes a significant contribution to the observed sporicidal activity of test fabric A.
Thus, the combination of polymeric biguanide and any or all of the remaining active
agents in Formulation A results in an unexpected sporicidal activity, which may be
regarded as a synergistic effect between the polymeric biguanide and the further
active agents. Furthermore, the further active agents each result in an unexpected
enhancement of the sporicidal activity of a composition comprising a polymeric
biguanide, which may also be regarded as a synergistic effect between each further
active agent and the polymeric biguanide and/or each other further active agent, in
the presence of the polymeric biguanide.
Additionally, an effect of polyorganosolixanes on the sporicidal activity of
impregnated fabric materials has been observed, indicating that the
polyorganosiloxanes advantageously enhance the interaction of the active agents,
and in particular the polymeric biguanide active agents, with the surface.

Claims
1. A method for killing spores from a surface or a material which comprising
applying an effective amount of a biocidal composition which comprises
one or more biguanide polymers, and one or more further active agents
on said surface or material, characterised in that the or each further active
agent is, when taken alone, sporicidally inactive.
2. The method of claim 1, wherein the composition further comprises a
polyorganosiloxanes or a blend of polyorganosiloxanes.
3. The method of claims 1 or 2, wherein one or more or all of the or each
polyoganosiloxane is a functionally terminated polyorganosiloxane.
4. The method of claim 1 or 2, wherein said surface is a textile and wherein
the method comprises the step of impregnating the textile with the
composition.
5. A method of providing a textile with a sporicidal activity according to
claims 2 or 3 comprises the step of fixing the impregnated composition to
said textile.
6. The method of claims 2 to 4, wherein the or each said polyorganosiloxane
is a polymer of formula B:
Formula B: T(Me)2SiO(SiMe20)r(SiMeTO)sSiMe2T
Wherein
r is an average value ranging from 1 to 100, preferably 80,
s is an average value ranging from 1 to 10, preferably 2,
T represents a group of the formula:
-(CH2)3OCH2CHOHCH2X
wherein X represents a primary alcohol, or an amine of the form:
-NMe2Y+ Acetate-

wherein Y represents a C11 - C13 alkyl.
7. The method of claims 1 to 5, wherein the or each said further active agent
is present in an amount of from 0.01% to 20% by weight based on the
weight of the composition.
8. The method of claims 2 to 6, wherein the or each said polyorganosiloxane
is present in an amount of from 10% to 50% by weight based on the total
weight of the composition.
9. The method according to any one preceding claim, wherein the or each
said further active agent is selected from the group consisting of a
biocidal, anti- microbial, bactericidal, fungicidal, germicidal, yeasticidal,
moldicidal, algicidal virucidal agent or a mixture thereof.
10. The method according to any one preceding claim, wherein the or each
said further active agent is an isothiazolone compound, such as
benzisothiazolone, methylisothiazolone or a mixture thereof.
11. The method according to any one preceding claim, wherein the or each
said further active agent is a quaternary monoammonium salt, or a
mixture thereof, such as C12-C14 alkylbenzyldimethylammonium
chloride, didecyldimethylammonium chloride, or a mixture thereof.
12. The method according to any one preceding claim, wherein the or each
said biguanide polymer is a polyhexamethylene biguanide having a
molecular weight ranging from 500 to 20,000.
13. The method according to claim 11, wherein the or each said biguanide
polymer having an average molecular weight of about 3,000.
14. The method according to any one preceding claim, wherein the
concentration of the or each said biguanide polymer in the composition is
lower than 10% w/w.

15. The method according to any one preceding claim, wherein the
concentration of the or each said biguanide polymer is at least 1000 ppm.
16. The method according to any one preceding claim, wherein the
composition comprises a non volatile diluent, excipient or carrier such as
water, a glycol, an ester derivative of a glycol or an ether derivative of a
glycol.
17. A textile for killing spores and/or the prevention of sporicidal
contamination, treated with a composition comprising one or more
biguanide polymers, one or more further active agents, and a
polyorganosiloxane or a blend of polyorganosiloxanes, characterised in
that the or each further active agent is, when taken alone, sporicidally
inactive.
18. A dry textile according to claim 16.
19. A textile according to claims 16 or 17, impregnated with the said
composition.
20. A textile according to claims 16 to 18, wherein the concentration of the or
each said biguanide polymer is between 100 ppm to up to 10,000 ppm,
and more preferably from 3,000-6,000 ppm.
21. A composition for use in providing a textile with a sporicidal property, the
composition comprising one or more biguanide polymers, and one or
more further active agents, and a polyorganosiloxane or a blend of
polyorganosiloxanes, characterised in that the or each further active agent
is, when taken alone, sporicidally inactive.
22. A textile according to claims 17 to 20, or a composition according to claim
21, wherein one or more or all of the or each polyoganosiloxane is a
functionally terminated polyorganosiloxane.
23. A textile according to claims 17 to 20 or 22, or a composition according to
claims 21 or 22, wherein the or each said polyorganosiloxane is polymer
of formula B:

Formula B: T(Me)2SiO(SiMe20)r(SiMeTO)sSiMe2T
Wherein
r is an average value ranging from 1 to 100, preferably 80,
s is an average value ranging from 1 to 10, preferably 2,
T represents a group of the formula:
-(CH2)3OCH2CHOHCH2X
wherein X represents a primary alcohol, or an amine of the form:
-NMe2Y+ Acetate-
wherein Y represents a C11 - C13 alkyl.
24. A textile according to claims 17 to 20, 22 or 23, or a composition
according to claim 21 to 23, wherein the or each said further active agent
is present in an amount of from 0.01% to 20% by weight based on the
weight of the composition.
25. A textile according to claims 17 to 20, or 22 to 24, or a composition
according to claims 21 to 24, wherein the or each said polyorganosiloxane
is present in an amount of from 10% to 50% by weight based on the total
weight of the composition.
26. A textile according to claims 17 to 20, or claims 22 to 25, or a composition
according to claims 21 to 25, wherein the or each said further active agent
is selected from the group consisting of a biocidal, anti- microbial,
bactericidal, fungicidal, germicidal, yeasticidal, moldicidal, algicidal
virucidal agent or a mixture thereof.
27. A textile according to claims 17 to 20, or claims 22 to 26, or a composition
according to claims 21 to 26, wherein the or each said further active agent
is an isothiazolone compound, such as benzisothiazolone,
methylisothiazolone or a mixture thereof.

28. A textile according to claims 17 to 20, or claims 22 to 27, or a composition
according to claims 21 to 27, wherein the or each said further active agent
is a quaternary monoammonium salt, or a mixture thereof, such as C12-
C14 alkylbenzyldimethylammonium chloride, didecyldimethylammonium
chloride, or a mixture thereof.
29. A textile according to claims 17 to 20, or claims 22 to 28, or a composition
according to claims 21 to 27, wherein the concentration of the or each
said biguanide polymer in the composition is lower than 10% w/w.
30. A textile according to claims 17 to 20, or claims 22 to 29, or a composition
according to claims 21 to 29, wherein the concentration of the or each
said biguanide polymer is at least 1000 ppm.
31. A textile according to claims 17 to 20, or claims 22 to 30, or a composition
according to claims 21 to 30, wherein the composition comprises a non
volatile diluent, excipient or carrier such as water, a glycol, an ester
derivative of a glycol or an ether derivative of a glycol.
32. Use of a composition comprising one or more biguanide polymers, and
one or more further active agents, as a sporicide, characterised in that the
or each further active agent is, when taken alone, sporicidally inactive.

Disclosed is a method for killing spores from a surface or a material, comprising applying an effective amount of a
biocidal composition which comprises one or more biguanide polymers, and one or more further active agents on said surface or
material, characterised in that the or each further active agent is, when taken alone, sporicidally inactive. Compositions comprising
polymeric biguanides and one or more further biocidal agents and, optionally, a polyorganosiloxane, have been found to be effective
as a sporicidal agent and are particularly effective against the spores of C.difficile. The compositions maybe used in industry,
in domestic applications and are particularly suitable for use in hospital due to their low toxicity. Furthermore, the method may
comprise impregnating a fabric to thereby provide long lasting sporicidal activity thereto.