Note: Descriptions are shown in the official language in which they were submitted.
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ORAL COMPOSITIONS
TE HNICAL FIELD
The present invention relates to oral compositions such as toothpastes,
toothpowders, liquid dentifrices, mouthwashes, denture cleansers,
chewing gums, candies and the like.' In particular, the invention relates to
oral compositions having enhanced antiplaque activity together with
excellent cleansing performance, physical characteristics, and in-use
performance characteristics.
EACKGRO~JND
Plaque is initiated when bacteria adhered to pellicle form a proteinaceous
film on the surface of teeth. The adherent bacteria metabolize dietary
constituents and reproduce and aggregate to form the tenacious deposit
known as plaque. Plaque generally consists of bacteria, bacterial end
products such as polysaccharides, inorganic salts and salivary proteins.
Plaque bacteria ferment dietary carbohydrates to organic acids which
demineralize enamel resulting in tooth decay.
Calculus is essentially plaque that has been mineralized with calcium
phosphates salts. As calculus matures and hardens, it tends to stain
noticeably due to adsorption of dietary chromagens. In addition to their
unattractive appearance, calculus deposits at the gum line are a
contributing source of gingivitis and periodontal disease. Besides the
hygienic and health problems resulting from plaque, research has shown
that the primary source of bad breath is the retention and subsequent
degradation of dead cellular material sloughed off continuously by the
normal, healthy mouth.
Modern dental hygiene and denture preparations typically contain
antiplaque and/or antitartar agents, as well as antimicrobial agents and
flavorants. Antimicrobial action could affect plaque formation by either
reducing the number of bacteria in the mouth/dentures or by killing those
bacteria trapped in the film to prevent further growth and metabolism.
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Flavorants may alleviate the problem of bad breath via a deodorizing
action. Some antimicrobial agents, e.g. menthol may, also serve as
breath deodorizers. However, the efficacy of antimicrobial agents
depends largely on their intraoral/denture retention, particularly their
retention on the surface of the teeth or dentures where plaque is formed.
A typical disadvantage of known dental preparations is that only a
relatively short time during which the teeth are being cleaned or the
mouth is being rinsed is available for antimicrobial agents in the
preparations to take effect. The problem is compounded by the fact that
dentifrice preparations are used infrequently: most are used once or,
perhaps, twice daily. Consequently, the long time period between
brushings for a majority of the population provides optimum plaque
forming conditions.
There has been a need, therefore, for developing an oral formulation
which has a prolonged, residual antimicrobial and/or flavor impact effect.
It is known to include silicones in dentifrice compositions, allegedly to
coat the teeth and prevent cavities and staining. For instance, GB-A-
689,679 discloses a mouthwash containing an organopolysiloxane for
preventing adhesion of, or for removing tars, stains, tartar and food
particles from the teeth. The mouthwash may include antiseptic
compounds, such as thymol, and flavoring and perfuming agents.
US-A-2,806,814 discloses dental preparations including, in combination,
a higher aliphatic acyl amide of an amino carboxylic acid compound as an
active and a silicone compound. The patent notes that silicone
compounds have been proposed for prevention of adhesion or to facilitate
the removal of tars, stains, tartar and the like from teeth. The silicone
compound is said to act as a synergist in improving the antibacterial and
acid inhibiting activity of the active ingredient. Dimethyl polysiloxanes
are said to be particularly effective. Flavoring oils and/or menthol may
be included.
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US-A-3624120 discloses quaternary ammonium salts of cyclic siloxane
polymers for use as cationic surfactants, bactericides and as
anticariogenic agents.
Accordingly, the present invention provides oral compositions having
improved efficacy on plaque, mucilaginous and bacterial deposits and
which at the same time provides excellent cleansing performance,
physical characteristics, and in-use performance characteristics.
The invention further provides oral compositions containing a lipophilic
compound such as a flavorant, physiological cooling agent or
antimicrobial, and which has improved substantivity, impact and/or
efficacy on teeth and dentures.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided an oral
composition in the form of a toothpaste, powder, liquid dentifrice,
mouthwash, denture cleanser, chewing gum or candy comprising one or
more oral composition components selected from abrasives, binders,
humectants, surfactants, fluoride ion sources, anti-calculus agents and
sweeteners and additionally comprising a dimethicone copolyol selected
from alkyl- and alkoxy-dimethicone copolyols having the formula (I):
CH3 CH3 CH3 CH3 H3
I I I I
CHI-- Si0 Si0 Si0 i i-CH3
CH3 CH3 (CH2)~ Y CH3
n (
(C2H40-)X(C3Hgo-)yX
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4
wherein X is selected from hydrogen, alkyl, alkoxy and acyl groups
having from about 1 io abou~~t 16 carbon atoms, Y is selected from alkyl
and alkoxy groups having from about 8 to about 22 carbon atoms, n is
from about 0 to about 200, m is from about 1 to about 40, q is from about
1 to about 100, the molecular weight of the residue
(C2H4O-)X(C3H6O-h,X is from about 50 to about 2000, preferably from
about 250 to about 1000 and ~; and y are such that the weight ratio of
oxyethylene:oxypropylene is from about 100:0 to about 0:100, preferably
from about 100:0 to about 20:80.
According to a further aspect of the invention, there is provided as oral
composition in the form of a toothpaste, powder, liquid dentifrice,
mouthwash, denture cleanser, chewing gum or candy comprising a
lipophilic compound selected from flavorants, physiological cooling
agents and antimicrobial compounds and a dimethicone copolyol selected
from alkyl- and alkoxy-dimethicone copolyols having the formula (n.
All percentages and ratios herein are by weight of total composition,
unless otherwise indicated.
The oral compositions of the invention thus comprise a dimethicone
copolyol antiplaque agent while preferred compositions additionally
comprise a lipophilic compound and/or one or more oral composition
components selected from abrasives, binders, humectants, surfactants,
fluoride ion sources, anti-calculus agents and sweeteners Each of these
will be discussed in turn.
In general terms, the dimethicone copolyol is selected from alkyl- and
alkoxy-dimethicone copolyols having the formula (n:
CH3 CH3 CHI CH3 H3
I I I !
CH3- Si0 Si0 Si0 i i-CH3
I IH I
CH3 3 (CH;r)3 Y CH3
n I
O ~ (C2H40_)x(C3H60_)vX 4
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wherein X is selected from hydrogen, alkyl, alkoxy and acyl groups
having from about 1 to about 16 carbon atoms, Y is selected from alkyl
and alkoxy groups having from about 8 to about 22 carbon atoms, n is
from about 0 to about 200, m is from about 1 to about 40, q is from about
1 to about 100, the molecular weight of the residue
(C2H40-)x(C3H60-h,X is from about 50 to about 2000, preferably from
about 250 to about 1000 and x and y are such that the weight ratio of
oxyethylene:oxypropylene ;is from about 100:0 to about 0:100, preferably
from about 100:0 to about 20:80.
In prefered embodiments, t:he dimethicone copolyol is selected from C12
to C20 alkyl dimethicone copolyols and mixtures thereof. Highly
preferred is cetyl dimethicone copolyol marketed under the Trade Mark
AbiI EM90. The dimethicone copolyol is generally present in a level of
from about 0.01 % to about 25 % , preferably from about 0.1 % to about
5 % , more preferably from about 0.5 % to about 1.5 % by weight.
The oral compositions of the invention preferably also include a lipophilic
compound. In general terms, lipophilic compounds suitable for use
herein are oil-like materials. which are soluble or solubilisable in the
dimethicone copolyol, preff;rably at a level of at least about 1 %, more
preferably at least about 5 % by weight at 25°C. Preferred Iipophilic
compounds are selected from flavorants, physiological cooling agents and
antimicrobial compounds. 'The dimethicone copolyol acts to enhance the
substantivity of the lipophil:ic compound to teeth and/or dentures, thereby
providing enhanced and/or sustained flavor impact and antimicrobial
efficacy.
Lipophilic flavorants suitable for use herein comprise one or more flavor
components selected from wintergreen oil, oregano oil, bay leaf oil,
peppermint oil, spearmint oil, clove oil, sage oil, sassafras oil, lemon oiI,
orange oil, anise oil, benzaldehyde, bitter almond oil, camphor, cedar leaf
oil, marjoram oil, citronella oil, Iavendar oil, mustard oil, pine oil, pine
needle oil, rosemary oil, thyme oil, cinnamon Leaf oil, and mixtures
thereof.
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6
Lipophilic antimicrobial compounds suitable for use herein include
thymol, menthol, triclosan, 4-hexyIresorcinol, phenol, eucalyptol, benzoic
acid, benzoyl peroxide, butyl paraben, methyl paraben, propyl paraben,
salicylamides, and mixtures thereof.
Physiological cooling agent suitable for use herein include carboxamides,
menthane esters and menthane ethers, and mixtures thereof.
Suitable menthane ethers for use herein are selected from those with the
formula:
X
ORS
where RS is an optionally hydroxy substituted aliphatic radical containing
up to 25 carbon atoms, preferably up to S carbon atoms, and where X is
hydrogen or hydroxy, such as those commercially available under the
trade mark Takasago, from Takasago International Corporation. A
particularly preferred cooling agent for use in the compositions of the
present invention is Takasago 10 [3-1-menthoxy propan-1,2-diol (MPD)].
MPD is a monoglycerin derivative of t-menthol and has excellent cooling
activity.
The carboxamides found most useful are those described in US-A-
4,136,163, January 23, 19'79 to Wason et al., and US-A-4,230, 688,
October 28, 1980 to Rawsell et al.
The level of lipophilic compound in the compositions of the invention is
generally in the range from about O.OI % to about 10°6, preferably from
about 0.05 % to about 5 %, more preferably from about 0.1 °b to about 3
k
by weight.
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Compositions in the form of toothpastes, denture cleansing liquids and
pastes and the like will generally comprise a binder or thickening agent.
Binders suitable for use herein include carboxyvinyl polymers,
carrrageenan, hydroxyethyl cellulose and water soluble salts of cellulose
ethers such as sodium carboxymethyl cellulose and sodium carboxymethyl
hydroxyethyl cellulose. Natural gums such as gum karaya, xanthan gum,
gum arabic, and gum tragacanth can also be used. Colloidal magnesium
aluminum silicate or finely divided silica can be used as part of the
thickening agent to further improve texture. Binders/thickening agents
can be used in an amount from about 0.1 % to about 5.0% , preferably
from about 0.1 to about 1 % by weight of the total composition.
It is also desirable to include some humectant material in a toothpaste to
keep the composition from hardening upon exposure to air. Certain
humectants can also impart a desirable sweetness to toothpaste
compositions. Liquid dentifrice and mouthwashes can also contain a
quantity of humectant. Suitable humectants include glycerin, sorbitol,
xylitol, polyethylene glycols, propylene glycol, other edible polyhydric
alcohols, and mixtures thereof. When present, humectants generally
represent from about 10% to about 70%, by weight of the compositions
of the invention.
Toothpastes, liquid dentifrices and denture cleansers in liquid or paste
form will generally comprise an abrasive polishing material. The
abrasive polishing material contemplated for use herein can be any
material which does not excessively abrade dentin or denture acrylic.
These include, for example, silicas including xerogels, hydrogels,
aerogels and precipitates, calcium and magnesium carbonates, calcium
ortho-, pyro- mete- and polyphosphates such as dicalcium orthophosphate
dihydrate, calcium pyrophosphate, tricalcium phosphate, and calcium
polymetaphosphate, insoluble sodium polymetaphosphate, alumina and
' hydrates thereof such as alpha alumina trihydrate, aluminosilicates such
as calcined aluminium silicate and aluminium silicate, magnesium and
zirconium silicates such as magnesium trisilicate and thermosetting
polymerised resins such as particulate condensation products of urea and
formaldehyde, polymethylmethacrylate, powdered polyethylene and
others such as disclosed in US-A-3,070,5 I0, December 25, 1962
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8
Mixtures of abrasives can also be used. The abrasive polishing materials
generally have an average particle size of from about 0.1 to about 30
microns, preferably from about 5 to 15 microns.
Silica dental abrasives of various types offer exceptional dental cleaning
and polishing performance: without unduly abrading tooth enamel or
dentin. The silica abrasive can be precipitated silica or silica gels such as
the silica xerogels described in Pader et al., US-A-3,538,230, issued
March 2, 1970 and DiGiullio, US-A-3,862,307, June 21, 1975, for
example silica xerogels marketed under the trademark "SyIoid" by W. R.
Grace & Company, Davis~on Chemical Division. Suitable precipitated
silica materials include those marketed by the J. M. Huber Corporation
under the trademark, "Zeodent", particularly the silica carrying the
designation "Zeodent 119". These silica abrasives are described in US-
A-4,340,583, July 29, 1982.
Highly preferred herein from the viewpoint of providing good cleansing
performance combined with excellent compatibility with the antiplaque
agent are calcium carbonate abrasives.
The abrasive is generally present in dentifrice formulations of the
invention at a level of from about 10% to about ?0%, preferably from
about 15 % to about 25 % by weight.
The present compositions can also contain surfactants. Suitable
surfactants are those which are reasonably stable and foam throughout a
wide pH range, including non-soap anionic, nonionic, cationic,
zwitterionic and amphoteric organic synthetic detergents. Many of these
suitable agents are disclosed by Gieske et al. in US-A-4,051,234,
September 27, 1977.
Examples of suitable surfactants include alkyl sulfates; condensation
products of ethylene oxidE; with fatty acids, fatty alcohols, fatty amides,
polyhydric alcohols (e.g. sorbitan monostearate, sorbitan oleate), alkyl
phenols ( M g. Tergitol) and polypropyleneoxide or polyoxybutylene (e.g.
Pluronics); amine oxides such as dimethyl cocamine oxide, dimethyl
TM
lauryl amine oxide and cocoalkyldimethyl amine oxide (Aromox);
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9
polysorbates such as Tween 40 and Tween 80 (Hercules); sorbitan
stearates, sorbitan monoaleate, etc; sarcosinates such as sodium
cocoylsarcosinate, sodium Iauroyl sarcosinate (Hamposyl-95 ex W. R.
Grace); cationic surfactants such as cetyl pyridinium chloride, celyl
trimethyl ammonium bromide, di-isobutyl phenoxy ethoxy ethyl-dimethyl
benzyl ammonium chloriide and coconut alkyl trimethyl ammonium nitrate
A soluble fluoride ion source can also be incorporated in the present
compositions. The soluble fluoride ion source is used in amounts
sufficient to provide fronn about 50 to about 3500 ppm of the fluoride ion.
Preferred fluorides are sodium fluoride, stannous fluoride; indium
fluoride, zinc ammonium fluoride, tin ammonium fluoride, calcium
fluoride and sodium mon.ofluorophosphate. Norris et al., US-A-
2,946,735, issued July 26, 1960 and Widder et al., US-A-3,678,154,
issued July 18, 1972 disclose such salts as well as others.
The present compositions can also include an anti-calculus agent.
Suitable anti-calculus agents include the di- and tetra-alkali metal
pyrophosphates as set ou~~t in EP-A-097476. Specific salts include tetra
alkali metal pyrophosphate, dialkali metal diacid pyrophosphate, trialkali
metal monoacid pyrophosphate and mixtures thereof, wherein the alkali
metals are sodium or potassium. The salts are useful in both their
hydrated and unhydrated forms. The amount of pyrophosphate salt useful
in these compositions is any effective amount and is generally enough to
provide in composition at: least 1.0 % P207-4, preferably from about
1.5 9b to about 10 ~ , more preferably from about 3 °b to about 6 ~ by
weight of composition. 7.'he pyrophosphate salts are described in more
detail in Kirk & Othmer, EncycloRedia o~Chemical Technoloev, Second
Edition, Volume 15, Interscience Publishers (1968).
Other anti-calculus agents suitable herein are zinc salts. Zinc salts are
disclosed in US-A-4,100,269, US-A-4,416,867, US-A-4,425,325 and US-
A-4,339,432. A preferred agent of the zinc variety is zinc citrate. Zinc
compounds can be present in amounts sufficient to provide from about
0.01 '~o to about 4 % , preferably from about 0.05 r6 to about 1 ~o by weight
of zinc ion.
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1~
Other suitable anti-calculus agents include the synthetic anionic polymers
(including polyacrylates and copolymers of malefic anhydride or acid and
methyl vinyl ether (eg Gantrez) as described in US-A-4,627,977,
polyamino propane sulfonic acid, polyphosphates (eg tripolyphosphate,
hexametaphosphate), diphosphonates (eg EHDP, AHP), polypeptides ( eg
polyaspartic and polyglut:amic acids), and mixtures thereof.
Sweetening agents which can be used include aspartame, acesulfame,
saccharin, dextrose, levulose and sodium cyclamate. Sweetening agents
are generally used at levels of from about 0.005 % to about 2 % by weight
of composition.
Other optional components for use herein include water-soluble
antibacterial agents, such as chlorhexidine digluconate, quaternary
ammonium antibacterial compounds and water-soluble sources of certain
metal ions such as zinc, copper, silver and stannous (e.g., zinc, copper
and stannous chloride, and silver nitrate); pigments such as titanium
dioxide; orally acceptable dyes/colorants such asFD&C Blue ~1, FD&C
Yellow X10, FD&C Red x#40; antioxidants, vitamins such as vitamin C
and E, other antiplaque agents such as stannous salts, copper salts,
strontium salts and magnesium salts; pH adjusting agents, anticaries
agents such as urea, calcium glycerophosphate, sodium trimetaphosphate,
plant extracts, desensitizing agents for sensitive teeth such as potassium
nitrate and potassium citrate, and mixtures thereof.
Typically, mouthwashes comprise a water/alcohol solution, flavor,
humectant, sweetener, sudsing agent, and colorant as described above.
Mouthwashes can include ethanol at a level of from 0 to 60°x,
preferably
from 5 to 30% by weight.
Denture cleanser compositions of the invention can additionally include
one or more bleaching agents, organic peroxyacid precursors,
effervescence generators, chelating agents, etc
The bleaching agent takes the form of an inorganic persalt and can be
selected from any of the well-known bleaching agents known for use in
denture cleansers such as the alkali metal and ammonium persulfates,
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perborates, percarbonates and perphosphates and the alkali metal and
alkaline earth metal peroxides. Examples of suitable bleaching agents
include potassium, ammonium, sodium and lithium persulfates and
perborate mono- and tetrahydrates, sodium pyrophosphate peroxyhydrate
and magnesium, calcium, strontium and zinc peroxides. Of these,
however, the alkali metal persulfates, perborates and mixtures thereof are
prefered for use herein, highly preferred being the alkali metal
perborates. Indeed, it is a feature of the invention that the tablet
compositions herein will provide excellent antimicrobial activity even in
the absence of alkali metal persulfates.
The amount of bleaching agent in the total composition is generally from
about 5 to about 70 % preferably from about 10 % to about 50 % . In
compositions comprising a mixture of alkali metal persulfates and
perborates, the overall persulfate:perborate ratio is suitably from about
S:1 to about 1:5, more especially from about 2:1 to about 1:2.
The denture cleansing compositions can also incorporate an effervescence
generator, ie a material which in the presence of water releases carbon
dioxide or oxygen with effervescence. The effervescence generator can
be selected from generators which are effective under acid, neutral or
alkaline pH conditions, but preferably it consists of a combination of a
generator which is effective or most effective under acid or neutral pH
conditions and a generator which is effective or most effective under
alkaline pH conditions. Effervescence generators which are effective
under acid or neutral pH conditions include a combination of at least one
alkali metal carbonate or bicarbonate, such as sodium bicarbonate,
sodium carbonate, sodium sesquicarbonate, potassium carbonate,
potassium bicarbonate, or mixtures thereof, in admixture with at least one
non-toxic, physiologically-acceptable organic acid, such as tartaric,
fumaric, citric, malic, malefic, gluconic, succinic, salicylic, adipic or
sulphamic acid, sodium fumarate, sodium or potassium acid phosphates,
betaine hydrochloride or mixtures thereof. Of these, malic acid is
preferred. Effervescence generators which are effective under alkaline
pH conditions include persalts such as alkali and alkaline earth metal
peroxoborates as well as perborates, persulphates, percarbonates,
perphosphates and mixtures thereof as previously described, for example,
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a mixture of an alkali metal perborate (anhydrous, mono- or tetrahydrate)
with a monopersulphate such as Caroat R marketed by E I du Point de
Nemours Co. and which is a 2:1:1 mixture of monopersulphate,
potassium sulphate and potassium bisulphate and which has an active
oxygen content of about 4.5 % .
In preferred denture cleansing compositions in tablet form, the
effervescence generator takes the form of a solid base material which in
the presence of water releases carbon dioxide or oxygen with
effervescence. Suitably, the solid base material incorporates a
(bi)carbonate/acid effervescent couple optionally in combination with a
perborate/persulphate oxygen effervescence generator. The combination
of generators is valuable for achieving optimum dissolution characteristics
and pH conditions for achieving optimum cleaning and antimicrobial
activity. 'The (bi)carbonate components generally comprise from about
S %a to about 65 % , preferably from about 25 % to 55 % of the total
composition; the acid components generally comprise from about ~ % to
about SO%, preferably from about 10% to about 30% of the total
composition.
The denture cleansing compositions of the invention can be supplemented
by other known components of such formulations. An especially
preferred additional component is an organic peroxyacid precursor, which
in general terms can be defined as a compound having a titre of at least
l.Sml of O.1N sodium thiosulfate in the following peracid formation test.
A test solution is prepared by dissolving the following materials in 1000
mls distilled water:
sodium pyrophosphate
(Na4P20~. l OH20) 2.Sg
sodium perborate
(NaB02.H202.3H20) having
10.4 % available oxygen 0.615g
sodium dodecylbenzene
sulphonate O.Sg
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To this solution at 60°C an amount of activator is added such that
for
each atom of available oxygen present one molecular equivalent of
activator is introduced.
The mixture obtained by addition of the activator is vigorously stirred and
maintained at 60°C. After S minutes from addition, a 100 ml portion of
the solution is withdrawn and immediately pipetted onto a mixture of 250
g cracked ice and 15 ml glacial acetic acid. Potassium iodide (0.4 g) is
then added and the liberated iodine is immediately titrated with 0.1 N
sodium thiosulphate with starch as indicator until the first disappearance
of the blue colour. The amount of sodium thiosulphate solution used in
ml is the titre of the bleach activator.
The organic peracid precursors are typically compounds containing one or
more acyl groups, which are susceptible to perhydrolysis. The preferred
activators are those of the N-acyl or ~-acyl compound type containing a
acyl radical R-CO wherein R is a hydrocarbon or substituted hydrocarbon
group having preferably from about 1 to about 20 carbon atoms.
Examples of suitable peracid precursors include:
1) Acyl organoamides of the formula RCONR1R2, where RCO is
carboxylic acyl radical, R1 is an acyl radical and R2 is an organic
radical, as disclosed in US-A-3,117,148. Examples of compounds
falling under this group include:
a) N,N - diacetylaniline and N-acetylphthalimide;
b) N-acylhydantoins, such as
N,N' -diacetyl-5,5-dimethylhydantoin;
c) Polyacylated alkylene diamines, such as
N,N,N'N' -tetraacetylethylenediamine (TAED) and the
corresponding hexamethylenediamine (TAHD) derivatives, as
disclosed in GB-A-907,356, GB-A-907,357 and GB-A-
907,358;
d) Acylated glycolurils, such as tetraacetylglycoluril, as disclosed
in GB-A-1,246,338, GB-A-1,246,339 and GB-A-1,247,429.
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2) Acylated sulphonamides, such as N-methyl-N-benzoyl-menthane
sulphonamide and N-phenyl-N-acetyl menthane sulphonamide, as
disclosed in GB-A-3,183,266.
3) Carboxylic esters as disclosed in GB-A-836,988, GB-A-963,135
and GB-A-1,147,871. Examples of compounds of this type include
phenyl acetate, sodium acetoxy benzene sulphonate,
trichloroethylacetate, sorbitol hexaacetate, fructose pentaacetate, p-
nitrobenzaldehyde diacetate, isopropeneyl acetate, acetyl aceto
hydroxamic acid, and acetyl salicylic acid. Other examples are
esters of a phenol or substituted phenol with an alpha-chlorinated
lower aliphatic carboxylic acid, such as chloroacetylphenol and
chloroacetylsalicylic acid, as disclosed in US-A-3,130,165.
4) Carboxylic esters having the gernal formal Ac L wherein Ac is the
acyl moiety of an organic carboxylic acid comprising an optionally
substituted, linear or branched C6-C20 alkyl or alkenyl moiety or a
C6-C20 alkyl-substituted aryl moiety and L is a leaving group, the
conjugate acid of which has a pKa in the range from 4 to 13, for
example oxybenzenesulfonate or oxybenzoate. Preferred
compounds of this type are those wherein:
a) Ac is R3-CO and R3 is a linear or branched alkyl group
containing from 6 to 20, preferably 6 to 12, more preferably 7
to 9 carbon atoms and wherein the longest linear alkyl chain
extending from and including the carbonyl carbon contains
from S to 18, preferably 5 to 10 carbon atoms, R3 optionally
being substituted (preferably alpha to the carbonyl moiety) by
C1, Br, OCH3 or OC2H5. Examples of this class of material
include sodium 3,5,5-trimethylhexanoyloxybenzene sulfonate,
sodium 3,5,5-trimethylhexanoyloxybenzoate, sodium 2-
ethylhexanoyl oxybenzenesulfonate, sodium nonanoyl
oxybenzene sulfonate and sodium octanoyl
oxybenezenesulfonate, the acyloxy group in each instance
preferably being p-substituted;
b) Ac has the formula R3(AO)mXA wherein R3 is a linear or
branched alkyl or alkylaryl group containing from 6 to 20,
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1$
preferably from 6 to 15 carbon atoms in the alkyl moiety, RS
being optionally substituted by C1, Br, OCH3, or OC2H5, AO
is oxyethylene or oxypropylene, m is from 0 to 100, X is O,
NRq. or CO-NRq., and A is CO, CO-CO, R6-CO, CO-R6-CO,
or CO-NRq.-R6-CO wherein R4 is C1-C4 alkyl and R6 is
alkylene, alkenylene, arylene or aikarylene containing from 1.
to 8 carbon atoms in the alkylene or alkenylene moiety.
Bleach activator compounds of this type include carbonic acid
derivatives of the formula R3(AO)mOCOL, succinic acid
derivatives of the formula R30CO(CH2)2COL, glycollic acid
derivatives of the formula R30CH2COL, hydroxypropionic
acid derivatives of the formula R3OCH2CH2COL, oxalic acid
derivatives of the formula R30COCOL, malefic and fumaric
acid derivatives of the formula R30COCH=CHCOL, acyl
aminocaproic acid derivatives of the formula
R3CONR1 (CH2)6COL, acyl glycine derivatives of the
formula R3CONR1CH2COL, and amino-6-oxocaproic acid
derivatives of the formula R3N(R1)CO(CH2)4COL. In the
above, m is preferably from 0 to 10, and R3 is preferably C6-
C 12, more preferably C6-C 10 alkyl when m is zero and C9-
C 15 when m is non-zero. The leaving group L is as defined
above.
5) Acyl-cyanurates, such as triacetyl- or tribenzoylcyanurates, as
disclosed in US patent specification No. 3,332,882.
6) Optionally substituted anhydrides of benzoic or phthalic acid, for
example, benzoic anhydride, m-chlorobenzoic anhydride and
phthalic anhydride.
Of all the above, preferred are organic peracid precursors of types 1 (c)
and 4(a).
Where present, the level of peroxyacid bleach precursor by weight of the
total composition is preferably from about 0.1 % to about 10 % , more
preferably from about 0.5 % to about 5 % and is generally added in the
form of a bleach precursor agglomerate.
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16
The bleach precursor aggllomerates preferred for use herein generally
comprise a binder or agglomerating agent in a level of from about 5 % to
about 40 % , more especially from about 10 % to about 30 % by weight
thereof. Suitable agglomerating agents include polyvinylpyrroIidone, poly
(oxyethylene) of molecular weight 20,000 to 500,000, polyethyleneglycols
of molecular weight of from about 1000 to about 50,000, Carbowax
having a molecular weight of from 4000 to 20,000, nonionic surfactants,
fatty acids, sodium carbox:ymethyl cellulose, gelatin, fatty alcohols,
phosphates and polyphosphates, clays, aluminosilicates and polymeric
polycarboxylates. Of the above, polyethyleneglycols are highly
preferred, especially those having molecular weight of from about 1,000
to about 30,000, preferably 2000 to about 10,000.
Preferred from the viewpoint of optimum dissolution and pH
characteristics are bleach precursor agglomerates which comprise from
about 10% to about 75%, preferably from about 20% to about 60% by
weight thereof of peroxyacid bleach precursor, from about 5 % to about
60% preferably from about 5% to about 50%, more preferably from
about 10% to about 40% of a (bi) carbonate/acid effervescent couple,
from about 0% to about 20% of a peroxoboroate, and from about 5% to
about 40%, preferably from about 10% to about 30% of an agglomerating
agent.
The final bleach precursor granules desirably have an average particle
size of from about 500 to about 1500, preferably from about 500 to about
1,000 um, this being valuable from the viewpoint of optimum dissolution
performance and aesthetic;>. The level of bleach precursor agglomerates,
moreover, is preferably from about 1 % to about 20%, more preferably
from about 5 % to about 1 ~i % by weight of composition.
The denture cleansing compositions of the invention can be in paste,
tablet, granular or powder form; although tablet-form compositions are
highly preferred herein. C.'ompositions in tablet form can be single or
multiple layered tablets.
Denture cleansing compositions of the invention can be supplemented by
other usual components of such formulations, especially surfactants,
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chelating agents, enzymes, flavorants, physiological cooling agents,
antimicrobial compounds, dyestuffs, sweeteners, tablet binders and fillers,
foam depressants such as dimethylpolysiloxanes, foam stabilizers such as
the fatty acid sugar esters, preservatives, lubricants such as talc,
magnesium stearate, finely divided amorphous pyrogenic silicas, etc. The
free moisture content of the final composition is desirably less than about
1 % and especially less than about 0.5 % .
Tablet binders and fillers suitable for use herein include
polyvinylpyrrolidone, poly (oxyethylene) of molecular weight 20,000 to
500,000, polyethyleneglycols of molecular weight of from about 1000 to
about 50,000, Carbowax having a molecular weight of from 4000 to
20,000, nonionic surfactants, fatty acids, sodium carboxymethyl cellulose,
gelatin, fatty alcohols, clays, polymeric polycarboxylates, sodium
carbonate, calcium carbonate, calcium hydroxide, magnesium oxide,
magnesium hydroxide carbonate, sodium sulfate, proteins, cellulose
ethers, cellulose esters, polyvinyl alcohol, alginic acid esters, vegetable
fatty materials of a pseudocolloidal character. Of the above,
polyethyleneglycols are highly preferred, especially those having
molecular weight of from about 1,000 to about 30,000, preferably from
about 12,000 to about 30,000.
The surface active agent used in the denture cleansing compositions of the
invention can .be selected from the many available that are compatible
with the other ingredients of the denture cleanser, both in the dry state
and in solution. Such materials are believed to improve the effectiveness
of the other ingredients of the composition by aiding their penetration into
the interdental surfaces. Also, these materials aid in the removal of food
debris attached to the teeth. Between 0.1 and S percent by weight of the
dry composition of a dry powder or granular anionic surface active agent,
such as sodium lauryl sulfate, sodium N-lauroylsarcosinate, sodium lauryl
sulfoacetate or dioctyl sodium sulfosuccinate or ricinoleyl sodium
sulfosuccinate, may, for example, be included in the composition and
preferably the surface active agent comprises between 0.5 and 4 percent
of the composition.
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Suitable cationic, non-ionic and ampholytic surface active agents include,
for example, quaternary ammonium compounds such as
cetyltrimethylammonium bromide, condensation products of alkylene
oxides such as ethylene or propylene oxide with fatty alcohols, phenols,
fatty amines or fatty acid alkanolamides, the fatty acid alkanolamides
themselves, esters of long-chained (Cg-C22) fatty acids with polyalcohols
or sugars, for example glycerylmonostearate or saccharosemonolaurate or
sorbitolpolyoxyethylenemono-or di-stearate, betaines, sulphobetaines or
long-chain alkylaminocarboxylic acids.
Chelating agents beneficially aid cleaning and bleach stability by keeping
metal ions, such as calcium, magnesium, and heavy metal rations in
solution. Examples of suitable chelating agents include sodium
tripolyphosphate, sodium acid pyrophosphate, tetrasodium pyrophosphate,
aminopolycarboxylates such as nitrilotriacetic acid and ethylenediamine
tetracetic acid and salts thereof, and polyphosphonates and
aminopolyphosphonates such as hydroxyethanediphosphonic acid,
ethylenediamine tetramethylenephosphonic acid,
diethylenetriaminepentamethylenephosphonic acid and salts thereof. The
chelating agent selected is not critical except that it must be compatible
with the other ingredients of the denture cleanser when in the dry state
and in aqueous solution. Advantageously, the chelating agent comprises
between 0.1 and 60 percent by weight of the composition and preferably
between 0.5 and 30 percent. Phosphonic acid chelating agents, however,
preferably comprise from about 0.1 to about 1 percent, preferably from
about 0.1 % to about 0.5 % by weight of composition.
Enzymes suitable for use herein are exemplified by proteases, alkalises,
amylases, lipases, dextranases, mutanases, glucanases etc.
The following Examples further describe and demonstrate the preferred
embodiments within the scope of the present invention.
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EXAMPLES I TO V
The following are representative denture
cleansing tablets according to
the invention. The percentages are by weight
of the total tablet. The
tablets are made by compressing a mixture
of the granulated components
in a punch and dye tabletting press at a of
pressure about
105
kPa.
I ~ ~ ~ v
~
Malic Acid 10 15 - 14
12
Citric Acid - 10 - 15 -
Sodium Carbonate 10 8 10 6 10
Sulphamic Acid S - - 3 3
PECK 20,000 - 3 7 8 5
PVP 40,000 6 3 - - -
Sodium Bicarbonate 22 25.2 25 13.9 2~3
Sodiurri-Per~oTate Monohydrate 15 12 16 30 15
Potassium Monopersulphate 15 18 13 - 14
Pyrogenic Silica - 0.3 0.1 0.1 -
Talc 2 _ _ _ _
EDTA _ _ 1 _ 3
EDTMP1 1 - - 1 -
Flavors 2 1 2 1 2
Abil EM904 1 1.5 5 10 1
Bleach Precursor Agglomerate 9 8 10 12 10
Bleach Precursor Agglomerate ~ ~ ~ ~V V
TAED2 2 - 4 5 2.5
TM~IOS3 2 3 - - -
Sulphamic Acid 2 2 2 2 3.5
Sodium Bicarbonate 0.5 0.2 0.2 0.5 2
PECK 6000 2.5 2 2.4 2.5 1.5
Dye - 0.8 1.4 2 0.5
1. Ethylenediaminetetramethylenephosphonic acid
' 2. Tetraacetylethylene diamine
3. Sodium 3,5,5-trimethylhexanoyloxybenzen e
sulfonate
4. Cetyl dimethicone copolyol
S Peppermint-based flavor
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In Examples I to V above, the overall tablet weight is 3 g; diameter 25 ,
mm.
The denture cleansing tablets of Examples I to V display improved
antiplaque,cleansing and anti-bacterial activity together with excellent
cohesion and other physical and in-use performance characteristics.
EXAMPLES VI TO VIII
The following are representative toothpaste/denture cleansing pastes
according to the invention. The percentages are by weight of total
composition.
VI VII VIII
Calcium Carbonate 20 25 15
Glycerine 10 12 8
Sodium CMC 3.5 3 4
Titanium Dioxide 0.7 0.5 0.6
Methyl/Propyl Parabens 0.1 0.1 0.1
Sodium Saccharin 0.3 0.4 0.2
Flavors 1 1 2
Abil EM904 1 1.5 0.5
Trichlosan - 0.5 -
Water To 100
The toothpastes/denture cleansing pastes of Examples VI to VIII display
improved antiplaque, flavor impact and anti-bacterial activity together
with excellent cleansing characteristics.
