Oral compositions for treating plaque and gingivitis

Disclosed are oral compositions which provide a pleasant feel to the mouth and have improved stability.

TECHNICAL FIELD 
The present invention relates to oral compositions which provide a pleasant 
feel to the mouth and exhibit improved stability. Oral care products 
containing a bicarbonate salt have achieved a significant level in certain 
markets of the world such as the U.S. The users of bicarbonate products 
indicate that their mouths feel refreshed after using such a product. 
References disclosing bicarbonate containing compositions include: U.S. 
Pat. Nos. 3,935,305; 3,927,321; 3,937,804; 3,943,240; 4,623,536; 
4,721,614; 4,547,362; and 4,663,153, all incorporated herein by reference. 
Although bicarbonate products have been disclosed, there is a continuing 
need to develop improved products. The present inventors have found that 
the inclusion of sodium carbonate as a buffer improves the stability of 
the products. 
It is therefore an object of the present invention to provide improved 
products containing a bicarbonate salt. 
It is a further object of the present invention to provide more effective 
products containing sodium bicarbonate. 
It is still a further object to provide methods for refreshing the oral 
cavity. 
These and other objects will become readily apparent from the disclosure 
which follows. 
All percentages and ratios used herein are by weight unless otherwise 
specified. Also, all measurements referred to herein are made at 
25.degree. C. in the composition unless otherwise specified. 
SUMMARY OF THE INVENTION 
The present invention, in certain aspects, embraces compositions containing 
a bicarbonate salt and sodium carbonate. 
The present invention also encompasses a method for refreshing the oral 
cavity using the specified compositions. 
By "oral compositions" as used herein means a product which in the ordinary 
course of usage is not intentionally swallowed for purposes of systemic 
administration of particular therapeutic agents, but is rather retained in 
the oral cavity for a time sufficient to contact substantially all of the 
dental surfaces and/or oral tissues for purposes of oral activity. 
By "safe and effective amount" as used herein means sufficient amount of 
material to provide the desired benefit while being safe to the hard and 
soft tissues of the oral cavity. 
By the term "comprising", as used herein, is meant that various additional 
components can be conjointly employed in the compositions of this 
invention as long as the listed materials perform their intended 
functions. 
By the term "carrier", as used herein, is meant a suitable vehicle which is 
pharmaceutically acceptable and can be used to apply the present 
compositions in the oral cavity.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention in a certain aspect involves forming an aqueous 
composition containing a bicarbonate salt and sodium carbonate. The 
essential and optional components of the compositions are set forth in 
detail below. 
Bicarbonate Salt 
An essential component of the present invention is a bicarbonate salt. The 
preferred bicarbonate salt is sodium bicarbonate which is a staple item of 
commerce. The bicarbonate is used at a level of from about 5% to about 
70%, preferably from about 10% to about 40%. 
Sodium Carbonate 
A second essential component of the present invention is sodium carbonate. 
This material serves as a buffer and helps to stabilize the compositions. 
This material is used at a level of from about 0.25% to about 2%, 
preferably from about 0.5% to about 1.5%. 
Water 
Water is also present in the compositions of this invention. Water employed 
in the preparation of commercially suitable compositions should preferably 
be deionized and free of organic impurities. Water generally comprises 
from about 10% to 50%, preferably from about 20% to 40%, by weight of the 
toothpaste compositions herein while mouthwashes contain from about 40% to 
about 95%, preferably 50% to 80%. These amounts of water include the free 
water which is added plus that which is introduced with other materials as 
with sorbitol. 
Optional Components 
The compositions of the present invention may contain an addition to the 
above-listed components many others which will be somewhat dependent on 
the type of composition (mouthwashes, toothpastes, topical gels, 
prophylaxis pastes and the like). Toothpastes and mouthwashes are the 
preferred systems with toothpastes being the most preferred. 
Toothpastes contain as a major component an abrasive. The abrasive 
polishing material contemplated for use in the present invention can be 
any material which does not excessively abrade dentin. These include, for 
example, silicas including gels and precipitates, calcium carbonate, 
dicalcium orthophosphate dihydrate, calcium pyrophosphate, tricalcium 
phosphate, calcium polymetaphosphate, insoluble sodium polymetaphosphate, 
hydrated alumina, and resinous abrasive materials such as particulate 
condensation products of urea and formaldehyde, and others such as 
disclosed by Cooley et al. in U.S. Pat. No. 3,070,510, Dec. 25, 1962, 
incorporated herein by reference. Mixtures of abrasives may also be used. 
Silica dental abrasives, of various types, can provide the unique benefits 
of exceptional dental cleaning and polishing performance without unduly 
abrading tooth enamel or dentin. Silica abrasive materials are also 
exceptionally compatible with sources of soluble fluoride and other ion 
sources. For these reasons they are preferred for use herein. 
The silica abrasive polishing materials useful herein, as well as the other 
abrasives, generally have an average particle size ranging between about 
0.1 and 30 microns, preferably 5 and 15 microns. The silica abrasive can 
be precipitated silica or silica gels such as the silica xerogels 
described in Pader et al., U.S. Pat. No. 3,538,230, issued Mar. 2, 1970 
and DiGiulio, U.S. Pat. No. 3,862,307, Jun. 21, 1975, both incorporated 
herein by reference. Preferred are the silica xerogels marketed under the 
tradename "Syloid" by the W. R. Grace & Company, Davison Chemical 
Division. Preferred precipitated silica materials include those marketed 
by the J. M. Huber Corporation under the tradename "Zeodent" particularly 
the silica carrying the designation "Zeodent 110". These silica abrasives 
are described in U.S. Pat. No. 4,340,583, Jul. 29, 1982, incorporated 
herein by reference. 
The abrasive in the dentifrice compositions described herein is present at 
a level of from about 6% to about 70%, preferably from about 15% to about 
30% when the dentifrice is a toothpaste. 
Flavoring agents can also be added to the dentifrice and other compositions 
of the present invention. Suitable flavoring agents include oil of 
wintergreen, oil of peppermint, oil of spearmint, oil of sassafras, and 
oil of clove. Sweetening agents are also useful and include aspartame, 
acesulfame, saccharin, dextrose, levulose and sodium cylclamate. Flavoring 
and sweetening agents are generally used in the compositions herein at 
levels of from about 0.005% to about 2% by weight. 
In preparing toothpastes, it is necessary to add some thickening material 
to provide a desirable consistency. Preferred thickening agents are 
carboxyvinyl polymers, carrageenan, hydroxy-ethyl cellulose and water 
soluble salts of cellulose ethers such as sodium carboxymethyl cellulose 
and sodium carboxymethyl hydroxyethyl cellulose. Natural gums such as gum 
karaya, gum arabic, and gum tragacanth and polysaccharide gums such as 
xanthan gum 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. Thickening agents in a combined amount from 0.5% 
to 5.0% by weight of the total composition may be used. 
Surfactants are also useful in the compositions of this invention and 
include many different types of materials. Suitable surfactants include 
any which are reasonably stable and function over a wide pH range. 
Included are non-soap anionic, nonionic, cationic, zwitterionic and 
amphoteric organic synthetic surfactants. Many of these are disclosed by 
Gieseke et al. in U.S. Pat. No. 4,051,234, Sep. 27, 1988 incorporated 
herein in total by reference. 
It is also desirable to include a humectant in a toothpaste to keep it from 
hardening. Suitable humectants include glycerin, sorbitol, and other 
edible polyhydric alcohols at a level of from about 10% to about 70%. 
Another preferred embodiment of the present invention is a mouthwash 
composition. Mouthwashes generally comprise from about 20:1 to about 2:1 
of a water/ethyl alcohol solution and preferably other ingredients such as 
flavor, sweeteners, humectants and sudsing agents such as those described 
above. The humectants, such as glycerin and sorbitol give a moist feel to 
the mouth. Generally, on a weight basis the mouthwashes of the invention 
comprise 5% to 60% (preferably 10% to 25%) ethyl alcohol, 0% to 20% 
(preferably 5% to 20%) of a humectant(s), 0% to 2% (preferably 0.01% to 
0.15%) emulsifying agent, 0% to 0.5% (preferably 0.005% to 0 06%) 
sweetening agent such as saccharin, 0% to 0.3% (preferably from 0.03% to 
0.3%) flavoring agent, and the balance water. 
The pH of the present compositions and/or its pH in the mouth can be any pH 
which is safe for the mouth's hard and soft tissues. Such pH's are 
generally from about 5 to about 10, preferably from about 8.5 to about 
9.5. This latter pH range is the range in which the neat product pH 
preferably falls. 
Another optional component of the compositions of this invention is an 
anionic polycarboxylate. The anionic polymeric polycarboxylates optionally 
but preferably employed herein are well known, being employed in the form 
of their free acids or partially or preferably fully neutralized water 
soluble alkali metal (e.g. preferably sodium) or ammonium salts. Preferred 
are 1:4 to 4:1 copolymers of maleic anhydride or acid with another 
polymerizable ethylenically unsaturated monomer, preferably methyl vinyl 
ether methoxyethylene) having a molecular weight (M.W.) of about 30,000 to 
about 1,000,000. These copolymers are available for example as Gantrez AN 
139 (M.W. 500,000), AN 119 (M.W. 250,000) and preferably S-97 
Pharmaceutical Grade (M.W. 70,000), of GAF Corporation. 
Other operative polymeric polycarboxylates include those such as the 1:1 
copolymers of maleic anhydride with ethyl acrylate, hydroxyethyl 
methacrylate, N-vinyl-2-pyrollidone, or ethylene, the latter being 
available for example as Monsanto EMA No. 1103, M.W. 10,000 and EMA Grade 
61, and 1:1 copolymers of acrylic acid with methyl or hydroxyethyl 
methacrylate, methyl or ethyl acrylate, isobutyl vinyl ether or 
N-vinyl-2-pyrrolidone. 
Additional operative polymeric polycarboxylates disclosed in above referred 
to U.S. Pat. Nos. 4,138,477 and 4,183,914, incorporated herein by 
reference, include copolymers of maleic anhydride with styrene, 
isobutylene or ethyl vinyl ether, polyacrylic, polyitaconic and polymaleic 
acids, and sulfoacrylic oligomers of M.W. as low as 1,000 available as 
Uniroyal ND-2. 
Suitable generally are polymerized olefinically or ethylenically 
unsaturated carboxylic acids containing an activated carbon-to-carbon 
olefinic double bond and at least one carboxyl group, that is, an acid 
containing an olefinic double bond which readily functions in 
polymerization because of its presence in the monomer molecule either in 
the alpha-beta position with respect to a carboxyl group or as part of a 
terminal methylene grouping. Illustrative of such acids are acrylic, 
methacrylic, ethacrylic, alpha-chloroacrylic, crotonic, beta-acryloxy 
propionic, sorbic, alpha-chlorsorbic, cinnamic, beta-styrylacrylic, 
muconic, itaconic, citraconic, mesaconic, glutaconic, aconitic, 
alpha-phenylacrylic, 2-benzyl acrylic, 2-cyclohexylacrylic, angelic, 
umbellic, fumaric, maleic acids and anhydrides. Other different olefinic 
monomers copolymerizable with such carboxylic toohomers include 
vinylacetate, vinyl chloride, dimethyl maleate and the like. Copolymers 
contain sufficient carboxylic salt groups for water-solubility. 
Also useful herein are carboxyvinyl polymers, referred to herein earlier as 
suitable binders, disclosed as toothpaste components in U.S. Pat. Nos. 
3,980,767 issued Sep. 14, 1976 to Choun et al., 3,935,306 issued Jan. 27, 
1976 to Roberts et al., 3,919,409 issued Nov. 11, 1975 to Peria et al., 
3,911,904 issued Oct. 7, 1975 to Harrison, and 3,711,604 issued Jan. 16, 
1973 to Colodney et al. They are commercially available for example under 
the trademarks Carbopol 934, 940, 941 and 956 of B.F. Goodrich, these 
products consisting essentially of a colloidally water-soluble polymer of 
polyacrylic acid crosslinked with from about 0.75% to about 2.0% of 
polyallyl sucrose or polyallyl pentaerythritol as crosslinking agent. 
The synthetic anionic polymeric polycarboxylate component is mainly a 
hydrocarbon with optional halogen and O-containing substituents and 
linkages as present in for example ester, ether and OH groups, and when 
present is generally employed in the instant compositions in approximate 
weight amounts of 0.05 to 3%, preferably 0.05 to 2%, more preferably 0.1 
to 2%. 
Another optional component is a fluoride ion source. The sources of 
fluoride ions, or fluoride-providing compounds, useful according to this 
invention are well known in the art as anticaries agents and 
pyrophosphatase inhibitors and also act as such agents in the practice of 
this invention. These compounds may be slightly soluble in water or may be 
fully water-soluble. They are characterized by their ability to release 
fluoride ions in water and by freedom from undesired reaction with other 
compounds of the oral preparation. Among these materials are inorganic 
fluoride salts, such as soluble alkali metal, alkaline earth metal salts, 
for example, sodium fluoride, barium fluoride, sodium fluorsilicate, 
ammonium fluorosilicate, sodium fluorozirconate, sodium 
monofluorophosphate, aluminum mono- and di-fluorophosphate, and 
fluorinated sodium calcium pyrophosphate. Alkali metal and tin fluorides, 
such as sodium and stannous fluorides, sodium monofluorophosphate (MFP) 
and mixtures thereof, are preferred. 
The amount of fluoride-providing compound is dependent to some extent upon 
the type of compound, its solubility, and the type of oral preparation, 
but it must be a nontoxic amount, generally about 0.005 to about 3.0% in 
the preparation. In a dentifrice preparation, e.g. dental gel, toothpaste 
(including cream), an amount of such compound which releases up to about 
5,000 ppm of F.sup.- ion by weight of the preparation is considered 
satisfactory. Any suitable minimum amount of such compound may be used, 
but it is preferable to employ sufficient compound to release about 300 to 
2,000 ppm, more preferably about 800 to about 1,500 ppm of fluoride ion. 
Typically, in the cases of alkali metal fluorides and stannous fluoride, 
this component is present in an amount up to about 2% by weight, based on 
the weight of the preparation, and preferably in the range of about 0.05% 
to 1%. In the case of sodium monofluorophosphate, the compound may be 
present in an amount of about 0.1-3%, more typically about 0.76%. 
Other anticalculus agents are metal ions such as zinc disclosed in U.S. 
Pat. No. 4,022,880, May 10, 1977 to Vinson incorporated herein by 
reference. Still others are polymers such as those described in U.S. Pat. 
No. 4,661,341, Apr. 28, 1987 to Benedict and U.S. Pat. No. 3,429,963, Feb. 
25, 1969 to Shedlovsky, both of which are incorporated herein by 
reference. Such metals are used in an amount of from about 0.01% to about 
5%, preferably about 0.1% to about 2%, while such polymers are used in 
amounts of from about 0.1% to about 10%, preferably from about 0.5% to 
about 5%. 
Still other anticalculus agents are pyrophosphate salts such as di- and 
tetra-alkali metal pyrophosphates and others disclosed in U.S. Pat. No. 
4,999,184, Mar. 12, 1991, to Parran et al., incorporated herein by 
reference. 
Other optional components for use in the present compositions are 
non-cationic water insoluble agents such as triclosan. Such materials are 
disclosed in U.S. Pat. No. 4,022,899 to Vinson et al., incorporated herein 
by reference. 
Method of Manufacture 
The compositions of the present invention can be prepared using the method 
described following the Examples. 
Composition Use 
The present invention in its method aspect involves applying to the oral 
cavity safe and effective amounts of the composition. Generally, amounts 
of at least about 1 gram of the composition is effective. 
Given below are examples representative of the present invention. They 
describe and demonstrate preferred embodiments within the invention's 
scope. 
The examples are given solely for the purpose of illustration and are not 
to be construed as limitations of this invention. Many variations thereof 
are possible without departing from the invention's spirit and scope. 
EXAMPLE I 
Given below is a dentifrice representative of the present invention: 
______________________________________ 
Paste Gel 
Material Wt. % Wt. % 
______________________________________ 
Sorbitol 40.040 40.240 
Bicarbonate 20.000 20.000 
Silica 15.000 15.000 
Water 10.000 10.000 
Glycerin 7.000 7.000 
SASS 4.000 4.000 
Carbonate 1.000 1.000 
Flavor 1.000 1.000 
CMC 0.850 0.850 
Saccharin 0.517 0.517 
Ti02 0.350 0.000 
Fluoride 0.243 0.243 
Blue Dye 0.000 0.150 
Totel 100.000 100.000 
______________________________________ 
EXAMPLE II 
Given below is another dentifrice representative of the present invention. 
______________________________________ 
Paste 
Material Wt. % 
______________________________________ 
Water 20.334 
Glycerin 19.000 
Sodium bicarbonate 17.000 
Silica 16.000 
Sorbitol (70%) 8.951 
Tetrasodium pyrophosphate 
7.644 
Sodium lauryl sulfate (27.9%) 
4.000 
PEG-6 3.000 
Sodium carbonate 1.250 
Flavor 1.000 
Carboxymethylcellulose 
0.700 
Sodium saccharin 0.528 
Titanium dioxide 0.350 
FD&C Blue No. 1 -- 
Sodium fluoride 0.243 
100.000 
______________________________________