CA1206100A - Toothpastes with reduced salinity - Google Patents

Abstract

TOOTHPASTES WITH REDUCED SALINITY Abstract of the Invention Toothpaste compositions having monoammonium glycyrrhizinate, strontium disodium ethylenediamine tetraacetate and sodium fluoride or sodium monofluoro-phosphate.

Description

~-1192 TOOTHPASTES WITH REDUCED SALINITY
.... _ Field of the Invention .. . ... . ... .. . .
This invention relates ~o toothpaste compositions containing strontium disodium ethylenediamine tetra-acetate and, as the source of available fluoride, either sodium fluoride or sodium monofluorophosphate or both, to which is added a minor amount of monoammonium glycyrrhiz-inate to substantially reduce or suppress salinity.
Background of the Invention It has heretofore been known to improve oral hygiene by applying to teeth certain non-fluoride containin~
dentifrice compositions containing a particular strontium chelate, namely strontium disodium ethylenediamine tetra-acetate, for example, as disclosed in U~S. Pat. Nos.
3,699,221 and 3,988,434. However, a problem associated with such dentifrices when strontium chloride is used as a reactant to form said strontium disodium ethylenedia-mine tetraacetate in situ is an unacceptable sal~tiness or metallic tastiness in the product. Amelioration of this problem by the ~addition of flavoring and/or sweetening agents has not always been achieved. Recently, in U.S.
Pat. No~ 4,224,310, a particular method of forming said strontium disodium ethylenediamine tetraacetate in situ is stated to avoid the salty or metallic taste problem in non-fluoride containing dentifrices.
~ owever, even with toothpastes containing strontium disodium ethylenediamine tetraacetate which have been ormulated in such a~ way as to~be~ relatively "salt-free"

or "clean" tastewise,`upon subse~uent inclusion of ei~ther .~ ~
sodium fluoride or sodiu\m~monoflu~orophosphate as a source :

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of available anti-caries fluoride, the resulting product inherently acquires an unacceptable salty taste due to the presence of such fluoride salt~
BRIEF DESCRIPTION OF THE INVENTION
It has now been discovered that a water-containing toothpaste composition which contains strontium disodium ethylenediamine tetraacetate (Sr-diNa-EDTA) plus sodium fluoride and/or sodium monofluorophosphate can be formu-lated such that the problem of saltiness in the resulting product ~s substantially ameliorated and a hiqhly accept-able pleasant tasting product lS obtained. This is accomplished by incorporation of a minor amount of mono-ammonium glycyrrhizinate (also known as monoammonium `, glycyrrhizate), a iicorice root derivative, into the `,~ toothpaste composition.
DETAILED DESCRIPTION OF THE INVENTION
A wide variety of dentifrice compositions containlng ; sodium fluoride and/or sodium monofluorophosphate to prevent tooth decay have been known for some time~(usual ~ fluorine content: 200 to~l000 ppm).- Similar~y, the use of;strontlum disodium ethylenediamine ~tetraacetate~in dentifrices is also known to~ he beneri~ial for promoting 'good dental ~hyglene and in~treatlng ~v~arlous;dental~dis-` ~ i orders (see U.S. Pat. Nos. 3,699,221'and 3,988,~34).
The combination of~sodium~fluoride~and~or~sodlum monofluorophosphate~with Sr-dlNa-EDTA`in~the same~tooth-psst~, how~ever, presents~a ~tasce~ problem~to the user due to saltiness. The immediate and lingering salinity is obtrusive and~ infl~uencss unfavorably the~overall flavor effect of the toothpas~e~, even with conventional sweeten-~Z~

ers and flavoring agents added. This serious drawback, from the viewpoint of consumer acceptance, is substan-tially overcome, in accordance with this invention, by the incorporation of at least 0.001 percent by weight of monoammonium glycyrrhizinate into the fluoride~Sr-diNa-EDTA containing toothpaste~ The monoammonium glycyrrhizinate is soluble in glycerin and is readily incorporated into the toothpaste compositions by standard formulating methodology.
The preferred amount of monoammonium glycyrrhizinate is from about 0.005 to about 0.025 percent by weight, and most preferably from about 0.005 to about 0.0125 percent by weight, based on the total weight of the toothpaste, although much higher amounts, for example~ up to about 0.5 percsnt by weight, may be effectively employed. At high concentrations, however, the characteristic licorice rlavor of the glycyrrhi2inate salt may become a taste factor to be considered in addition to the reduction o~
taste-saltiness.

In addition to the three essential components of the sub~ect toothpastes, namely ti) strontium disodium ethylenediamine tetraacetate, (ii~ sodium fluoride, sodium monofluorophosphate or mixtures thereof, and (iii) monoammonium glycyrrhizinatel the other components of the toothpas e composition include all conventional ingredients such as polishing agents or abrasives, thickening agents, whitening agents, wetting agents or .
surfactants, flavoring agents, sweeteners, coloring agents and the llke. `W~lth regard to the selection of such other components, however, it should be understoo~

~-3-. ., Y-llg2 that, as taught in U.S. Pat. No. 3,699,221, toothpastes containin~ Sr-diNa-EDTA chelate are characterized by the substantial absence of substances which can repiace strontium from the chelate. Accordinyly, the toothpastes of this invention should not include those wherein any of the water-insoluble calcium, magnesium or aluminum com-pounds generally used as abrasives in dentifrices are present. In contrast, those dentifrices wherein an abra-sive inert to the Sr-diNA-EDTA chelate are recommended, preferably silicon dioxide.
In view of the foregoing examples hereinafter, the instant invention provides a vastly improved toothpaste containing Sr-diNA-EDTA and sodium fluoride or sodium monofluophosphate or both, the improvement being due to the incorporation of a minor amount of monoammonium glycyrrhizinate. By means of this ammoniated licorice root derivative, untoward flavor effects due to excessive salinity arising from said fluoride components are markedly reduced or suppressed. In its broadest aspect, the subject invention thus provides a water-containlng toothpaste comprisin~ an effective amount of strontium disodium ethylenediamine tetraacetate for alleviating sensitivity of hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride, sodium monofluorophos-phate or mixtures thereof and at least 0 001 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinate.
The following Examples are designed to illustrate the practice of the p`re\sent invention bat not to limit the scope of the inventi~on.
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Example l Toothpaste Ingredients % w/w Sr-diNa-EDTA 5.0 Sodium monofluorophosphate 0.76 Insoluhle sodium metaphosphate 32.0 Glycerin 13.0 : Sorbitol (70% solution) 10.0 Sodium ricinoleate powder 1.2 Sodium lauryl sulfate 2.0 Sodium carboxymethylcellulose ` 1.5 Silicon dioxide 1.2 Xanthan gum 0.7 Sodium saccharin 0.25 Methyl paraben 0.06 Propyl paraben 0.02 Color (FD&C Blue #1) 0.001 Flavor tmint oil mix) 1.35 Distilled water 30.959 100 . 000 This fluoride/Sr-diNa-EDTA toothpaste imparts a distinctly salty initial taste, based on subjective evaluations, which lingers for about 20-30 minutes although the minty flavor is intense and pleasing. In contrast, the same formulation absent the sodium mono-fluorophosphate (q.s. lO0 distilled water) is neither salty to the taste upon immediate usage nor thereafter.
Example 2 % w/w Toothpaste Inqredients A B C
-- _ _ Example l formulation 99.95 99.9 99.875 Monoammonium gIycyrrhizinate 0.05 0.1 0.125 (10% solution) ~ loO.0 I~

Saltiness in each of the above toothpastes, contain-ing from 0.005 to 0.0125~ w/w of monoammonium glycyrrhi-zinate, was absent initially and in after-taste. In each instance the flavor is rather intense but very good with the mint character, free of any licorice taste, being \

even richer than in Exa~ple l.

~ _5_ Example 3 Substitution of sodium fluoride for the sodium monofluorophosphate of Example 1 in amounts equivalent to provide 200, 600 and 1000 ppm of available ~luoride (q.s.
100 distilled water~ similarly produces toothpastes with appreciable lingering saltiness. Incorporation of 0.001, 0.005 and 0.025 w/w, respectively, of monoammonium glycyrrhizinate to such toothpastes substantially elimi-nates the saline tastiness without any licori~e taste.

Example 4 Toothpaste Inqredients A B

Sr-diNa-EDTA 10.0 5 Sodium monofluorophosphate 0.76 0.76 Monoammonium glycyrrhizinate 0.007 0.007 Silica, hydrated 28.50 28.50 Sorbitol t70~ solution) 27.20 30.20 Glycerin 7.24 9.24 Sodium lauryl sulfate 2.00 2.00 Sodium ricinoleate (35% solution)1.43 1.43 Sodium saccharin 0.45 0.45 Silica, colloidal 0.55 0.55 Xanthan gum Q.40 0.40 Methylparaben 0.06 0.06 Propylparaben 0.02 0.02 ~lavor (mint oil mix) 1.25 1.25 Color (FD~C Blue #l) 0.001 0.001 Distilled water 20.13225.132 The formulations of this Example 4~represent further toothpastes of this invention with subs-~antially reduced saline tastiness.

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Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating sensitivity of hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride, sodium monofluorophosphate or mixtures thereof and at least 0.001 percent by weight, based on the total weight of the tooth-paste, of monoammonium glycyrrhizinate, wherein said tooth-paste is characterized by the substantial absence of sub-stances which can replace strontium from said strontium di-sodium ethylenediamine tetraacetate.

2. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium monofluorophosphate and from about 0.005 to about 0.5 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhiz-inate, wherein said toothpaste is characterized by the sub-stantial absence of substances which can replace strontium from said strontium disodium ethylenediamine tetraacetate.

3. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium monofluorophosphate and from about 0.005 to about 0.025 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhiz-inate, wherein said toothpaste is characterized by the sub-stantial absence of substances which can replace strontium from said strontium disodium ethylenediamine tetraacetate.

4. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium monofluorophosphate and from about 0.005 to about 0.0125 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhiz-inate, wherein said toothpaste is characterized by the sub-stantial absence of substances which can replace strontium from said strontium disodium ethylenediamine tetraacetate.

5. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium monofluorophosphate and about 0.007 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinatef wherein said toothpaste is characterized by the substantial absence of substances which can replace strontium from said strontium disodium ethylenediamine tetraacetate.

6. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviatlng hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride and from about 0.005 to about 0.5 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinate, wherein said toothpaste is characterized by the substantial absence of substances which can replace strontium from said stron-tium disodium ethylenediamine tetraacetate.

7. A water-containing tnothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride and from 0.005 to about 00025 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinate, wherein said toothpaste is characterized by the substantial absence of substances which can replace strontium from said strontium disodium ethylenediamine tetraacetate.

8. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride and from about 0.005 to about 0.0125 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinate, wherein said toothpaste is characterized by the substantial absence of substances which can replace strontium from said stron-tium disodium ethylenediamine tetraacetate.

9. A water-containing toothpaste comprising an effec-tive amount of strontium disodium ethylenediamine tetraace-tate for alleviating hyper-sensitive dentin, an effective anti-caries amount of sodium fluoride and about 0.007 percent by weight, based on the total weight of the toothpaste, of monoammonium glycyrrhizinate, wherein said toothpaste is characterized by the substantial absence of substances which can replace strontium from said.strontium disodium ethylene-diamine tetraacetate.