A dentifrice suitable for removing calculus and preventing the build-up of calculus on tooth enamel which contains strontium edatate and a ricinoleate, which have been found to provide a synergistic effect in both removal of calculus and prevention of its build-up.

Patent
   RE30675
Priority
Dec 26 1979
Filed
Dec 26 1979
Issued
Jul 14 1981
Expiry
Dec 26 1999
Assg.orig
Entity
unknown
4
9
EXPIRED
1. A water-containing dentifrice consisting essentially of strontium edatate in an amount sufficient to provide from about 2.5 wt. % to about 25 wt. % of strontium ion edatate and from about 0.1 wt. % to about 10 wt. % of a ricinoleate compound said dentifrice being free from strontium edatate-sequestering Ca, Mg, Al, Sn metal.
3. A method for controlling calculus which comprises applying to the teeth a water-containing dentifrice consisting essentially of strontium edatate in an amount sufficient to provide from about 2.5 wt. % to about 25 wt. % of strontium ion edatate and about 0.1 wt. % to about 10 wt. % of a ricinoleate said dentifrice being free from strontium edatate-sequestering Ca, Mg, Al, Sn metal.
2. A dentrifrice according to claim 1 in which the ricinoleate is sodium ricinoleate.

This invention relates to dental hygiene and, in particular, provides a dentifrice having valuable properties in the removal and prevention of calculus.

It is known that water-containing dentifrices which include strontium and sequestering agents such as EDTA are effective in the treatment of hyper-sensitive dentin, gingivitis and periodontitis, apparently through the mechanism of substituting strontium for calcium in the calcium hydroxy apatite of the tooth (Schole et al. U.S. Pat. No. 3,699,221 and 3,988,434).

It is also known that ricinoleic acid and various esters and salts which are surface active agents exhibit a higher contact angle with tooth enamel than other surface active agents.

In accordance with the present invention, a water-containing dentifrice including both strontium edatate and a ricinoleate provide a synergistic action in the removal of calculus from teeth and also in the prevention of its build-up.

It is understood by strontium edatate reference is made to the strontium chelate of EDTA and preferably the disodium strontium salt of ethylene diamine tetraacetic acid. When strontium edatate is present in an aqueous composition, the strontium is available in ionic form. Generally, the amount of strontium present in the dentrifrice can be up to about 25 wt. % of strontium ion edatate in the toothpaste, but much smaller amounts, as low as 2.5 wt. %, are effective. The strontium edatate can be formed in advance or can be prepared in the dentifrice as a mixture of a water soluble salt of EDTA together with a pharmacalogically innocuous water-soluble strontium salt, preferably in equivalents such that the pH will remain neutral.

The ricinoleate can be any of the alkali metal salts of ricinoleic acid (d-12-hydroxy-cis-9-octadecenoic acid), but preferably is the sodium salt. The amount of the ricinoleate is not particularly critical and can be as high as 10 wt. %. Amounts as low as 0.1 wt. % are, however, also effective.

The preferred proportions in the water-containing dentifrice are 10% by weight of strontium, calculated as disodium strontium ethylene diamine tetra acetate and 0.5% by weight of ricinoleate, calculated as the sodium salt.

The dentifrice product used should not include any calcium or other metal, salt or compound, from which any such metal would be sequestered by, and form the corresponding calcium or other metal chelate with the EDTA salt or chelate residue of the strontium chelate in the product.

In other words, the dentrifice products of the invention should not include any of the water-insoluble calcium, magnesium or aluminum compounds ordinarily incorporated as adjuvant bulk excipients in dentrifices, for example, as the abrasive ingredient, such as calcium carbonate, calcium pyrophosphate, magnesium oxide, aluminum oxide or hydroxide, and the like. So also, tin compounds, e.g., stannous fluoride and stannous chlorofluoride, likewise should be excluded.

In place of the foregoing water-insoluble bulk excipients for abrasive and other purposes, water-insoluble barium and strontium salts, for example, barium sulphate, barium carbonate, strontium carbonate and strontium phosphate can be used. The ricinoleate, being a surface-active wetting agent which is compatible with strontium, generally will obviate the need of other wetting agents.

The following are examples of several dentrifices in accordance with the invention.

______________________________________
Disodium Salt
of Ethylenediamine Tetraacetic Acid
20 grams
Strontium Chloride (6H2 0)
20 grams
Strontium Carbonate 25 grams
Sodium Ricinoleate 0.5 grams
Algin 1 gram
Essential Oils (for flavoring)
1 gram
Propylene Glycol 25 grams
Alcohol 0.9 gram
Water quantity sufficient to make
100 grams
______________________________________
______________________________________
Strontium Edatate 30 grams
Barium Sulfate 30 grams
Sodium Ricinoleate 1.0 gram
Algin 1 gram
Essential Oils (for flavoring)
1 gram
Propylene Glycol 20 grams
Alcohol 0.9 gram
Water quantity sufficient to make
100 grams
______________________________________
______________________________________
Strontium Edatate 8.0 grams
Strontium Carbonate
25.0 grams
Methyl Salicylate 1.25 grams
Water 33 cc
Natrosol 1.7 grams
Sodium Ricinoleate .1 gram
Cpc .3 gram
Sodium Saccharin 1.2 grams
Propylene glycol 25 cc
Water sufficient to make
100 grams
______________________________________
______________________________________
Preparation
4 5 6
______________________________________
Strontium Edatate
30 20 10 grams
Strontium Carbonate
25.0 25.0 25.0 grams
Cetyl pyridinium chloride
0.5 0.5 0.5 gram
Oil of cassia 0.75 0.75 0.75 gram
Oil of wintergreen
1.0 1.0 1.0 gram
Propylene glycol
25.0 25.0 25.0 grams
Natrosol 1.7 1.7 1.7 grams
Saccharin 1.2 1.2 1.2 grams
Sodium Ricinoleate
1.5 .5 .1 grams
Water QSAD to 100 grams
______________________________________

Strontium edatate is prepared by mixing equimolar amounts of strontium chloride hexahydrate and disodium ethylene diamine tetraacetic acid in hot distilled water, typically at 70°C, for a period of 20 minutes. The weight of strontium edatate is calculated as disodium strontium ethylene diamine tetraacetate and does not include the chloride present. As the ligand is formed, the two hydrogen ions are released for each molecule of Na2 EDTA which results in a decrease of solution pH from about neutral to about 4, indicating the formation of the ligand. Strontium carbonate or other abrasive then is slowly added to the mixture and heating and mixing are continued as the strontium carbonate or other abrasive is mixed. When strontium carbonate is used, a reaction takes place with a visible evolution of carbon dioxide as the vapor. This reaction continues for about three to four hours at 70°C The mixture is allowed to cool and additional ingredients such as propylene glycol and the like are added as well as make up water for that lost during the mixing of the strontium carbonate, Na2 EDTA and strontium chloride. In Example 1, an excess of strontium chloride was utilized and hence this is separately stated. In Example 2, barium sulfate was substituted for strontium carbonate.

In a preferred alternate method of manufacture, Strontium edetate can be made by adding Strontium Carbonate to an aqueous solution of Disodium EDTA at a temperature 70°C-80°C The Strontium Carbonate is added slowly. At the completion of the reaction the pH will be between 7 and 8 which is adjusted by adding HCl. The bulk excipient or abrasive, such as Insoluble Metaphosphate (IMP) or Strontium Carbonate is added. The mixture is completed with the addition of Thickening Agent (Natrosol), Humectant (Sorbitol and Glycerine), Surfactant (Sodium Ricinoleate) and flavoring.

______________________________________
Liquid Dentrifice
______________________________________
Sodium Ricinoleate 0.5 gram
Glycerine 20 grams
Oil of cloves 0.3 gram
Oil of spearmint 0.3 gram
Oil of cassia 0.3 gram
Saccharin 0.5 gram
Strontium edatate 10 grams
Tincture cudbear 0.6 gram
Water quantity sufficient to make
100 cc
______________________________________
The alcohol and glycerine are added to one another and stirred together,
and, the ricinoleate then is dissolved in the alcohol and glycerine
solution. The saccharin then is stirred in and also the tincture cudbear
for coloring. Then the stronium edatate (crystalline) is stirred in and
followed by the flavoring ingredients, namely, the oils of cloves,
spearmint, and cassia; and finally the water is added, and the whole is
stirred to uniformity.

The toothpastes of Examples 1-6 are utilized following a regular daily routine preferably twice a day. The liquid dentifrice of Example 7 is preferably used as a mouthwash and can be diluted in water, as with any ordinary mouthwash, and preferably is used at least twice a day.

Schole, Murray L.

Patent Priority Assignee Title
4355022, Jul 01 1981 INTERON, INC Method of dental treatment
4367219, Nov 25 1981 Fluoride containing dentifrice
4415549, May 17 1982 RICHARDSON-VICKS INC Toothpastes with reduced salinity
6190642, Feb 19 1988 Dentsply Research & Development Corp. Irrigating and lavage compositions
Patent Priority Assignee Title
1633336,
1936456,
3004897,
3122483,
3452049,
3699221,
3988434, Dec 05 1958 Dental preparation
4130638, Nov 03 1976 RICHARDSON-VICKS, INC Mouthwash compositions
4175120, Oct 30 1978 Dentifrice
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