US 2647073 A
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Patented July 28,1953
I AMMONIATED DENTIFRICE CONTAINING ANHYDROUS DICALCIUM PHOSPHATE Arnold J. Singer Newark, N. J., assignor to Amm-I-Dent, Inc., Jersey City, N. J., a corporation of New Jersey No Drawing. Application April 13, 1951, Serial No. 220,990
4 Claims. (01. 161-93) The present invention relates to improvements in dentifrices, and it relates more particularly to improvements in dentifrice pastes of the amfmoniated type. T
t unsuitable for use in dentifrice pastes, particu- 'larly in dentifrice pastes of the ammoniated type.
For example, calcium carbonate as a result of its high alkalinity which causes a degradation of the ammoniated ingredients of the paste is un- 'fit-for use in an ammoniated type dentifrice ;paste;
While tricalcium; phosphate has been heretofore employed as. a polishing agent in ammoniated dentifrice pastes by itself, it does not possess sufficient abrasiveness to adequately polish the teeth.
Recently, hydrous dicalcium orthophosphate Cal-IPO42H2O' has been widely employed. Previously, this compound could not be used because of its tendency to harden in the presence of moisture and other chemicals. This has been overcome by the addition of a suitable stabilizer or hardening inhibitor, such as magnesium trisilicate or other sequestering agent. However, in the presence of certain chemicals or ions, for example urea, ammonia or ammoniated ingredients, such inhibitors have proved entirely ineffective with the result that the hydrous dicalcium orthophosphate (CaHPO4.2I-I2O) completely hardens, thereby destroying the dentifrice.
It is thus a principal object of the present invention to provide an improved dentifrice.
Another object of the present invention is to provide an improved dentifrice paste having superior tooth polishing characteristics.
Still another object of the present invention is to provide an improved dentifrice paste having superior keeping qualities.
A further object of the present, invention is to provide an improved dentifrice of the ammoniated type which possesses superior tooth polishing characteristics and keeping qualities, and is subject to a minimum of caking or hardening.
It has been discovered that anhydrous dicalcium orthophosphate (CaHPOr) is entirely compatible with and stable in the presence of urea, ammonia, ammoniated and ammonia forming 2 compounds and ammonium ions, and is not subject to caking, setting or hardening in their presence. Many unusual and entirely unanticipated properties have been discovered in anhydrous dicalcium orthophosphate (CaHPOl) as used in dentifrices. By varying the relative proportion of the anhydrous dicalcium orthophosphate (Cal-IP04) in a dentifrice paste, the abrasiveness or polishing power of the dentifrice paste can be varied and controlled at will. Furthermore, it has been found that the addition of even relatively small amounts of the anhydrous dicalcium orthophosphate to the polishing agent in a dentifrice paste altered the polishing characteristics thereof considerably beyond the extent normally to be expected or anticipated by the addition of such small quantities. The polishing power of the combined polishing agents or abrasives was far in excess of the mathematical sum of their individual polishing powers. For example, the addition of five percent by weight of anhydrous dicalcium orthophosphate to a dentifrice paste containing tricalcium phosphate as a polishing agent increases the polishing power of the dentifrice paste from three to five times, whereas the addition of twenty-five percent by weight of anhydrous dicalcium orthophosphate will increase the abrasiveness or polishing power from seven to fifteen times that of a dentifrice paste containing tricalcium phosphate alone. It thus appears that while anhydrous dicalcium orthophosphate is particularly useful in ammoniated or ureacontaining dentifrices, it may be employed to great advantage in any dentifrice. Therefore, the present invention broadly contemplates a dentifrice containing anhydrous dicalcium orthophosphate, and in a narrower sense contemplates an ammoniated or urea-containing dentifrice containing anhydrous dicalcium orthophosphate. It is preferable that the anhydrous dicalcium orthophosphate is not the only polishing agent in the dentifrice but that some other compatible polishing agent be employed with it, such as tricalcium phosphate. The total polishing agents should preferably constitute from forty to fifty percent by weight of the dentifrice paste, the anhydrous dicalcium phosphate being present in amounts from one to twenty-five percent, the remainder being another abrasive such as tricalcium orthophosphate. In order to avoid scratching the enamel, the particle size of the anhydrous dicalcium orthophosphate should not exceed from one to ten microns.
The active ingredients of the improved tooth paste may be one or more of the following: urea, thiourea, non-toxic water soluble ammonium compounds such as the ammonium phosphates or other alkaline ammonium salts, or other substance capable of producing ammonia in an oral environment. The active ingredients should constitute between one-half percent and fifty percent of the dentifrice.
A preferred ammoniated dentifrice paste in accordance with the present invention would contain from three to fifty percent urea; from one to seven percent diammonium hydrogen phosphate (N114) 2HPO4; from .one to live percent anhydrous dicalcium orthophosphate; from twentyfive to fifty percent tricalcium phosphate, water and other ingredients such as humectants, for example glycerin or sorbitol, detergents, flavoring agents and a thicknening agent such as carboxy methyl cellulose.
A specific example of an ammoniated tooth paste embodying the present invention is as follows:
Ingredient: Percentage by weight Water 16:66 Urea 13.00 Detergent 2.00 Humectants 1 22.50 Anhydrous dicalcium orthoph'osphate 5.00 Tricalcium phosphate 35.64 Thickening agent 0.28 Flavoring agent 1.92 Diammonium hydrogen phosphate 3.00
It is obvious that the percentages of the above ingredients may be varied in accordance with the present disclosure and in accordance with the practices in the art.
While there has been described preferred embodiments of the present invention, it is obvious that numerous omissions and alterations may be made without departing from the spirit thereof.
1. A dentifrice comprising the following in- 4 gredients in substantially the percentages shown:
Water 16.66 Urea 13.00 Detergent 2.00 Humectants 22.50 Anhydrous dicalcium orthophospha'te 5.00 Tricalcium phosphate 35.64 Thickening agent 0.28 Flavoring agent 1.92 Diammonium hydrogen phosphate 3.00
'2. A dentifrice paste comprisin from 3% to 50% by weight of urea, from 1% to 7% by weight of diarmnonium hydrogen phosphate, from 1% to 5% anhydrous dicalcium orthophosphate, from 25% to 50% tricalcium phosphate, a humectant and sufficient water to form a paste.
'3. A dentifrice paste as claimed in claim 2, including a detergent and a thickening agent.
4. A dentifrice paste comprising from 3% to 50% .by weight of urea, from 1% to 7% by weight of diammonium hydrogen phosphate, between and 50% of polishing agents including tricalcium phosphate, and from 1% to 25% anhydrous dicalcium phosphate, 2, humectant and suflicient water to form a paste.
ARNOLD J. SINGER.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,477,177 Kuever Dec. 11, 1923 1,817,664 Badanes Aug. 4, 1931 2,018,410 McDonald Oct. '22, 1-935 2,519,665 Klippert Aug. 22, 1950 2,542,518 Henschel Feb. '20, 1951 2,542,886 Wach Feb. 20, 1951 2,556,959 .Connelly June 12, 1951 OTHER REFERENCES Manufacturing Chemist, March 1950., page 106. J ourna1 American Pharmaceutical Association, Prac. Pharm. Edition, January 1950, page 50.