Dentifrice Compositions Having Improved Fluoride Ion Stability or Fluoride Uptake

Abstract

Certain dentifrice compositions having a pyrophosphate ion and an alkaline pH have improved fluoride ion stability or fluoride uptake.

What is claimed is: 
     
         1 . A dentifrice composition comprising:
 (a) 25% to 60% of a calcium-containing abrasive by weight of the composition, wherein the calcium-containing abrasive comprises calcium carbonate;   (b) 20% to 75% of water by weight of the composition   (c) 0.0025% to 4.0% of a sodium monofluorophosphate by weight of the composition;   (d) 0.001% to 4% of a calcium chelating agent by weight of the composition, wherein the calcium chelating agent is a pyrophosphate ion; and   (e) pH is greater than 8.3.   
     
     
         2 . The composition of  claim 1 , wherein the composition comprises 27% to 47% of the calcium carbonate composition, and the pyrophosphate ion is from 0.01% to 1.35% by weight of the composition. 
     
     
         3 . The composition of  claim 2 , wherein the calcium carbonate is selected from fine ground natural chalk, ground calcium carbonate, and combinations thereof, and wherein the calcium carbonate has a D50 from 2 microns to 7 microns. 
     
     
         4 . The composition of  claim 3 , wherein an monofluorophosphate ion degrades less than less than 30% after 14 days at 60° C. relative to the monofluorophosphate ion in freshly prepared dentifrice composition. 
     
     
         5 . The composition of  claim 4 , wherein the pH is from 9 to 12. 
     
     
         6 . The composition of  claim 1 , wherein an monofluorophosphate ion degrades less than 40% after 14 days at 60° C. relative to the monofluorophosphate ion in freshly prepared dentifrice composition. 
     
     
         7 . The composition of  claim 6 , wherein a percentage of degraded monofluorophosphate ion that remains as free fluoride ion after 14 days at 60° C. is greater than 50%. 
     
     
         8 . The composition of  claim 7 , wherein the composition contains greater than 3,660 parts per million (ppm) monofluorophosphate ion after 14 days at 60° C. 
     
     
         9 . The composition of  claim 8 , wherein the composition contains greater than 3,260 parts per million (ppm) monofluorophosphate ion after 43 weeks at 30° C. 
     
     
         10 . The composition according to  claim 1 , wherein calcium chelating agent is from 0.1% to less than 1.0% of a pyrophosphate salt by weight of the composition. 
     
     
         11 . The composition according to  claim 5 , wherein calcium chelating agent is from 0.1% to less than 1.0% of a pyrophosphate salt by weight of the composition, wherein the pyrophosphate is tetrasodium pyrophosphate. 
     
     
         12 . The composition of  claim 2 , further comprising: 0.01% to 7% of a linear sulfated polysaccharide by weight of the composition, wherein the linear sulfated polysaccharide is a carrageenan; 0.5% to 2% of a carboxymethyl cellulose by weight of the composition; and wherein the pH is from 9 to 12. 
     
     
         13 . The composition according to  claim 1 , further comprising from 0.5% to less than 10% polyethylene glycol (PEG) by weight of the composition. 
     
     
         14 . The composition according to  claim 12 , further comprising from 1% to 8% of polyethylene glycol (PEG) by weight of the composition, wherein the PEG is selected from a molecular weight range from PEG 200 to PEG 600. 
     
     
         15 . The composition according to  claim 14 , further comprising 0.01% to 0.11% of a paraben by weight of the composition, wherein the paraben is selected from methyl paraben, propyl paraben, or combinations thereof. 
     
     
         16 . The composition according to  claim 1 , wherein the composition is substantially free of glycerin and sorbitol. 
     
     
         17 . The composition according to  claim 1 , wherein the water is from 50% to 60% by weight of the composition. 
     
     
         18 . The composition according to  claim 5 , wherein the water is from 50% to 60% by weight of the composition. 
     
     
         19 . The composition according to  claim 14 , wherein the water is from 50% to 60% by weight of the composition. 
     
     
         20 . A method of treating tooth enamel comprising the step of contacting teeth with the dentifrice composition according to  claim 1 .