NATIVE AND POROUS STARCH AS WHITE PIGMENT IN TOOTHPASTE

Abstract

The present invention relates to the use of native and/or porous starch as white pigment in dental health products and in particular in toothpastes. The present invention also relates to the process of fabricating a dental health product composition and in particular a toothpaste composition.

Claims

1. A use of starch as white pigment to replace titanium dioxide in a dental health product composition, the starch being a native starch, a porous starch or a mixture thereof.

2. The use according to claim 1, wherein the starch is a porous starch.

3. The use according to claim 1, wherein the starch is selected from the group consisting of tapioca starch, waxy tapioca starch, maize starch, pea starch, potato starch, waxy potato starch, wheat starch, waxy wheat starch, waxy maize starch, high-amylose maize starch, mung bean starch, rice starch, waxy rice starch, sweet potato starch, waxy sweet potato starch, millet starch, sago starch, sorghum starch, quinoa starch, arrowroot starch, amaranth starch, lotus root starch and buckwheat starch.

4. The use according to claim 1, wherein the dental health product is selected from the group consisting of a toothpaste and a chewing gum, preferably the dental product is a toothpaste.

5. The use according to claim 1, wherein the starch replaces up to 30%, preferably up to 60% and more preferably up to 100% by weight of the titanium dioxide in the dental health product composition.

6. The use according to claim 1, wherein the dental health product composition comprises from 0.5% to 30%, preferably from 1% to 20% and more preferably from 2% to 15%, and even more preferably from 5 to 10% by weight of native starch with respect to the total weight of the dental health product composition.

7. The use according to claim 1, wherein the dental health product composition comprises from 0.5% to 30%, preferably from 1% to 20% and more preferably from 2% to 15%, and even more preferably from 5 to 10% by weight of porous starch with respect to the total weight of the dental health product composition.

8. A dental health product composition comprising a white pigment containing or consisting of a native starch, a porous starch or a mixture thereof.

9. A process of fabricating the dental health product composition comprising the step of adding native starch, porous starch or mixture thereof as white pigment.

10. The process according to claim 9, wherein said process does not comprise a step of adding titanium dioxide as white pigment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] FIG. 1: scanning electron micrograph of porous waxy maize starch

[0070] FIG. 2: pH-telemetry results of the toothpaste made with native waxy maize starch of example 1.

[0071] FIG. 3: pH-telemetry results of the toothpaste made with porous waxy maize starch of example 2.

EXAMPLES

[0072] In the following examples, the following commercial products are used:

Neosorb 70/70B (liquid sorbitol) commercialized by Roquette
Sodium lauryl sulfate commercialized by Sinopharm
Carboxymethyl cellulose commercialized by Ashland
Ethanol commercialized by Sinopharm
Flavor commercialized by IFF
Sodium saccharin commercialized by Sinopharm
Methyl p-hydroxy benzoate commercialized by Sinopharm
Propyl p-hydroxybenzoate commercialized by Sinopharm
Sodium monofluorophosphate commercialized by Sinopharm

[0073] The native waxy maize starch used in example 1 was produced according to the protocol mentioned in the first example of starch extraction process described in the description.

[0074] The porous waxy maize starch used in example 2 was produced from the native waxy maize according to the following protocol. [0075] 1. Suspending native waxy maize starch in decarbonated water to 26% solid content. [0076] 2. Adjusting pH of starch slurry to 7.0 using 3.3% NaOH solution. [0077] 3. Adding thermosable α-amylase (Liquozyme Supra from Novozymes, 2.67 mg enzyme/g dry starch) and reacting at 55° C. for 4 hours. [0078] 4. Stopping the reaction by adjusting the pH to 3-3.5 using 5% hydrochloric solution and holding for one hour. [0079] 5. Adjusting back the pH to 4.5-5.5 using 3.3% sodium hydroxide solution. [0080] 6. Cooling the starch slurry to about 25° C. [0081] 7. Press filtering the slurry to obtain porous starch cake. [0082] 8. Washing the cake with decarbonated water. [0083] 9. Drying the cake using a flash dryer into powder with moisture content below 12%.

[0084] The scanning electron micrograph of porous waxy maize starch is shown on FIG. 1.

Example 1: Analysis of Abrasivity and Fermentability of Toothpaste Made Using Native Waxy Maize Starch

[0085] The recipe of the toothpaste sample to be tested is presented in table 1.

TABLE-US-00001 TABLE 1 Percentage by Ingredients weight (%) Neosorb 70/70B 45.00 (liquid sorbitol) (humectant) Water 20.00 Waxy maize starch (white 28.4 pigment/potential abrasive) Sodium lauryl sulfate 3.00 (surfactant) Carboxymethyl cellulose 1.2 (thickening agent) Ethanol 1.00 Flavor (flavoring agent) 1.00 Sodium saccharin (sweetener) 0.2 methyl p-hydroxy benzoate 0.18 (preservative) propyl p-hydroxybenzoate 0.02 (preservative) Sodium monofluorophosphate 0.76 (anti-tartar agent)

[0086] The toothpaste sample was prepared according to the following protocol:

1. Preparing a first solution by dissolving sodium saccharin and sodium monofluorophosphate in water at 50° C.
2. Preparing a second solution by adding the preservatives to the NEOSORB 70/70B sorbitol solution at 80° C. This second solution is then cooled to 50° C. and the carboxymethyl cellulose is dispersed under conditions of vigorous agitation.
3. Adding the first solution to the second solution. Allowing the resulting mixture to stand for 30 minutes.
4. Vacuum-mixing for 5 minutes.
5. Adding half of the waxy maize starch and mixing for 10 minutes.
6. Adding the second half of the waxy maize starch and mixing for another 10 minutes.
7. Adding sodium lauryl sulfate solution and ethanol, followed by 3 minutes of mixing.
8. Finally, adding flavoring agent and mix for 5 minutes under vacuum.

[0087] The “toothfriendly quality” of the resulting toothpaste was tested by using the pH-telemetric standardized method (Toothfriendly International's Standard Operation Procedures described in Imfeld, Th. N., Identification of Law Caries Risk Dietary Components, Monographs in Oral Science, Vol. 11, 198 pp., H. M. Myers (ed.), S. Karger A G, Basel, 1983). The sample has been tested in a volunteer having a 5-day old plaque.

[0088] Results are shown on FIG. 2.

[0089] As shown on FIG. 2, the obtained plaque pH-curve demonstrated that the toothpaste sample was not associated with a depression of interdental plaque pH below 5.7, neither during nor after 30 min of swirling the toothpaste slurry in the mouth. The increase of the interdental plaque pH during water rising (W) and paraffin chewing (PC) as well as the drop of the interdental plaque pH below 5 following positive control treatment (with 10% sucrose solution) demonstrated the proper functioning of the plaque-covered electrodes. The obtained pH curve with the plaque-covered electrode demonstrated that the tested product also lacked of an erosive potential.

[0090] Thus, the toothpaste sample made using waxy maize starch has low fermentability (pH5.7).

[0091] The abrasion (RDA) of the toothpaste sample made using waxy maize starch was tested according to the following protocol.

[0092] Six bovine tooth roots were radioactively irradiated. Due to the irradiation, the phosphorus of the apatite was changed to radioactive .sup.32P and gamma radiation. The roots were embedded in an acrylic resin and later brushed using an automatized 8 placebrushing machine for 25 min with a total of 1,500 horizontal brushing strokes (60 strokes per min). The brushing load was amounted to 2.5 N. As a reference toothbrush, manual toothbrushes with a plane bristle layout (Paro M43 medium, Esro AG) were used. The brushing medium was either a slurry prepared from the toothpaste sample or a slurry prepared from a standard abrasive. For the slurry preparation, 25 g toothpaste, 40 mL artificial saliva and 50 μL silicon anti anti-frothing agent (Fluka Chemie) were dispersed for 5 min. The standard slurry was prepared by mixing 10 g ISO Sident, 50 g solution from carboxymethyl cellulose (0.5%), glycerine (10%) and artificial saliva. The brushing runs were performed in a so-called “sandwich” technique. The first run was performed with the standard abrasive slurry, followed by a run with the toothpaste slurry and finally with the standard abrasive slurry. After each run, 0.5 g of the used slurries were pipetted and the .sup.32P-irradiation in “decays per minute” (dpm) were measured with a Phosphorimagers® (Molecular Dynamics). The amount of .sup.32P in the slurry after brushing is a measure for the dental hard tissue abrasion of the tested products. The values for the standard abrasive slurry runs of the “sandwich” technique were averaged and set as 100. The relative dentine abrasion of the toothpaste sample was expressed as a percentage of the standard abrasive value.

[0093] The tested toothpaste sample presented an average RDA value of 2.05, which means that the toothpaste made using waxy maize starch falls in the category “rarely abrasive” (RDA 0-20) toothpaste (Tawakoli et al., 2015, Swiss Dent J, 125, 1210-9).

[0094] These results demonstrated that toothpaste made using waxy maize starch has no abrasive effects on teeth, lacks of cariogenic and erosive potential and hence is “toothfriendly”.

Example 2: Analysis of Abrasivity and Fermentability of Toothpaste Made Using Porous Waxy Maize Starch

[0095] The recipe of the toothpaste sample to be tested is presented in table 2.

TABLE-US-00002 TABLE 2 Percentage by Ingredients weight (%) Neosorb 70/70B 45.00 (liquid sorbitol) (humectant) Water 20.00 Porous waxy maize starch 28.4 (white pigment/potential abrasive) Sodium lauryl sulfate 3.00 (surfactant) carboxymethyl cellulose 1.2 (thickening agent) Ethanol 1.00 Flavor (flavoring agent) 1.00 Sodium saccharin (sweetener) 0.2 methyl p-hydroxy benzoate 0.18 (preservative) propyl p-hydroxybenzoate 0.02 (preservative) Sodium monofluorophosphate 0.76 (anti tartar agent)

[0096] The toothpaste sample was prepared according to the protocol of example 1 wherein waxy maize starch has been replaced by porous waxy maize starch.

[0097] The “toothfriendly quality” of the resulting toothpaste was tested by using a pH-telemetric standardized method as in example 1. The product was tested in a volunteer having a 6-day old plaque.

[0098] Results are shown on FIG. 3.

[0099] As shown on FIG. 3, the obtained plaque pH-curve demonstrates that the toothpaste made with porous waxy maize starch was not associated with a depression of interdental plaque pH below 5.7, neither during nor after 30 min of swirling the toothpaste slurry in the mouth. The increase of the interdental plaque pH during water rising (W) and paraffin chewing (PC) as well as the drop of the plaque pH below 5 following positive control treatment (with 10% sucrose solution) demonstrated the proper functioning of the plaque-covered electrodes. The obtained pH curve with the plaque-covered electrode demonstrated that the tested product also lacked of an erosive potential.

[0100] Thus, the toothpaste made with porous waxy maize starch has low fermentability (pH5.7).

[0101] The abrasion (RDA) of the toothpaste sample made using porous waxy maize starch was tested according to the protocol of example 1.

[0102] The tested toothpaste made using porous waxy maize starch presented a RDA value of 1.3, which means that the toothpaste falls in the category “rarely abrasive” (RDA 0-20) toothpaste (Tawakoli et al., 2015, Swiss Dent J, 125, 1210-9).

[0103] These results demonstrated that toothpaste made using porous waxy maize starch has no abrasive effects on teeth, lacks of cariogenic and erosive potential and hence is “toothfriendly”.

[0104] Conclusion: It was proven that when native and porous starches were used as white pigments in toothpastes, the resulting toothpastes had low abrasivity and low fermentability in the mouth.