Oral care composition

Abstract

A toothpaste composition comprising: i) 40% by weight or more of water based on the total composition, ii) a silica abrasive, iii) from 0.05% to 0.15% by weight of the total composition of sodium fluoride, iv) from 0.4% by weight of the total composition of zinc sulfate.

Description

Technical Field

[0001] The present invention relates to oral care compositions, particularly oral care compositions which do not contain preservatives. Background Art

[0002] A key attribute of oral care products is their freedom from microbial and fungal contamination. Therefore, there is a need for oral care products that provide consistent and reproducible resistance to bacterial growth and mold while maintaining their efficacy and consumer acceptability. Oral care products with high water content and silica abrasives can be difficult to preserve, especially in the absence of preservatives.

[0003] WO 2013 / 095370 provides an oral care composition comprising: greater than 50% by weight water; an effective amount of benzyl alcohol; and a silica abrasive which is said to provide adequate preservation.

[0004] WO 2018 / 145988 discloses oral care compositions comprising low levels of sodium fluoride.

[0005] WO 2014 / 100930 discloses the use of a water-soluble stannous ion source for improving the robustness of oral care compositions to microbial challenge.

[0006] From a cost and sustainability standpoint, there is a need for toothpastes containing higher levels of water.With today's consumer preference for products that minimize the use of preservatives and reduce fluoride levels, self-preserving products are desirable. Summary of the invention

[0007] The present invention relates to a toothpaste composition comprising:

[0008] i) 40% by weight or more of water based on the total composition,

[0009] ii) silica abrasive,

[0010] iii) 0.05% to 0.15% by weight of the total composition of sodium fluoride,

[0011] iv) 0.4% by weight of the total composition of zinc sulphate.

[0012] The present invention also relates to the use of zinc sulfate in a toothpaste composition for reducing fungal stains, the toothpaste composition comprising 40% or more of water by weight of the total composition and 0.05% to 0.15% of fluoride by weight of the total composition. DETAILED DESCRIPTION OF THE INVENTION

[0014] Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or reaction conditions, physical properties of materials and / or use may optionally be understood as modified by the word "about".

[0015] Unless otherwise stated, all amounts are by weight of the composition.

[0016] It should be noted that when specifying any range of values, any upper value may be associated with any particular lower value.

[0017] Where a feature is disclosed with respect to a particular aspect of the invention (eg, the composition of the invention), such disclosure is also considered to be applicable, mutatis mutandis, to any other aspect of the invention (eg, the method of the invention).

[0018] Any natural or naturally derived ingredients mentioned in this application are of European origin.

[0019] In the context of the present invention, the term "free of" may be interpreted as comprising less than 0.05 wt. %, preferably less than 0.01 wt. % of the ingredient of the total composition.

[0020] The compositions of the present invention are preferably used to clean the surfaces of the oral cavity and are referred to as oral care compositions.

[0021] Toothpastes are in the form of an extrudable semi-solid such as a cream, paste or gel (or mixtures thereof).Preferred product forms of the compositions of the present invention are therefore those suitable for brushing and / or rinsing oral surfaces.

[0022] The toothpaste comprises a silica-based abrasive. It can be used as the sole abrasive silica, or in combination with low levels of other abrasive silicas, such as those according to EP 236070. The low refractive index silica used as abrasive in the present invention is preferably a silica having an apparent refractive index (Rl) in the range of 1.41-1.47, preferably in the range of 1.435-1.445, preferably having a weight average particle size between 5 mm and 15 mm, with a particle size of 10 mm. 2 / g and 100m 2 / g, and a BET (nitrogen) surface area of ​​about 70-150 cm 3 The oil absorption of 1 / 100 g is preferably 0.1 g, but abrasive silicas with a lower apparent refractive index may also be used. Typical examples of suitable low refractive index abrasive silicas (e.g., with an Rl between 1.435 and 1.445) are Tixosil 63 and 73 available from Rhone Poulenc; Sident 10 available from Degussa; Zeodent 113 available from Zeofinn; Zeodent 124 available from Evonik, Sorbosil AC 77 available from PQ Corporation (with an Rl of about 1.440). The amount of these silicas in the composition is generally in the range of 5-60 wt%, usually 5-20 wt%.

[0023] The composition according to the invention comprises 0.4 wt% zinc sulphate of the total composition, preferably the zinc sulphate content is 0.5 to 3 wt%, more preferably 0.6 to 1.5 wt% of the total composition. It is preferred if the zinc sulphate is zinc sulphate heptahydrate.

[0024] Other metal salts may be present, but preferably zinc sulfate is present in an amount of 60% by weight or more of the total zinc salt content, and more preferably it is the only zinc salt present. If present, other metal salts include zinc chloride, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglyceride, zinc tartrate, zinc pyrophosphate and zinc maleate. Stannous ions, such as stannous fluoride and stannous chloride, may also be suitable for use in the present invention.

[0025] The toothpaste composition may further comprise a polyol in an amount of 5 to 35 wt %, preferably 10 to 30 wt %, of the total composition. Preferably, the polyol is selected from glycerol, sorbitol, and mixtures thereof. Sorbitol is particularly preferred.

[0026] The composition of the present invention comprises sodium fluoride in an amount of 0.05 to 0.15 wt % based on the total composition, preferably 0.07 to 0.13 wt % of the total composition. Preferably, the fluoride content is less than 800 ppm, more preferably 300 to 600 ppm.

[0027] Preferably, the composition contains no other fluoride sources, but if other fluoride sources are present, they may be sources such as stannous fluoride, sodium monofluorophosphate, ammonium zinc fluoride, ammonium stannous fluoride, calcium fluoride, ammonium cobalt fluoride, and mixtures thereof.

[0028] Preferably, the toothpaste does not contain sodium benzoate and / or benzoic acid.

[0029] In addition to the ingredients specified above, the compositions according to the invention may typically contain other ingredients to enhance performance and / or consumer acceptability.

[0030] Depending on the materials selected, the composition, especially if a toothpaste, preferably contains an inorganic or natural or synthetic thickener or gelling agent in a proportion of about 0.10 to about 15% by weight. These proportions of thickener in the dentifrice composition of the present invention allow the formation of an extrudable shape-retaining product that can be extruded from a tube onto a toothbrush without falling between the bristles of the toothbrush, but rather substantially retains its shape on the bristles. Suitable thickeners or gelling agents that can be used in the practice of the present invention include inorganic thickening silicas, such as amorphous silica available from Huber Corporation under the trade name Zeodent 165, Irish moss, iota-carrageenan, tragacanth gum, and polyvinylpyrrolidone.

[0031] The composition according to the invention preferably comprises a polymeric deposition aid. Preferably, the composition comprises an anhydride polymer, particularly preferably a copolymer of maleic anhydride and methyl vinyl ether, wherein the anhydride portion may be in partially or completely hydrolyzed or alcoholyzed form. Preferred copolymers include Gantrez(R) polymers such as:

[0032] Gantrez S-95: molecular weight 216,000; free acid;

[0033] Gantrez S-96: molecular weight 700,000; free acid;

[0034] Gantrez S-97: molecular weight 1,500,000; free acid; and

[0035] Gantrez MS-955: molecular weight 1,060,000; calcium / sodium salt.

[0036] A particularly preferred copolymer of maleic acid and methyl vinyl ether has a molecular weight of 1,000,000 or greater, with an especially preferred material being Gantrez S-97.

[0037] The composition according to the invention may comprise a tooth whitening agent. The whitening agent preferably comprises a green and / or blue pigment. In the context of the present invention, a pigment is generally understood to be an opacifier / material that is insoluble in the relevant medium at the relevant temperature. This is in contrast to a soluble dye. In the context of the present invention, the "relevant medium" is human saliva, i.e. the liquid medium in which the composition is used at the temperature of the mouth during brushing, i.e. at most 37°C. As a reasonable approximation, the relevant medium can be considered to be water, and the relevant temperature is 25°C.

[0038] Preferably, the blue pigment is Pigment Blue 15, more preferably Pigment Blue 15: 1, 15: 2, 15: 3, 15: 4, 15: 5 or 15: 6, most preferably 15: 1. The preferred pigment is a blue pigment, Phthalocyanine Blue Pigment, Cl No. 74160, Blue Covarine.

[0039] A preferred green pigment is phthalocyanine green, preferably phthalocyanine green CI-74260.

[0040] Preferably, the total content of pigments in the composition is from 0.01 to 3 wt%, more preferably from 0.02 to 2 wt%.

[0041] If the composition is a toothpaste, it may be a two-phase paste in which the whitening pigment is present in one phase.

[0042] The composition according to the invention may comprise an oral care enzyme system, such as an enzyme system generating hydrogen peroxide (e.g. the oxidoreductase glucose oxidase), amyloglucosidase, glucanase and / or mutanase (optionally in the presence of a compound providing zinc ions and / or an 8-hydroxyquinoline derivative), lactoperoxidase, lactoferrin, lysozyme and mixtures thereof.

[0043] In one embodiment, a preferred class of oral care actives for inclusion in the compositions of the present invention includes agents for tooth remineralization.In the context of the present invention, the term "remineralization" refers to the in situ generation of hydroxyapatite on teeth.

[0044] One specific example of a suitable agent for tooth remineralization is a mixture of a calcium source and a phosphate source which, when delivered to the teeth, results in the in situ formation of hydroxyapatite on the teeth.

[0045] Illustrative examples of the types of calcium sources (hereinafter referred to as "remineralizing calcium sources") that can be used in the present application include, for example, calcium phosphate, calcium gluconate, calcium oxide, calcium lactate, calcium glycerophosphate, calcium carbonate, calcium hydroxide, calcium sulfate, calcium carboxymethylcellulose, calcium alginate, calcium salts of citric acid, calcium silicate, and mixtures thereof. Preferably, the remineralizing calcium source is calcium silicate.

[0046] The amount of remineralizing calcium source (eg calcium silicate) in the composition of the present invention is typically 1 to 30%, preferably 5 to 20%, by total weight of the remineralizing calcium source, based on the total weight of the oral care composition.

[0047] Illustrative examples of types of phosphate sources (hereinafter referred to as "remineralized phosphate sources") that can be used in the present application include, for example, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, and mixtures thereof. Preferably, the remineralized phosphate source is a mixture of trisodium phosphate and sodium dihydrogen phosphate.

[0048] The amount of remineralizing phosphate source (eg, trisodium phosphate and sodium dihydrogen phosphate) in the composition of the present invention is typically 2 to 15%, preferably 4 to 10%, by total weight of the remineralizing phosphate source, based on the total weight of the oral care composition.

[0049] Mixtures of any of the above materials may also be used.

[0050] The composition according to the present invention may contain other ingredients commonly used in the art, such as:

[0051] Antimicrobial agents, for example, chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds such as cetylpyridinium chloride; cetylpyridinium chloride clay complex biguanides such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenol compounds such as 2,2'methylenebis-(4-chloro-6-bromophenol);

[0052] Anti-inflammatory agents, such as ibuprofen, flurbiprofen, aspirin, indomethacin, etc.;

[0053] anticaries agents such as sodium and stannous fluoride, amine fluorides, sodium monofluorophosphate, sodium trimetaphosphate, and casein;

[0054] plaque buffers, such as urea, calcium lactate, calcium glycerophosphate, and strontium polyacrylate;

[0055] Vitamins, such as vitamins A, C, and E;

[0056] Plant extracts;

[0057] antioxidants that may be derived from plants, such as flavonoids, catechins, polyphenols, and tannin compounds and mixtures thereof;

[0058] desensitizing agents, e.g., potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate, and strontium salts;

[0059] anticalculus agents, for example, alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates;

[0060] Biomolecules, e.g., bacteriocins, antibodies, enzymes, etc.;

[0061] flavorings, such as peppermint and spearmint oils;

[0062] Proteinaceous materials, such as collagen;

[0063] sunscreen;

[0064] Hyaluronic acid;

[0065] Amino acids, such as arginine; glycine

[0066] Colorants;

[0067] pH adjusters;

[0068] Sweeteners;

[0069] Pharmaceutically acceptable carriers, for example, starch, sucrose, water or water / alcohol system, etc.;

[0070] Surfactants, such as anionic, nonionic, cationic, and zwitterionic or amphoteric surfactants;

[0071] Humectants, such as glycerin, sorbitol, propylene glycol, xylitol, lactitol, etc.;

[0072] Binders and thickeners, such as sodium carboxymethylcellulose, hydroxyethylcellulose Xanthan gum, gum arabic, etc., and synthetic polymers such as polyacrylates and carboxyvinyl polymers such as

[0073] Also included may be polymeric compounds that can enhance the delivery of active ingredients such as antimicrobial agents; buffers and salts that buffer the pH and ionic strength of the oral care composition; and

[0074] Other optional ingredients that may be included are, for example, bleaching agents such as peroxy compounds, for example potassium peroxydiphosphate, effervescent systems such as a sodium bicarbonate / citric acid system, color change systems, and the like.

[0075] The invention will now be illustrated by the following non-limiting examples. Examples according to the invention are indicated by numbers and comparative examples are indicated by letters. DETAILED DESCRIPTION

[0076] Example

[0077] The examples were formulated as shown in the table below. They were tested for mold contamination using the method of ISO 11930 Cosmetics - Microbiology - Evaluation of antimicrobial protection of cosmetic products.

[0078] Table 1

[0079]

[0080]

[0081] Table 2

[0082] A B C 1 2 3 Fungal CT log reduction 1.82 1.19 1.35 2.97 2.6 2.46

[0083] Table 3

[0084]

[0085] Table 4

[0086] D E F G H I Fungal CT log reduction 0.77 0.58 0.74 0.63 0.61 0.68

[0087] The results show that the examples according to the present invention are significantly better in reducing fungal contamination than the comparative examples.

Claims

1. A toothpaste composition comprising: i) 40% by weight or more of water in the total composition, ii) silica abrasive, iii) 0.05% to 0.15% by weight of sodium fluoride, based on the total composition, iv) from 0.4% by weight of zinc sulfate based on the total composition.

2. The toothpaste composition according to claim 1, further comprising a polyol in an amount of 5 to 35 wt%, preferably 10 to 30 wt%, based on the total composition.

3. The toothpaste composition according to claim 1 or 2, wherein the polyol is selected from glycerol, sorbitol, and a mixture thereof.

4. The toothpaste composition according to claim 3, wherein the polyol is sorbitol.

5. A toothpaste composition according to any preceding claim which is free of sodium benzoate.

6. A toothpaste composition according to any preceding claim which is free of benzoic acid.

7. A toothpaste composition according to any one of the preceding claims, wherein the zinc sulphate is present in an amount of 0.5 to 3 wt% of the total composition.

8. A toothpaste composition according to any one of the preceding claims, wherein the zinc sulphate is present in an amount of 0.6 to 1.5 wt% of the total composition.

9. A toothpaste composition according to any one of the preceding claims, wherein the zinc sulphate is zinc sulphate heptahydrate.

10. A toothpaste composition according to any preceding claim comprising from 0.07% to 0.13% by weight of the total composition of sodium fluoride.

11. Use of zinc sulfate for reducing fungal contamination in a toothpaste composition comprising 40% or more water, based on the weight of the total composition, and 0.05% to 0.15% sodium fluoride, based on the weight of the total composition.

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