Liquid oral composition

Abstract

To provide a liquid oral composition that offers superior fluoride ion (F-) retention in the oral cavity, suppresses the formation of viscous substances after storage, ensures favorable usability, and provides a pleasant feel during application.SOLUTION: A liquid oral composition comprises: (A) at least one or more calcium salts selected from calcium chloride, calcium gluconate, calcium lactate, and calcium pantothenate in an amount of 0.005-0.5 mass%; (B) at least one or more selected from polyols having a valency of three or more, diols, and sugar alcohols in an amount of 5-20 mass%; (C) a nonionic surfactant in an amount of 0.2-1 mass%; (D) condensed phosphate or a salt thereof in an amount of 0.05-1 mass%; and (E) sodium fluoride in an amount of 0.005-0.21 mass%, wherein a mass ratio of (B) to (A) is 20-1,000, and a mass ratio of (C) to (A) is 1-100.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing fluoride ions (F - The present invention relates to a liquid oral composition which has excellent retention in the oral cavity and is easy to use even after storage. [Background technology]

[0002] Fluorides such as sodium fluoride are widely used as medicinal ingredients (active ingredients) in oral compositions such as dentifrices because of their caries prevention effects. For fluoride to be effective, it is necessary to have fluoride ions (F - It is effective to leave the fluoride ion on the oral mucosa and teeth for a long period of time, and it is desirable to leave a large amount of fluoride ions in the oral cavity even after gargling and rinsing the oral cavity with water after use. However, liquid oral compositions such as mouthwashes have almost no viscosity compared to toothpaste and are used for treatment in a short period of time, such as a few tens of seconds, so there is the problem that active ingredients such as fluoride are less likely to remain in the oral cavity.

[0003] By the way, in the case of a liquid oral composition, it is effective to maintain the effect of the active ingredient contained in the composition by retaining the composition in the oral cavity. Patent Document 1 (JP 2019-206492 A) proposes an external composition that improves the retention of the formulation itself by blending polyvinylpyrrolidone and a polyhydric alcohol such as glycerin to increase the viscosity of the formulation. However, liquid oral compositions, especially mouthwashes, are designed to be ejected after use in the oral cavity, and there was a problem that if the viscosity became too high, the feel of use after ejection would be compromised.

[0004] A method for improving the retention of fluoride ions in the oral cavity is known to be the coexistence of calcium ions and fluoride ions. However, calcium ions and fluoride ions are highly reactive, and when they coexist, they become an insoluble substance called calcium fluoride, and the effect is not sufficient. In Patent Document 2 (JP Patent Publication No. 2009-137863), a complex formed in an aqueous solution containing a water-soluble polyphosphate, a calcium salt, and a fluoride salt is incorporated into an oral composition to improve the retention of fluoride ions in the oral cavity. However, in the liquid preparation, a viscous substance thought to be due to the complex forms over time, which can impair usability after storage. In addition, Patent Document 3 (JP 2017-66036 A) proposes a liquid oral composition that contains sodium fluoride, calcium glycerophosphate, condensed phosphoric acid or a salt thereof, and a cationic bactericide, and that combines excellent remineralization-promoting effects with sustained bactericidal effects against caries-causing bacteria, and is effective in preventing or suppressing dental caries. However, there is room for improvement in terms of the retention of fluoride ions in the oral cavity, and a viscous substance is generated over time, which can impair usability after storage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-206492 A [Patent Document 2] JP 2009-137863 A [Patent Document 3] JP 2017-66036 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and provides a method for producing a fluoride ion (F - The object of the present invention is to provide a liquid oral composition which has excellent retention in the oral cavity, inhibits the formation of viscous matter even after storage, is easy to use, and has a pleasant taste when used. [Means for solving the problem]

[0007] As a result of intensive research conducted by the present inventors to achieve the above object, it has been found that when a specific calcium salt described below, one or more selected from polyols, diols and sugar alcohols, a nonionic surfactant, condensed phosphoric acid or a salt thereof, and a specific fluoride salt are combined in specific amounts and in specific ratios in a liquid oral composition, fluoride ions (F - The inventors have found that the composition has excellent retention in the oral cavity, reduces the formation of viscous matter even after storage, ensures good usability, and maintains a pleasant taste when used, and have thus completed the present invention.

[0008] According to the present invention, by combining and blending (A) one or more calcium salts selected from calcium chloride, calcium gluconate, calcium lactate, and calcium pantothenate, (B) one or more selected from polyols, diols, and sugar alcohols, (C) a nonionic surfactant, (D) condensed phosphoric acid or a salt thereof, and (E) sodium fluoride, the amount of each component falls within a specific range and the amount ratio of components (A), (B), and (C) falls within a specific range, whereby these components specifically interact with each other, thereby providing the above-mentioned exceptional action and effect in the liquid oral composition. In this case, the use of component (A) as a calcium salt and the combination of components (D) and (E) with component (A) improves the retention of fluoride ions in the oral cavity, and further, the combination of components (B) and (C) prevents the formation of a complex or a viscous substance that is thought to be derived from the complex by components (A), (D) and (E) over time, and the formation of viscous substances is significantly suppressed even after storage. Thus, in the present invention, by combining and blending the above five components, a liquid oral composition can be obtained that is significantly excellent in the retention of fluoride ions in the oral cavity and in the suppression of the formation of viscous substances, and has a good aftertaste and other usability. As will be apparent from the comparative examples described later, in the present invention, when other water-soluble calcium salts such as calcium glycerophosphate or calcium malate were used instead of component (A), the inhibitory effect on the formation of viscous matter was poor (Comparative Examples 1 and 2), and the effect was inferior to that of the present invention.

[0009] Therefore, the present invention provides the following liquid oral composition. [1] (A) 0.005 to 0.5 mass% of one or more calcium salts selected from calcium chloride, calcium gluconate, calcium lactate, and calcium pantothenate, (B) 5 to 20% by mass of one or more selected from trihydric or higher polyols, diols, and sugar alcohols, (C) 0.2 to 1 mass% of a nonionic surfactant, (D) Condensed phosphoric acid or a salt thereof 0.05 to 1% by mass and (E) Sodium fluoride 0.005 to 0.21 mass% wherein the mass ratio of (B) / (A) is 20 to 1,000 and the mass ratio of (C) / (A) is 1 to 100. [2] The liquid oral composition described in [1], wherein the (B) component is one or more selected from glycerin, propylene glycol, sorbitol and maltitol. [3] A liquid oral composition as described in [2], wherein component (B) is a combination of glycerin, propylene glycol, and sorbitol. [4] A liquid oral composition described in any of [1] to [3], wherein component (C) is one or more nonionic surfactants selected from polyoxyethylene hydrogenated castor oil, polyoxyethylene polyoxypropylene glycol, and polyoxyethylene alkyl ether. [5] The liquid oral composition described in [4], wherein component (C) is polyoxyethylene hydrogenated castor oil having an average added mole number of polyoxyethylene chains of 40 or more. [6] A liquid oral composition according to any one of [1] to [5], wherein component (D) is one or more condensed phosphoric acids or salts thereof selected from pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, and salts thereof. [7] A liquid oral composition described in any of [1] to [6], which is a mouthwash. Effect of the Invention

[0010] According to the present invention, a liquid oral composition can be provided which has excellent retention of fluoride ions in the oral cavity, and also has good usability and a good feeling of use because the formation of viscous matter is suppressed even after storage. Since the liquid oral composition has excellent retention of fluoride ions in the oral cavity, the effect can be sustained, and the liquid oral composition is effective for preventing or suppressing dental caries. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will now be described in further detail. The liquid oral composition of the present invention contains (A) a specific calcium salt described later, (B) one or more selected from trivalent or higher polyols, diols, and sugar alcohols, (C) a nonionic surfactant, (D) a condensed phosphoric acid or its salt, and (E) sodium fluoride.

[0012] Component (A) is one or more calcium salts selected from calcium chloride, calcium gluconate, calcium lactate, and calcium pantothenate. These water-soluble calcium salts have the effect of improving the retention of fluoride ions in the oral cavity. As component (A), calcium chloride is particularly preferred from the viewpoints of the retention of fluoride ions in the oral cavity and the inhibition of the formation of viscous substances.

[0013] The blending amount of component (A) is 0.005 to 0.5% (mass%, the same applies below) of the entire composition, and preferably 0.01 to 0.2%. If the blending amount is less than 0.005%, the retention of fluoride ions in the oral cavity will be poor, and if it exceeds 0.5%, the astringent taste and unpleasant taste derived from component (A) will be strongly expressed, which may impair the feeling of use.

[0014] In the liquid oral composition of the present invention, water-soluble calcium salts other than component (A) can be blended within a range that does not interfere with the present effect, but it is preferable not to blend calcium glycerophosphate and calcium malate, especially from the viewpoint of the effect of inhibiting the formation of viscous substances and the feeling of use such as taste, etc. When a water-soluble calcium salt other than component (A) is blended, the blending amount is preferably 0.001% or less of the total composition, more preferably 0.0001% or less.

[0015] The component (B) is one or more selected from trihydric or higher polyols, diols (glycols) and sugar alcohols. These have the effect of improving the retention of fluoride ions in the oral cavity and inhibiting the formation of viscous substances. They also act as moisturizers. The trivalent or higher polyol is preferably a chain-like aliphatic compound having three or more hydroxyl groups (-OH), and examples thereof include glycerin and polyglycerin. The diol is preferably propylene glycol, butylene glycol, polyethylene glycol, and the like. The polyethylene glycol has a weight-average molecular weight of 200 to 1000, particularly 200 to 800, and the names of polyethylene glycols labeled as quasi-drugs are preferably polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 1000, or mixtures thereof. The sugar alcohol is preferably one having a solubility of 50% or more in water at 20°C, and examples thereof include sorbitol, maltitol, and xylitol. As component (B), glycerin, propylene glycol, sorbitol, maltitol, and xylitol are preferred, glycerin, propylene glycol, and sorbitol are more preferred, and glycerin and propylene glycol are even more preferred, and it is particularly preferred that the component (B) contains at least glycerin. It is particularly preferred that component (B) contains glycerin and propylene glycol, and it is most preferred to use a combination of glycerin, propylene glycol and sorbitol from the standpoint of the retention of fluoride ions in the oral cavity and the effect of inhibiting the formation of viscous substances.

[0016] The blending amount of the (B) component is 5-20% of the total composition, preferably 6-20%, and more preferably 8-15%. If the blending amount is less than 5%, the retention of fluoride ions in the oral cavity and the feeling of use (pleasant aftertaste) are inferior, and if it exceeds 20%, viscous matter is easily generated and the effect of inhibiting the generation of viscous matter is inferior. In addition, the astringent taste and unpleasant taste derived from the (B) component may continue strongly even after ejection, impairing the feeling of use. In addition, when the (B) component is two or more types including glycerin, the amount of glycerin is preferably 1% or more of the total composition, and the upper limit is preferably 10% or less, more preferably 8% or less, and particularly preferably 5% or less.

[0017] (C) The nonionic surfactant has an effect of suppressing the formation of viscous matter. The nonionic surfactant is preferably one having a polyoxyethylene chain, such as polyoxyethylene hydrogenated castor oil, polyoxyethylene polyoxypropylene glycol, polyoxyethylene alkyl ethers having a hydrocarbon group with 12 to 18 carbon atoms (e.g., polyoxyethylene cetyl ether), and the like. Among them, polyoxyethylene hydrogenated castor oil and polyoxyethylene polyoxypropylene glycol are preferred, and polyoxyethylene hydrogenated castor oil is more preferred. These can be used alone or in combination of two or more. The average number of moles of polyoxyethylene chains added (average number of moles of ethylene oxide added) is preferably 40 or more, particularly preferably 60 or more, more preferably 80 or more, and particularly preferably 100. The larger the average number of moles of polyoxyethylene chains added, the higher the effect of inhibiting the formation of viscous substances, and if it is less than 40, the effect of inhibiting the formation of viscous substances may be poor. There is no particular upper limit, but usually 100 or less is preferred.

[0018] The blending amount of component (C) is 0.2 to 1% of the total composition, preferably 0.3 to 0.7%, and more preferably 0.3 to 0.5%. If the blending amount is less than 0.2%, the effect of inhibiting the formation of viscous matter is inferior, and if it exceeds 1%, a strong unpleasant taste derived from component (C) may be generated, resulting in a poor feeling in use.

[0019] The ratio (mass ratio) of the blend amounts of the (A), (B) and (C) components can be (A):(B):(C) 1:20-1000:1-100 in terms of the retention of fluoride ions in the oral cavity, the effect of inhibiting the formation of viscous matter, and the sensation of use, such as aftertaste. In this case, the ratio of the amount of the component (A) to the component (B), (B) / (A), is a mass ratio of 20 to 1,000, preferably 30 to 800, and more preferably 40 to 600. If the mass ratio of (B) / (A) is less than 20, the retention of fluoride ions in the oral cavity and the feeling of use, such as aftertaste, are inferior, whereas if it exceeds 1,000, the effect of inhibiting the formation of viscous substances and the feeling of use are inferior. The ratio (C) / (A) of the amount of the component (A) to the component (C) is 1 to 100, preferably 1.5 to 90, and more preferably 2 to 20, as a mass ratio. If the mass ratio (C) / (A) is less than 1, the effect of inhibiting the formation of viscous substances and the feeling of use are inferior. If it exceeds 100, the retention of fluoride ions in the oral cavity and the feeling of use such as aftertaste are inferior, and even if the components (A) and (C) are mixed in appropriate amounts, the retention of fluoride ions in the oral cavity is low.

[0020] Component (D) is a condensed phosphoric acid or a salt thereof, and has the effect of improving the retention of fluoride ions in the oral cavity. Examples of the condensed phosphoric acid include linear polyphosphoric acids such as pyrophosphoric acid, tripolyphosphoric acid, and tetrapolyphosphoric acid, and cyclic polyphosphoric acids such as metaphosphoric acids such as trimetaphosphoric acid and tetrametaphosphoric acid, and examples of the salts thereof include sodium salts and potassium salts. Among these, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, and salts thereof are preferred, and linear polyphosphates such as sodium pyrophosphate, potassium pyrophosphate, sodium tripolyphosphate, and potassium tripolyphosphate are particularly preferred. These may be used alone or in combination of two or more, and commercially available products may be used.

[0021] The blending amount of component (D) is 0.05 to 1% of the total composition, preferably 0.05 to 0.5%, and more preferably 0.1 to 0.3%. If the blending amount is less than 0.05%, the retention of fluoride ions in the oral cavity will be poor, and if it exceeds 1%, a strong unpleasant taste derived from component (D) will be generated, which may result in a poor usability.

[0022] (E) Sodium fluoride is a source of fluoride ions. The amount of sodium fluoride is 0.005-0.21% of the total composition, preferably 0.01-0.1%, and more preferably 0.01-0.05%. If the amount is less than 0.005%, the retention of fluoride ions in the oral cavity is not improved. The greater the amount, the better the retention of fluoride ions in the oral cavity, but if the amount exceeds 0.21%, the risk of accidental ingestion increases, making the composition less safe.

[0023] Furthermore, the molar ratio of the component (D) to the component (E), (D) / (E), is preferably 0.1 to 3, particularly from the viewpoint of retention of fluoride ions in the oral cavity. The molar ratio of the component (A) to the component (E), (A) / (E), is preferably 0.3 to 15, particularly from the viewpoint of retention of fluoride ions in the oral cavity.

[0024] The liquid oral composition of the present invention can be prepared and applied as a liquid toothpaste, a mouthwash, a mouth freshener, etc., and is particularly suitable as a mouthwash. In addition to the above-mentioned components, other known components can be added as necessary depending on the formulation. Examples of components that can be added optionally include surfactants other than component (C), thickeners, sweeteners, colorants, flavors, active ingredients other than component (E), pH adjusters, solvents, etc.

[0025] The optional surfactant may be an amphoteric surfactant or an anionic surfactant. These optional surfactants do not have to be added, but if they are added, their amount should be 1% or less, particularly 0.01 to 0.5%, and especially 0.05 to 0.3%.

[0026] Examples of thickeners include xanthan gum, carrageenan, hydroxyethyl cellulose, sodium alginate, polyvinyl alcohol, and carboxymethyl cellulose (usually in an amount of 0 to 1%).

[0027] Examples of sweeteners include saccharin, sodium saccharin, sucralose, stevioside, aspartame, sucrose, and fructose. Coloring agents include safe water-soluble dyes such as Blue No. 1, Green No. 3, Yellow No. 4, and Red No. 105.

[0028] The fragrances are natural essential oils such as peppermint oil, spearmint oil, eucalyptus oil, wintergreen oil, clove oil, thyme oil, sage oil, cardamom oil, rosemary oil, marjoram oil, lemon oil, nutmeg oil, lavender oil, and parakress oil, as well as fragrance components contained in the above natural essential oils such as L-menthol, carvone, cinnamic aldehyde, orange oil, anethole, 1,8-cineole, methyl salicylate, eugenol, thymol, linalool, limonene, menthone, menthyl acetate, citral, camphor, borneol, pinene, and spilanthol, as well as ethyl acetate, ethyl butyrate, isoamyl acetate, hexanal, hexenal, methyl Examples of blended flavors include anthranilate, ethyl methylphenyl glycidate, benzaldehyde, vanillin, ethyl vanillin, furaneol, maltol, ethyl maltol, gamma / delta decalactone, gamma / delta decalactone, N-ethyl-p-menthane-3-carboxamide, menthyl lactate, ethylene glycol-l-menthyl carbonate, and further, blended flavors such as apple, banana, strawberry, blueberry, melon, peach, pineapple, grape, muscat, wine, cherry, squash, coffee, brandy, yogurt, etc., which are made by combining several fragrance ingredients and natural essential oils (the blending amount is usually 0.00001 to 3%).

[0029] Examples of the active ingredient include nonionic bactericides such as isopropylmethylphenol and thymol, cationic bactericides such as cetylpyridinium chloride, anionic bactericides such as sodium lauroyl sarcosine, anti-inflammatory agents such as tranexamic acid and allantoin, enzymes such as dextranase, sodium chloride, vitamins, and plant extracts. The active ingredient can be blended in an effective amount within a range that does not interfere with the effects of the present invention.

[0030] Examples of the pH adjuster include phthalic acid, phosphoric acid, citric acid, succinic acid, acetic acid, fumaric acid, malic acid, carbonic acid, and salts thereof such as potassium salts, sodium salts, and ammonium salts, and sodium hydroxide. It is preferable that the liquid oral composition of the present invention has a pH adjusted to 5.5 to 8.0 at 25° C., and a combination of citric acid and sodium citrate is suitable as a pH adjuster in this range.

[0031] The solvent is generally purified water, and may also contain a lower monohydric alcohol having 1 to 3 carbon atoms, such as ethanol.

[0032] The method for producing the liquid oral composition of the present invention is not particularly limited, and it can be produced by a known method depending on the dosage form. For example, it can be produced by mixing the components (A) to (E), water, and optional components by a conventional method. Regarding the blending of components (A), (D), and (E), it is preferable in view of ease of production to blend components (E) and (D) first and then blend component (A), or to blend components (D) and (A) first and then blend component (E).

[0033] The liquid oral composition of the present invention can be stored in a container generally known for liquid oral compositions, such as the container described in Patent No. 7154003. The container material is not particularly limited and may be a normal one, such as PET (polyethylene terephthalate), glass, polypropylene, polyethylene, etc. EXAMPLES

[0034] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, % indicates % by mass unless otherwise specified.

[0035] [Examples and Comparative Examples] Liquid oral compositions (mouthwashes) having the compositions shown in Tables 1 to 4 were prepared by a conventional method and evaluated by the following methods. The results are also shown in the tables. The numbers in parentheses for polyoxyethylene hydrogenated castor oil are the average number of moles of polyoxyethylene chains added.

[0036] (1) Suppressive effect on viscous production A test for measuring the formation of viscous matter and the torque required for opening the cap was carried out to evaluate the effect of inhibiting the formation of viscous matter. The container body and cap of the container described in Patent No. 7154003 were used, and the container body was filled with the mouthwash, and the cap was attached and closed at 0.05 MPa. The container was inverted and left to stand at 50°C for 30 days, and then the opening torque when opening the cap was measured using a DIGITAL TORQUE METER 2TME900CN (manufactured by Tohnichi Manufacturing Co., Ltd.), and the effect of inhibiting the formation of viscous substances was evaluated according to the following evaluation criteria. Note that, since the opening torque value increases when viscous substances are formed, it was determined that the smaller the opening torque value, the more the formation of viscous substances is inhibited. Evaluation criteria ◎: Opening torque <300cN m ○: 300cN·m≦opening torque<400cN·m △: 400cN·m≦opening torque<500cN·m ×: 500cN·m≦opening torque

[0037] (2) Fluoride ion (F - ) retention in the oral cavity The retention of fluoride ions on a saliva-coated substrate was evaluated. 2 mL of human exhaled saliva was placed on a polyethylene plate (hereinafter abbreviated as PE plate) (8 cm x 5 cm) and treated for 30 minutes. After that, it was washed with ion-exchanged water to prepare a pellicle-formed PE plate. 2 g of mouthwash was placed on the pellicle-formed PE plate and treated for 5 minutes, and then washed with 15 g of exhaled saliva. After treatment, the complex adsorbed on the pellicle-formed PE plate was solubilized with citrate buffer, and the fluoride ion concentration was measured. For the measurement of fluoride ion concentration, each sample was diluted 5 times with citrate buffer in advance so that the fluoride ion concentration was within 1,000 ppm. About 0.5 g of this was placed in a 24-hole polystyrene plate so as not to adsorb fluoride ions, and measured at room temperature using a fluoride ion concentration measuring device (Orion9609BNWP fluorine composite electrode, manufactured by Thermo Electron Co., Ltd.), and the value after 3 minutes was taken as the fluoride ion concentration. From the obtained fluoride ion concentration, the retention of fluoride ions in the oral cavity was evaluated according to the following evaluation criteria. Evaluation criteria ◎: Fluoride ion concentration ≦1.5ppm ○: 1.0 ppm or less fluoride ion concentration < 1.5 ppm △: 0.5ppm≦fluoride ion concentration<1.0ppm ×: 0 ppm ≦ fluoride ion concentration < 0.5 ppm

[0038] (3) Usability (good aftertaste) Eight subjects (six men and two women) rinsed their mouths with 10 mL of the mouthwash, and then spit it out and evaluated the aftertaste using the following criteria. Distilled water was used as a control and the sensory evaluation was performed with a score of 5. Evaluation criteria 5: Good aftertaste 4: Slightly good aftertaste 3: Neutral aftertaste 2: Slightly bad aftertaste 1: Bad aftertaste The average scores of the eight subjects were calculated and judged according to the following criteria. Judgment criteria: ◎: Average score 4 or higher ○: Average value 3 points or more and less than 4 points △: Average value is 2 points or more and less than 3 points ×: Average value less than 2 points

[0039] [Table 1]

[0040] [Table 2]

[0041] [Table 3] Note: In Comparative Examples 3 and 4, no viscous matter was produced.

[0042] [Table 4]

Claims

1. (A) 0.005 to 0.5 mass% of one or more calcium salts selected from calcium chloride, calcium gluconate, calcium lactate, and calcium pantothenate, (B) 5 to 20% by mass of one or more selected from trihydric or higher polyols, diols, and sugar alcohols, (C) 0.2 to 1 mass% of a nonionic surfactant, (D) Condensed phosphoric acid or a salt thereof 0.05 to 1% by mass and (E) Sodium fluoride 0.005 to 0.21 mass% A liquid oral composition comprising: (B) / (A) in a mass ratio of 20 to 1,000; and (C) / (A) in a mass ratio of 1 to 100.

2. A liquid oral composition as described in claim 1, wherein the (B) component is one or more selected from glycerin, propylene glycol, sorbitol and maltitol.

3. A liquid oral composition as described in claim 2, wherein the (B) component is a combination of glycerin, propylene glycol, and sorbitol.

4. A liquid oral composition as described in claim 1, wherein component (C) is one or more nonionic surfactants selected from polyoxyethylene hydrogenated castor oil, polyoxyethylene polyoxypropylene glycol, and polyoxyethylene alkyl ether.

5. A liquid oral composition as described in claim 4, wherein component (C) is polyoxyethylene hydrogenated castor oil having an average added mole number of 40 or more polyoxyethylene chains.

6. A liquid oral composition as described in claim 1, wherein component (D) is one or more condensed phosphoric acids or salts thereof selected from pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, and salts thereof.

7. A liquid oral composition according to any one of claims 1 to 6, which is a mouthwash.

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