Liquid oral composition

Abstract

To provide a liquid oral composition which ensures good solubility of glycyrrhetinic acid in a composition, further increases the adsorption amount of glycyrrhetinic acid to a mucous membrane in the oral cavity, and exhibits excellent storage stability over a low to high temperature range.SOLUTION: There is provided a liquid oral composition which comprises the following components (A) to (D): (A) 0.01 mass% or more and 0.2 mass% or less of glycyrrhetinic acid or its derivative or its salt; (B) a betaine type amphoteric surfactant; (C) one or two or more nonionic surfactants selected from a polyoxyethylene hydrogenated castor oil and a polyglyceryl fatty acid ester; and (D) water, wherein the mass ratio ((C) / (B)) between the content of the component (C) and the content of the component (B) is 0.5 or more and 3 or less and the liquid oral composition has a pH at 25°C of 8 or more and 11 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a liquid oral composition. [Background technology]

[0002] Glycyrrhetinic acid and its derivatives, which are known to have anti-inflammatory effects, have been used in various oral compositions because they are expected to have preventive or ameliorative effects on periodontitis, periodontal disease, and the like. For example, Patent Document 1 discloses a liquid oral composition that is alkaline but stably contains a sufficient amount of fragrance and may also contain β-glycyrrhetinic acid as an oil-soluble medicinal ingredient. Patent Document 2 discloses a liquid oral composition in a foaming container that contains a specific amount and a specific mass ratio of a nonionic surfactant and sodium alkyl sulfate, etc., and promotes the adsorption of oil-soluble medicinal ingredients such as β-glycyrrhetinic acid to the oral cavity surface while improving low-temperature storage stability. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-119636 A [Patent Document 2] JP 2018-123086 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, any of the liquid oral compositions described in the above patent documents requires further improvement in order to maintain the solubility of glycyrrhetinic acid and other substances in the composition, increase the amount of glycyrrhetinic acid and other substances adsorbed to the oral mucosa, and ensure storage stability that can withstand a wide range of temperature changes from low to high.

[0005] In other words, the present invention relates to a liquid oral composition that ensures good solubility of glycyrrhetinic acid and the like in the composition, further increases the amount of glycyrrhetinic acid and the like adsorbed to the oral mucosa, and exhibits excellent storage stability from low to high temperature ranges. [Means for solving the problem]

[0006] Therefore, after various investigations, the inventors have found a liquid oral composition which contains a specific amount of glycyrrhetinic acid or its derivative or salt (hereinafter also referred to as "glycyrrhetinic acid, etc.") in the alkaline range, and a specific mass ratio of a betaine-type amphoteric surfactant and a specific nonionic surfactant, thereby achieving both good solubility of glycyrrhetinic acid and an increased amount adsorption to the oral mucosa, and also exhibiting excellent storage stability over a wide temperature range.

[0007] Therefore, the present invention provides the following components (A) to (D): (A) Glycyrrhetinic acid or its derivative or its salt: 0.01% by mass or more and 0.2% by mass or less (B) Betaine-type amphoteric surfactant (C) One or more nonionic surfactants selected from polyoxyethylene hydrogenated castor oil and polyglycerin fatty acid esters (D)Water The present invention provides a liquid oral composition comprising: a liquid oral composition having a mass ratio ((C) / (B)) of the content of component (C) to the content of component (B) of 0.5 or more and 3 or less; and a pH at 25°C of 8 or more and 11 or less. Effect of the Invention

[0008] According to the liquid oral composition of the present invention, it is possible to increase the amount of glycyrrhetinic acid, etc. adsorbed to the oral mucosa while maintaining good solubility of glycyrrhetinic acid, etc. in the composition. In addition, it is possible to exhibit excellent storage stability even in low temperature and high temperature environments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described in detail below. The liquid oral composition of the present invention contains glycyrrhetinic acid or its derivative or salt as component (A) in an amount of 0.01% by mass to 0.2% by mass. Component (A) is a component that provides anti-inflammatory effects, alveolar bone resorption inhibitory effects, histamine release inhibitory effects, etc., and can be obtained from licorice, etc. The liquid oral composition of the present invention can effectively increase the amount of component (A) adsorbed to the oral mucosa while keeping it well dissolved regardless of temperature changes.

[0010] Examples of the glycyrrhetinic acid of component (A) include α-glycyrrhetinic acid, β-glycyrrhetinic acid, etc. Examples of the derivatives of glycyrrhetinic acid of component (A) include pyridoxine glycyrrhetinate, stearyl glycyrrhetinate, glyceryl glycyrrhetinate, monoglucuronide glycyrrhetinic acid, etc. Examples of the salts of glycyrrhetinic acid of component (A) include alkali metal salts such as sodium salts and potassium salts, and ammonium salts. Of these, β-glycyrrhetinic acid is preferred.

[0011] The content of component (A) in the liquid oral composition of the present invention is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.03% by mass or more, from the viewpoint of fully enjoying the effective action of component (A). The content of component (A) in the liquid oral composition of the present invention is 0.2% by mass or less, preferably 0.15% by mass or less, more preferably 0.08% by mass or less, from the viewpoint of maintaining good solubility of component (A). The content of component (A) in the liquid oral composition of the present invention is 0.01% by mass or more and 0.2% by mass or less, preferably 0.02 to 0.15% by mass, more preferably 0.03 to 0.08% by mass.

[0012] The liquid oral composition of the present invention contains a betaine-type amphoteric surfactant as component (B). By containing such component (B) and having a specific mass ratio ((C) / (B)) between the component (B) and a specific nonionic surfactant component (C) described later, the composition can effectively promote the adsorption of the component (A) to the oral mucosa while maintaining the high solubility of the component (A), and can effectively increase the storage stability over a wide temperature range, not only at low temperatures but also at high temperatures.

[0013] Examples of component (B) include one or more selected from acetate betaines such as lauryl dimethylamino acetate betaine; imidazolinium betaines such as 2-alkyl-N-carboxymethyl-N-hydroxyethyl-N-imidazolium betaine; alkyl sulfobetaines such as lauryl sulfobetaine and lauryl hydroxysulfobetaine; coconut oil fatty acid amido alkyl betaines such as coconut oil fatty acid amidopropyl betaine; and long-chain alkyl imidazoline betaine salts such as N-alkyl-1-hydroxyethyl imidazoline betaine sodium. Among these, from the viewpoint of effectively suppressing the generation of precipitates in the low temperature range and effectively exhibiting excellent storage stability in the high temperature range, one or more selected from coconut oil fatty acid amido alkyl betaines and alkyl sulfobetaines are preferred, one or more selected from coconut oil fatty acid amido alkyl betaines are more preferred, coconut oil fatty acid amido alkyl betaines having an alkyl carbon number of 2 to 5 are even more preferred, and coconut oil fatty acid amido propyl betaine is even more preferred.

[0014] The content of component (B) in the liquid oral composition of the present invention is preferably 0.02% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of increasing the amount of adsorption of component (A) to the oral mucosa, and from the viewpoint of effectively suppressing the generation of precipitates in the low temperature range and effectively exhibiting excellent storage stability in the high temperature range. Also, the content of component (B) in the liquid oral composition of the present invention is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1.5% by mass or less, and even more preferably 0.45% by mass or less, from the viewpoint of maintaining good solubility of component (A) and ensuring excellent storage stability that is not affected by temperature changes. The content of component (B) in the liquid oral composition of the present invention is preferably 0.02 mass% or more and 5 mass% or less, more preferably 0.05 to 4 mass%, even more preferably 0.1 to 3 mass%, even more preferably 0.15 to 2 mass%, even more preferably 0.2 to 1.5 mass%, and even more preferably 0.3 to 0.45 mass%.

[0015] The liquid oral composition of the present invention contains, as component (C), one or more nonionic surfactants selected from polyoxyethylene hydrogenated castor oil and polyglycerol fatty acid ester. By containing such component (C), although the nonionic surfactant is easily hydrolyzed, especially at high temperatures, in combination with the above-mentioned component (B), it is possible to effectively promote adsorption to the oral mucosa while ensuring good solubility of component (A), and it is possible to ensure excellent storage stability even at high temperatures.

[0016] Examples of polyoxyethylene hydrogenated castor oil include those having an average number of moles of ethylene oxide added of 20 to 100. In particular, the average number of moles of ethylene oxide added in such polyoxyethylene hydrogenated castor oil is more preferably 20 to 60 from the viewpoint of effectively realizing both good solubility of component (A) and an increase in the amount of component (A) adsorbed to the oral mucosa, and is preferably 20 to 50, more preferably 30 to 50 from the viewpoint of the adsorption of component (A) to the oral mucosa.

[0017] Examples of polyglycerol fatty acid esters include those in which 1 to 4 fatty acids having 8 to 24 carbon atoms are ester-bonded to polyglycerol formed by condensing 2 to 20 glycerols. Among them, from the viewpoint of effectively realizing both good solubility of component (A) and an increase in the amount of adsorption to the oral mucosa, those derived from fatty acids having 12 to 20 carbon atoms are preferred, those derived from fatty acids having 12 to 18 carbon atoms are more preferred, those derived from fatty acids having 12 to 14 carbon atoms are even more preferred, and monoesters are preferred. From the same viewpoint, the average degree of condensation of glycerin in the polyglycerol fatty acid ester is preferably 2 to 20, more preferably 5 to 12.

[0018] The content of component (C) in the liquid oral composition of the present invention is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, from the viewpoint of effectively increasing the amount of component (A) adsorbed to the oral mucosa while ensuring good solubility. The content of component (C) in the liquid oral composition of the present invention is preferably 1.2% by mass or less, more preferably 1.1% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of suppressing the deterioration of the storage stability of the composition due to unnecessary hydrolysis of component (C), especially in a high temperature range. The content of component (C) in the liquid oral composition of the present invention is preferably 0.05 to 1.2% by mass, more preferably 0.1 to 1.1% by mass, and even more preferably 0.2 to 1% by mass.

[0019] In the liquid oral composition of the present invention, the mass ratio of the content of component (C) to the content of component (B) ((C) / (B)) is 0.5 or more, preferably 0.8 or more, and more preferably 1.2 or more, from the viewpoint of achieving both good solubility of component (A) and increased adsorption to the oral mucosa. The mass ratio of the content of component (C) to the content of component (B) ((C) / (B)) is 3 or less, preferably 2.5 or less, and more preferably 1.5 or less, from the viewpoint of ensuring excellent storage stability over a wide temperature range. The mass ratio of the content of component (C) to the content of component (B) ((C) / (B)) is 0.5 or more and 3 or less, preferably 0.8 to 2.5, and more preferably 1.2 to 1.5.

[0020] The total content of component (B) and component (C) in the liquid oral composition of the present invention is preferably 0.07 to 6 mass%, more preferably 0.7 to 3 mass%, and even more preferably 0.85 to 2.5 mass%, in order to exhibit sufficient cleaning performance in the alkaline range while exhibiting excellent storage stability from low to high temperature ranges.

[0021] The liquid oral composition of the present invention contains water as component (D). The water of component (D) in the present invention means the total water contained in the liquid oral composition, including not only purified water or ion-exchanged water, etc., contained in the liquid oral composition, but also the water contained in each of the components contained. By containing such water as component (D), each component can be well dispersed or dissolved and well diffused in the oral cavity, and excellent storage stability can be ensured while effectively increasing the amount of component (A) adsorbed to the oral mucosa.

[0022] The content of component (D) in the liquid oral composition of the present invention is preferably 55% by mass or more, more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more, from the viewpoint of achieving both good solubility of component (A) and an increase in the amount of adsorption to the oral mucosa, and from the viewpoint of ensuring excellent storage stability that is not affected by temperature changes. The content of component (D) in the liquid oral composition of the present invention is preferably 99.6% by mass or less, more preferably 99.4% by mass or less, and even more preferably 99.2% by mass or less, from the viewpoint of effectively increasing the amount of adsorption of component (A) to the oral mucosa. The content of component (D) in the liquid oral composition of the present invention is preferably 55 to 99.6% by mass, more preferably 60 to 99.4% by mass, and even more preferably 65 to 99.2% by mass.

[0023] In addition to the above components, the liquid oral composition of the present invention preferably contains a pH adjuster from the viewpoint of easily adjusting the pH at 25°C to a specified range described below and effectively exerting the desired effect. Such pH adjusters include one or more selected from carbonates and bicarbonates; potassium hydroxide and sodium hydroxide; and organic acids such as citric acid, malic acid, lactic acid, tartaric acid, and succinic acid or salts thereof. Among them, one or more selected from sodium carbonate, sodium hydrogen carbonate, and sodium sesquicarbonate are preferred, and it is more preferred to contain sodium carbonate and sodium hydrogen carbonate.

[0024] From the viewpoint of stabilizing the pH of the liquid oral composition, the content of the pH adjuster in the liquid oral composition of the present invention is preferably 0.1 to 2 mass%, more preferably 0.15 to 1.5 mass%, even more preferably 0.18 to 1 mass%, and even more preferably 0.2 to 0.8 mass%. In addition, when sodium carbonate and sodium bicarbonate are contained, the content of sodium bicarbonate is preferably 40 to 70 mass%, more preferably 45 to 60 mass% of the total content of sodium carbonate and sodium bicarbonate.

[0025] It is preferable to limit the content of anionic surfactants in the liquid oral composition of the present invention in order to ensure good solubility of component (A) and excellent storage stability that is not affected by temperature changes. Examples of such anionic surfactants include one or more selected from alkyl sulfate ester salts such as sodium alkyl sulfate, acylamino acid salts such as sodium acyl glutamate and sodium acyl sarcosine, N-methyl long-chain acyltaurate sodium salts such as sodium lauryl methyl taurine, alkyl phosphates such as sodium alkyl phosphate, higher fatty acid sulfonated monoglyceride salts, fatty acid ester salts of isethionic acid, and polyoxyethylene monoalkyl phosphates. In order to ensure good stability from immediately after production to after storage at low temperatures, the content of anionic surfactant in the liquid oral composition of the present invention is preferably 0.05 mass% or less, more preferably 0.03 mass% or less, and even more preferably 0.01 mass% or less, or it is preferable that the liquid oral composition of the present invention substantially does not contain anionic surfactant.

[0026] The liquid oral composition of the present invention may contain, in addition to the above-mentioned components, appropriate amounts of humectants such as glycerin, polyethylene glycol, and propylene glycol; sugar alcohols such as sorbitol, erythritol, reduced palatinose, and mannitol; binders such as sodium alginate, carboxymethylcellulose or its salts, hydroxyethylcellulose, carrageenan, and xanthan gum; preservatives such as isobutyl parahydroxybenzoate and methyl salicylate; fluorides; bactericides such as cetylpyridinium chloride and benzethonium chloride; amphoteric surfactants other than the above component (B); nonionic surfactants other than the above component (C); fragrances; pigments; colorants, etc., within the range that does not inhibit the effects of the present invention.

[0027] The pH of the liquid oral composition of the present invention at 25°C is from 8 to 11, preferably from 8.5 or more, and more preferably from 9 or more, from the viewpoint of effectively increasing the amount of component (A) adsorbed to the oral mucosa while exhibiting high cleaning performance, and from the viewpoint of ensuring excellent storage stability unaffected by temperature changes, and is preferably from 8.5 or more, and more preferably from 9 or more, and is preferably from 10.8 to 10.5. In addition, the pH of the liquid oral composition of the present invention means the value measured at 25°C using a pH electrode.

[0028] Examples of the liquid oral composition of the present invention include mouthwash, mouth spray, liquid toothpaste, and gel toothpaste. When applying the liquid oral composition of the present invention, it is sufficient to directly gargle the oral cavity and then rinse with water or the like, without the need for brushing as with toothpaste compositions. With the liquid oral composition of the present invention, component (A) can be effectively adsorbed to the oral mucosa even after rinsing. Alternatively, the liquid oral composition of the present invention can be filled into a foam-dispensing container and discharged into the oral cavity as a foam-like composition from a discharge port, and then applied. EXAMPLES

[0029] The present invention will now be described in detail with reference to the following examples. In the tables, the content of each component is expressed as mass % unless otherwise specified.

[0030] [Examples 1 to 7, Comparative Examples 1 to 7] A liquid oral composition was prepared according to the formulation shown in Table 1. Next, the obtained liquid oral composition was used to carry out various measurements and evaluations according to the following methods. The results are shown in Table 1.

[0031] <pH measurement at 25℃> The measurement was performed at 25°C using a pH electrode.

[0032] Evaluation of the solubility of component (A) Immediately after production, each liquid oral composition was visually observed and evaluated according to the following criteria. A: Completely uniform and transparent B: Although it was slightly cloudy, it was in a homogeneous dissolved state. C: It was cloudy, but there was nothing undissolved. D: Undissolved material was confirmed

[0033] Evaluation of low-temperature storage stability Each of the obtained liquid oral compositions was filled into a glass bottle and stored at 5°C for 7 days. The liquid oral composition contents were then visually observed from the outside of the glass bottle and evaluated according to the following criteria. A: Completely transparent and uniform B: It was slightly cloudy, but uniform. C: It was cloudy, but no precipitate was observed. D: Precipitation was confirmed.

[0034] Evaluation of high-temperature storage stability Each of the obtained liquid oral compositions was filled into a glass bottle and stored at 60°C for 3 days. The liquid oral composition contents were then visually observed from the outside of the glass bottle and evaluated according to the following criteria. A: Completely transparent and uniform B: It was slightly cloudy, but uniform. C: It was cloudy, but no precipitate was observed. D: Precipitation was confirmed.

[0035] <<Measurement of the adsorption amount of component (A)>> Using each of the obtained liquid oral compositions, a silicone sheet was employed as a model of the oral mucosa, and the amount of β-glycyrrhetinic acid adsorbed onto the silicone sheet was measured according to the following method. Specifically, a cylindrical tube (cross-sectional area 7.07 × 10 -4 m 2)(0) was placed with one open end surface in close contact with the surface of the silicone sheet. Next, 1.0 g of each sample was introduced into the cylindrical tube from the other open end of the cylindrical tube so that the contact area between the sample and the silicone sheet became the same as the inner cross-sectional area of the cylindrical tube, and was applied onto the surface of the silicone sheet inside the cylindrical tube surrounded by the circumferential surface of the cylindrical tube. The sample and the silicone sheet were left in contact for 2 minutes. Each obtained silicone sheet was immersed in ion-exchanged water in a 50 mL beaker for 30 seconds, then taken out from the beaker, 1.5 mL of an extract (mobile phase shown below) was applied for 30 seconds to recover component (A), and β-glycyrrhetinic acid (A) was quantified (μmol / m 2 ) by high performance liquid chromatography (HPLC) according to the following measurement conditions.

[0036] <HPLC Measurement Conditions> Apparatus: Hitachi High Performance Liquid Chromatogram La chromElite Detector: Ultraviolet Absorption Photometer (Measurement Wavelength: 250 nm) Column: CAPCELL PAK SCX UG80 (4.6 × 100 mm, 5 μm) (Shiseido Co., Ltd.) Column Temperature: 40°C Mobile Phase: Mixed solution of methanol / water (4:1) + 0.1 mol / L phosphoric acid Flow Rate: 1.0 mL / min

[0037]

Table 1

Claims

1. The following components (A) to (D): (A) Glycyrrhetinic acid or a salt thereof: 0.01% by mass or more and 0.2% by mass or less (B) Coconut oil fatty acid amidoalkyl betaine 0.02% by mass or more and 5% by mass or less (C) one or more nonionic surfactants selected from polyoxyethylene hydrogenated castor oil and polyglycerin fatty acid esters (D) Water A liquid oral composition comprising: a mass ratio (C) / (B) of the content of component (C) to the content of component (B) of 0.5 or more and 1.5 or less; and a pH at 25°C of 8 or more and 11 or less.

2. A liquid oral composition as described in claim 1, wherein the content of component (D) is 55% by mass or more and 99.6% by mass or less.

3. A liquid oral composition described in claim 1 or 2, wherein the sum of the content of component (B) and the content of component (C) is 0.07 to 6 mass%.

4. A liquid oral composition described in any one of claims 1 to 3, having an anionic surfactant content of 0.05 mass% or less, or containing no anionic surfactant.

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