Liquid oral components

Abstract

To provide a liquid oral composition containing activated carbon, with the dispersion stability of the activated carbon being improved, and the adsorption ability of the activated carbon to be effectively expressed.SOLUTION: A liquid oral composition comprises activated carbon with an average particle size of 10 μm or less, and at least one surfactant selected from anionic surfactants, ampholytic surfactants, and polyoxyethylene hydrogenated castor oil.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a liquid oral composition containing activated carbon, wherein the dispersibility and stability of the activated carbon are improved, and the adsorption ability of the activated carbon can be effectively exhibited.

Background Art

[0002] Activated carbon is known to function as an adsorbent, and in the field of oral compositions, activated carbon has been conventionally used for purposes such as prevention or removal of plaque and tartar, tooth whitening, and prevention or removal of bad breath.

[0003] Various formulations of oral compositions containing activated carbon have been conventionally reported. For example, Patent Document 1 reports that a dentifrice containing carbide powder with a particle diameter of 10 to 500 µm has no danger to the human body even after long-term use, is excellent in toothbrushing effects such as food residue removal, and provides a good brushing feeling. In addition, Patent Document 2 reports that a toothpaste comprising (A) granules containing charcoal powder and / or charcoal granules and (B) charcoal powder makes it difficult to visually recognize the contours of the granules and / or charcoal granules, and can have an excellent appearance.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problem to be Solved by the Invention

[0005] Activated carbon has the characteristic of easily settling in liquids and is difficult to maintain a uniform dispersion state. Therefore, when incorporating activated carbon into liquid oral compositions such as mouthwashes and liquid toothpastes, it is important to design the formulation so that the activated carbon is uniformly dispersed. Furthermore, in liquid oral compositions containing activated carbon, if other additives are adsorbed onto the activated carbon and the pores of the activated carbon become clogged, the adsorption capacity is reduced. Therefore, when designing a formulation to ensure uniform dispersion of activated carbon in a liquid oral composition containing activated carbon, care must be taken not to adversely affect the adsorption capacity of the activated carbon. However, in conventional technology, no formulation techniques have been reported that improve the dispersibility stability of activated carbon while effectively expressing its adsorption capacity in liquid oral compositions containing activated carbon.

[0006] Therefore, the object of the present invention is to provide a liquid oral composition containing activated carbon, wherein the dispersibility and stability of the activated carbon are improved, and the adsorption capacity of the activated carbon can be effectively expressed. [Means for solving the problem]

[0007] The inventors of the present invention conducted diligent research to solve the aforementioned problems and found that by selecting activated carbon with an average particle size of 10 μm or less, and incorporating this activated carbon into a liquid oral composition together with at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil, the dispersion stability of the activated carbon can be improved and its adsorption capacity can be effectively expressed. The present invention was completed by further research based on this finding.

[0008] In other words, the present invention provides inventions in the following embodiments. Item 1. Activated carbon with an average particle size of 10 μm or less, and A liquid oral composition containing at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil. Item 2. The liquid oral composition according to Item 1, wherein the surfactant is at least one selected from alkyl sulfate esters and their salts, higher fatty acid amidosulfonic acid and its salts, imidazoline-type amphoteric surfactants, and polyoxyethylene hydrogenated castor oil. Item 3. The liquid oral composition according to item 1 or 2, comprising 0.001 to 0.1% by weight of the activated carbon. Item 4. A liquid oral composition according to any one of items 1 to 3, containing 0.001 to 8% by weight of the surfactant. Item 5. A liquid oral composition according to any one of items 1 to 4, which is a mouthwash. [Effects of the Invention]

[0009] According to the liquid oral composition of the present invention, the adsorption capacity of activated carbon can be effectively expressed while improving the dispersibility stability of activated carbon. [Modes for carrying out the invention]

[0010] 1.Liquid oral composition The liquid oral composition of the present invention is characterized by containing activated carbon with an average particle size of 10 μm or less, and at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil. In the liquid oral composition of the present invention, by selecting activated carbon with an average particle size of 10 μm or less and coexisting it with a specific surfactant, it is possible to improve the dispersion stability of the activated carbon and effectively express the adsorption capacity of the activated carbon. The liquid oral composition of the present invention will be described in detail below.

[0011] [Activated carbon] The liquid oral composition of the present invention contains activated carbon with an average particle size of 10 μm or less. While the average particle size of the activated carbon used in the present invention may be 10 μm or less, from the viewpoint of further improving the dispersion stability of the activated carbon and more effectively exhibiting its adsorption capacity, it is preferably 8 μm or less, more preferably 7 μm or less, and even more preferably 6 μm or less. The lower limit of the average particle size of the activated carbon used in the present invention is not particularly limited, but for example, it is 1 μm or more, preferably 2 μm or more, and more preferably 4 μm or more. More specifically, the average particle size of the activated carbon used in the present invention is 1 to 10 μm, preferably 2 to 8 μm, more preferably 3 to 7 μm, and even more preferably 4 to 6 μm. In the present invention, the average particle size of the activated carbon is the particle size (median diameter, D) at which the cumulativeity in the volume cumulative reference particle size distribution measured by a wet method using a laser diffraction / scattering particle size distribution analyzer reaches 50%. 50 )

[0012] D of the activated carbon used in this invention 10 Regarding this, there are no particular limitations as long as it satisfies the above-mentioned average particle size range, but for example, 0.5 to 3 μm, preferably 1 to 1.5 μm. In the present invention, the D of activated carbon 10 This refers to the particle size at which the cumulative percentage reaches 10% in the volume-cumulative reference particle size distribution measured by a wet method using a laser diffraction / scattering particle size distribution analyzer.

[0013] Furthermore, the D of the activated carbon used in this invention 90 Regarding this, there are no particular limitations as long as it satisfies the above-mentioned average particle size range, but for example, 10 to 30 μm, preferably 15 to 20 μm. In the present invention, the D of activated carbon 90 This refers to the particle size at which the cumulative percentage reaches 90% in the volume-cumulative reference particle size distribution measured by a wet method using a laser diffraction / scattering particle size distribution analyzer.

[0014] Examples of activated carbon content in the liquid oral composition of the present invention include 0.0001 to 1% by weight, preferably 0.001 to 0.1% by weight, and more preferably 0.005 to 0.05% by weight.

[0015] [Surfactants] The liquid oral composition of the present invention contains, together with the activated carbon, at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil.

[0016] The types of anionic surfactants used in the present invention are not particularly limited, as long as they are applicable to oral cavity use, but examples include alkyl sulfate esters and their salts such as lauryl sulfate, laureth sulfate, myristyl sulfate, cetyl sulfate, and oleyl sulfate; higher fatty acid amide sulfonic acids and their salts such as lauroyl methyl taurine, myristoyl methyl taurine, coconut oil fatty acid methyl taurine, and lauryl methyl taurine; α-olefin sulfonic acids and their salts; N-acyl amino acids and their salts such as N-myristoyl glutamic acid, cocoyl glutamic acid, N-lauroyl glutamic acid, N-stearoyl glutamic acid, and cocoyl glycine; alkylbenzene sulfonic acids and their salts such as dodecylbenzene sulfonic acid; polyoxyethylene alkyl ether sulfates and their salts such as polyoxyethylene lauryl ether sulfate; and N-acyl sarcosinic acids and their salts such as lauroyl sarcosine. Examples of salt forms of these anionic surfactants include alkali metal salts such as sodium salts and potassium salts. Among these anionic surfactants, alkyl sulfate esters, higher fatty acid amidosulfonic acids, and their salts are preferred, more preferably lauryl sulfate, lauroyl methyl taurate, and their salts, and even more preferably sodium lauryl sulfate and sodium lauroyl methyl taurate.

[0017] The type of amphoteric surfactant used in the present invention is not particularly limited, as long as it can be applied to the oral cavity. Examples thereof include imidazoline-type amphoteric surfactants such as N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine, N-coconut oil fatty acid acyl-N-carboxyethyl-N-hydroxyethylethylenediamine, N-coconut oil fatty acid-N-carboxymethoxyethyl-N-carboxymethylethylenediamine, N-coconut oil fatty acid acyl-N-carboxyethoxyethyl-N-carboxyethylethylenediamine, and salts thereof; alkylbetaine-type amphoteric surfactants such as lauryldimethylaminoacetic acid betaine, myristyldimethylaminoacetic acid betaine, palmityldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, coconut oil fatty acid dimethylaminoacetic acid betaine, palm kernel oil fatty acid dimethylaminoacetic acid betaine, lauryldihydroxyethylaminoacetic acid betaine, and salts thereof; and amide betaine-type amphoteric surfactants such as laurylamidopropyldimethylaminoacetic acid betaine, myristylamidopropyldimethylaminoacetic acid betaine, palmitylamidopropyldimethylaminoacetic acid betaine, stearylamidopropyldimethylaminoacetic acid betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, palm kernel oil fatty acid amidopropyldimethylaminoacetic acid betaine laurylamidopropyldimethylaminoacetic acid betaine, and salts thereof. Examples of the salt form of these amphoteric surfactants include alkali metal salts such as sodium salts and potassium salts. Among these amphoteric surfactants, imidazoline-type amphoteric surfactants are preferred, N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine and salts thereof are more preferred, and N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine sodium is even more preferred.

[0018] The type of polyoxyethylene hydrogenated castor oil used in the present invention is not particularly limited as long as it is applicable to the oral cavity. Examples thereof include polyoxyethylene hydrogenated castor oil 5, polyoxyethylene hydrogenated castor oil 10, polyoxyethylene hydrogenated castor oil 20, polyoxyethylene hydrogenated castor oil 30, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 50, polyoxyethylene hydrogenated castor oil 60, polyoxyethylene hydrogenated castor oil 70, polyoxyethylene hydrogenated castor oil 80, polyoxyethylene hydrogenated castor oil 90, polyoxyethylene hydrogenated castor oil 100, and the like. Among these polyoxyethylene hydrogenated castor oils, preferred are polyoxyethylene hydrogenated castor oil 10, polyoxyethylene hydrogenated castor oil 20, polyoxyethylene hydrogenated castor oil 30, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 50, polyoxyethylene hydrogenated castor oil 60, and polyoxyethylene hydrogenated castor oil 70; more preferred are polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 50, and polyoxyethylene hydrogenated castor oil 60.

[0019] These surfactants may be used singly, or two or more of them may be used in combination.

[0020] Among these surfactants, from the viewpoint of improving the dispersion stability of activated carbon and more effectively exhibiting the adsorption ability of activated carbon, anionic surfactants and amphoteric surfactants are preferred; alkyl sulfate esters and salts thereof, higher fatty acid amide sulfonic acids and salts thereof, and imidazoline-type amphoteric surfactants are more preferred; lauryl sulfuric acid, lauroylmethyltaurine, N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine, and salts thereof are even more preferred; lauroylmethyltaurine, N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethylethylenediamine, and salts thereof are particularly preferred.

[0021] Examples of the surfactant content in the liquid oral composition of the present invention include 0.001 to 8% by weight, preferably 0.01 to 5% by weight, and more preferably 0.1 to 2% by weight.

[0022] Furthermore, in the liquid oral composition of the present invention, the ratio of activated carbon to the surfactant is determined according to the respective content ranges described above, but for example, the surfactant is present in an amount of 0.1 to 5000 parts by weight, preferably 1 to 1000 parts by weight, and more preferably 10 to 250 parts by weight per 1 part by weight of activated carbon.

[0023] [water] The liquid oral composition of the present invention contains water as a solvent. The water content in the liquid oral composition of the present invention may be the remainder after excluding the added components.

[0024] [Other ingredients] In addition to the components described above, the oral composition of the present invention may optionally contain other pharmacoactive ingredients. Such pharmacoactive ingredients are not particularly limited as long as they can be incorporated into the oral composition, but examples include bactericides, bronchodilators, antitussives, expectorants, anti-inflammatory agents, glucosyltransferase inhibitors, plaque inhibitors, hypersensitivity inhibitors, tartar preventives, antipyretic analgesics, antihistamines, bactericides, gastric mucosal protectants, caffeines, vitamins, herbal medicines, and crude drug components.

[0025] Furthermore, the liquid oral composition of the present invention may contain bases and additives in order to obtain a desired formulation. Such bases and additives are not particularly limited as long as they can be incorporated into the oral composition, but examples include lower alcohols, polyhydric alcohols, oily components, sugar alcohols, surfactants other than those mentioned above, cooling agents, preservatives, thickeners, fragrances, flavoring agents, pigments, deodorizing components, pigments other than activated carbon, buffers, pH adjusters, and the like.

[0026] [Formulation] The formulation form of the liquid oral composition of the present invention is not limited as long as it can be applied to the oral cavity and remain there for a certain period of time. Examples include mouthwash, liquid toothpaste, oral spray (including throat spray), gargle, and mouth freshener. Among these, mouthwash and liquid toothpaste are preferred, and mouthwash is more preferred.

[0027] 2. Method for improving dispersibility The present invention provides a method for improving the dispersion stability of activated carbon in a liquid oral composition, characterized in that the liquid oral composition contains activated carbon with an average particle size of 10 μm or less, and at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil.

[0028] In the dispersibility improvement method of the present invention, the types and amounts of components used, the formulation form of the liquid oral composition, etc., are as shown in the "1. Liquid Oral Composition" section above.

[0029] 3. Methods for improving adsorption capacity The present invention provides a method for improving the adsorption capacity of activated carbon in a liquid oral composition, characterized in that the liquid oral composition contains activated carbon with an average particle size of 10 μm or less, and at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil.

[0030] The present invention provides a method for improving adsorption capacity, which is implemented to suppress the decrease in the adsorption capacity of activated carbon in a liquid oral composition. The types and amounts of components used, the formulation form of the liquid oral composition, etc., are as described in section "1. Liquid Oral Composition" above. [Examples]

[0031] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0032] Test Example 1 Mouthwashes with the compositions shown in Tables 1 and 2 were prepared. The dispersion stability and adsorption capacity of the activated carbon in the obtained mouthwashes were evaluated by the following methods. Note that the average particle size (D50) and D of the activated carbon used in the following examples and comparative examples were as follows. 10 , and D 90 This value was obtained using the MT3300 particle size distribution analyzer (Microtrac-Bell Co., Ltd.) with laser diffraction and scattering methods, using a wet measurement method and a measurement time of 10 seconds.

[0033] <Dispersion stability of activated carbon> 100 ml of thoroughly mixed mouthwash was filled into a 150 ml glass container and left to stand at room temperature for 3 days. After observation, the appearance was observed, and the dispersion stability of the activated carbon was evaluated according to the following criteria. Immediately after filling the glass container, the activated carbon was sufficiently dispersed in each mouthwash (except for Comparative Example 1), and the entire mouthwash was black due to the activated carbon. Criteria for determining the dispersion stability of activated carbon ◎: The entire mouthwash is black in color, and the activated charcoal is evenly dispersed. ○: The top of the mouthwash is slightly transparent, but the dispersion state of the activated carbon is almost maintained. ×: The top of the mouthwash is completely clear, and the activated charcoal has settled and is unevenly distributed.

[0034] <Adsorption capacity of activated carbon> Methylene blue (0.12 g / 100 ml) was added to each mouthwash to a 100-fold dilution and mixed for 20 seconds. The solution was then filtered through activated carbon, and the absorbance (644 nm) of the resulting filtrate was measured. As a control, the absorbance of a solution prepared by diluting methylene blue (0.12 g / 100 ml) 100-fold with purified water was also measured. The methylene blue adsorption rate was calculated according to the following formula.

number

[0035] The results obtained are shown in Tables 1 and 2. When activated carbon was included alone, dispersion stability could not be achieved at both average particle sizes of 5 μm and 75 μm (Comparative Examples 2 and 3). Furthermore, when activated carbon with an average particle size of 75 μm was combined with a surfactant, dispersion stability was not improved with any of the surfactants, and the adsorption capacity of the activated carbon was reduced (Comparative Examples 4-6 and 8-11). In addition, when activated carbon with an average particle size of 75 μm was combined with polyoxyethylene cetyl ether, dispersion stability was improved, but a reduction in the adsorption capacity of the activated carbon was observed (Comparative Example 7). In contrast, when activated carbon with an average particle size of 5 μm was combined with an anionic surfactant (sodium lauryl sulfate, sodium lauroyl methyl taurate), an amphoteric surfactant (sodium N-coconut oil fatty acid acyl-N-carboxymethyl-N-hydroxyethyl ethylenediamine sodium), or polyoxyethylene hydrogenated castor oil, dispersion stability was improved, and the adsorption capacity of the activated carbon was also excellent (Examples 1-6). In particular, when activated carbon with an average particle size of 5 μm was combined with an anionic surfactant or an amphoteric surfactant, the decrease in the adsorption capacity of the activated carbon was suppressed remarkably effectively (Examples 1-3). Furthermore, when activated carbon with an average particle size of 5 μm was combined with polyoxyethylene hydrogenated castor oil, in particular with polyoxyethylene hydrogenated castor oil 60, We were able to obtain favorable results (Examples 4-6).

[0036] [Table 1]

[0037] [Table 2]

[0038] Prescription examples Mouthwashes (Formulation Examples 1-6), liquid toothpastes (Formulation Examples 7 and 8), and oral sprays (Formulation Example 9) with the compositions shown below were prepared. The dispersion stability and adsorption capacity of the activated carbon in the obtained mouthwashes, liquid toothpastes, and oral sprays were evaluated in the same manner as in Test Example 1. In all cases, the activated carbon was uniformly dispersed and the adsorption capacity was excellent.

[0039] Prescription Example 1 (Mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.006 Polyoxyethylene (20) hydrogenated castor oil 0.05 Polyoxyethylene (60) hydrogenated castor oil 0.1 l-Menthol 0.05 Methyl parahydroxybenzoate 0.05 Glycerin 10 1,3-Butylene glycol 5 Sodium saccharin 0.01 Ethanol 7 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0040] Prescription example 2 (mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.01 Polyoxyethylene (60) hydrogenated castor oil 0.5 l-menthol 0.1 Methyl parahydroxybenzoate 0.1 Ethyl parahydroxybenzoate 0.05 Glycerin 10 Propylene glycol 5 Sodium saccharin 0.02 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0041] Prescription example 3 (mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.05 Polyoxyethylene (40) hydrogenated castor oil 1.0 Sodium lauroyl methyl taurate 0.5 l-menthol 0.1 Methyl parahydroxybenzoate 0.1 Ethyl parahydroxybenzoate 0.05 Glycerin 10 Propylene glycol 5 Sodium saccharin 0.01 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0042] Prescription example 4 (mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 3μm) 0.006 Polyoxyethylene (20) hydrogenated castor oil 0.05 Polyoxyethylene (60) hydrogenated castor oil 0.1 l-Menthol 0.05 Methyl parahydroxybenzoate 0.05 Glycerin 10 1,3-Butylene glycol 5 Sodium saccharin 0.01 Ethanol 7 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0043] Prescription Example 5 (Mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 8μm) 0.01 Polyoxyethylene (60) hydrogenated castor oil 0.5 l-menthol 0.1 Methyl parahydroxybenzoate 0.1 Ethyl parahydroxybenzoate 0.05 Glycerin 10 Propylene glycol 5 Sodium saccharin 0.02 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0044] Prescription Example 6 (Mouthwash) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.1 Polyoxyethylene (40) hydrogenated castor oil 1.0 Sodium lauroyl methyl taurate 0.5 l-menthol 0.1 Methyl parahydroxybenzoate 0.1 Ethyl parahydroxybenzoate 0.05 Glycerin 10 Propylene glycol 5 Sodium saccharin 0.01 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

[0045] Prescription Example 7 (Liquid Toothpaste) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.01 Polyoxyethylene (60) hydrogenated castor oil 0.1 Sodium lauryl sulfate 0.1 Cetylpyridinium chloride 0.3 Peppermint-based fragrance (oil-based component) 0.1 Sorbitol 10 1,3-Butylene glycol 5 Sodium saccharin 0.01 pH adjuster (sodium dihydrogen phosphate, sodium monohydrogen phosphate) appropriate amount Purified water remainder Total 100

[0046] Prescription Example 8 (Liquid Toothpaste) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.01 Polyoxyethylene (20) hydrogenated castor oil 0.8 Polyoxyethylene (40) hydrogenated castor oil 0.8 Cetylpyridinium chloride 0.3 Peppermint-based fragrance (oil-based component) 0.1 Glycerin 10 Propylene glycol 5 Sodium saccharin 0.01 pH adjuster (sodium dihydrogen phosphate, sodium monohydrogen phosphate) appropriate amount Purified water remainder Total 100

[0047] Prescription Example 9 (Mouth Spray) Ingredients Amount (wt%) Activated carbon (average particle size 5μm) 0.01 Polyoxyethylene (60) hydrogenated castor oil 0.1 Polyoxyethylene (20) hydrogenated castor oil 0.05 Peppermint oil (oil-based component) 0.2 l-Menthol 0.05 Ethanol 35 Glycerin 10 Sodium saccharin 0.1 pH adjuster (citric acid, sodium citrate) appropriate amount Purified water remainder Total 100

Claims

1. Activated carbon with an average particle size of 10 μm or less, in an amount of 0.0001 to 0.05% by weight, A liquid oral composition containing at least one surfactant selected from anionic surfactants, amphoteric surfactants, and polyoxyethylene hydrogenated castor oil.

2. The liquid oral composition according to claim 1, wherein the surfactant is at least one selected from alkyl sulfate esters and their salts, higher fatty acid amidosulfonic acid and its salts, imidazoline-type amphoteric surfactants, and polyoxyethylene hydrogenated castor oil.

3. The liquid oral composition according to claim 1 or 2, comprising 0.001 to 8% by weight of the surfactant.

4. A liquid oral composition according to any one of claims 1 to 3, which is a mouthwash.

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