Oral components

Abstract

To inhibit the formation and maturation of plaque on the surfaces of teeth.SOLUTION: A composition contains dodecylpyridinium chloride, and at least one selected from the group consisting of glycyrrhizinic acid and salts thereof.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a composition for inhibiting plaque formation, etc. The contents of all documents described in this specification are incorporated herein by reference. [Background technology]

[0002] Plaque (dental plaque) is a biofilm formed by the aggregation of oral microorganisms and is thought to be a cause of dental caries and periodontal disease. Therefore, plaque control, especially the inhibition of plaque formation, is important.

[0003] Roughly speaking, plaque forms as follows: First, a thin film of proteins derived from saliva and physiological gingival crevicular fluid called a "pellicle" forms on the tooth surface. Facultative anaerobic bacteria (early-adhering bacteria) such as streptococci adhere to the tooth surface through this pellicle. These early-adhering bacteria are then joined by vector bacteria such as Fusobacterium, which coaggregate with various oral bacteria. Later-adhering bacteria, such as anaerobic bacteria Porphyromonas gingivalis and Treponema denticola, then adhere and aggregate through these vector bacteria, resulting in the maturation of plaque. Late-adhering bacteria, in particular, are known to cause periodontal disease and are directly and indirectly involved in the destruction of periodontal tissues. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] J Dent Res 90(11):1271-1278, 2011 Summary of the Invention [Problem to be solved by the invention]

[0005] Based on the above, it is important to prevent plaque formation on tooth surfaces, especially to prevent the adhesion and aggregation of late-adherent bacteria and the maturation of plaque, in order to prevent periodontal disease. [Means for solving the problem]

[0006] The present inventors conducted research focusing on the vector bacteria Fusobacterium, because they believe that if the activity of Fusobacterium, a vector bacteria capable of coaggregating with various bacteria, can be inhibited, it will be possible to inhibit the adhesion and aggregation of late-adherent bacteria to the tooth surface, and ultimately to inhibit the maturation of plaque formation.

[0007] Therefore, we investigated methods for killing Fusobacterium. However, even after examining various disinfectants typically used in oral compositions, we were unable to find one that could efficiently kill Fusobacterium.

[0008] Cetylpyridinium chloride, an example of a bactericide commonly used in oral compositions, is no exception, and no effective bactericidal effect against Fusobacterium was observed. However, the inventors continued their research and discovered that cetylpyridinium chloride is a C16 alkylpyridinium chloride, and the length of the alkyl group may affect its bactericidal effect against Fusobacterium, leading to further improvements. As a result, they found that dodecylpyridinium chloride, a C12 alkylpyridinium chloride, exhibits excellent bactericidal effect against Fusobacterium.

[0009] Therefore, further investigation was carried out to actually use dodecylpyridinium chloride to kill Fusobacterium in the oral cavity, and it was found that dodecylpyridinium chloride has poorer retention on the tooth surface than cetylpyridinium chloride. Therefore, further investigation was carried out to improve the retention of dodecylpyridinium chloride on the tooth surface.

[0010] The present disclosure includes, for example, the subject matter described in the following sections: Section 1. Dodecylpyridinium chloride, and At least one selected from the group consisting of glycyrrhizinic acid and its salts An oral composition comprising: Section 2. Dodecylpyridinium chloride, and At least one selected from the group consisting of glycyrrhizinic acid and its salts A composition for inhibiting plaque formation comprising: Section 3. Dodecylpyridinium chloride, and At least one selected from the group consisting of glycyrrhizinic acid and its salts A composition for killing Fusobacterium containing the compound. Section 4. At least one selected from the group consisting of glycyrrhizinic acid and salts thereof, Dipotassium glycyrrhizinate, Item 4. The composition according to any one of Items 1 to 3. Section 5. For 1 part by mass of dodecylpyridinium chloride, 0.1 to 20 parts by mass of at least one selected from the group consisting of glycyrrhizinic acid and salts thereof 5. The composition according to any one of items 1 to 4, comprising Section 6. Item 6. The composition according to any one of items 1 to 5, containing 0.01 to 0.5% by mass of dodecylpyridinium chloride. Section 7. Item 7. The composition according to any one of Items 1 to 6, comprising 0.01 to 1 mass % of at least one selected from the group consisting of glycyrrhizinic acid and salts thereof. Section 8. 8. The composition according to any one of items 1 to 7, further comprising at least one selected from the group consisting of citric acid and salts thereof. [Effects of the Invention]

[0011] This provides a method for efficiently killing Fusobacterium, a bacterium that mediates plaque formation, and also provides a method for efficiently retaining the bactericidal active ingredient (dodecylpyridinium chloride) on the tooth surface, thereby making it possible to efficiently suppress plaque formation. [Brief explanation of the drawings]

[0012] [Figure 1] The results of a study on the bactericidal effect of alkylpyridinium chlorides (CPC and DPC) on Fusobacterium are shown below. [Figure 2] The results of a study on the bactericidal effect of alkylpyridinium chlorides (CPC and OPC) on Fusobacterium are shown below. [Figure 3] 1 shows the results of examining the retention of DPC on the tooth surface in a composition containing DPC and dipotassium glycyrrhizinate. [Figure 4] 1 shows the results of examining the retention of DPC on the tooth surface in a composition containing DPC and dipotassium glycyrrhizinate. DETAILED DESCRIPTION OF THE INVENTION

[0013] Each embodiment included in the present disclosure will be described in more detail below. The present disclosure includes a composition containing a C12 linear alkylpyridinium chloride (i.e., dodecylpyridinium chloride) and glycyrrhizinic acid or a salt thereof, as well as uses of the composition. The composition can be preferably used as, for example, an oral composition, a composition for killing Fusobacterium, and a composition for inhibiting plaque formation, and the present disclosure also preferably includes these uses. However, the present disclosure is not limited to these, and includes all of the disclosures herein that would be recognized by a person skilled in the art.

[0014] A composition comprising dodecylpyridinium chloride and glycyrrhizinic acid or a salt thereof encompassed by the present disclosure may be referred to as the "composition of the present disclosure."

[0015] The Fusobacterium herein is not particularly limited as long as it is a bacterium of the genus Fusobacterium, which is an intermediate bacterium between early and late adherent bacteria in plaque formation, but a preferred example is Fusobacterium nucleatum.

[0016] As described above, the composition of the present disclosure contains dodecylpyridinium chloride. The content of dodecylpyridinium chloride is not particularly limited as long as it is within a range in which the effect is exhibited, but may be, for example, about 0.01 to 0.5% by mass. The upper and lower limits of this range may be, for example, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24 , 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, or 0.49% by mass. For example, the range may be about 0.02 to 0.3% by mass.

[0017] As described above, the composition of the present disclosure also contains glycyrrhizinic acid or a salt thereof. As the salt, an alkali metal salt is preferred, and a disodium salt or dipotassium salt is more preferred. Dipotassium glycyrrhizinate is particularly preferred. Glycyrrhizinic acid or a salt thereof can be used alone or in combination of two or more. That is, the composition of the present disclosure can contain at least one selected from the group consisting of glycyrrhizinic acid and its salts. The content of glycyrrhizinic acid or a salt thereof in the composition of the present disclosure is not particularly limited as long as the effect is achieved, but can be, for example, about 0.01 to 1% by mass. The upper or lower limit of this range may be, for example, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95% by mass. For example, the range may be about 0.02 to 2% by mass. When two or more types of glycyrrhizinic acid or salts thereof are used in combination, it is preferable that the total amount is within the above range.

[0018] In the composition of the present disclosure, the ratio of the content of dodecylpyridinium chloride to at least one selected from the group consisting of glycyrrhizinic acid and its salts is not particularly limited as long as it is within a range that exhibits the desired effect. For example, the ratio may be approximately 0.1 to 20 parts by mass of the latter relative to 1 part by mass of the former. The upper or lower limit of this range (0.1 to 20 parts by mass) may be, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 parts by mass. For example, the range may be 0.2 to 10 parts by mass. Furthermore, a ratio of 1 part by mass or more of the latter relative to 1 part by mass of the former is particularly preferred, as this exhibits a particularly excellent effect of improving the retention of dodecylpyridinium chloride on the tooth surface.

[0019] The composition of the present disclosure contains dodecylpyridinium chloride, which is useful for killing Fusobacterium, and further contains glycyrrhizinic acid or a salt thereof, which can improve the retention of dodecylpyridinium chloride on the tooth surface, and therefore can be preferably used for killing Fusobacterium. Furthermore, as described above, it can be said that plaque formation on the tooth surface can be inhibited by killing Fusobacterium, and therefore the composition of the present disclosure can also be preferably used as a composition for inhibiting plaque formation. For these reasons, the composition of the present disclosure can also be preferably used as an oral composition. The oral composition can be preferably used for inhibiting plaque formation, killing Fusobacterium, etc.

[0020] The composition of the present disclosure can be a solid composition or a liquid composition. The composition can be used, for example, as a pharmaceutical or quasi-drug. The form of the composition of the present disclosure is not particularly limited, and can be made into forms (dosage forms) such as ointments, pastes, pastes, gels, liquids, sprays, mouthwashes, liquid dentifrices, toothpastes, and gums in accordance with conventional methods. Of these, mouthwashes, liquid dentifrices, toothpastes, ointments, pastes, liquids, and gels are preferred.

[0021] The composition of the present disclosure may further contain, for example, one or more optional components that can be incorporated into oral compositions, as long as the effects are not impaired.

[0022] For example, nonionic surfactants, anionic surfactants, or amphoteric surfactants can be blended as surfactants. Specific examples of nonionic surfactants include sugar fatty acid esters such as sucrose fatty acid esters, maltose fatty acid esters, and lactose fatty acid esters; fatty acid alkanolamides; glycerin fatty acid esters; sorbitan fatty acid esters; fatty acid monoglycerides; polyoxyethylene alkyl ethers having a polyoxyethylene addition coefficient of 8 to 10 and an alkyl group having 13 to 15 carbon atoms; polyoxyethylene alkylphenyl ethers having a polyoxyethylene addition coefficient of 10 to 18 and an alkyl group having 9 carbon atoms; diethyl sebacate; polyoxyethylene hydrogenated castor oil; and fatty acid polyoxyethylene sorbitan. Examples of anionic surfactants include sulfate ester salts such as sodium lauryl sulfate and polyoxyethylene lauryl ether sodium sulfate; sulfosuccinates such as sodium lauryl sulfosuccinate and polyoxyethylene lauryl ether sodium sulfosuccinate; acylamino acid salts such as sodium cocoyl sarcosinate and sodium lauroyl methyl alanine; and sodium cocoyl methyl taurate. Examples of zwitterionic surfactants include acetate betaine surfactants such as lauryl dimethylaminoacetate betaine and coconut oil fatty acid amidopropyl dimethylaminoacetate betaine; imidazoline surfactants such as N-cocoyl-N-carboxymethyl-N-hydroxyethylethylenediamine sodium; and amino acid surfactants such as N-lauryldiaminoethylglycine. These surfactants can be used alone or in combination of two or more. The amount of surfactant used is usually 0.1 to 5% by mass based on the total amount of the composition.

[0023] Flavoring agents that can be used include, for example, menthol, carboxylic acid, anethole, eugenol, methyl salicylate, limonene, ocimene, n-decyl alcohol, citronellol, α-terpineol, methyl acetate, citronenyl acetate, methyl eugenol, cineole, linalool, ethyl linalool, thymol, spearmint oil, peppermint oil, lemon oil, orange oil, sage oil, rosemary oil, cinnamon oil, perilla oil, wintergreen oil, clove oil, eucalyptus oil, pimento oil, d-camphor, d-borneol, fennel oil, cinnamon oil, cinnamon aldehyde, peppermint oil, vanillin, etc. These can be blended alone or in combination of two or more types, in an amount of, for example, 0.001 to 1.5% by mass based on the total amount of the composition.

[0024] In addition, sweeteners that can be used include, for example, saccharin sodium, acesulfame potassium, stevioside, neohesperidyl dihydrochalcone, perillartine, thaumatin, aspartyl phenylalanyl methyl ester, p-methoxycinnamic aldehyde, etc. These can be blended in an amount of, for example, 0.01 to 1% by mass based on the total amount of the composition.

[0025] Furthermore, as a wetting agent, sorbitol, ethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, polypropylene glycol, xylitol, maltitol, lactite, polyoxyethylene glycol, etc. may be blended alone or in combination of two or more kinds.

[0026] As preservatives, parabens such as methylparaben, ethylparaben, propylparaben, and butylparaben, sodium benzoate, phenoxyethanol, alkyldiaminoethylglycine hydrochloride, and the like can be added.

[0027] As coloring agents, legal pigments such as Blue No. 1, Yellow No. 4, Red No. 202, and Green No. 3, mineral pigments such as ultramarine, enhanced ultramarine, and Prussian blue, titanium oxide, and the like may be blended.

[0028] The pH adjuster may be citric acid, phosphoric acid, malic acid, pyrophosphoric acid, lactic acid, tartaric acid, glycerophosphoric acid, acetic acid, nitric acid, or chemically acceptable salts thereof, or sodium hydroxide. These may be added alone or in combination of two or more so that the pH of the composition is in the range of 4 to 8, preferably 5 to 7. The amount of pH adjuster added may be, for example, 0.01 to 2% by weight.

[0029] When a pH adjuster is used in the composition of the present disclosure, citric acid or a salt thereof is particularly preferred. As the salt, an alkali metal salt is preferred, and a sodium salt or a potassium salt is more preferred. Citric acid or a salt thereof can be used alone or in combination of two or more. That is, the composition of the present disclosure can use at least one selected from the group consisting of citric acid and its salts. The content of citric acid or a salt thereof in the composition of the present disclosure is not particularly limited as long as the effect is achieved, but may be, for example, about 0.01 to 2% by mass. The upper or lower limit of the range may be, for example, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, or 2.9% by mass. For example, the range may be about 0.02 to 2% by mass. Furthermore, when two or more types of citric acid or salts thereof are used in combination, the total amount is preferably within the above range. Furthermore, when citric acid and a citrate are used in combination, although there are no particular limitations, the ratio is preferably about 1 to 15 parts by mass of citrate to 1 part by mass of citric acid. The upper or lower limit of this range (1 to 15 parts by mass) may be, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 parts by mass. For example, the range may be 2 to 10 parts by mass.

[0030] In the composition of the present disclosure, the ratio of the content of dodecylpyridinium chloride to at least one selected from the group consisting of citric acid and its salts is not particularly limited as long as it is within a range in which the effect is exhibited. For example, the ratio may be about 0.5 to 20 parts by mass of the latter per 1 part by mass of the former. The upper or lower limit of this range (0.5 to 20 parts by mass) may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 parts by mass. For example, the range may be 1 to 15 parts by mass.

[0031] The composition of the present disclosure contains not only dodecylpyridinium chloride, but also other active ingredients such as vitamin E compounds such as dl-α-tocopherol acetate, tocopherol succinate, or tocopherol nicotinate, amphoteric bactericides such as dodecyldiaminoethylglycine, nonionic bactericides such as triclosan, isopropylmethylphenol, and hinokitiol, anionic bactericides such as sodium lauroyl sarcosinate, cationic bactericides such as cetylpyridinium chloride, chlorhexidine hydrochloride, benzalkonium chloride, and benzethonium chloride, dextranase, amylase, protease, mutanase, lysozyme, and bacteriolytic enzymes (lyte). Enzymes such as methicillin-resistant lecithin (methicillin-resistant lecithin), alkali metal monofluorophosphates such as sodium monofluorophosphate and potassium monofluorophosphate, fluorides such as sodium fluoride and stannous fluoride, tranexamic acid, epsilon aminocaproic acid, aluminum chlorohydroxyl allantoin, dihydrocholesterol, glycyrrhetinic acid, glycyrrhizinic acid, copper chlorophyllin sodium, glycerophosphate, chlorophyll, sodium chloride, callopeptide, allantoin, carbazochrome, hinokitiol, potassium nitrate, palatinit, etc. can be blended alone or in combination of two or more.

[0032] Although not particularly limited, it is particularly preferred that the composition of the present disclosure further contains cetylpyridinium chloride. When cetylpyridinium chloride is further contained, the content thereof can be, for example, about 0.01 to 0.5% by mass. The upper and lower limits of this range can be, for example, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24 , 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, or 0.49% by mass. For example, the range may be about 0.02 to 0.3% by mass.

[0033] Furthermore, it is also possible to add alcohols, silicone, apatite, white petrolatum, paraffin, liquid paraffin, microcrystalline wax, squalane, plastibase, etc. as bases.

[0034] The composition of the present disclosure can be prepared by a known method or a method easily derived from a known method, for example, by appropriately mixing dodecylpyridinium chloride, glycyrrhizinic acid or a salt thereof, and, if necessary, other components.

[0035] The subject to which the composition of the present disclosure is applied is not particularly limited, and preferably includes humans and non-human mammals. Non-human mammals are preferably livestock and pets, and more specifically, examples thereof include dogs, cats, mice, rats, horses, cows, sheep, and monkeys. Furthermore, the composition of the present disclosure is not particularly limited, but as described above, dodecylpyridinium chloride can efficiently kill the vector bacteria Fusobacterium, and therefore, it can be said to be particularly suitable for application to the oral cavity of a subject in which plaque has not formed or is in the process of forming (no late-stage adherent bacteria have adhered).

[0036] Furthermore, the above-mentioned description of the compositions of the present disclosure can also be applied to, for example, compositions for inhibiting plaque formation that are not used as oral compositions, and compositions containing the above-mentioned Fusobacterium bactericide (for example, when used for cleaning dentures).

[0037] As used herein, the term "comprising" includes "consisting essentially of" and "consisting of." In addition, the present disclosure encompasses any and all combinations of the constituent features described herein.

[0038] Furthermore, the various characteristics (properties, structures, functions, etc.) described in each embodiment of the present disclosure above may be combined in any way to specify the subject matter encompassed by the present disclosure, i.e., the present disclosure encompasses all subject matter consisting of any combination of the combinable characteristics described herein. [Example]

[0039] Hereinafter, the embodiments of the present disclosure will be described more specifically with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

[0040] Examination of the bactericidal effect of alkylpyridinium chlorides on Fusobacteria The following three types of alkylpyridinium chloride were dissolved in water to various concentrations (0.03%, 0.05%, or 0.10%) and used as disinfectant solutions. Note that the alkylpyridinium chloride concentration (%) of the disinfectant solution is w / v%, but because the solvent is water and the concentration is relatively low, it is almost the same as mass % (w / w%) and can be approximated. This also applies to all of the following studies. Octylpyridinium chloride (OPC): R = (CH2)7CH3 in the following formula Dodecylpyridinium chloride (DPC): R = (CH2) 11 CH3 Cetylpyridinium chloride (CPC): R = (CH2) 15 CH3

[0041] [ka]

[0042] In addition, the following two subspecies of Fusobacterium were used as test bacteria. Bacteria 1: Fusobacterium nucleatum subsp. nucleatum ATCC23726 Bacteria 2: Fusobacterium nucleatum subsp. nucleatum ATCC25586

[0043] The test bacteria were inoculated into 10 ml of GAM bouillon medium (Nissui Pharmaceutical Co., Ltd.) and anaerobically cultured for 2 days at 37° C. The culture solution was used as the test bacteria solution.

[0044] 200 μl of bactericide solution of different concentrations was mixed with 200 μl of test bacteria solution. 30 seconds after mixing, 100 μl of the mixture was collected, and 900 μl of drug-inactivated PBS (phosphate buffered saline (PBS) with soybean lecithin and Tween 80 added to final concentrations of 0.07% and 0.5%, respectively) was added (diluting the mixture 10 times) to inactivate the bactericidal action of the bactericide. In addition, the mixture was serially diluted with drug-inactivated PBS, and the mixture was diluted 10 times. 1 ~10 7 The mixture was diluted 1:1 (serial dilutions).

[0045] 100 μl of each of the prepared serially diluted mixtures was smeared onto CDC anaerobic sheep blood agar medium (Becton Dickinson Japan Co., Ltd.), anaerobically cultured at 37°C for 3 days, and the number of viable bacteria was counted.

[0046] The results are shown in Figures 1 and 2. These figures are graphs with Log (viable cell count) CFU / ml on the vertical axis. The concentrations of CPC, DPC, and OPC in these figures indicate the concentrations of the corresponding components when prepared as a disinfectant solution. It was found that while CPC and OPC did not exhibit a bactericidal effect against Fusobacterium, DPC exhibited a bactericidal effect against Fusobacterium even at relatively low concentrations.

[0047] Next, the retention of DPC on the tooth surface was examined as follows.

[0048] [Saliva collection] Saliva was collected in a clean room. Saliva was collected from the subjects until approximately 3 ml of naturally secreted saliva was obtained. The collected saliva was centrifuged at 5°C, 11,000 rpm, and 10 minutes using a swing rotor centrifuge, and the supernatant fraction was collected. The collected supernatant fraction was irradiated with ultraviolet light for approximately 1 hour on ice and then refrigerated until use in the test.

[0049] [Preparation of HAP (hydroxyapatite) carrier] A HAP carrier (hydroxyapatite powder treated with saliva) that exhibits behavior similar to that of a tooth surface was prepared according to the following procedure.

[0050] 50 mg of hydroxyapatite powder (Bio-Gel HTP Gel; manufactured by BIO-RAD Lab.) was weighed into a PP tube (Falcon 2059), 2 ml of distilled water was added, and the mixture was shaken for 1 hour. After the treatment, the mixture was centrifuged at room temperature, 3000 rpm, and 5 minutes, and the supernatant was removed. Next, 2 ml of the saliva obtained above was added, and the mixture was homogenized using a touch mixer. The mixture was then shaken for approximately 15 hours in a thermostatic chamber set at 37°C. After that, the mixture was again centrifuged at room temperature, 3000 rpm, and 5 minutes, and the supernatant was removed, yielding an "HAP carrier."

[0051] [Adsorption test] 2 ml of each test sample was added to the HAP carrier (approximately 50 mg) obtained above, homogenized using a touch mixer, and then shaken for 15 minutes in a thermostatic chamber set at 37°C. Centrifuged at room temperature, 3000 rpm, and 5 minutes to remove the supernatant. 2 ml of distilled water was added to the resulting residue, homogenized using a touch mixer, and then centrifuged at room temperature, 3000 rpm, and 5 minutes to remove the supernatant. The resulting residue was washed with distilled water under the same conditions as above, and the HAP carrier after adsorption was obtained as the residue.

[0052] [Measurement of adsorption amount] The pH of 1000 ml of distilled water containing citric acid (4.2 g) and monosodium dihydrogen citrate (4.64 g) was adjusted to 3.0. Sodium lauryl sulfate (2.88 g) was then added, and 3000 ml of acetonitrile was added. The mixture was homogenized and degassed to prepare the extraction solvent. 5 ml of extraction solvent was added to the adsorption-treated HAP carrier obtained above, homogenized using a touch mixer, and then shaken for 10 minutes. After the treatment, the mixture was centrifuged at room temperature at 3000 rpm for 5 minutes, and the resulting supernatant was dispensed into a 20 ml volumetric flask. The extraction process was repeated once more, and the resulting supernatant was weighed into the same volumetric flask. The volume was then adjusted to 20 ml, and the alkylpyridinium chloride (DPC, CPC) content in the resulting solution was measured using HPLC. Specifically, standard solutions of known concentrations of DPC and CPC were prepared, and the adsorption amount was calculated by comparing the peak area with that of the retention test sample. The HPLC analysis conditions were as follows: <Analysis conditions> Column: C18 column (reverse phase) Mobile phase: Perchloric acid solution / acetonitrile mixture Temperature: 50℃ Detector: PDA (around 250-260 nm)

[0053] The results were obtained by calculating the amount of dodecylpyridinium chloride (μg) and the amount of cetylpyridinium chloride (μg) adsorbed to 50 mg of the HAP carrier.

[0054] [Specific contents and results of the study] First, three types of aqueous solutions, namely, a 0.05% DPC solution, a 0.05% CPC solution, and a 0.05% DPC and 0.05% CPC solution, were subjected to an adsorption test as test subjects. The results are shown in Table 1.

[0055] [Table 1]

[0056] These results show that dodecylpyridinium chloride (DPC) has poor retention on the tooth surface.

[0057] Therefore, in order to find a material that improves the retention of DPC on the tooth surface, aqueous solutions containing various ingredients and DPC were prepared, and it was found that glycyrrhizinic acid or a salt thereof improves the retention of DPC on the tooth surface. Data demonstrating this is set forth below. Specifically, each composition (Examples 1a to 1d and Comparative Example A) was prepared according to the formulation shown in Table 2 and subjected to an adsorption test as a subject. The results are also shown in Table 2. The results are also graphed in Figure 3.

[0058] [Table 2]

[0059] Furthermore, we investigated whether the retention of DPC on the tooth surface would change by varying the amount of dipotassium glycyrrhizinate. Specifically, each composition (Examples 2a to 2d and Comparative Example A) was prepared according to the formulation shown in Table 3 and subjected to an adsorption test as a test subject. The results are also shown in Table 3. The results are also graphed in Figure 4.

[0060] [Table 3]

[0061] These results demonstrate that when the content of glycyrrhizinic acid or a salt thereof is greater than the content of DPC, particularly excellent retention of DPC on the tooth surface is achieved.

[0062] Furthermore, we searched for materials that improve the retention of DPC on the tooth surface and found that citric acid or its salts also improve the retention of DPC on the tooth surface. The data demonstrating this are shown below. Each composition was prepared according to the formulation shown in Table 4 and subjected to an adsorption test. The results are also shown in Table 4.

[0063] [Table 4]

[0064] These results demonstrate that citric acid or a salt thereof can improve retention of DPC on the tooth surface.

[0065] Therefore, the tooth surface retention of DPC was further investigated by changing the content of citric acid or its salt. It was also investigated whether the tooth surface retention of DPC could be improved by using a pH adjuster other than citric acid or its salt. Specifically, each composition (Examples 1 to 11 and Comparative Examples 1 to 3) was prepared according to the formulation shown in Table 5 and subjected to an adsorption test as a subject. The results are also shown in Table 3. The pH of each composition was measured at 25°C using a pH meter. The results are also shown in Table 3.

[0066] [Table 5]

[0067] These results demonstrate that the retention of DPC on the tooth surface can be improved by using citric acid or its salts among pH adjusters.

Claims

1. 0.02 to 0.05% by weight of dodecylpyridinium chloride, and 0.02 to 0.3% by mass of at least one selected from the group consisting of glycyrrhizinic acid and salts thereof, An oral composition for killing Fusobacterium on tooth surfaces, comprising:

2. At least one selected from the group consisting of glycyrrhizinic acid and salts thereof, Dipotassium glycyrrhizinate, The composition of claim 1.

3. For 1 part by mass of dodecylpyridinium chloride, 0.4 to 15 parts by mass of at least one selected from the group consisting of glycyrrhizinic acid and salts thereof The composition according to claim 1 or 2, comprising

4. The composition according to any one of claims 1 to 3, comprising 0.02 to 0.1 mass% of at least one selected from the group consisting of glycyrrhizinic acid and salts thereof.

5. The composition according to any one of claims 1 to 4, further comprising at least one selected from the group consisting of citric acid and salts thereof.

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