JP6547324B2 - Liquid oral composition - Google Patents

Description

  The present invention relates to a potassium nitrate-containing ethanol-free liquid oral cavity composition containing potassium nitrate, which is excellent in the hypersensitivity suppressing effect and the floating bacteria killing effect in the oral cavity.

As a preventive measure of dentine hypersensitivity, potassium nitrate known as an active ingredient is blended in a composition for oral cavity (Patent Documents 1 and 2). This potassium nitrate has a problem that an insoluble precipitate is formed in the presence of sodium lauryl sulfate which is generally blended in oral compositions, and in Patent Document 3, potassium nitrate and sodium lauryl sulfate containing oral compositions are frequently used. By blending a polyhydric alcohol and an amphoteric surfactant, precipitation of potassium lauryl sulfate is prevented and precipitation at low temperature is suppressed.
In addition, non-alcoholic liquid preparations that are less irritating to mucous membranes and are less irritating are more suitable for suppressing hypersensitivity in particular in liquid oral compositions.

  On the other hand, cetyl pyridinium chloride, a cationic bactericidal agent, has excellent bactericidal effects on suspended bacteria in the oral cavity and is effective for the prevention or suppression of oral diseases such as caries, but is easily affected by surfactants, resulting in In Document 4, a specific compound is added to an oral composition containing a biguanide cationic bactericide and a nonionic surfactant to prevent the deactivation of the cationic bactericide by the nonionic surfactant. Stabilized compounding techniques have been proposed.

U.S. Pat. No. 3,863,006 Japanese Patent Application Laid-Open No. 7-101842 JP, 2005-68071, A Japanese Patent Application Laid-Open No. 60-255717 JP, 2013-35792, A JP 2007-84471 A

  Therefore, if it is possible to suppress hypersensitivity with a non-alcohol type liquid oral preparation containing potassium nitrate and at the same time exert a high bactericidal activity against orally floating bacteria, it is more effective for prevention or suppression of oral diseases. It is desirable to develop a suitable liquid oral preparation.

  This invention is made in view of the said situation, and an object of this invention is to provide the composition for liquid oral cavity containing no potassium nitrate containing potassium which is excellent in the hypersensitivity suppression effect and the floating microbe killing effect in the oral cavity.

  The inventors of the present invention conducted intensive studies to achieve the above object, and as a result, a liquid oral composition containing no (A) potassium nitrate and (B) cetyl pyridinium chloride in a liquid oral composition containing no ethanol (C) non-ionic By blending the surfactant and (D) amphoteric surfactant, (E) making the water content 55% by mass or more and less than 92% by mass, and making the pH of the composition 6.8 or more and less than 8.0, A) The composition of the non-alcohol type liquid oral cavity composition is obtained which suppresses the precipitation of insoluble precipitates generated by the combined use of the components (B) and is excellent in the hypersensitivity suppressing effect and the floating bacteria killing effect in the oral cavity. The present inventors have found that the present invention can be suitably used for the inhibition of caries.

That is, it is expected that the addition of the cationic bactericidal agent cetyl pyridinium chloride to the liquid composition for oral cavity containing potassium nitrate can impart the hypersensitivity suppressing effect and the floating bacteria killing effect in the oral cavity, but potassium nitrate and chloride Even though there is no problem at all when cetyl pyridinium is blended in the ethanol-containing liquid oral composition, the combination of potassium nitrate and cetyl pyridinium chloride in a low-stimulus ethanol-free liquid oral composition It has been found that, when incorporated, an insoluble precipitate is produced and precipitated, which causes a problem that the hypersensitivity suppressing effect is reduced and the bactericidal effect is not sufficiently expressed. For this reason, the new problem that potassium nitrate and cetyl pyridinium chloride are used in combination without insoluble precipitates in the composition for liquid oral cavity not containing ethanol, and the good function and effect of potassium nitrate and cetyl pyridinium chloride is exhibited did. Then, as a result that the present inventors advanced examination further in order to solve these subjects, it combines and adds (C) nonionic surfactant and (D) amphoteric surfactant, and the water | moisture content in a composition is added. By setting the amount and pH within the above range, precipitation of the insoluble precipitate generated by the combined use of the components (A) and (B) described above is suppressed, and a high hypersensitivity suppressing effect and a suspended germ killing effect are simultaneously provided. It was also possible to keep the appearance stable and suppress the bitter taste to give a good feeling of use. In this case, although cetyl pyridinium chloride is easily inactivated under the influence of a surfactant such as a nonionic surfactant, in the present invention, a combination of surfactants of components (C) and (D) is used. However, the amount of water in the composition and the pH act specifically within a specific range to give the above-mentioned remarkable and remarkable effects.
Therefore, the composition for liquid oral cavity containing no ethanol according to the present invention has almost no precipitation of insoluble precipitates after 4 weeks after preparation of the composition for liquid oral cavity, as apparent from the examples described later. It is stable over time, has a high hypersensitivity suppressing effect and a high ability to kill suspended bacteria in the oral cavity, and has a good taste after use, with suppressed bitter taste.

  In addition, patent document 3 suppresses precipitation of potassium lauryl sulfate which is generated by the combined use of potassium nitrate and sodium lauryl sulfate in the composition for oral cavity, and patent document 4 is a cationic bactericidal agent using a nonionic surfactant. No mention is made of using cationic bactericides in combination with potassium nitrate. Patent Literatures 5 and 6 describe liquid oral cavity compositions containing potassium nitrate and cetyl pyridinium chloride, but these are ethanol-blended compositions. From patent documents 3-6, precipitation control of the insoluble precipitate which arises by combined use of potassium nitrate and cetyl pyridinium chloride in the composition for liquid oral cavity do not mix can not be predicted.

Accordingly, the present invention provides the following composition for liquid oral cavity and a method for suppressing precipitation of insoluble precipitates in the composition.
[1]
A liquid oral composition containing no (A) potassium nitrate in an amount of 0.01 to 10% by mass and (B) cetylpyridinium chloride in an amount of 0.001 to 0.1% by mass.
(C) the average number of moles of added ethylene oxide is 40 to 100 moles of polyoxyethylene hydrogenated castor oil 0.2 to 2% by weight, and (D) an alkyl amido betaine or a salt thereof from 0.2 to 2 wt%
(E) A composition for liquid oral cavity comprising: (E) a water content of 55% by mass to less than 92% by mass, and a pH of the composition at 25 ° C. of 6.8 to less than 8.0.
[2]
A liquid oral composition containing no (A) potassium nitrate in an amount of 0.01 to 10% by mass and (B) cetylpyridinium chloride in an amount of 0.001 to 0.1% by mass.
(C) the average number of moles of added ethylene oxide is 40 to 100 moles of polyoxyethylene hydrogenated castor oil 0.2 to 2% by weight, and (D) an alkyl amido betaine or a salt thereof from 0.2 to 2 wt%
In the composition for a liquid oral cavity, it is characterized in that (E) the water content is 55% by mass to less than 92% by mass, and the pH of the composition at 25 ° C. is 6.8 or more and less than 8.0. The precipitation suppression method of the insoluble precipitate produced by combined use of (A) potassium nitrate and (B) cetyl pyridinium chloride.

  According to the present invention, it is possible to provide a potassium nitrate-containing ethanol-free liquid oral composition containing potassium nitrate which is excellent in the hypersensitivity suppressing effect and the floating bacteria killing effect in the oral cavity.

  Hereinafter, the present invention will be described in more detail. The liquid composition for oral cavity of the present invention contains (A) potassium nitrate, (B) cetyl pyridinium chloride, (C) non-ionic surfactant, (D) amphoteric surfactant, (E) water, and contains no ethanol. It is.

(A) Potassium nitrate is formulated as an active ingredient for preventing or treating dentine hypersensitivity and is a hypersensitivity inhibitor.
The blending amount of potassium nitrate as the component (A) is preferably 0.01 to 10% (% by mass, hereinafter, the same) of the whole composition, and more preferably 0.1 to 7%. The greater the compounding amount, the higher the hypersensitivity-suppressing effect, but 10% or less is more suitable for sufficient precipitation suppression and bitterness suppression.

(B) Cetyl pyridinium chloride is a cationic bactericidal agent and is a bactericidal agent against orally floating bacteria. Commercially available cetyl pyridinium chloride can be used.
The blending amount of cetyl pyridinium chloride as the component (B) is preferably 0.001 to 0.1%, more preferably 0.005 to 0.1%, still more preferably 0.01 to 0.05 of the whole composition. %. The more the compounding effect is, the higher the bactericidal effect is, but 0.1% or less is more suitable for sufficiently suppressing precipitation and suppressing bitterness.

  In the present invention, it is important to exert the effect by combining the (C) nonionic surfactant and the (D) amphoteric surfactant. In the absence of the component (C) or the component (D), an insoluble precipitate is deposited, and the hypersensitivity-suppressing effect and the suspended germ killing effect are inferior. In addition, the bitter taste is not suppressed and the feeling of use is inferior.

  (C) Examples of the nonionic surfactant include polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether and polyglycerin fatty acid ester, and one or more of them may be used, and in particular ethylene oxide. The average addition mole number of (E.O.) is 40 to 100 moles, particularly 60 to 100 moles of polyoxyethylene hydrogenated castor oil, the carbon number of the alkyl group is 16 to 18, and E.O. O. Polyoxyethylene alkyl ethers having an average added mole number of 10 to 40 moles, particularly 20 to 40 moles, and decaglycerin mono fatty acid esters polyglycerin fatty acid esters having 12 to 18 carbon atoms, particularly 12 to 14 carbon atoms of fatty acids are preferred, among E. O. Polyoxyethylene hydrogenated castor oil having an average added mole number of 40 to 100 moles is preferable.

Specifically, commercially available commercial products as shown below can be used.
Polyoxyethylene hydrogenated castor oil;
NIKKOL HCO system manufactured by Nikko Chemicals, Emarex HC system manufactured by Nippon Emulsion, Uniox HC system polyoxyethylene alkyl ether manufactured by Nippon Oil and Fats Co.
NIKKOL BC system manufactured by Nikko Chemicals, NIKKOL BS system, Emarex 100 system manufactured by Nippon Emulsion Co., Ltd. Emarex 600 system decaglycerin mono fatty acid ester;
NIKKOL Decagln series manufactured by Nikko Chemicals Co., Ltd. and Ryoto (registered trademark) polyglyester D series manufactured by Mitsubishi Chemical Foods Co., Ltd.

  The blending amount of the nonionic surfactant of the component (C) is preferably 0.1 to 2% of the whole composition, more preferably 0.1 to 1%, and still more preferably 0.2 to 0.5%. is there. When 0.1% or more is blended, sufficient precipitation suppressing effect, hypersensitivity suppressing effect and suspended bacteria killing effect can be exhibited, and bitter taste can be sufficiently suppressed. It is more suitable for preventing that a hypersensitivity inhibitory effect and a floating microbe bactericidal effect fall that it is 2% or less.

(D) As amphoteric surfactants, alkylamide betaines such as coconut oil fatty acid amidopropyl betaine or salts thereof, betaine acetate type such as lauryl dimethylaminoacetic acid betaine, N-fatty acid acyl-N-carboxymethyl-N-hydroxyethyl The imidazoline type such as ethylene diamine salt, the amino acid type such as N-fatty acid acyl-L-alginate salt, etc. may be mentioned, and one or two or more of them may be used, and alkylamide betaine or its salt is particularly preferable. Among them, coconut oil fatty acid amidopropyl betaine is preferred.
Specifically, commercial products such as coconut oil fatty acid amidopropyl betaine (TEGO Betain CK OK (30% aqueous solution manufactured by Degussa), Anthol 55 AB (30% aqueous solution) manufactured by Kao Corporation) can be used.

  The blending amount of the amphoteric surfactant of the component (D) is preferably 0.1 to 2%, more preferably 0.1 to 1%, and still more preferably 0.2 to 0.5% of the whole composition. . When 0.1% or more is blended, sufficient precipitation suppressing effect, hypersensitivity suppressing effect and suspended bacteria killing effect can be exhibited, and bitter taste can be sufficiently suppressed. It is more suitable for preventing that a hypersensitivity inhibitory effect and a floating microbe bactericidal effect fall that it is 2% or less.

  The composition for a liquid oral cavity of the present invention has (E) water content, that is, the water content in the composition is 55% or more and less than 92% of the whole composition, preferably 60% or more and 91% or less Preferably it is 60% or more and 70% or less. An insoluble precipitate can be precipitation-suppressed as a water content is in the said range, and the outstanding hypersensitivity suppression effect and the bitter taste suppression effect can be provided. If it is less than 55%, the precipitation can not be suppressed, and the hypersensitivity-suppressing effect and the suspended germ killing effect are inferior. If it is 92% or more, the precipitation suppression effect is inferior, the hypersensitivity suppression effect and the floating bacteria sterilization effect are also inferior, and bitterness can not be suppressed.

In the present invention, the pH of the liquid oral composition is 6.8 or more and less than 8.0, preferably 6.8 to 7.8, and more preferably 6.8 to 7.5. The precipitation inhibitory effect, the hypersensitivity inhibitory effect, and the bitter taste inhibitory effect are excellent in it being in the said range. If the pH is less than 6.8 or pH 8.0 or more, precipitation can not be suppressed, and the hypersensitivity-suppressing effect and the suspended germ killing effect are inferior.
The pH is a value measured at 25 ° C. for 3 minutes immediately after preparation of the composition using a pH meter (model Hm-30S) manufactured by Toa Denpa Kogyo Co., Ltd. (the same applies hereinafter).

  In the present invention, known pH adjusters may be added to adjust the pH of the composition within the above range. For example, alkali metal hydrogenphosphates such as sodium dihydrogenphosphate and hydroxides of alkali metals such as sodium hydroxide can be mentioned.

The composition for liquid oral cavity of the present invention does not contain ethanol. Here, "no ethanol blending" means that ethanol is not blended, but in the composition for liquid oral cavity, a small amount of ethanol derived from the raw material may be contained in the flavor blended in the composition. In consideration of these reasons, it does not contain ethanol other than ethanol contained in a trace amount in a perfume or the like. In this case, the amount of ethanol in the composition is preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 10 ppm or less, based on the entire composition.
In the present invention, with such a composition containing no ethanol, precipitation of insoluble precipitates is suppressed, and an excellent hypersensitivity suppressing effect and suspended bacteria killing effect are exhibited.

The liquid oral cavity composition of the present invention is particularly suitable as a mouthwash. In addition to the above components, other known components can be added to the composition of the present invention, as needed, in a range that does not impair the effects of the present invention. Specifically, wetting agents, solvents, and, if necessary, sweeteners, coloring agents, preservatives, flavors, active ingredients and the like are blended.
In addition, it is preferable that the solid component which does not solubilize, such as an abrasive | polishing agent, is not normally mix | blended with the composition for liquid oral cavity, especially a mouthwash, and does not contain an abrasive | polishing agent normally.
Further, as the surfactant, a surfactant other than (C) nonionic surfactant and (D) amphoteric surfactant may not be blended, but in the case of blending it is 0.5% or less, particularly 0 .05-0.2% is desirable.

  Examples of the wetting agent include sugar alcohols such as sorbitol, and polyhydric alcohols such as glycerin and polyethylene glycol. The blending amount of these wetting agents is usually 2 to 40%.

  Purified water is generally used as a solvent, and the amount of water in the composition can be added within the above range. In addition, lower monohydric alcohols having 1 to 3 carbon atoms such as ethanol, propylene glycol and the like may be blended.

  As a sweetening agent, xylitol, maltitol, saccharin, saccharin sodium, stevioside, aspartame etc. can be blended. As coloring agents, highly safe water-soluble dyes such as Blue No. 1, Green No. 3, Yellow No. 4, Red No. 105 can be added. Preservatives include p-oxybenzoic acid esters, benzoic acid or salts thereof.

  As the flavor, peppermint oil, spearmint oil, eucalyptus oil, winter green oil, clove oil, thyme oil, sage oil, cardamom oil, rosemary oil, marjoram oil, lemon oil, lemon oil, nutmeg oil, lavender oil, paracres oil etc. Essential oils and l-menthol, l-carvone, cinnamic aldehyde, orange oil, anethole, 1,8-cineole, methyl salicylate, eugenol, thymol, linalool, limonene, menthone, menthyl acetate, citral, camphor, borneol, pinene, Flavor components contained in the above-mentioned natural essential oils such as spilanthol, and also ethyl acetate, ethyl butyrate, isoamyl acetate, hexanal, hexenal, methyl anthranilate, ethyl methyl phenyl glycidate Benzaldehyde, vanillin, ethyl vanillin, furaneol, maltol, ethyl maltol, gamma / delta decalactone, gamma / deltown decalactone, N-ethyl-p-menthane-3-carboxamide, menthyl lactate, ethylene glycol-l-mentyl carbonate Etc. Consists of fragrant ingredients such as, and, additionally, some fragrant ingredients and natural essential oils, apple, banana, strawberry, blueberry, melon, peach, pineapple, grape, muscat, wine, cherry, squash, coffee, brandy, yogurt And the like can be used in an amount of 0.00001 to 3% in the composition as long as the effects of the present invention are not impaired.

  As an active ingredient, in addition to potassium nitrate and cetyl pyridinium chloride, a bactericidal agent such as isopropylmethylphenol, an anti-inflammatory agent such as tranexamic acid, epsilon-aminocaproic acid, an enzyme such as dextranase, sodium fluoride, monofluorophosphate Fluorides such as sodium, allantoin, vitamins such as vitamin C, copper compounds, plant extracts and the like can be mentioned. In addition, the addition amount of these active ingredients can be made into the range which does not prevent the effect of this invention.

  EXAMPLES The present invention will be specifically described below by showing Examples, Comparative Examples, and Formulation Examples, but the present invention is not limited to the following Examples. In the following examples,% indicates% by mass unless otherwise specified. The pH was measured at 25 ° C. in the same manner as above.

Example, Comparative Example
A liquid oral composition (mouthwash) having the composition shown in Tables 1 and 2 was prepared by a conventional method. The obtained mouthrinse was evaluated by the following method and criteria, and the results shown in Tables 1 and 2 were obtained.

(1) Evaluation method of appearance stability (precipitation suppression effect) 80 mL of each mouthwash as described in the table is put in a 100 mL PET bottle, stored still in a 25 ° C. thermostat, and appearance after 4 weeks It judged visually according to the grading standard of. The average value of 5 samples was determined and evaluated according to the following evaluation criteria.
Rating criteria:
4 points: There was no precipitate 3 points: There was a slight precipitate 2 points: There was a slight precipitate 1 point: There was a large amount of precipitate Evaluation criteria of appearance stability (precipitation inhibition effect):
A: Average point 3.5 or more and 4.0 or less ○: Average point 3.0 or more and less than 3.5 points Δ: Average point 2.0 or more and less than 3.0 points ×: Average point 2.0 Less than

(2) Evaluation Method of Hypersensitivity Suppressive Effect Each mouthwash described in the table is used for 1 month cleaning of 5 persons with dentine hypersensitivity in the usual way, and the hypersensitivity suppressive effect Was determined according to the following rating criteria. The average value of 5 subjects was determined and evaluated according to the following evaluation criteria.
Rating criteria for hypersensitivity suppression effect:
3 points: I no longer feel pain 2 points: I hardly feel pain 1 point: I feel pain Evaluation criteria for hypersensitivity suppression effect:
:: 2.5 or more and 3.0 or less ○: 2.0 or more and less than 2.5 points △: 1.5 or more and less than 2.0 points ×: less than 1.5 points

(3) Evaluation method of bactericidal effect on oral cavity floating bacteria As a culture solution, a solution obtained by dissolving 30 g of trypticase soy broth (manufactured by Difco) in 1 L of purified water is used as Streptococcus as an oral cavity resident bacteria. Prepared by adding saline so that the permeability at 550 nm of the solution cultured for 1 day under anaerobic conditions (5% by volume carbon dioxide, 95% by volume nitrogen) at 37 ° C. using mutans ATCC 10449 strain is 20. did. 0.3 mL of bacterial solution is added to 2.7 mL of a sample (liquid oral composition), stirred, reacted at 37 ° C. for 1 minute, stirred again, and five test tubes containing 2.7 mL of culture fluid in advance In the first test tube, 0.3 mL of the sample to which the bacterial solution was added was added and stirred. 0.3 mL of this solution was collected, added to a second test tube and stirred. This operation was similarly performed to the third to fifth test tubes in order. After stirring the culture solutions in the first, third and fifth test tubes, 50 μL of the culture solution was smeared on trypticase soy agar plates (manufactured by Difco) containing 10% cotton defibrillated blood and cultured under anaerobic conditions. The grown colonies were counted to determine the viable count (cfu) of the remaining Streptococcus mutans bacteria, and the bactericidal activity was determined based on the following criteria.
Judgment criteria:
:: viable count is less than 10 ² ○: viable count is 10 ^{2 to} 10 ³ Δ: viable count is 10 ^{3 to} 10 ⁴ ×: viable count is 10 ⁴ or more

(4) Evaluation method for feeling in use (no bitterness) 10 mL of each mouthwash described in the table is included in the mouth, and after rinsing for 30 seconds, five judges judged the bitterness after mouth rinsing according to the following rating criteria did. The average value of 5 persons was determined and evaluated according to the following evaluation criteria.
Rating criteria:
4 points: There was no bitterness 3 points: There was almost no bitterness 2 points: There was some bitterness.
1 point: Bitterness was considerable. Evaluation criteria (no bitterness after mouth washing) Evaluation criteria:
A: Average point 3.5 or more and 4.0 or less ○: Average point 3.0 or more and less than 3.5 points Δ: Average point 2.0 or more and less than 3.0 points ×: Average point 2.0 Less than

Details of the raw materials used are shown below.
(A) potassium nitrate; potassium nitrate super tablet (manufactured by Otsuka Food Chemicals Co., Ltd.)
(B) cetyl pyridinium chloride; cetyl pyridinium chloride (manufactured by Wako Pure Chemical Industries, Ltd.)
(C) polyoxyethylene (100) hydrogenated castor oil;
Average added mole number of ethylene oxide 100 (manufactured by Nikko Chemicals)
Polyoxyethylene (40) hydrogenated castor oil;
Average added mole number of ethylene oxide 40 (manufactured by Nikko Chemicals Co., Ltd.)
(D) alkylamido betaines;
30% aqueous solution of coconut oil fatty acid amidopropyl betaine, TEGO Betain
CK OK (made by Degussa)
In addition, the compounding quantity of the alkylamide betaine also in the table | surface is a pure part conversion value (following, the same).

＊；比較例８のエタノール配合組成では、（Ａ）、（Ｂ）成分が配合されていても不溶性沈殿物の析出がなく、知覚過敏抑制効果、浮遊菌殺菌効果が低下することもなかった。

*: In the ethanol-blended composition of Comparative Example 8, even when the components (A) and (B) were blended, there was no precipitation of the insoluble precipitate, and the hypersensitivity-suppressing effect and the suspended germ killing effect did not decrease either.

  An example of prescription is shown below. The raw materials used are the same as above. This mouthwash was all excellent in appearance stability (precipitation suppressing effect), hypersensitivity suppressing effect, floating bacteria killing effect and feeling in use (no bitter taste).

[Formulation example] mouthwash (A) potassium nitrate 5.0%
(B) cetyl pyridinium chloride 0.05
(C) Polyoxyethylene (60) hydrogenated castor oil 0.5
(D) alkylamido betaine 0.3
Glycerin 3.0
Propylene glycol 8.0
Saccharin sodium 0.1
Sodium dihydrogen phosphate 0.5
Sodium hydroxide 0.16
Fragrance 0.2
Purified water 82.19
100.0% in total
pH 6.8

Claims (5)

A liquid oral composition containing no (A) potassium nitrate in an amount of 0.01 to 10% by mass and (B) cetylpyridinium chloride in an amount of 0.001 to 0.1% by mass.
(C) the average number of moles of added ethylene oxide is 40 to 100 moles of polyoxyethylene hydrogenated castor oil 0.2 to 2% by weight, and (D) an alkyl amido betaine or a salt thereof from 0.2 to 2 wt%
(E) A composition for liquid oral cavity comprising: (E) a water content of 55% by mass to less than 92% by mass, and a pH of the composition at 25 ° C. of 6.8 to less than 8.0.   The liquid oral cavity composition according to claim 1, wherein the alkylamide betaine (D) or a salt thereof is coconut oil fatty acid amidopropyl betaine.   The composition for liquid oral cavity according to claim 1 or 2, which is a mouthwash.   The composition for liquid oral cavity according to any one of claims 1 to 3, which is for hypersensitivity and caries inhibition. A liquid oral composition containing no (A) potassium nitrate in an amount of 0.01 to 10% by mass and (B) cetylpyridinium chloride in an amount of 0.001 to 0.1% by mass.
(C) the average number of moles of added ethylene oxide is 40 to 100 moles of polyoxyethylene hydrogenated castor oil 0.2 to 2% by weight, and (D) an alkyl amido betaine or a salt thereof from 0.2 to 2 wt%
In the composition for a liquid oral cavity, it is characterized in that it is blended, (E) the water content is 55% by mass or more and less than 92% by mass, and the pH of the composition at 25 ° C. is 6.8 or more and less than 8.0. The precipitation suppression method of the insoluble precipitate produced by combined use of (A) potassium nitrate and (B) cetyl pyridinium chloride.