JP4826790B2 - Oral composition containing hydrolyzed silk - Google Patents

Description

  The present invention coats teeth with hydrolyzed silk that has high ability to adsorb teeth to dentin, thereby effectively protecting teeth from bacteria, acids, enzymes, etc. that cause caries, and The present invention relates to a composition for oral cavity in which the retention of an antibacterial agent is improved and the dental caries preventive effect is remarkably improved by remarkably preventing dissolution and decomposition of the tooth.

  Conventionally, as means for causing an active ingredient to act on teeth, means such as dentifrice, mouthwash, gel, tablet, gummi, gum and the like have been taken. However, in the case of dentifrices and mouthwashes, the amount of active ingredient in the oral cavity is insufficient after vomiting, creams and gels are poor in usability, and solid inserts are painful There was a problem. Moreover, in any case, the concentration of the active ingredient is lowered due to the cleaning action by the saliva, and the effect is lowered.

  Dentin, on the other hand, has a more porous and organic structure than enamel, and the majority of the organic matter is type I collagen. The onset mechanism of dentin caries is as follows. First, plaque adheres to the dentin surface, and metabolism of sugar occurs by bacteria in the plaque to produce an acid. The mineral component of dentin elutes (demineralizes) by the acid, and collagen is exposed. Furthermore, collagen is decomposed by collagenase derived from bacteria or saliva to form an axilla (dent). Dentin caries progress to deeper caries by repeated decalcification and collagen degradation. For these reasons, it is important to effectively suppress both decalcification and collagen degradation in order to improve the effect of preventing dentine caries.

  On the other hand, a technique for protecting the dentine has been proposed. For example, a technique that improves the appearance of a composition by combining a natural or synthetic cationized peptide / protein with a nonionic or amphoteric active agent (Japanese Patent Laid-Open No. 6-9354) improves fluorine tooth surface uptake. However, cationized peptides and proteins are not sufficiently effective in that they are effective in a long-term treatment with an application time of 1 hour. Mouthwash containing collagen or gelatin (Japanese Patent Laid-Open No. 2003-119157) shows high adsorbability for type II collagen contained in the vitreous body and cartilage of the eye, while dentin, bone, and oral mucosa Since the adsorptive capacity for type I collagen contained in the tooth is small, there is a big problem in adsorbing the composition to the teeth. Tooth surface coating agents containing fatty acid salts (Japanese Patent Laid-Open No. 2000-103726) have a fatty acid salt tooth, and the active ingredient flows out of the oral cavity by gargle after drug treatment due to the surfactant activity of the fatty acid salt itself. There remain significant problems with the surface coating effect and the tooth surface retention of active ingredients. Further, the tooth acid-resistant strengthening composition (Japanese Patent Laid-Open No. 6-298632) comprising tea polyphenol, fluorine, and aluminum salt has a bad taste and can exhibit an effect in an acidic region. When the pH under normal use, such as a mouthpiece, is near neutral, an insoluble precipitate is formed between fluorine and aluminum ions, and in the case of a dentifrice, between the abrasive and the fluorine tooth. The effect of improving quality uptake cannot be expected.

Furthermore, as a technique using silk, a stress inhibitor containing a silk protein degradation product (Japanese Patent Laid-Open No. 2003-81868) and a physiologically active composition derived from a silk protein hydrolyzate (Japanese Patent Laid-Open No. 11-139986). However, these are not designed as oral compositions such as dentifrices and mouthwashes, and their effects are unclear. Further, although there is a scrub agent made of silk fibroin (Japanese Patent Laid-Open No. 2003-113072), when it is used in the oral cavity, a scrub effect is recognized, but a protective effect on the tooth quality is not recognized. Furthermore, since the composition for oral cavity made of silk fibroin (Japanese Patent Laid-Open No. 2001-226242) is not hydrolyzed silk as well as Japanese Patent Laid-Open No. 2003-113062, the number average molecular weight of fibroin is about 350,000. Although it is excellent in the film-forming protective effect on the mucous membranes such as the tongue and buccal mucosa, the effect of protecting the tooth surface is inferior because the adsorbing effect on hard teeth is low. In general, naturally-occurring polypeptide compounds have higher permeability and adsorptivity as the molecular weight is lower, while film-forming properties are lower. Adsorbability and permeability are lower as the molecular weight is higher, while film-forming performance is improved. It is said. For example, according to the product catalog (Promois (registered trademark)) of Seiwa Kasei Co., Ltd., the lower the molecular weight, the higher the adsorptivity and permeability of the collagen polypeptide to the hair, and the higher the molecular weight, the better the film-forming property. On the other hand, the adsorptivity and permeability are likely to decrease.
As described above, all known techniques have the effect of adsorbing and protecting teeth on dentin in a short time treatment, retention of tooth surfaces of active ingredients such as fluorine and antibacterial agents, stability in preparations, There are major issues in flavor and the like.

  In order to solve these problems, effective adsorption ability of teeth to dentin in a short time treatment, retention of tooth surfaces of active ingredients such as fluorine and antibacterial agents, stability in preparation, flavor, etc. Therefore, a composition having both of these is desired.

  An object of the present invention is to solve the above-mentioned problems and to provide an oral composition having a high effect of preventing dentine caries in a short time treatment.

As a result of intensive studies to achieve the above object, the present inventors have further obtained a combination of a peptide compound obtained by further hydrolyzing silk fibroin obtained by refining silk thread with an acid, alkali, enzyme, etc. and a fluorine compound, The present inventors have found an excellent ability to inhibit collagen degradation and demineralization against dentin containing an organic substance mainly composed of type I collagen. Furthermore, by adding a hardly water-soluble nonionic antibacterial agent, the inventors have found that the ability to suppress collagen degradation and the ability to suppress decalcification are further improved, and the present invention has been completed.
Therefore, the present invention
[I] An oral composition comprising hydrolyzed silk having a number average molecular weight of 200 to 6,000 calculated based on the total nitrogen amount and amino nitrogen amount, and a fluorine compound,
[II] The oral composition according to [I], wherein the hydrolyzed silk is obtained by phosphoric acid hydrolysis,
[III] The compounding amount of hydrolyzed silk is 0.1 to 10% by mass of the entire composition, and the compounding amount of the fluorine compound is 0.02 to 3% by mass of the entire composition [I] or [II] The composition for oral cavity,
[IV] A composition for oral cavity according to any one of [I] to [III], further comprising a slightly water-soluble nonionic antibacterial agent, a surfactant and / or an alcohol,
[V] The poorly water-soluble nonionic antibacterial agent is triclosan or isopropylmethylphenol, the surfactant is polyoxyethylene hydrogenated castor oil or alkyl sulfate salt having an average addition mole number of 5 to 100, and alcohol The composition for oral cavity according to [IV], in which is propylene glycol, polyethylene glycol (# 200 to 6000), ethylene glycol, glycerin, sorbitol or ethanol,
[VI] The amount of the poorly water-soluble nonionic antibacterial agent is 0.01 to 2% by mass of the whole composition, and the amount of the surfactant is 0.1 to 5% by mass of the whole composition, The composition for oral cavity according to [IV] or [V], wherein the blending amount of alcohol is 0.1 to 50% by mass of the whole composition.

  According to the present invention, by using hydrolyzed silk having a specific number average molecular weight and a fluorine compound, collagen degradation and decalcification of dentin can be remarkably suppressed. Furthermore, by adding both a poorly water-soluble nonionic antibacterial agent and a surfactant and / or alcohol for solubilizing it, the collagen degradation inhibitory effect and decalcification inhibitory effect of dentin are improved. It is possible to provide a composition for oral cavity in which the effect of preventing dentin caries has been dramatically improved.

The composition for oral cavity of the present invention is characterized by containing hydrolyzed silk.
Here, the hydrolyzed silk can be obtained by hydrolyzing silk fibroin obtained by refining the silk thread spun from the silkworm with an acid, alkali, enzyme or the like. It is known that the silk thread has fibroin in the center and sericin in the periphery, and the abundance ratio is generally fibroin: sericin = 70-80%: 20-30% (mass percentage).
As for silk thread, first, silkworms produced at a sericulture farmhouse are dried and dried and then spun to produce raw silk, and then raw silk is scoured to obtain silk thread or silk fabric. The most common refining method is boiling in an aqueous solution containing an alkaline sodium salt or soap (alkaline soap refining). By this refining, sericin outside the silk thread is removed, and only the fibroin in the center is purified. Is done. Hydrolyzed silk can be obtained by hydrolyzing this fibroin (average molecular weight: about 350,000) with acid, alkali, enzyme, etc., but can be prepared with various molecular weights depending on the degree of hydrolysis. In the present invention, hydrolyzed silk obtained by phosphoric acid hydrolysis is particularly preferable.
The hydrolyzed silk used in the present invention has a number average molecular weight of 200 to 6,000, preferably 500 to 5,000, more preferably 500 to 1,000. If the number average molecular weight is less than 200, the adsorptivity to teeth is extremely low, but the film-forming property is extremely low, and if it exceeds 6,000, the film-forming property is high, but the adsorptivity is reduced. descend. Hydrolyzed silk is commercially available from various companies in grades with various number average molecular weights, and they can be used properly as needed. Examples of commercially available products include silk BN-P (manufactured by NDC Co., Ltd., number average molecular weight 500) as hydrolyzed silk by phosphoric acid hydrolysis, and silk peptide M-500 (hydrolytic silk by enzymatic hydrolysis). Cosmo Foods Co., Ltd., number average molecular weight 500), other hydrolyzed silks by Promois (registered trademark) Silk 1000p (manufactured by Seiwa Kasei Co., Ltd., number average molecular weight 1,000), silk peptide 5 ( Kanebo Co., Ltd., number average molecular weight 1,500), silk powder FD (Kanebo Co., Ltd., number average molecular weight 5,000), and the like. The hydrolyzed silk of the present invention is non-cationic or nonionic.

The number average molecular weight is generally calculated by gel filtration chromatography (GPC) or calculation of analytical nitrogen value, but the latter is used for polypeptide compounds such as hydrolyzed silk used in the present invention. There are many cases. More specifically, the number average molecular weight of the hydrolyzed silk of the present invention is calculated by the following formula (1) based on the total nitrogen amount in the molecule, the amino nitrogen amount, and the average molecular weight of the constituent amino acids.

  In the above formula (1), the average molecular weight of the constituent amino acids is obtained by multiplying the abundance ratio (%) of constituent amino acids obtained by ordinary amino acid analysis by the molecular weight of each amino acid, and the total nitrogen amount is based on cosmetic raw material standards The first nitrogen determination method of general test methods or gas chromatography (GC), and the amount of amino nitrogen can be measured by the formol titration method.

  Although the compounding quantity of the said hydrolysis silk is not restrict | limited in particular, 0.1 to 10% (mass percentage, the following is the same) of the whole composition is suitable, and 0.5 to 5% is especially desirable. If it is lower than 0.1%, the effects of the present invention cannot be obtained sufficiently, and if it exceeds 10%, the taste and feeling of use may deteriorate.

  The oral composition of the present invention contains a fluorine compound. Examples of the fluorine compound used in the present invention include sodium fluoride, sodium monofluorophosphate, stannous fluoride, and sodium fluoride and sodium monofluorophosphate are particularly preferable. From the viewpoint of caries prevention, it is preferable to blend these fluorine compounds in an amount of 0.02 to 3% of the whole composition, particularly in the case of sodium fluoride, 0.02 to 1% of the whole composition, more preferably 0. 0.02 to 0.7%, and in the case of sodium monofluorophosphate, it is preferably 0.05 to 3%, more preferably 0.07 to 2.5% of the entire composition.

  Further, in the present invention, it is preferable to further blend a poorly water-soluble nonionic antibacterial agent. As poorly water-soluble nonionic antibacterial agents, triclosan (solubility in water; 0.001 g / 100 mL (20 ° C.), the value stated on the Ministry of the Environment website), isopropylmethylphenol (same; 0.015 g / 100 mL (25 ° C.)) , Osaka Kasei Co., Ltd. catalog value), thymol (0.098 g / 100 mL (25 ° C.), Osaka Kasei Co., Ltd. catalog value), etc. The solubility in water at 20-25 ° C. is 0.1 g. / 100 mL or less nonionic antibacterial agents can be mentioned, among which triclosan and isopropylmethylphenol are preferable. In the present invention, one or two or more of the poorly water-soluble nonionic antibacterial agents can be used in combination. The blending amount is preferably 0.001 to 2%, more preferably 0.01 to 1% of the entire composition. If it is less than 0.001%, the sufficient bactericidal effect may not be exhibited, and if it exceeds 2%, solubilization in the preparation may be difficult, and the taste and usability may be deteriorated.

  Furthermore, in order to improve the solubility of a poorly water-soluble nonionic antibacterial agent and an oil-soluble fragrance | flavor, the surfactant for oral cavity of this invention can be mix | blended. As the surfactant, polyoxyethylene hydrogenated castor oil and alkyl sulfate ester salts are preferable. The polyoxyethylene hydrogenated castor oil has an average added mole number of ethylene oxide of 5 to 100, particularly 5 to 20 for a dentifrice and 40 to 100 for a mouthwash. When the average number of added moles is less than 5, oil solubility increases, leading to a reduction in foaming power, and when it exceeds 100, the stability of the poorly water-soluble nonionic antibacterial agent may be lowered. The blending amount of the polyoxyethylene hydrogenated castor oil is 0.1 to 5%, particularly 0.5 to 2.5% in the case of a dentifrice, and 0.2 to 2 in the case of a mouthwash. % Is preferred. If it is less than 0.1%, the stabilizing effect of the poorly water-soluble nonionic antibacterial agent cannot be sufficiently obtained, and if it exceeds 5%, sufficient foaming power may not be obtained.

  Examples of the alkyl sulfate ester salts include alkali metal salts such as sodium, potassium and lithium such as octyl sulfate, decyl sulfate, lauryl sulfate, myristyl sulfate, palmityl sulfate and stearyl sulfate, and sodium lauryl sulfate which has excellent foaming power. Is most preferred. The blending amount of the alkyl sulfate salt is preferably 0.05 to 5%, more preferably 0.1 to 2.5% in the case of a dentifrice, and 0.005 in the case of a mouthwash. 1 to 0.5% is preferable. If it is less than 0.05%, sufficient foaming property cannot be obtained, and if it exceeds 5%, foamability is strong and the feeling of use may be lowered.

  Moreover, it can replace with surfactant or can mix | blend alcohols with surfactant. As the alcohols, one or more of propylene glycol, polyethylene glycol (# 200 to 6000), ethylene glycol, glycerin, sorbitol, ethanol and the like can be used, and the blending amount is 0.1 to 50% of the entire composition. Is preferable, and more preferably 1 to 40%. If the amount is less than 0.1%, the poorly water-soluble nonionic antibacterial agent may not be stably blended, and if it exceeds 50%, the taste and usability may be deteriorated.

  Furthermore, as other caries prevention components, known effective drugs can be used. Inorganic calcium compounds such as calcium chloride, calcium nitrate, calcium sulfate, calcium glycerophosphate, calcium hydroxide, calcium lactate, calcium acetate, malon Organic calcium compounds such as calcium acid, calcium citrate, calcium gluconate, calcium glycerate, calcium tartrate and calcium phytate, and enzyme agents such as dextranase, mutanase and lysozyme can be used in combination. The compounding amount of these agents is preferably in the range of 0.005 to 10%, particularly preferably in the range of 0.05 to 5% of the entire composition. When the amount is less than 0.005%, the effect is not exhibited. When the amount exceeds 10%, a problem may occur in taste and usability.

  The oral composition of the present invention can be in the form of toothpaste, toothpaste, toothpaste such as liquid toothpaste, mouthwash, mouth freshener, gargle tablet, denture cleaner, chewing gum, etc. Each composition can be prepared by an ordinary method according to the characteristics, using other components as long as the effects of the present invention are not impaired. In this case, in the case of dentifrice, abrasives, wetting agents, binders and the like are usually blended.

  As abrasives, precipitated silica, silica gel, aluminosilicate, zeolite, zirconosilicate, dicalcium phosphate dihydrate and anhydride, calcium pyrophosphate, calcium carbonate, aluminum hydroxide, alumina, magnesium carbonate, tertiary phosphorus Examples thereof include magnesium acid, insoluble sodium metaphosphate, insoluble potassium metaphosphate, titanium oxide, hydroxyapatite, and synthetic resin-based abrasive (mixing amount: usually 5 to 50% based on the entire composition).

  Examples of the wetting agent include polyhydric alcohols among the above alcohols (mixing amount: usually 10 to 50% based on the entire composition).

  As binder, carrageenan, hydroxyethylcellulose sodium, carboxymethylcellulose sodium, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, propylene glycol ester alginate, polyacrylic acid, sodium polyacrylate, xanthan gum, tara gum, Guam gum, locust bean gum, gellan gum, gelatin, curdlan, gum arabic, agar, pectin, polyvinyl alcohol, polyvinyl pyrrolidone, pullulan, etc. (blending amount: usually 0.1 to 5% based on the whole composition) .

  Further, if necessary, anionic surfactants other than the above-mentioned surfactants, cationic surfactants, nonionic surfactants and the like can be blended, for example, sodium α-olefin sulfonate, N-acyl glutamate 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, N-acyl taurate, sucrose fatty acid ester, alkylol amide, polyglycerin fatty acid ester, polyoxyethylene polyoxypropylene glycol, polyoxyethylene Sorbitan monostearate, sodium lauroyl sarcosine, alkyl polyglucoside, polyoxyethylene alkyl ether sulfosuccinate and the like may be added in an amount of 0 to 5% based on the entire composition.

  In the case of a liquid oral composition such as a mouthwash, the above thickener and other surfactants can be blended.

  Furthermore, sweeteners such as saccharin and xylitol, other preservatives, fragrances, colorants, pH adjusters, excipients, various medicinal ingredients, and the like can be blended in the oral composition of the present invention as necessary. .

  The pH of the composition of the present invention is not particularly limited as long as it is within the range of safety in the oral cavity and human body, but is preferably pH 4 to 10, more preferably pH 5.5 to 9. . When the pH is less than 4, there is a concern of decalcification depending on the application time, and when the pH is more than 10, the usability and taste may be deteriorated. As pH adjusters, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, citric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, sodium citrate, sodium hydrogen citrate, sodium phosphate, sodium hydrogen phosphate Etc. may be blended in an appropriate amount.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In addition, all% in each example is a mass percentage. In the following examples, the number average molecular weight is the number average molecular weight calculated by the formula (1).

Experiment 1: Experiment for inhibiting collagen degradation of initial demineralized dentin [Examples 1-21, Comparative Examples 1-6]
(1) Preparation of model dentifrice (Examples 1-7)
A model dentifrice was prepared according to the formulation shown in Table 1 below. Silk BN-P made by NDC Co., Ltd. having a number average molecular weight of 500 was used as the hydrolyzed silk by the phosphoric acid hydrolysis method. As a hydrolyzed silk other than the phosphoric acid hydrolysis method, silk peptide M-500 (Cosmo Foods Co., Ltd., number average molecular weight 500), Promois (registered trademark) Silk 1000p (manufactured by Seiwa Kasei Co., Ltd., number average molecular weight) 1,000), silk peptide 5 (manufactured by Kanebo Co., Ltd., number average molecular weight 1,500), and silk powder FD (manufactured by Kanebo Co., Ltd., number average molecular weight 5,000) were used. A 7% silk fibroin aqueous solution was prepared by referring to Reference Example 1 <Production Method of Fibroin Aqueous Solution> of JP-A-2001-226242. Similarly, a silk fibroin scrubbing agent was disclosed in JP-A-2003-113072. What was prepared with reference to Example 1 was used. Furthermore, NMP collagen PS manufactured by Nippon Ham Co., Ltd. is used for pig skin collagen, and 20% higher alkyl cationized silk peptide solution (Promois (registered trademark) S-CAQ) manufactured by Seiwa Kasei Co., Ltd. is used. It was.
As a method for preparing a dentifrice, a phase A was prepared by mixing and dissolving water-soluble components (sodium fluoride, sodium monofluorophosphate, hydrolyzed silk, cationized silk, pig skin collagen, etc.) in purified water at room temperature. In addition, since sodium fluoride and sodium monofluorophosphate have a content approved in Japan of 1,000 ppm or less as fluorine ions, sodium fluoride is 0.21% and sodium monofluorophosphate in the examples. Was blended around 0.73%. On the other hand, B phase was prepared by dispersing sodium polyacrylate (Rheojic 250H, manufactured by Nippon Pure Chemical Co., Ltd.) in purified water at room temperature. B phase was added and mixed in A phase under stirring, sodium polyacrylate was swollen, and C phase was prepared. Furthermore, in the C phase, other components (silk fibroin scrub agent, polyoxyethylene (20 mol) hydrogenated castor oil) and other components are mixed at room temperature using a 1.5 L kneader (manufactured by Ishiyama Kogyo Co., Ltd.) The pressure was reduced to 4 kPa and defoaming was performed to obtain 1.0 kg of a dentifrice.
The number average molecular weights of hydrolyzed silk, silk fibroin, and pig skin collagen are the total nitrogen content, the first nitrogen determination method of the cosmetic raw material standard general test method, the amino nitrogen content is measured by the formol titration method, Calculated according to (1).

(2) Preparation of dentifrice (Examples 8 to 19)
A phase A was prepared by mixing and dissolving water-soluble components (hydrolyzed silk, sodium fluoride, sodium monofluorophosphate, sodium saccharin, xylitol, 70% sorbit, etc.) in purified water at room temperature. In addition, the silk BN-P made from NDC with a number average molecular weight 500 was used as the hydrolysis silk by the phosphoric acid hydrolysis method similarly to said (1). As a hydrolyzed silk other than the phosphoric acid hydrolysis method, silk peptide M-500 (Cosmo Foods Co., Ltd., number average molecular weight 500), Promois (registered trademark) Silk 1000p (manufactured by Seiwa Kasei Co., Ltd., number average molecular weight) 1,000), silk peptide 5 (manufactured by Kanebo Co., Ltd., number average molecular weight 1,500), and silk powder FD (manufactured by Kanebo Co., Ltd., number average molecular weight 5,000) were used. Furthermore, since sodium fluoride and sodium monofluorophosphate have a content approved in Japan of 1,000 ppm or less as fluorine ions, in the examples, sodium fluoride is 0.21%, and sodium monofluorophosphate is The blend was centered on 0.73%. On the other hand, B phase is prepared by dissolving and dispersing triclosan, isopropylmethylphenol, thymol, sodium polyacrylate (Rheojic 250H, manufactured by Nippon Pure Chemicals Co., Ltd.), xanthan gum, sodium carboxymethylcellulose, etc. in propylene glycol at room temperature. did. Next, the B phase was added and mixed into the A phase being stirred, and the C phase was prepared by adding and mixing the examples in which polyoxyethylene hydrogenated castor oil was blended. In Phase C, fragrance, anhydrous silicic acid, and other ingredients (dextranase, sodium lauryl sulfate, etc.) are mixed at room temperature using a 1.5 L kneader (manufactured by Ishiyama Kogyo Co., Ltd.), depressurized to 4 kPa and removed. Foaming was performed to obtain 1.0 kg of a dentifrice.

(3) Preparation of mouthwash (Examples 20, 21)
A specified amount of purified water was charged into a stainless steel container equipped with a three-one motor and a stirrer having rotating blades, and water-soluble components such as hydrolyzed silk among the blended components were charged and dissolved. On the other hand, a specified amount of an organic solvent such as ethanol was charged into another stainless steel vessel equipped with a three-one motor and a stirrer having rotating blades, and oil-soluble components among the blended components were charged and dissolved. Furthermore, the oil-soluble component was added to a container in which the water-soluble component was dissolved, and the mixture was stirred for 1 to 30 minutes to obtain a uniform solution to obtain a mouthwash.

(4) Dentin Collagen Degradation Inhibition Experiment JM, Ten Cate et al. (The influx of the organic matrix on demineralization of bovine root dentin in vitro, 15: 9 sent den re ent ent. For reference, a degradation test of bovine dentin collagen was performed.
Specifically, the root surface dentin of the incisor extracted from a healthy cow was cut out to prepare a dentin block having a length of 5 mm × width of 5 mm × height of 3 mm. Further, one surface of the block was mirror-polished with # 4000 water-resistant abrasive paper, and a 2 mm × 2 mm portion of the surface was removed, and a commercially available nail burnish was applied to all surfaces, and a test surface (size 2 mm × 2 mm) ( Window portion). This test surface was decalcified with 0.1 M acetic acid (pH 5.0) for 2 days to obtain a demineralized layer having a depth of about 300 μm, that is, a collagen layer.

The model dentifrices and dentifrices of Examples 1 to 19 and Comparative Examples 1 to 6 were diluted 3 times with distilled water in consideration of the usage volume under human use, and the diluted solution was used as a treatment solution. For the mouth washes of Examples 20 and 21, the stock solution was used as the treatment liquid.
After immersing the test surface of the bovine dentin block in the treatment solution of each Example and Comparative Example for 3 minutes at room temperature, the dentifrice was rinsed well with distilled water in consideration of the usage volume, and the mouthwash Was not rinsed with distilled water, but was treated with a collagenase (Type VII, manufactured by Sigma) solution (400 units / mL 50 mM HEPES, pH 7.8) derived from Clostridium histolyticum for 18 hours. After repeating this process three times, a slice of about 200 μm in thickness was cut out in a direction perpendicular to the test surface with a microcutter (MC-201, manufactured by Marto Co., Ltd.) to prepare a wet preparation.
Finally, an image of the collagen degradation layer of each section was obtained with a polarizing microscope (BH-2, Olympus Optical Co., Ltd.), and the collagen degradation depth was obtained with an image analyzer (PIAS-V, Pierce Co., Ltd.). The thickness (μm) was determined. Furthermore, based on the average collagen decomposition depth of the sample subjected to only the collagen decomposition treatment, the collagen decomposition inhibition rate of each example and comparative example was calculated (the following formula (2)). In addition, a series of experiment operation was performed by N = 3 for each Example and the comparative example, and the average value was shown. The evaluation criteria for the dentin collagen degradation inhibitory effect were as follows.

評価基準； 象牙質コラーゲン分解抑制率が、
◎ ：８０％以上
○〜◎：６０％以上８０％未満
○ ：４０％以上６０％未満
△ ：２０％以上４０％未満
× ：２０％未満

Evaluation criteria: Dentin collagen degradation inhibition rate is
◎: 80% or more
○ to ◎: 60% or more and less than 80%
○: 40% or more and less than 60%
Δ: 20% or more and less than 40%
×: Less than 20%

Experiment 2: Healthy dentin demineralization suppression experiment using artificial plaque [Examples 1-21, Comparative Examples 1-6]
This experiment evaluates the comprehensive demineralization phenomenon due to the adsorption of causative bacteria on the dentin surface, acid production by the sugar metabolism of the causative bacteria, and production of various enzymes of the causative bacteria. An evaluation experiment close to the intraoral environment was performed. In the same manner as in Experiment 1, the root surface dentin of the incisor extracted from a healthy cow was cut out to prepare a dentin block of 5 mm length × 5 mm width × 3 mm height. Further, one surface of the block was mirror-polished with # 4000 water-resistant abrasive paper, and a 2 mm × 2 mm portion of the surface was removed, and a commercially available nail burnish was applied to all surfaces, and a test surface (size 2 mm × 2 mm) ( Window portion). This sample was sterilized by irradiation with cobalt 60 gamma rays at a dose of 10.4 kJ / kg.
As the preparation to be used, the model dentifrice, dentifrice and mouthwash prepared in Experiment 1 were used as they were. The model dentifrices and dentifrices of Examples 1 to 19 and Comparative Examples 1 to 6 were diluted 3 times with distilled water and 3,000 rpm with a centrifuge (Hitachi 05PR-22, manufactured by Hitachi Koki Co., Ltd.). The supernatant obtained by centrifuging at room temperature for 10 minutes was further sterilized by filtration with a filter having a pore size of 0.22 μm (Millex-GS, manufactured by Nippon Millipore Co., Ltd.), and used as a treatment solution. Moreover, about Example 20, 21, since it was a mouthwash, what sterilized the stock solution by filtration was made into the process liquid.

Next, after immersing the test surface of the bovine dentin block in the treatment solution of each Example and Comparative Example for 3 minutes at room temperature and rinsing well with sterilized distilled water, mutans bacteria that are caries-causing bacteria THB (Todd Height Broth, manufactured by Difco) medium containing (Streptococcus mutans ATCC25175) was added to 1.5 mL of medium and cultured at 37 ° C. in an anaerobic state for 1 day to form artificial plaques on the test surface of the dentin block. In this case, Examples 20 and 21 were not rinsed with sterilized distilled water because of the mouthwash. Thereafter, the dentin block was taken out, and the treatment solution of each Example and Comparative Example was again immersed in the test surface on which the artificial plaque was formed for 3 minutes at room temperature, rinsed well with sterile distilled water, The solution was added to 1.5 mL of sugar-containing THB medium and cultured at 37 ° C. in an anaerobic state for 1 day. Also in this case, Examples 20 and 21 were not rinsed with sterilized distilled water because of the mouthwash. This treatment was repeated once a day for a total of 4 days. In addition, the culture medium immersed after chemical | medical agent treatment used the new thing each time. Thereafter, the artificial plaque on the test surface is carefully removed with a brush, and a section of about 200 μm in thickness is placed under running water so that it is perpendicular to the test surface with a microcutter (MC-201, manufactured by Marto). Carefully cut out. Furthermore, in a wet state, a soft X-ray generator (CMRII, manufactured by Softex Co., Ltd.) was used to irradiate 2.8 mA, 18 kVp, 60 minutes on a soft X-ray film (SO-343, manufactured by Kodak) A TMR (Transverse Micro Radiography) image of each section was obtained.
Finally, draw the mineral profile for each TMR image with the image analyzer (PIAS-V, manufactured by Pierce Co., Ltd.) Mineral loss amount ΔZ (decalcification amount) was calculated. Further, the average ΔZ of the samples not treated with the drug (culture only) was defined as the reference decalcification amount, and the dentin demineralization inhibition rate of each example and comparative example was calculated (the following formula (3)). A series of experimental operations were performed with N = 3 for each of the examples and comparative examples, and the average value was shown. The evaluation criteria were as follows.

評価基準； 象牙質の脱灰抑制率が、
◎：７０％以上
○：５０％以上７０％未満
△：３０％以上５０％未満
×：３０％未満

Evaluation criteria: Dentin demineralization inhibition rate is
A: 70% or more
○: 50% or more and less than 70%
Δ: 30% or more and less than 50%
X: Less than 30%

  The evaluation results of Examples 1 to 7 and Comparative Examples 1 to 6 are summarized in Table 1. The evaluation results of Examples 8 to 21 are summarized in Table 2.

＊１ リン酸加水分解法によるシルクＢＮ−Ｐ
＊２ 酵素加水分解法によるシルクペプチドＭ−５００

* 1 Silk BN-P by phosphoric acid hydrolysis method
* 2 Silk peptide M-500 by enzymatic hydrolysis method

  As in Examples 1 to 7, those containing hydrolyzed silk having a number average molecular weight of 500 to 5,000 and a fluorine compound showed excellent dentin collagen degradation inhibitory effect and decalcification inhibitory effect. Among them, particularly those containing hydrolyzed silk having a number average molecular weight of 500 to 1,000 and a fluorine compound showed a high dentin collagen degradation inhibitory effect. In addition, when the effects of hydrolyzed silk having the same number average molecular weight are compared, hydrolyzed silk that has not been hydrolyzed with phosphoric acid and fluorine are particularly those containing hydrolyzed phosphoric acid hydrolyzed with phosphoric acid and fluorine compounds. The dentin collagen degradation inhibitory effect was higher than that containing the compound. This was presumed to be because the hydrolyzed silk hydrolyzed with phosphoric acid had a higher peptide content. On the other hand, when only hydrolyzed silk, only fluorine compounds, or cationized silk or silk fibroin or collagen with a considerably large number average molecular weight are contained as in the comparative example, dentin collagen degradation inhibitory effect and decalcification The suppression effect was not sufficient.

[Example 8] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Sodium lauryl sulfate 0.1
Sodium polyacrylate 0.8
Xanthan gum 0.3
Fragrance 0.1
Purified water remaining
Total 100.0%

[Example 9] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk peptide M-500, manufactured by Cosmo Foods Co., Ltd.)
Sodium lauryl sulfate 0.1
Sodium polyacrylate 0.8
Xanthan gum 0.3
Fragrance 0.1
Purified water remaining
Total 100.0%

[Example 10] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 5,000) 1.0
(Silk powder FD, Kanebo Co., Ltd.)
Sodium lauryl sulfate 0.1
Sodium polyacrylate 0.8
Xanthan gum 0.8
Saccharin sodium 0.02
Fragrance 0.1
Purified water remaining
Total 100.0%

[Example 11] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 1,000) 1.0
(Promois (registered trademark) Silk 1000p, manufactured by Seiwa Kasei Co., Ltd.)
Sodium lauryl sulfate 0.1
Sodium polyacrylate 0.5
Sodium carboxymethylcellulose 0.3
Xanthan gum 0.5
Xylitol 9.0
Sodium citrate 0.3
Fragrance 0.1
Purified water remaining
Total 100.0%

[Example 12] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 1,500) 1.0
(Silk Peptide 5, manufactured by Kanebo Corporation)
Sodium lauryl sulfate 0.1
Sodium polyacrylate 0.3
Sodium carboxymethylcellulose 0.5
Xanthan gum 0.8
Xylitol 2.0
Dextranase 0.3
Fragrance 0.1
Purified water remaining
Total 100.0%

[Example 13] Dentifrice Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Triclosan 0.05
Polyoxyethylene (20 mol) hydrogenated castor oil 1.4
Sodium lauryl sulfate 1.0
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.8
Sodium carboxymethylcellulose 0.4
Xanthan gum 0.4
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 14] Dentifrice Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Isopropyl methylphenol 0.05
Polyoxyethylene (20 mol) hydrogenated castor oil 1.4
Sodium lauryl sulfate 1.0
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.4
Sodium carboxymethylcellulose 0.2
Xanthan gum 0.2
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 15] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Timor 0.05
Polyoxyethylene (20 mol) hydrogenated castor oil 1.4
Sodium lauryl sulfate 1.0
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.5
Xanthan gum 0.8
Xylitol 9.0
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 16] Dentifrice Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Triclosan 0.05
Isopropyl methylphenol 0.05
Polyoxyethylene (20 mol) hydrogenated castor oil 1.4
Sodium lauryl sulfate 1.0
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.8
Sodium carboxymethylcellulose 0.8
Sodium hydroxide 0.3
Saccharin sodium 0.05
Xylitol 9.0
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 17] Dentifrice Dibasic calcium phosphate 15.0
Sodium monofluorophosphate 0.73
Hydrolyzed silk (number average molecular weight: 500) 1.0
(Silk BN-P, manufactured by NDC)
Triclosan 0.03
Polyoxyethylene (20 mol) hydrogenated castor oil 1.2
Sodium lauryl sulfate 0.8
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.5
Sodium carboxymethylcellulose 0.5
Sodium hydroxide 0.3
Saccharin sodium 0.05
Xylitol 9.0
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 18] Dentifrice Sodium fluoride 0.4
Hydrolyzed silk (number average molecular weight: 500) 0.5
(Silk BN-P, manufactured by NDC)
Isopropyl methylphenol 0.05
Polyoxyethylene (20 mol) hydrogenated castor oil 1.4
Sodium lauryl sulfate 0.5
70% sorbit 30.0
Propylene glycol 5.0
Sodium polyacrylate 0.5
Sodium hydroxide 0.3
Saccharin sodium 0.05
Dextranase 0.3
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 19] Dentifrice Silicic anhydride 15.0
Sodium fluoride 0.21
Hydrolyzed silk (number average molecular weight: 500) 2.0
(Silk BN-P, manufactured by NDC)
Triclosan 0.1
Polyoxyethylene (10 mol) hydrogenated castor oil 0.8
Sodium lauryl sulfate 1.0
70% sorbit 40.0
Propylene glycol 5.0
Sodium polyacrylate 0.8
Sodium carboxymethylcellulose 0.5
Xanthan gum 0.3
Sodium hydroxide 0.3
Saccharin sodium 0.05
Fragrance 0.5
Purified water remaining
Total 100.0%

[Example 20] Mouthwash Hydrolyzed silk (number average molecular weight: 500) 1.5
(Silk BN-P, manufactured by NDC)
Sodium fluoride 0.05
Triclosan 0.02
Polyoxyethylene (60 mol) hydrogenated castor oil 0.3
Ethanol 10.0
Citric acid 0.01
Trisodium citrate 0.3
Saccharin sodium 0.1
Xylitol 5.0
0.1% green No.3 0.8
Fragrance 0.3
Purified water remaining
Total 100.0%

[Example 21] Mouthwash Hydrolyzed silk (number average molecular weight: 1,000) 2.0
(Promois (registered trademark) Silk 1000p, manufactured by Seiwa Kasei Co., Ltd.)
Sodium fluoride 0.05
Isopropylmethylphenol 0.08
Triclosan 0.05
Polyoxyethylene (60 mol) hydrogenated castor oil 0.3
Ethanol 10.0
Citric acid 0.01
Trisodium citrate 0.3
Saccharin sodium 0.1
Dextranase 3.0
0.1% green No.3 0.8
Fragrance 0.3
Purified water remaining
Total 100.0%

  From Table 2, the thing containing the hydrolysis silk with a number average molecular weight of 500-5,000 and a fluorine compound showed the excellent dentine collagen degradation inhibitory effect and demineralization inhibitory effect. Among them, particularly those containing hydrolyzed silk having a number average molecular weight of 500 to 1,000 and a fluorine compound showed a high dentin collagen degradation inhibitory effect. In addition, when the effects of hydrolyzed silk having the same number average molecular weight are compared, hydrolyzed silk that has not been hydrolyzed with phosphoric acid and fluorine are particularly those containing hydrolyzed phosphoric acid hydrolyzed with phosphoric acid and fluorine compounds. The dentin collagen degradation inhibitory effect was higher than that containing the compound. This is presumably because hydrolyzed silk that had been hydrolyzed with phosphoric acid had a higher peptide content as described above. Furthermore, the combined use of a poorly water-soluble nonionic antibacterial agent and a surfactant and / or alcohol for solubilizing it improves the dentin collagen degradation inhibitory effect and decalcification inhibitory effect. It was suggested that the effect of preventing caries was drastically improved.

From the above experimental examples, Examples 1 to 21 protected dentin in a short time treatment and effectively suppressed degradation of dentin collagen, as compared with Comparative Examples 1 to 6. It has been speculated that the retention of the fluorine compound and antibacterial agent on the tooth surface is greatly improved, so that it has a synergistic high demineralization suppressing effect.
Therefore, according to the present invention, collagen degradation and decalcification of dentin can be remarkably suppressed by using hydrolyzed silk and a fluorine compound having a specific number average molecular weight. Furthermore, by adding both a poorly water-soluble nonionic antibacterial agent and a surfactant and / or alcohol for solubilizing it, the collagen degradation inhibitory effect and decalcification inhibitory effect of dentin are improved. It is possible to provide a composition for oral cavity in which the effect of preventing dentin caries has been dramatically improved.

Claims (6)

  An oral composition comprising hydrolyzed silk having a number average molecular weight of 200 to 6,000 calculated based on the total nitrogen amount and amino nitrogen amount, and a fluorine compound.   The composition for oral cavity according to claim 1, wherein the hydrolyzed silk is obtained by phosphoric acid hydrolysis.   The composition for oral cavity according to claim 1 or 2, wherein the blending amount of hydrolyzed silk is 0.1 to 10% by weight of the whole composition, and the blending amount of the fluorine compound is 0.02 to 3% by weight of the whole composition. object.   The oral composition according to any one of claims 1 to 3, further comprising a slightly water-soluble nonionic antibacterial agent, a surfactant and / or an alcohol.   The slightly water-soluble nonionic antibacterial agent is triclosan or isopropylmethylphenol, the surfactant is polyoxyethylene hydrogenated castor oil or alkyl sulfate ester salt having an average addition mole number of 5 to 100, and the alcohol is propylene glycol The composition for oral cavity according to claim 4, which is polyethylene glycol (# 200-6000), ethylene glycol, glycerin, sorbitol or ethanol.   The blending amount of the hardly water-soluble nonionic antibacterial agent is 0.01 to 2% by mass of the entire composition, the blending amount of the surfactant is 0.1 to 5% by mass of the entire composition, and the blending of alcohol The composition for oral cavity according to claim 4 or 5, wherein the amount is 0.1 to 50% by mass of the whole composition.