Composition for tooth whitening

Abstract

According to one embodiment of the present application, there is provided a liquid composition for tooth whitening comprising sodium metaphosphate and sodium fluoride (NaF) and having a pH of 4 to 6. The liquid composition for tooth whitening according to the present application can provide a tooth whitening effect excellent in whitening effect while reducing irritation in the oral cavity.

Description

Technical Field

[0001] This invention relates to a teeth whitening composition, and more specifically, to a teeth whitening composition that provides excellent whitening effect while reducing oral irritation. Background Technology

[0002] A radiant smile is highly helpful in building confident interpersonal relationships. Furthermore, a confident smile creates a more positive first impression. Recently, with increasing attention to oral health and even teeth whitening, toothpaste compositions with teeth whitening effects are being launched.

[0003] Teeth whitening is a dental treatment procedure that whitens and brightens teeth without damaging them that have become discolored due to various reasons. Recently, teeth whitening products that can be used at home are being developed.

[0004] There are various types and methods of dental whitening, but most utilize high concentrations of hydrogen peroxide to oxidize the staining agents in teeth, a method that has been used in dentistry for over 100 years, and its whitening effect has been proven. Peroxides, such as hydrogen peroxide, are used as oxidizing agents to oxidize the staining substances in teeth, causing them to deform or decompose and be removed, thus achieving teeth whitening. However, their high reactivity limits their storage. Furthermore, the oxidation reaction of peroxides is highly irritating, producing strong irritation when in contact with the lips, gums, and tongue.

[0005] Therefore, research on sodium metaphosphate is actively underway as an excellent alternative to peroxides in removing and preventing staining substances. However, with increasing sodium metaphosphate content, its unique astringent properties can irritate the oral mucosa. Additionally, pyrophosphate is also effective in removing staining substances, but depending on the type, improper pH conditions and dosage can reduce its whitening efficacy and negatively impact user experience due to its acidic taste.

[0006] Against this backdrop, the inventors have dedicated themselves to research and development to solve the aforementioned problems. As a result, they derived the appropriate content of sodium hexametaphosphate and acidic sodium pyrophosphate and the appropriate pH for the best whitening effect, confirmed the effect of improving whitening efficiency, reducing oral irritation, and not reducing the user experience and satisfaction, and thus completed the present invention. Summary of the Invention

[0007] Technical issues

[0008] The inventors have confirmed that a teeth whitening composition containing sodium hexametaphosphate and acidic sodium pyrophosphate improves whitening efficiency, reduces oral irritation, and does not reduce user experience and satisfaction, and have thus completed this invention.

[0009] Technical solution

[0010] The purpose of this invention is to provide a low-irritation liquid composition for teeth whitening comprising sodium hexametaphosphate, sodium fluoride (NaF), and acidic sodium pyrophosphate.

[0011] Invention Effects

[0012] The liquid composition for teeth whitening according to the present invention has the effects of minimal oral irritation, excellent user experience, and excellent removal of staining components. Attached Figure Description

[0013] The liquid composition for teeth whitening according to the present invention has the effects of minimal oral irritation, excellent user experience, and excellent removal of staining components. Detailed Implementation

[0014] According to one embodiment of the present invention, a liquid composition for teeth whitening is provided, comprising sodium metaphosphate and sodium fluoride (NaF) and having a pH of 4 to 6.

[0015] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the sodium metaphosphate comprises sodium hexametaphosphate (SHMP), and the sodium hexametaphosphate (SHMP) is contained in a proportion of 1% to 3.5% by weight relative to the total weight of the liquid composition for teeth whitening.

[0016] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the sodium fluoride (NaF) is contained in a proportion of 0.01% to 0.33% by weight, specifically 0.02% by weight, relative to the total weight of the liquid composition for teeth whitening.

[0017] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein, relative to the total weight of the above-mentioned liquid composition for teeth whitening, an anionic surfactant or an amphoteric surfactant is further included in a proportion of 0.01% by weight or more and less than 1.5% by weight.

[0018] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the anionic surfactant comprises sodium lauryl sulfate (SLS) or an amino acid surfactant, and the amphoteric surfactant comprises cocamidopropyl betaine (CAPB).

[0019] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, which further comprises sodium acid pyrophosphate (SAPP).

[0020] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the sodium acid pyrophosphate (SAPP) is contained in a proportion of 0.05% to 0.45% by weight relative to the total weight of the liquid composition for teeth whitening.

[0021] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, which further comprises zinc gluconate.

[0022] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the zinc gluconate is contained in a proportion of 0.1% to 0.3% by weight relative to the total weight of the liquid composition for teeth whitening.

[0023] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the liquid composition for teeth whitening further comprises one or more components selected from the group consisting of wetting agents, fragrances, sweeteners, preservatives, binders, foaming agents, whitening agents, flavorings and pigments.

[0024] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the liquid composition for teeth whitening does not contain hydrogen peroxide.

[0025] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening is provided, wherein the liquid composition for teeth whitening does not contain tetrasodium pyrophosphate (TSPP).

[0026] In addition, according to one embodiment of the present invention, a teeth whitening product comprising the above-described liquid composition for teeth whitening is provided.

[0027] In addition, according to one embodiment of the present invention, a teeth whitening product is provided, wherein the teeth whitening product is selected from any one of the group consisting of liquid toothpaste, oral spray, oral rinse, oral ointment, oral cleaner and gargling products.

[0028] Implementation

[0029] The specific details are explained below. Furthermore, the various descriptions and embodiments disclosed in this invention can also be applied to other descriptions and embodiments. That is, all combinations of the various elements disclosed in this invention fall within the scope of this invention. Additionally, the scope of this invention should not be considered limited by the specific descriptions below.

[0030] All ingredients described in this invention preferably do not exceed the maximum usage values ​​specified in relevant regulations such as cosmetic safety standards (Korean regulations) and cosmetic safety technical specifications (Chinese regulations).

[0031] In this invention, teeth whitening can refer to removing substances that adhere to or penetrate the tooth surface and enamel and cause a staining effect, or deforming the chemical structure of such substances to remove the staining effect.

[0032] Furthermore, in this invention, a liquid composition can refer to a composition containing water and provided in liquid form. Therefore, those skilled in the art can add water to obtain the desired weight of the liquid composition for teeth whitening, and the total weight of the composition used to illustrate the weight ratio of the liquid composition for teeth whitening described below refers to the weight of the composition with added water.

[0033] In addition, in this invention, oral stimulation can include all kinds of irritation phenomena, including swelling, redness, pain, etc., that may occur on the teeth and gums due to the activation of peroxides in the teeth whitening ingredients.

[0034] Furthermore, in this invention, relief refers to the reduction or mitigation of the aforementioned oral irritation, and can be understood as a broad concept including improvement, prevention, treatment, etc.

[0035] According to one embodiment of the present invention, a liquid composition for teeth whitening is provided, comprising sodium metaphosphate and sodium fluoride (NaF) and having a pH of 4 to 6.

[0036] In this invention, sodium metaphosphate generally refers to compounds represented by the molecular formula (NaPO3)n. When sodium metaphosphate is included, it exhibits superior stain removal compared to other polyphosphates and can prevent staining. The sodium metaphosphate may contain sodium hexametaphosphate (SHMP). Sodium hexametaphosphate (SHMP) prevents staining by pushing away and removing staining substances from the tooth surface, and then adsorbing onto the tooth surface to block staining substances. Phosphates containing sodium metaphosphate are known to have whitening-related uses, but depending on the type, improper pH and dosage can lead to reduced whitening efficacy, decreased user experience, and oral irritation. However, in one embodiment of this invention, it was confirmed that sodium hexametaphosphate (SHMP) has less irritation compared to other phosphates, while exhibiting superior stain removal and stain prevention effects.

[0037] Relative to the total weight of the above-mentioned liquid composition for teeth whitening, the sodium hexametaphosphate (SHMP) may be contained in proportions of 1% to 3.5% by weight, specifically 1% to 3.0% by weight, more specifically 1.5% to 2.5% by weight, and most specifically 2% by weight. When sodium hexametaphosphate (SHMP) is added to the liquid composition for teeth whitening in the above proportions, it can achieve excellent stain removal efficiency while minimizing irritation in the oral cavity.

[0038] In this invention, sodium fluoride (NaF) forms a film on the tooth surface, thereby preventing tooth decay caused by acids produced by cariogenic bacteria and inhibiting bacterial enzymatic activity, thus helping to prevent tooth decay. Therefore, when sodium fluoride (NaF) is included in a liquid composition for teeth whitening, it can enhance tooth enamel and increase acid resistance.

[0039] Furthermore, relative to the total weight of the aforementioned liquid composition for teeth whitening, the sodium fluoride may be contained in proportions of 0.01% to 1.0% by weight, specifically 0.01% to 0.5% by weight, more specifically 0.01% to 0.4% by weight, even more specifically 0.01% to 0.33% by weight, and most specifically 0.01% to 0.03% by weight. By including sodium fluoride within the aforementioned range, the caries prevention effect can be improved.

[0040] In this invention, the pH of the liquid composition for teeth whitening can be 4 to 6, specifically 4 to 5.5, and more specifically 4 to 5. The liquid composition for teeth whitening of this invention exhibits the best stain removal effect within the aforementioned pH range. In particular, within the aforementioned pH range, the stain removal and stain prevention effects of the sodium hexametaphosphate (SHMP) component contained in the liquid composition for teeth whitening can be maximized. Within the aforementioned pH range, the sodium or hydrogen ions of sodium hexametaphosphate (SHMP) have a strong affinity for calcium ions exposed on the tooth surface, thereby adhering to the tooth enamel surface, disrupting the pellicle on the enamel, repelling and removing staining substances, and forming a sodium hexametaphosphate coating on the tooth surface, thereby exhibiting excellent prevention of new extrinsic staining. Therefore, an appropriate pH environment is required for suitable binding force with metal ions. For example, when the pH of the liquid composition for teeth whitening is below 4, sodium hexametaphosphate (SHMP) decomposes, reducing the active ingredients that exert the whitening effect. As a result, the ability of sodium hexametaphosphate (SHMP) to bind with metal ions may decrease. When the pH of the liquid composition for teeth whitening is above 6, the binding of sodium hexametaphosphate (SHMP) may be inhibited due to increased competition with metal ions. Therefore, the best whitening effect can be achieved within the above pH range.

[0041] Furthermore, to achieve a pH buffering system and maintain the pH of the formulation at 4 to 6, a pH adjuster may be further included. The aforementioned pH adjuster is characterized by comprising one or more of the following: citric acid, sodium citrate, tartaric acid, sodium tartrate, phosphoric acid, sodium phosphate, calcium lactate, monosodium phosphate, trisodium phosphate, monopotassium phosphate, tripotassium phosphate, sodium bicarbonate, and potassium pyrophosphate. The content of the pH adjuster relative to the total weight of the entire liquid composition for teeth whitening can be from 0.01% to 2.0% by weight, preferably from 0.01% to 1.0% by weight, and more preferably from 0.01% to 0.5% by weight. When the pH adjuster in the composition is used at less than 0.01% by weight, a pH buffering effect cannot be expected, while when the content of the pH adjuster is higher than 2% by weight, a decrease in usability may occur.

[0042] In addition, according to one embodiment of the present invention, relative to the total weight of the above-described liquid composition for teeth whitening, the anionic surfactant or amphoteric surfactant may be further included in proportions of 0.01% by weight or more and less than 4% by weight, specifically 0.01% by weight or more and less than 3% by weight, more specifically 0.01% by weight or more and less than 2% by weight, and most specifically 0.01% by weight or more and less than 1.5% by weight.

[0043] The aforementioned anionic surfactants primarily utilize sulfate esters, glutamates, or taurines, and may include sodium lauryl sulfate (SLS), sodium myristoyl glutamate, sodium cocoyl glutamate, sodium methyl cocoyl glutamate, sodium methyl cocoyl taurate (SMCT), or amino acid surfactants other than glutamates and taurines. Preferably, they may include sodium lauryl sulfate (SLS) or amino acid surfactants; more preferably, they may include sodium lauryl sulfate (SLS) or sodium methyl taurate (SMCT). Additionally, the aforementioned amphoteric surfactants may include cocamidopropyl betaine (CAPB).

[0044] The term "surfactant" as used above refers to a component characterized by both hydrophobic and hydrophilic properties within a single molecule. It is an effective remover of organic contaminants such as those from greasy foods and helps clean the tooth film. Sodium hexametaphosphate has a high affinity for calcium ions present on the tooth surface, thus forming a coating. However, in the presence of organic contaminants, it hinders effective contact with the tooth surface. Therefore, using surfactants to remove these contaminants can enhance stain removal and inhibition effects. Surfactants have contact affinity not only with the tooth surface but also with the oral mucosa. Therefore, excessive use at 3.0% by weight or more may cause oral irritation. Thus, when surfactants are included within the aforementioned range, stain removal and inhibition effects can be enhanced without oral irritation.

[0045] In addition, when the above-mentioned anionic surfactant and amphoteric surfactant are included together, the functional group corresponding to the cation and the anionic part of the anionic surfactant form a complex through their combination. This can counteract the phenomenon of irritation caused by the interaction of ions with the oral mucosa, prevent irritation and excessive foaming, and increase the stain removal efficiency while providing excellent user satisfaction.

[0046] In addition, according to one embodiment of the present invention, the liquid composition for teeth whitening may further comprise sodium acid pyrophosphate (SAPP).

[0047] In addition, according to one embodiment of the present invention, the above-mentioned liquid composition for teeth whitening may not contain tetrasodium pyrophosphate (TSPP).

[0048] When pyrophosphates are included in a teeth whitening composition, they can form complexes with metal ions that induce staining on the tooth surface, thereby increasing the teeth whitening effect. Sodium pyrophosphate, a commonly used pyrophosphate, has a pH of approximately 10; therefore, teeth whitening compositions containing sodium pyrophosphate typically have a relatively high pH. In contrast, the teeth whitening composition according to the present invention contains sodium metaphosphate and is provided to maintain a pH of 4 to 6, thereby improving the removal of staining substances. Therefore, when sodium pyrophosphate is applied, there is a concern that the increased pH of the teeth whitening composition may lead to a decrease in the teeth whitening effect. In this case, if large amounts of acidic substances such as phosphoric acid / citric acid are applied to lower the pH of the teeth whitening composition while applying sodium pyrophosphate, the teeth whitening composition may produce a sour taste, potentially reducing the user experience. For example, when using tetrasodium pyrophosphate (TSPP), it may be difficult to achieve a pH range of 4 to 6, and therefore, increasing the content of phosphoric acid / citric acid can result in a strong sour taste, potentially significantly reducing the user experience and reducing the overall teeth whitening function.

[0049] Therefore, according to one embodiment of the present invention, by using acidic sodium pyrophosphate (SAPP) as sodium pyrophosphate, the content of citric acid or phosphoric acid, which are used alone to lower the pH, can be reduced. In this case, a sour taste may not be produced, thus enhancing the whitening efficiency without reducing the user experience.

[0050] Furthermore, according to one embodiment of the present invention, the acidic sodium pyrophosphate (SAPP) may be included in a proportion of 0.1% to 0.45% by weight relative to the total weight of the above-described liquid composition for teeth whitening. When the acidic sodium pyrophosphate (SAPP) is added within the above range, the acidic taste of the raw material itself can be prevented, thereby improving the user experience of the product.

[0051] Furthermore, according to one embodiment of the present invention, a liquid composition for teeth whitening further comprising zinc gluconate can be provided. When zinc gluconate is included, plaque formation and halitosis can be prevented by inhibiting the growth of harmful bacteria in the oral cavity, and a protective film can be formed on the tooth surface to protect it from external irritants. Additionally, according to one embodiment of the present invention, the halitosis suppression effect can be enhanced when zinc gluconate is included compared to the case where zinc gluconate is included alone. Therefore, the zinc gluconate used in one embodiment of the present invention can exert an excellent halitosis reduction effect without affecting the whitening effect of the composition comprising sodium metaphosphate and sodium fluoride.

[0052] In addition, according to one embodiment of the present invention, the zinc gluconate may be contained in proportions of 0.1% to 0.3% by weight, specifically 0.1% to 0.25% by weight, more specifically 0.1% to 0.2% by weight, and most specifically 0.15% by weight, relative to the total weight of the above-described liquid composition for teeth whitening.

[0053] In addition, according to one embodiment of the present invention, a liquid composition for teeth whitening can be provided, wherein the liquid composition for teeth whitening further comprises one or more components selected from the group consisting of wetting agents, fragrances, solubilizers, sweeteners, preservatives, foaming agents, flavorings, pigments, etc.

[0054] In addition, according to one embodiment of the invention, abrasives that are generally not soluble or solubilized in water but are simply dispersed and therefore unsuitable for use in liquids may not be included.

[0055] A humectant is an ingredient used to prevent toothpaste from drying out and to maintain its moist state. The humectant may include, but is not limited to, any one selected from the group consisting of polyethylene glycol, glycerin, propylene glycol, ethylene glycol, polypropylene glycol, sorbitol, and mixtures thereof. Preferably, it may include any one selected from the group consisting of polyethylene glycol 200 to 600, glycerin, propylene glycol, ethylene glycol, polypropylene glycol, and mixtures thereof. Preferably, as a liquid humectant, petroleum oils, animal and vegetable oils, synthetic lubricants, etc., can be used. Most preferably, liquid polyols can be used for stability of the composition and excellent user experience. Alternatively, the humectant is not limited to liquid polyols and may also include high molecular weight polyols such as polyethylene glycol and polypropylene glycol, which, at a certain molecular weight or above, can exist in a solid state at room temperature due to the internal attraction (intramolecular interaction) of the polymer, but can be liquefied by adjusting the preparation temperature, and can maintain a stable state through productization.

[0056] Solubilizers are used to help dissolve components that are not easily soluble in water. Liquid olive oil, polysorbate, and PEG-40 hydrogenated castor oil can be used as solubilizers.

[0057] Fragrances leave a lingering scent in the mouth, providing a sustained fresh feeling and serving to cleanse and eliminate bad breath. Fragrances that can be used include peppermint, spearmint, wintergreen, methyl salicylate, eugenol, cantaloupe, strawberry, orange, and vanillin.

[0058] Sweeteners are added to overcome the inherent taste of the dosage form. They remain in the mouth and provide a sustained taste, thus promoting saliva production. Sweeteners can be a mixture of one or more of the following substances: saccharin, sucralose, sugar, xylitol, sorbitol, lactose, mannitol, maltitol, erythritol, aspartame, taurine, saccharin salt, D-tryptophan, stevioside, and enzyme-treated stevioside.

[0059] Benzoic acid, methylparaben, propylparaben, sodium benzoate, etc. can be used as preservatives.

[0060] Surfactants can be used to enhance the user experience and aid in cleaning.

[0061] The content and type of the aforementioned wetting agents, flavoring agents, sweeteners, preservatives, binders, surfactants, fragrances, and colorants can be determined by considering their effect on phosphates.

[0062] In addition, according to one embodiment of the present invention, the above-mentioned liquid composition for teeth whitening may not contain hydrogen peroxide.

[0063] Furthermore, according to one embodiment of the present invention, a teeth whitening product comprising the above-described liquid composition for teeth whitening is provided. The dosage form of the teeth whitening product prepared using the liquid composition for teeth whitening of the present invention can be prepared by methods commonly used in the art. The teeth whitening product of the present invention can be in liquid, solid, suspension, gel, or aerosol form, but is not limited thereto.

[0064] In addition, according to an embodiment of the present invention, a teeth whitening product is provided, characterized in that the teeth whitening product has one or more dosage forms selected from the group consisting of liquid toothpaste, oral spray, oral cleaning agent, oral cleanser and mouthwash.

[0065] In order to make the teeth whitening product applicable to the present invention, appropriate additives, carriers, etc. may be further included in the above-mentioned liquid composition for teeth whitening, and the above-mentioned additives and carriers, etc. may be appropriately selected and combined by those skilled in the art.

[0066] The teeth whitening composition according to an embodiment of the present invention has been described above. Hereinafter, based on the preparation examples and experimental results of the teeth whitening compositions of the examples and comparative examples, the advantageous effects of the present invention are confirmed.

[0067] Preparation Example 1. Preparation of Examples 1 to 15 and Comparative Examples 1 to 8

[0068] The mouthwash compositions of Examples 1 to 15 were prepared according to the ingredients and combination ratios shown in Table 1 below.

[0069] Specifically, the flavoring, ethanol, and solubilizer are thoroughly stirred and dissolved, then the remaining ingredients are added, and the mixture is stirred for approximately 30 minutes to prepare the mouthwash. Poloxamer or HCO-40 is used as the solubilizer.

[0070] [Table 1]

[0071] In addition, except for the presence or absence of sodium metaphosphate or its content, the presence or absence of acidic sodium pyrophosphate (SAPP) or its content, the presence or absence of tetrasodium pyrophosphate (TSPP) or its content, and the presence or absence of surfactant or its content, the mouthwash compositions of Comparative Examples 1 to 8 were prepared using the same method as those in the above examples, according to the ingredients and combination ratios shown in Table 2 below.

[0072] [Table 2]

[0073] Experimental Example 1. In vitro ( In vitro Whitening effect test

[0074] To confirm the stain removal effect of the composition according to this application, the following method was used: after tooth staining caused by staining substances, the degree of stain removal was confirmed by using the mouthwashes of the various examples and comparative examples.

[0075] Specifically, test pieces were prepared using artificial tooth powder (hydroxyapatite; HAP) and then stained using Stookey's method. The initial L, a, and b values ​​of the stained HAP test pieces were measured using a colorimeter and allocated to ensure that the lightness values ​​did not differ significantly between experimental groups. The stained test pieces were placed in 15 mL of mouthwash and stirred at 300 rpm for 30 minutes at approximately 37°C. After the test pieces were thoroughly dried, the colorimetry was measured using a colorimeter and compared with the initial values. The change in color (ΔE) was then analyzed.

[0076] in vitro( In-vitro The whitening evaluation indicates that the higher the ΔE value, the greater the effect of removing pigmentation substances.

[0077] Experimental Example 2. Evaluation of Stimulation and User Satisfaction

[0078] To confirm the improvement in irritation and user experience of the compositions according to this application, 20 volunteers used the mouthwashes of the various examples and comparative examples at 3-day intervals. A questionnaire was then used to evaluate irritation and user experience satisfaction. Each mouthwash was used at least twice daily, approximately 20 mL, for 1 minute.

[0079] Specifically, volunteers were provided with the mouthwash composition prepared in the above preparation example and asked to use it. They were then asked to express whether they felt irritation during use and their level of satisfaction with the use using a 5-point scale.

[0080] The closer the stimulation rating is to 5, the higher the stimulation level. Similarly, the closer the user satisfaction rating is to 5, the higher the user satisfaction level.

[0081] Tables 3 and 4 below show the results of Experimental Examples 1 and 2 and the pH of each composition. Figure 1 This is a graph showing the values ​​of color change analyzed to confirm the whitening effect of the embodiments and comparative examples of this application.

[0082] [Table 3]

[0083] [Table 4]

[0084] Refer to Tables 1 to 4 and Figure 1 It can be seen that Examples 1 to 4, which used 1 to 3% sodium metaphosphate (SHMP), showed superior stain removal compared to Comparative Example 4, which did not use sodium metaphosphate (SHMP).

[0085] Furthermore, compared to Comparative Example 1 with a pH of 7, Examples 1 to 3, with relatively lower pH values, exhibited superior stain removal effects, and the lower the pH, the better the results. It was confirmed that Comparative Example 5, which used 4% by weight of sodium metaphosphate (SHMP), while showing increased stain removal, also significantly increased irritation, and was therefore unsuitable.

[0086] Therefore, it can be confirmed that when the liquid composition for teeth whitening contains 1 to 3.5% sodium metaphosphate relative to the total weight of the liquid composition for teeth whitening and the pH is within 4 to 6, the stain removal effect is excellent and the irritation is low.

[0087] Furthermore, it was confirmed that for Examples 5 to 10, in which 0.05 to 0.45% by weight of acidic sodium pyrophosphate (SAPP) was added, the color removal effect was further increased. For Comparative Example 3, which had a higher content of acidic sodium pyrophosphate (SAPP), the user satisfaction was lower, because the acidic characteristics of the raw material also affected the product.

[0088] This confirms that while sodium acid pyrophosphate (SAPP) helps remove tooth stains, its characteristic acidic taste becomes a negative factor for the user experience when the content increases. Therefore, it is preferable to limit its content to below 0.45% by weight.

[0089] Furthermore, Example 11, which used the anionic surfactant sodium lauryl sulfate (SLS), exhibited the best color removal effect, which is attributed to the enhanced cleaning power of SLS. However, Comparative Example 2, which used 0.4% by weight of SLS, confirmed that the irritation and excessive foaming caused by SLS resulted in very low satisfaction. Therefore, it is preferable to use SLS at a content of less than 0.4% by weight.

[0090] Further confirmation revealed that the results of Example 13, using only 0.3 wt% of the anionic surfactant, sodium methyl cocoyl taurate (SMCT), and Example 14, using only 1.0 wt% of the amphoteric surfactant, cocamidopropyl betaine (CAPB), were similar to those of Example 11. In contrast, Example 15, which used both anionic and cationic surfactants in combination, exhibited the lowest irritation and thus demonstrated the best performance. That is, the highest color removal ability, low irritation, and good satisfaction were confirmed.

[0091] In addition, Comparative Example 6, which replaced acidic sodium pyrophosphate (SAPP) with tetrasodium pyrophosphate (TSPP) and lowered the pH to 4, also had very low user satisfaction. This is because when tetrasodium pyrophosphate (TSPP) is included, the pH is about 10. In order to lower the pH to 4, the content of citric acid or phosphoric acid is increased, which leads to an increase in sourness.

[0092] Furthermore, in Comparative Example 7, where acidic sodium pyrophosphate (SAPP) was replaced with tetrasodium pyrophosphate (TSPP) and the pH was lowered to 6, the effect was lower compared to an equal amount of acidic sodium pyrophosphate (SAPP). Therefore, it was confirmed that the use of tetrasodium pyrophosphate (TSPP) in liquid compositions for teeth whitening is not preferred in terms of user experience and effectiveness.

[0093] In addition, it was confirmed that for Example 12 with added zinc gluconate, the teeth whitening effect remained at a similar level compared to Example 11.

[0094] Example 3. Clinical evaluation of halitosis

[0095] To confirm the halitosis removal effect of the compositions according to this application, the halitosis of the mouthwashes of Examples 11 and 12 and the mouthwashes of Comparative Examples 4 and 8 according to this application were clinically evaluated before and after use.

[0096] Specifically, healthy individuals who reported having bad breath were assessed using sensory evaluation and an instrumental method (Halimeter) to determine the initial degree of halitosis in a fasting state. Fasting was defined as brushing teeth with previously used products 12 hours prior to the test and not brushing on the day of the test, with all food intake, smoking, alcohol consumption, and oral hygiene activities prohibited until the halitosis measurement. Each participant then mixed approximately 10-15 mL of mouthwash and used it for 30 seconds. Halitosis was measured 30 minutes to 1 hour after use using the same method as before. With a sterile syringe held in the mouth, 1 cc of gas was collected and measured using gas chromatography.

[0097] Sensory evaluation was conducted on a 5-point scale, with 5 points indicating very strong halitosis. The halitosis evaluation unit was measured in ppb.

[0098] The results of Experiment Example 3 are shown in Table 5 below.

[0099] [Table 5]

[0100] Referring to Table 5, it can be confirmed that Example 11 of this application suppresses volatile sulfur compounds, thereby achieving excellent halitosis removal effect.

[0101] In addition, it can be confirmed that Comparative Example 8, which uses zinc gluconate alone, exhibits a similar level of halitosis removal effect to Example 11, but for Example 12, where zinc gluconate is included in the whitening liquid composition according to this application, the halitosis reduction effect is significantly improved.

[0102] Based on the foregoing description, those skilled in the art will understand that the present invention can be implemented in other specific forms without altering the technical concept or essential features of the invention. Relatedly, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the invention should be interpreted to include the meaning and scope of the following claims and all variations or modifications derived from their equivalents, and should not be construed as including only the detailed description above.

Claims

1. A liquid composition for teeth whitening, comprising sodium metaphosphate and sodium fluoride (NaF), and having a pH of 4 to 6.

2. The liquid composition for teeth whitening according to claim 1, wherein, The aforementioned sodium metaphosphate includes sodium hexametaphosphate (SHMP). The sodium hexametaphosphate (SHMP) is contained in a proportion of 1% to 3.5% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

3. The liquid composition for teeth whitening according to claim 1, wherein, The sodium fluoride (NaF) is contained in a proportion of 0.01% to 0.33% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

4. The liquid composition for teeth whitening according to claim 1, wherein, The anionic surfactant or amphoteric surfactant is further included in proportions of 0.01% by weight or more and less than 3.0% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

5. The liquid composition for teeth whitening according to claim 4, wherein, The aforementioned anionic surfactants include sodium lauryl sulfate (SLS) or amino acid-based surfactants. The aforementioned amphoteric surfactants include cocamidopropyl betaine (CAPB). The content of sodium lauryl sulfate (SLS) is less than 0.4% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

6. The liquid composition for teeth whitening according to claim 1, further comprising sodium acid pyrophosphate (SAPP).

7. The liquid composition for teeth whitening according to claim 6, wherein, The sodium acid pyrophosphate (SAPP) is contained in a proportion of 0.05% to 0.45% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

8. The liquid composition for teeth whitening according to claim 1, further comprising zinc gluconate.

9. The liquid composition for teeth whitening according to claim 8, wherein, The zinc gluconate is contained in a proportion of 0.1% to 0.3% by weight relative to the total weight of the above-mentioned liquid composition for teeth whitening.

10. The liquid composition for teeth whitening according to claim 1, wherein, The above-mentioned liquid composition for teeth whitening further comprises one or more ingredients selected from the group consisting of wetting agents, fragrances, sweeteners, preservatives, binders, foaming agents, whitening agents, flavorings, and pigments.

11. The liquid composition for teeth whitening according to claim 1, wherein, The above-mentioned liquid composition for teeth whitening does not contain hydrogen peroxide.

12. The liquid composition for teeth whitening according to claim 1, wherein, The above-mentioned liquid composition for teeth whitening does not contain tetrasodium pyrophosphate (TSPP).

13. A teeth whitening product comprising the liquid composition for teeth whitening as described in claim 1.

14. The teeth whitening product according to claim 13, wherein, The teeth whitening products mentioned above are selected from any one of the following groups: toothpaste, oral spray, oral rinse, oral ointment, oral cleaner and mouthwash.

Images