Oral care composition and method for improving structural stability of oral care composition

Abstract

The invention discloses an oral care composition and a method for improving the structural stability of the composition. The oral care composition comprises 1) flaky hydroxyapatite, 2) xanthan gum and 3) an orally acceptable carrier, the average molecular weight of the xanthan gum ranges from 250 million Daltons to 5 million Daltons. The oral care composition has good effects of blocking dentinal tubules and remineralizing the dentinal tubules, and meanwhile, the structural stability of the paste can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oral care, in particular to an oral care composition and a method for improving the structural stability of the composition. Background Art

[0002] Hydroxyapatite (HAp) is the main inorganic component of teeth. It has good bioactivity and biocompatibility and can be used for sealing dental tubules or tooth remineralization.

[0003] For example, Chinese patent application CN1751678A discloses that needle-shaped hydroxyapatite with a diameter of less than 50 nanometers has better remineralization hardness, demineralization coverage and adsorption properties for demineralized teeth.

[0004] For example, Chinese patent application CN105686960A discloses an anti-sensitivity composition comprising hydroxyapatite, a polycarboxyl compound, soluble calcium, and an orally acceptable carrier. The composition can penetrate into and block dentinal tubules. The hydroxyapatite disclosed in this document is needle- or rod-shaped.

[0005] Another example is Chinese invention patent CN1107211099A, which discloses an oral care composition comprising flake-shaped hydroxyapatite and an orally acceptable carrier. This composition significantly reduces re-exposure to dental tubules after occlusion, significantly improves remineralization on teeth, and stabilizes the free fluoride ions in the composition.

[0006] In actual use, other ingredients in the oral care composition are needed to retain hydroxyapatite on the tooth surface so that it can play the above-mentioned role. The gelling agent in the composition is one of the retention aids; for example, international patent application WO2025031689A1 discloses an oral care composition, which comprises xanthan gum with a molecular weight of 5-15 million Daltons and hydroxyapatite with a median particle size of 0.05-10 microns; the xanthan gum in the composition can help the hydroxyapatite stay on the tooth surface.

[0007] Although gelling agents can help hydroxyapatite stay on the tooth surface, the choice of gelling agent will also affect the structural stability of the paste containing hydroxyapatite composition; therefore, further research is still needed to enable hydroxyapatite to exert its efficacy while maintaining the stability of the composition paste. Summary of the Invention

[0008] The first technical problem to be solved by the present invention is to provide an oral care composition; the oral care composition has good efficacy in blocking dentinal tubules and remineralizing dentinal tubules, while improving the structural stability of the paste.

[0009] The second technical problem to be solved by the present invention is to provide a method for improving the paste structure stability of an oral care composition containing platelet-shaped hydroxyapatite.

[0010] In order to solve the above-mentioned first technical problem, the invention adopts the following technical solution:

[0011] An oral care composition comprising:

[0012] 1) flaky hydroxyapatite,

[0013] 2) Xanthan gum, and

[0014] 3) an orally acceptable carrier;

[0015] The average molecular weight of the xanthan gum is 2.5 to 5 million Daltons.

[0016] As an embodiment, the average thickness of the flaky hydroxyapatite is 30-57 nanometers.

[0017] As an embodiment, the average thickness of the flaky hydroxyapatite is 36-51 nanometers.

[0018] As an embodiment, the flake-like hydroxyapatite is aggregated to form spherical particles.

[0019] As an embodiment, the median particle size of the spherical particles formed by agglomeration of the flaky hydroxyapatite is 2.5-12.2 microns.

[0020] As an embodiment, the median particle size of the spherical particles formed by agglomeration of the flaky hydroxyapatite is 3.3-10.1 microns.

[0021] As an embodiment, the mass proportion of the flake hydroxyapatite in the oral care composition is 0.01-25%.

[0022] As an embodiment, the mass proportion of the flake hydroxyapatite in the oral care composition is 4-25%.

[0023] As an embodiment, the mass proportion of the xanthan gum in the oral care composition is 0.4-1%.

[0024] As an embodiment, the oral care composition further comprises cellulose gum.

[0025] As an embodiment, the oral care composition further comprises zinc citrate.

[0026] In order to solve the above second technical problem, the present invention adopts the following technical solution:

[0027] A method for improving the paste structure stability of an oral care composition containing flake hydroxyapatite comprises the following steps:

[0028] Xanthan gum with an average molecular weight of 2.5 to 5 million Daltons is added as a gelling agent to an oral care composition containing plate-like hydroxyapatite.

[0029] Any range described in the present invention includes the end value and any numerical value between the end values and any sub-range formed by the end value or any numerical value between the end values.

[0030] Unless otherwise specified, all raw materials in the present invention can be purchased commercially, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The oral care composition of the present invention can improve the structural stability of the composition paste while providing better dentinal tubule blocking and tubule remineralization effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a scanning electron microscope image of existing flaky hydroxyapatite;

[0034] Figure 2 This is a scanning electron microscope image of existing spherical particles of flake hydroxyapatite;

[0035] Figure 3 This is a scanning electron microscope image of existing needle-shaped hydroxyapatite;

[0036] Figure 4 This is a scanning electron microscope image of existing rod-shaped hydroxyapatite. DETAILED DESCRIPTION

[0037] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0038] Unless otherwise indicated, all percentages and ratios used herein are by weight of the total composition. Unless otherwise indicated, all percentages, ratios and amounts of ingredients mentioned herein are based on the actual amount of the ingredient and do not include solvents, fillers or other materials that may be combined with these ingredients in commercially available products.

[0039] The term "comprises / comprising" herein means that other steps and ingredients which do not affect the end result can be added.

[0040] The term "preferably" and its variants herein refer to embodiments of the present invention that can provide specific beneficial effects under specific circumstances. However, other embodiments may also be preferred under the same or other circumstances. In addition, the detailed description of one or more preferred embodiments does not mean that other embodiments are useless and is not intended to exclude other embodiments from the scope of the present invention.

[0041] If no specific conditions are specified in the examples of the present invention, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0042] As one aspect of the present invention, an oral care composition of the present invention comprises:

[0043] 1) flaky hydroxyapatite,

[0044] 2) Xanthan gum, and

[0045] 3) an orally acceptable carrier;

[0046] The average molecular weight of the xanthan gum is 2.5 to 5 million Daltons.

[0047] It is well known in the art that oral care compositions containing platelet-shaped hydroxyapatite have the same tubule-blocking effect as other types of hydroxyapatite (rod-shaped or needle-shaped), and have better remineralization efficacy. However, the gelling agent component in the composition can affect the tubule-blocking and remineralization efficacy of the composition, and can also affect the stability of the paste, resulting in liquid-solid demixing. The present invention unexpectedly discovered that only when the gelling agent component in the oral care composition containing platelet-shaped hydroxyapatite includes xanthan gum with an average molecular weight of 2.5 to 5 million Daltons can the composition maintain good tubule-blocking and remineralization efficacy while also maintaining the stability of the paste.

[0048] Platelet-shaped hydroxyapatite

[0049] An important component of dentin is hydroxyapatite, abbreviated as HAp. Hydroxyapatite has good biocompatibility and can be used to block dentinal tubules. There are three main morphologies of HAp available on the market: needle-shaped HAp, rod-shaped HAp, and flake-shaped HAp.

[0050] Rod: See Figure 4 As shown, rod-shaped hydroxyapatite generally refers to a solid nanomaterial with a one-dimensional cylindrical shape (or a polygonal cross-section) that is relatively straight in the longitudinal direction; its particle length is usually 80-100 nm and its width is about 20 nm.

[0051] Needle-shaped: see Figure 3As shown, the needle-shaped nano-hydroxyapatite particles are relatively straight in longitudinal shape, and the diameters at both ends or one end are relatively thin and pointed, and are solid nanoparticles with a smaller diameter than the middle of the particles.

[0052] Flake: See Figure 1 As shown, flaky hydroxyapatite is a two-dimensional structural material with a thickness usually below 100 nanometers and a diameter of tens of nanometers, hundreds of nanometers or even micrometers. The ratio of its thickness to diameter is less than 0.4.

[0053] The present invention unexpectedly discovered that adding plate-shaped hydroxyapatite particles to an oral care composition has the same effect of blocking dental tubules as adding other types of hydroxyapatite (rod-shaped or needle-shaped) to an oral care composition, and also has good remineralization efficacy.

[0054] In certain embodiments of the present invention, the average thickness of the platelet-shaped hydroxyapatite is 30-57 nm, including but not limited to 30-52 nm, 30-47 nm, 30-42 nm, 30-35 nm, 35-40 nm, 36-51 nm, 36-47 nm, 36-42 nm, 40-51 nm, 40-47 nm, 40-45 nm, 45-50 nm, 50-55 nm and 55-57 nm.

[0055] In certain embodiments of the present invention, the flake-like hydroxyapatite is aggregated into spherical particles, see Figure 2 shown.

[0056] In certain embodiments of the present invention, the median particle size of the spherical flaky hydroxyapatite particles is 2.5-12.2 microns, including but not limited to 2.5-10.1 microns, 3.3-10.1 microns, 4.3-10.1 microns, 5.4-10.1 microns, 8.6-10.1 microns, 3.3-8.6 microns, 3.3-5.4 microns, 5.4-10.1 microns, and 5.4-8.6 microns.

[0057] In the present invention, the thickness of the flaky hydroxyapatite can be measured by a scanning electron microscope.

[0058] In the present invention, the median particle size of the spherical flaky hydroxyapatite particles can be measured by the particle size distribution laser diffraction method according to GB / T19077-206.

[0059] In certain embodiments of the present invention, the mass percentage of the platelet-shaped hydroxyapatite in the oral care composition is 0.01%-25%, including but not limited to 0.01-20%, 0.01-10%, 0.01-5%, 0.1-25%, 0.1-20%, 0.1-15%, 0.1-10%, 0.1-5%, 4-25%, 4-20%, 4-10%, 4-5%, 6-25%, 8- 25%, 10-25%, 12-25%, 14-25%, 16-25%, 18-25%, 20-25%, 22-25%, 6-20%, 8-20%, 10-20%, 12-20%, 14-20%, 16-20%, 18-20%, 20-20%, 22-20%, 6-15%, 8-15%, 10-15%, 12-15%, 14-15%.

[0060] In certain embodiments of the present invention, the thickness of the flaky hydroxyapatite and the median particle size of the spherical particles formed by agglomeration are in the range of:

[0061] 1# Flake HAp 2# Flake HAp 3# Flake HAp 4# Flake HAp 5# Flake HAp 6# Flake HAp 7# Flake HAp Average thickness (nm) 36 47 51 42 40 30 57 Particle D50 (μm) 5.4 10.1 3.3 12.2 2.5 4.3 8.6

[0062] Xanthan gum

[0063] Xanthan gum, also known as yellow gum or xanthan gum, is an extracellular acidic heteropolysaccharide produced by fermentation of Xanthomonas; it is a polysaccharide polymer compound with a "pentasaccharide repeating unit" structure composed of D-glucose, D-mannose, D-glucuronic acid, acetic acid and pyruvic acid, with a relative molecular mass of more than 1 million; it is often used as a thickener or gelling agent in oral care compositions.

[0064] The present inventors unexpectedly discovered that when an oral care composition contains flake-shaped hydroxyapatite, the choice of gelling agent in the composition affects the stability of the composition paste. The present inventors examined different gelling agent components and found that only when the gelling agent contained xanthan gum with an average molecular weight of 2.5 to 5 million daltons, the composition paste itself remained stable and the liquid-solid delamination phenomenon was improved.

[0065] In certain embodiments of the present invention, the xanthan gum has an average molecular weight of 2.5-5 million Daltons, including but not limited to 2.5-4.5 million Daltons, 2.5-4 million Daltons, 2.5-3.5 million Daltons, 2.5-3 million Daltons, 3-5 million Daltons, 3-4.5 million Daltons, 3-4 million Daltons, 3-3.5 million Daltons, 3.5-5 million Daltons, 3.5-4.5 million Daltons, 3.5-4 million Daltons, 4-5 million Daltons, 4-4.5 million Daltons, or 4.5-5 million Daltons.

[0066] In certain embodiments of the present invention, the average molecular weight of the xanthan gum is:

[0067] 1# xanthan gum 2# xanthan gum 3# xanthan gum 4# xanthan gum Average molecular weight (10,000 Daltons) 250-500 <250 500-1000 1000-1500

[0068] In certain embodiments of the present invention, the mass proportion of xanthan gum in the oral care composition is 0.4-1.0%, including but not limited to 0.4-0.9%, 0.4-0.8%, 0.4-0.7%, 0.4-0.5%, 0.5-1.0%, 0.5-0.7%, 0.5-0.6%, 0.6-1.0%, 0.6-0.9%, 0.6-0.8%, 0.6-0.7%, 0.7-1.0%, 0.7-0.9%, 0.7-0.8%, 0.8-1.0%, or 0.8-0.9%.

[0069] Cellulose gum

[0070] In certain embodiments of the present invention, the oral care composition further comprises cellulose gum.

[0071] Cellulose gum is a commonly used thickener in the oral care field, including but not limited to one or more of sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, cellulose ether, and hydroxyethylpropyl cellulose.

[0072] In certain embodiments of the present invention, the mass proportion of the cellulose gum in the oral care composition is 0.4-1.0%, including but not limited to 0.4-0.9%, 0.4-0.8%, 0.4-0.7%, 0.4-0.5%, 0.5-1.0%, 0.5-0.7%, 0.5-0.6%, 0.6-1.0%, 0.6-0.9%, 0.6-0.8%, 0.6-0.7%, 0.7-1.0%, 0.7-0.9%, 0.7-0.8%, 0.8-1.0%, or 0.8-0.9%.

[0073] Zinc citrate

[0074] In certain embodiments of the present invention, the oral care composition further comprises zinc citrate.

[0075] In certain embodiments of the present invention, the zinc citrate comprises zinc citrate trihydrate.

[0076] In certain embodiments of the present invention, the oral care composition comprises a toothpaste, a gel, a mouthwash, or a tooth powder.

[0077] In certain embodiments of the present invention, the weight percentage of the zinc ion source in the composition is 0.1-2%, for example, but not limited to 0.1-1.5%, 0.1-1.0%, 0.1-0.8%, 0.1-0.5%, 0.1-0.3%, 0.2-2.0%, 0.2-1.5%, 0.2-1.0%, 0.2-0.8%, 0.2-0.5%, 0.5-2.0%, 0.5-1.5%, 0.5-1.0%, 0.5-0.8%, 0.8-2%, 0.8-1.5%, 0.8-1.0%, 1.0-2%, 1.0-1.8%, 1.0-1.5%, 1.0-1.2%, 1.2-2%, 1.2-1.8%, 1.2-1.5%, 1.5-2%, 1.5-1.8%.

[0078] Orally acceptable carrier

[0079] The "orally acceptable carrier" as used herein refers to any vehicle suitable for formulating the oral care composition disclosed herein; the orally acceptable carrier is harmless to mammals when retained in the mouth in the amount disclosed herein without being swallowed for a period of time sufficient to allow effective contact with the tooth surface as required by the present invention; generally, the orally acceptable carrier is not harmful even if swallowed unintentionally; suitable orally acceptable carriers include, for example, one or more of the following substances: water, thickeners, buffers, wetting agents, surfactants, abrasives, sweeteners, flavorings, visual aids (e.g., pigments, dyes or mixtures thereof), anti-caries agents, antibacterial agents, whitening agents, desensitizing agents, vitamins, preservatives, enzymes and mixtures thereof, etc.

[0080] The method for evaluating the dentin remineralization efficacy and sealing efficacy of the present invention comprises the following steps: :

[0081] 1) Preparation of dentin samples

[0082] Select bovine incisors with no root caries or cracks, and completely remove the crown at the junction of the root and crown. Prepare dentin specimens from the root portion. Using a low-speed cutter under water cooling, cut a 1mm thick dentin slice as close to the pulp cavity as possible along the long axis of the tooth. Tests were performed using dentin slices near the cervical region of the tooth. The dentin test area should be intact, with three samples collected at each test time point.

[0083] 2) Processing of dentin samples

[0084] All dentin slices were etched with 40% (mass fraction) phosphoric acid for 5 min and then ultrasonically cleaned in deionized water for 5 min.

[0085] 3) Artificial saliva preparation

[0086] 20 mM HEPES, 16 mM KCl, 1 mM CaCl2.2H2O, 4 mM KH2PO4, 4.5 mM NH4Cl, 0.2 mM MgCl2.6H2O, pH = 7.0 adjusted with 1 mol / L KOH solution;

[0087] 4) Loop processing

[0088] Simulating daily life, brushing teeth twice a day, morning and evening, and placing dentin samples in artificial saliva at other times; using an electric toothbrush to brush the distal pulp surface of the test group's dentin slices with toothpaste for 1 minute, rinsing with deionized water, and placing them in artificial saliva for 6 hours, with 10 mL of artificial saliva per dentin sample; brushing with toothpaste for 1 minute, rinsing with deionized water, and placing them in artificial saliva for 18 hours, with 10 mL of artificial saliva per sample, was repeated. This treatment process constituted one cycle, i.e., 1 day.

[0089] 5) Remineralization efficacy test after recycling treatment

[0090] Three dentin samples from each group were removed after recycling, rinsed with deionized water, and dried in a drying oven. The dentin was cut in the middle, and a separate area was selected from each dentin sample cross section. Scanning electron microscopy was used to photograph and measure the thickness of the remineralized layer.

[0091] 6) Plugging efficacy test after circulation treatment

[0092] Three dentin samples were taken from each group after the cycle treatment, rinsed with deionized water, and dried in a drying oven. Three independent areas of each dentin sample were selected and photographed using a scanning electron microscope.

[0093] The occlusion rate of dentinal tubules was calculated according to the following formula:

[0094]

[0095] n0—number of completely opened dentinal tubules in the blank group dentin slice, in pieces;

[0096] n1—number of completely opened dentinal tubules in the dentin slice of the experimental group, in pieces. Specific embodiments

[0098] Example 1, Comparative Examples 1-2

[0099] Comparative Examples 1-2 were prepared according to the conventional method according to the formulation in Table 1 below, and all data in the table are weight percentages.

[0100] Table 1:

[0101]

[0102] As can be seen from Table 1, Example 1 and Comparative Examples 1-2 have the same formula skeleton, the difference being the different structures of the added HAp, wherein:

[0103] The HAp added in Example 1 was a sheet-like structure;

[0104] The HAp added in Comparative Example 1 had a needle-like structure;

[0105] The HAp added in Comparative Example 2 had a rod-like structure.

[0106] The occlusion rate of the dental tubules after 15 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule occlusion efficacy test. The results are shown in Table 2 below.

[0107] Table 2

[0108] Example 1 Comparative Example 1 Comparative Example 2 Plugging rate 98％ 96％ 97％

[0109] It can be seen from Table 1 and Table 2 that under the same addition amount:

[0110] 1) The tubular occlusion rate of HAp sheet was 98%;

[0111] 2) The tubule occlusion rate of needle-shaped HAp was 96%;

[0112] 3) The tubule occlusion rate of rod-shaped HAp was 97%;

[0113] 4) That is, the efficacy of the three HAp with different structures in the oral care composition in blocking dental tubules is basically the same.

[0114] The thickness of the remineralized layer of the dental tubules after 3 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule blocking efficacy test. The results are shown in Table 3 below.

[0115] Table 3:

[0116] Example 1 Comparative Example 1 Comparative Example 2 Remineralized layer thickness (μm) 3.2 1.1 0.9

[0117] It can be seen from Table 3 that under the same addition amount:

[0118] 1) The thickness of the dentin remineralized layer of the composition with added flake HAp was 3.2 μm;

[0119] 2) The thickness of the dentin remineralized layer of the composition with needle-shaped HAp added was 1.1 μm;

[0120] 3) The thickness of the dentin remineralized layer of the composition with rod-shaped HAp was 0.9 μm;

[0121] 4) Although the three types of HAp structures have similar efficacy in blocking dental tubules, the sheet-like HAp is significantly superior to the needle-like and rod-like HAp in remineralization efficacy.

[0122] Comparative Examples 3-5

[0123] Comparative Examples 3-5 were prepared according to the conventional method according to the formulation in Table 4 below. The data in the table are all weight percentages. For ease of comparison, the data of Example 1 are included in Table 4.

[0124] Table 4:

[0125]

[0126]

[0127] As can be seen from Table 4, 4% of flake HAp was added to the formulations of Example 1 and Comparative Examples 3-5. The difference lies in the different gelling agents added, among which:

[0128] 1) The gelling agent of Example 1 contains 0.7% of 1# xanthan gum;

[0129] 2) The gelling agent of Comparative Example 3 contains 0.7% cellulose gum;

[0130] 3) The gelling agent of Comparative Example 4 contains 0.7% gellan gum;

[0131] 4) The gelling agent of Comparative Example 5 contains 0.7% of carbomer.

[0132] The occlusion rate of the dental tubules after 15 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule occlusion efficacy test. The results are shown in Table 5 below.

[0133] Table 5:

[0134] Example 1 Comparative Example 3 Comparative Example 4 Comparative Example 5 Plugging rate 98％ 96％ 97％ 90％

[0135] From Table 5 we can see that:

[0136] 1) The occlusion rate of dental tubules after treatment with the composition of Example 1 was 98%;

[0137] 2) The dental tubule occlusion rate after treatment with the composition of Comparative Example 3 was 96%;

[0138] 3) The occlusion rate of dental tubules after treatment with the composition of Comparative Example 4 was 97%;

[0139] 4) The occlusion rate of the dental tubules after treatment with the composition of Comparative Example 5 was 90%;

[0140] 5) That is, different gelling agent components have basically the same effect on the efficacy of sealing dental tubules.

[0141] The thickness of the remineralized layer of the dental tubules after 3 days of cycle treatment was evaluated according to the evaluation method of the dentin remineralization efficacy test. The results are shown in Table 6 below.

[0142] Table 6:

[0143] Example 1 Comparative Example 3 Comparative Example 4 Comparative Example 5 Remineralized layer thickness (μm) 3.2 3.1 3.2 0.6

[0144] From Table 6 we can see that:

[0145] 1) The thickness of the remineralized dentin layer after treatment with the composition of Example 1 was 3.2 μm;

[0146] 2) The thickness of the dentin remineralized layer after treatment with the composition of Comparative Example 3 was 3.1 μm;

[0147] 3) The thickness of the dentin remineralized layer after treatment with the composition of Comparative Example 4 was 3.2 μm;

[0148] 4) The thickness of the remineralized dentin layer after treatment with the composition of Comparative Example 5 was 0.6 μm.

[0149] 5) The oral care compositions comprising xanthan gum, cellulose gum and gellan gum all have good dentin remineralization efficacy, while the oral care composition comprising only carbomer has significantly poorer dentin remineralization efficacy; in general, the gelling agent has little effect on the dentin remineralization efficacy.

[0150] The compositions of Example 1 and Comparative Examples 3-5 were aged at 40° C. for one month, and the paste state of the compositions was examined. The results are shown in Table 7 below.

[0151] Table 7:

[0152] Example 1 Comparative Example 3 Comparative Example 4 Comparative Example 5 Appearance after aging No stratification Layering Layering Layering

[0153] From Table 7 we can see that:

[0154] 1) After aging the composition of Example 1 at 40°C for one month, no liquid-solid separation occurred in the paste;

[0155] 2) After aging for one month at 40° C., the pastes of the compositions of Comparative Examples 3-5 all underwent liquid-solid separation.

[0156] 3) Although the gelling agent in the oral care composition has little effect on the efficacy of tubule occlusion and dentin remineralization, it affects the stability of the composition paste. Only when the gelling agent in the oral care composition is xanthan gum can the paste remain stable after aging for one month at 40°C.

[0157] Comparative Examples 6-8

[0158] Comparative Examples 6-8 were prepared according to the conventional method according to the formulation in Table 8 below. The data in the table are all weight percentages; for ease of comparison, Example 1 is included in Table 8.

[0159] Table 8:

[0160] raw material Example 1 Comparative Example 6 Comparative Example 7 Comparative Example 8 sorbitol 30 30 30 30 polyethylene glycol 1 1 1 1 1# xanthan gum 0.7 / / / 2# xanthan gum / 0.7 / / 3# xanthan gum / / 0.7 / 4# xanthan gum / / / 0.7 glycerin 13 13 13 13 1# Flake HAp 4 4 4 4 50% NaOH solution 0.4 0.4 0.4 0.4 Silicon dioxide 17.5 17.5 17.5 17.5 Sodium lauryl sulfate 2 2 2 2 Betaine 1.25 1.25 1.25 1.25 Sodium fluoride 0.32 0.32 0.32 0.32 Saccharin sodium 0.15 0.15 0.15 0.15 essence 1.1 1.1 1.1 1.1 Potassium citrate 5 5 5 5 water Margin to 100% Margin to 100% Margin to 100% Margin to 100%

[0161] As can be seen from Table 8, the formulas of Example 1 and Comparative Examples 6-8 all use xanthan gum as the gelling agent, but the difference lies in the different average molecular weights of the added xanthan gum, among which:

[0162] 1) The gelling agent in Example 1 is 1# xanthan gum, which has an average molecular weight of 2.5-5 million Daltons;

[0163] 2) The gelling agent in Comparative Example 6 is 2# xanthan gum, which has an average molecular weight of less than 2.5 million Daltons;

[0164] 3) The gelling agent in Comparative Example 7 is 3# xanthan gum, which has an average molecular weight of 5-10 million Daltons;

[0165] 4) Comparative Example 8: The gelling agent is 4# xanthan gum, which has an average molecular weight of 10-15 million Daltons.

[0166] The occlusion rate of the dental tubules after 15 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule occlusion efficacy test. The results are shown in Table 9.

[0167] Table 9:

[0168] Example 1 Comparative Example 6 Comparative Example 7 Comparative Example 8 Plugging rate 98％ 97％ 98％ 99％

[0169] From Table 9 we can see that:

[0170] 1) The occlusion rate of dental tubules after treatment with the composition of Example 1 was 98%;

[0171] 2) The dental tubule occlusion rate after treatment with the composition of Comparative Example 6 was 97%;

[0172] 3) The dental tubule occlusion rate after treatment with the composition of Comparative Example 7 was 98%;

[0173] 4) The dental tubule occlusion rate after treatment with the composition of Comparative Example 8 was 99%;

[0174] 5) That is, xanthan gums with different average molecular weights will not affect the efficacy of the oral care composition in blocking dental tubules.

[0175] The thickness of the remineralized layer of the dental tubules after 3 days of cycle treatment was evaluated according to the evaluation method of the dentin remineralization efficacy test. The results are shown in Table 10 below.

[0176] Table 10:

[0177] Example 1 Comparative Example 6 Comparative Example 7 Comparative Example 8 Remineralized layer thickness (μm) 3.2 1.8 3.1 3.3

[0178] From Table 10 we can see that:

[0179] 1) The thickness of the remineralized dentin layer after treatment with the composition of Example 1 was 3.2 μm;

[0180] 2) The thickness of the dentin remineralized layer after treatment with the composition of Comparative Example 6 was 1.8 μm;

[0181] 3) The thickness of the dentin remineralized layer after treatment with the composition of Comparative Example 7 was 3.1 μm;

[0182] 4) The thickness of the remineralized dentin layer after treatment with the composition of Comparative Example 8 was 3.3 μm.

[0183] 5) That is, when the average molecular weight of xanthan gum is less than 2.5 million Daltons, the thickness of the remineralized layer of dentin is significantly reduced; when the average molecular weight of xanthan gum is not less than 2.5 million Daltons, the thickness of the remineralized layer of dentin is significantly increased, and the thickness is basically the same.

[0184] The compositions of Example 1 and Comparative Examples 6-8 were aged at 40° C. for one month, and the pastes of the compositions were examined. The results are shown in Table 11 below.

[0185] Table 11:

[0186] Example 1 Comparative Example 6 Comparative Example 7 Comparative Example 8 Appearance after aging No stratification No stratification Layering Layering

[0187] From Table 11 we can see that:

[0188] 1) After aging for one month at 40°C, no liquid-solid separation occurred in the pastes of Example 1 and Comparative Example 6;

[0189] 2) Comparative Examples 7-8 were aged at 40° C. for one month, and liquid-solid separation occurred in the pastes.

[0190] 3) That is, xanthan gum with different average molecular weights will affect the stability of the paste of the composition; when the average molecular weight of xanthan gum is greater than 5 million Daltons, liquid-solid stratification occurs in the paste; when the average molecular weight of xanthan gum is not greater than 5 million Daltons, no stratification occurs in the paste.

[0191] 4) In summary, only when the average molecular weight of xanthan gum is 2.5-5 million Daltons can the composition achieve both tubule blocking effects and dentin remineralization effects, and also ensure the stability of the composition paste.

[0192] Examples 2-7

[0193] Examples 2-7 were prepared according to the conventional method according to the formulation in Table 12 below. The data in the table are all weight percentages; for ease of comparison, Example 1 is included in Table 12.

[0194] Table 12:

[0195]

[0196] As can be seen from Table 12, the formulations of Examples 1-7 all use 1# xanthan gum as the gelling agent, and the difference lies in the addition of HAp of different thicknesses and median particle sizes, among which:

[0197] 1) Example 1 added 1# flake HAp, which had an average thickness of 36 nm and a median particle size of spherical particles of 5.4 μm;

[0198] 2) Example 2 added 2# flake HAp, which had an average thickness of 47 nm and a median particle size of spherical particles of 10.1 μm;

[0199] 3) Example 3 added 3# flake HAp, which had an average thickness of 51 nm and a median particle size of spherical particles of 5.3 μm;

[0200] 4) Example 4 added 4# flake HAp, which had an average thickness of 42 nm and a median particle size of spherical particles of 12.2 μm;

[0201] 5) Example 5 added 5# flake HAp, which had an average thickness of 40 nm and a median particle size of spherical particles of 2.5 μm;

[0202] 6) Example 6 added 6# flake HAp, which had an average thickness of 30 nm and a median particle size of spherical particles of 4.3 μm;

[0203] 7) Example 7 added 7# flake HAp, which had an average thickness of 57 nanometers and a median particle size of spherical particles of 8.6 microns.

[0204] The occlusion rate of the dental tubules after 15 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule occlusion efficacy test. The results are shown in Table 13.

[0205] Table 13:

[0206] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Plugging rate 98％ 97％ 99％ 93％ 98％ 96％ 92％

[0207] From Table 13 we can see that:

[0208] 1) The occlusion rate of dental tubules after treatment with the composition of Example 1 was 98%;

[0209] 2) The occlusion rate of dental tubules after treatment with the composition of Example 2 was 97%;

[0210] 3) The occlusion rate of dental tubules after treatment with the composition of Example 3 was 99%;

[0211] 4) The tubule occlusion rate after treatment with the composition of Example 4 was 93%;

[0212] 5) The occlusion rate of dental tubules after treatment with the composition of Example 5 was 98%;

[0213] 6) The tubule occlusion rate after treatment with the composition of Example 6 was 96%;

[0214] 7) The tubule occlusion rate after treatment with the composition of Example 7 was 92%;

[0215] 8) That is, the compositions containing flaky HAp of different thicknesses and median particle sizes all have good efficacy in blocking dentinal tubules, and the blocking rates of dentinal tubules are basically the same; however, when the average thickness is 57 nm or the median particle size is 12.2 μm, the dentinal tubule blocking rate decreases slightly.

[0216] The thickness of the remineralized layer of the dental tubules after 3 days of cycle treatment was evaluated according to the evaluation method of the dentin remineralization efficacy test. The results are shown in Table 14 below.

[0217] Table 14:

[0218] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Remineralized layer thickness (μm) 3.2 3.4 3.1 2.6 3.5 3.2 2.7

[0219] From Table 14 we can see that:

[0220] 1) The thickness of the remineralized dentin layer after treatment with the composition of Example 1 was 3.2 μm;

[0221] 2) The thickness of the remineralized dentin layer after treatment with the composition of Example 2 was 3.4 μm;

[0222] 3) The thickness of the remineralized dentin layer after treatment with the composition of Example 3 was 3.1 μm;

[0223] 4) The thickness of the remineralized dentin layer after treatment with the composition of Example 4 was 2.6 μm;

[0224] 5) The thickness of the remineralized dentin layer after treatment with the composition of Example 5 was 3.5 μm;

[0225] 6) The thickness of the remineralized dentin layer after treatment with the composition of Example 6 was 3.2 μm;

[0226] 7) The thickness of the remineralized dentin layer after treatment with the composition of Example 7 was 2.7 μm.

[0227] 8) That is, the compositions containing flaky HAp with different thicknesses and median particle sizes of spherical particles all have good efficacy in sealing dental tubules; however, when the average thickness reaches 57 nanometers or the median particle size of the spherical particles reaches 12.2 microns, the thickness of the remineralized layer of dentin begins to decrease slightly.

[0228] The compositions of Examples 1-7 were aged at 40° C. for one month, and the pastes of the compositions were examined. The results are shown in Table 15 below.

[0229] Table 15:

[0230] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Appearance after aging No stratification No stratification No stratification No stratification No stratification No stratification No stratification

[0231] As can be seen from Table 15, after aging at 40° C. for one month, no liquid-solid separation occurred in the pastes of Examples 1-7, that is, the compositions all had relatively stable paste structures.

[0232] The compositions of Examples 1-7 were aged at 40° C. for two months, and the composition pastes were examined. The results are shown in Table 16.

[0233] Table 16:

[0234] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Appearance after aging No stratification No stratification No stratification No stratification Layering Layering No stratification

[0235] From Table 16 we can see that:

[0236] 1) After aging for two months at 40°C, no liquid-solid separation occurred in Examples 1-4 and 7;

[0237] 2) After aging for two months at 40°C, liquid-solid separation occurred in Example 5-6.

[0238] 3) That is, when the average thickness of the flaky HAp is as low as 30 nm or the median particle size of the spherical particles is as low as 2.5 μm, the composition will undergo liquid-solid demixing after aging for two months at 40°C.

[0239] From Tables 13, 14, and 16, it can be seen that when the average thickness of the flaky HAp is between 30 and 57 nanometers and the median particle size of the spherical particles is between 2.5 and 12.2 micrometers, the compositions have good tubule blocking and remineralization effects and a stable composition structure; and when the average thickness of the flaky HAp is between 36 and 51 nanometers and the median particle size of the spherical particles is between 3.3 and 10.1 micrometers, the compositions have better tubule blocking and remineralization effects, and the composition formula structure is more stable.

[0240] Examples 8-9, Comparative Examples 9-10

[0241] Examples 8-9 and Comparative Examples 9-10 were prepared according to the conventional method according to the formulation in Table 17 below. All data in the table are weight percentages. For ease of comparison, Example 1 is included in Table 17.

[0242] Table 17:

[0243] raw material Example 1 Example 8 Example 9 Comparative Example 9 Comparative Example 10 sorbitol 30 30 30 30 30 polyethylene glycol 1 1 1 1 1 1# xanthan gum 0.7 0.4 1 0.2 1.2 Cellulose gum / 0.3 / 0.5 / 1# Flake HAp 4 4 4 4 4 glycerin 13 13 13 13 13 50% NaOH solution 0.4 0.4 0.4 0.4 0.4 Silicon dioxide 17.5 17.5 17.5 17.5 17.5 Sodium lauryl sulfate 2 2 2 2 2 Betaine 1.25 1.25 1.25 1.25 1.25 Sodium fluoride 0.32 0.32 0.32 0.32 0.32 Saccharin sodium 0.15 0.15 0.15 0.15 0.15 essence 1.1 1.1 1.1 1.1 1.1 Potassium citrate 5 5 5 5 5 water Margin to 100% Margin to 100% Margin to 100% Margin to 100% Margin to 100%

[0244] As can be seen from Table 17, Example 1, Examples 8-9, and Comparative Examples 9-10 all added 4% of 1# flake HAp, and the difference lies in the different gelling systems of the compositions, among which:

[0245] 1) In Example 1, 0.7% of 1# xanthan gum was used as the gelling system;

[0246] 2) Example 8 uses 0.4% 1# xanthan gum and 0.3% cellulose gum as the gelling system;

[0247] 3) Example 9 uses 1% 1# xanthan gum as the gelling system;

[0248] 4) Comparative Example 9 uses 0.2% 1# xanthan gum and 0.5% cellulose gum as the gelling system;

[0249] 5) Comparative Example 10 uses 1.2% 1# xanthan gum as the gelling system, but this system has the problem of too high viscosity of the paste when preparing the paste.

[0250] The compositions of Example 1, Examples 8-9, and Comparative Examples 9-10 were aged at 40° C. for one month, and the pastes of the compositions were examined. The results are shown in Table 18 below.

[0251] Table 18:

[0252] Example 1 Example 8 Example 9 Comparative Example 9 Appearance after aging No stratification No stratification No stratification Layering

[0253] From Table 18 we can see that:

[0254] 1) The compositions of Examples 1 and 8-9 were aged at 40° C. for one month, and no liquid-solid separation occurred in the pastes;

[0255] 2) The composition of Comparative Example 9 was aged at 40°C for one month, and liquid-solid separation occurred in the paste;

[0256] From Table 17 and Table 18, it can be seen that the amount of xanthan gum added in the composition affects the stability of the paste structure. When the mass percentage of xanthan gum in the composition is only 0.2%, the composition has structural instability, while when the mass percentage of xanthan gum in the composition is 0.4-1%, the paste structure of the composition is more stable.

[0257] The compositions of Example 1, Examples 8-9, and Comparative Examples 9-10 were aged at 40° C. for 3 months, and the pastes of the compositions were examined. The results are shown in Table 19.

[0258] Table 19:

[0259] Example 1 Example 8 Example 9 Comparative Example 9 Appearance after aging Slight delamination No stratification No stratification Layering

[0260] From Table 19 we can see that:

[0261] 1) After aging for three months at 40°C, the paste of Example 1 exhibited slight stratification;

[0262] 2) After aging for three months at 40°C, no liquid-solid separation occurred in the pastes of Examples 8-9;

[0263] 3) Comparative Example 9 was aged at 40°C for three months, and liquid-solid separation occurred in the paste;

[0264] From Tables 17 to 19, it can be seen that the amount of xanthan gum added in the composition affects the stability of the paste structure. When the mass percentage of xanthan gum in the composition is as low as 0.2%, the composition has structural instability. When the mass percentage of xanthan gum in the composition is 0.4-1%, the paste structure of the composition is more stable. When xanthan gum is combined with cellulose gum to form a new gel system, the stability of the paste structure is further improved.

[0265] Examples 10-12

[0266] Examples 10-12 were prepared according to the conventional method according to the formulation in Table 20 below. The data in the table are all weight percentages; for ease of comparison, Example 1 is included in Table 20.

[0267] Table 20:

[0268]

[0269] As can be seen from Table 20, different weight ratios of 1# flake HAp were added in Example 1 and Examples 10-12, where:

[0270] 1) Example 10 added 0.01% of 1# flaky HAp;

[0271] 2) Example 11 added 0.1% of 1# flaky HAp;

[0272] 3) Example 1 added 4% of 1# flake HAp;

[0273] 4) Example 12 added 25% of 1# flaky HAp;

[0274] The occlusion rate of the dental tubules after 15 days of cyclic treatment was evaluated according to the evaluation method of the dental tubule occlusion efficacy test. The results are shown in Table 21 below.

[0275] Table 21:

[0276] Example 10 Example 11 Example 1 Example 12 Plugging rate 8％ 25％ 98％ 100％

[0277] From Table 21 we can see that:

[0278] 1) The tubule occlusion rate after treatment with the composition of Example 10 was 8%;

[0279] 2) The tubule occlusion rate after treatment with the composition of Example 11 was 25%;

[0280] 3) The occlusion rate of dental tubules after treatment with the composition of Example 1 was 98%;

[0281] 4) The tubule occlusion rate after treatment with the composition of Example 12 was 100%;

[0282] 5) That is, the compositions with different weight ratios of 1# flaky HAp added all have the effect of blocking dental tubules.

[0283] The thickness of the remineralized layer of the dental tubules after 3 days of cycle treatment was evaluated according to the evaluation method of the above-mentioned dentin remineralization efficacy test. The results are shown in Table 22 below.

[0284] Table 22:

[0285] Example 10 Example 11 Example 1 Example 12 Remineralized layer thickness (μm) 0.4 1.3 3.2 5.3

[0286] From Table 22 we can see that:

[0287] 1) The thickness of the remineralized dentin layer after treatment with the composition of Example 10 was 0.4 μm;

[0288] 2) The thickness of the remineralized dentin layer after treatment with the composition of Example 11 was 1.3 μm;

[0289] 3) The thickness of the remineralized dentin layer after treatment with the composition of Example 1 was 3.2 μm;

[0290] 4) The thickness of the remineralized dentin layer after treatment with the composition of Example 12 was 5.3 μm;

[0291] 5) That is, the compositions with different weight ratios of 1# flake HAp all have the effect of dentin remineralization.

[0292] The compositions of Examples 10-11, Example 1, and Example 12 were aged at 40° C. for one month, and the composition pastes were examined. The results are shown in Table 23.

[0293] Table 23:

[0294] Example 10 Example 11 Example 1 Example 12 Appearance after aging No stratification No stratification No stratification No stratification

[0295] As shown in Table 23, the pastes of Examples 10-11, Example 1, and Example 12 did not undergo liquid-solid separation after aging at 40°C for one month. However, the pastes of Comparative Example 9 underwent liquid-solid separation after aging at 40°C for one month. This indicates that when the weight percentage of 1# flaky HAp in the composition is within the range of 0.01-25%, the paste structure of the composition remains stable.

[0296] In summary, when the weight percentage of 1# flaky HAp in the composition is in the range of 0.01-25%, the composition has obvious tubular occlusion rate and remineralization effect, and the structure of the paste can also remain stable; especially when the weight percentage of 1# flaky HAp is in the range of 4-25%, the composition has excellent tubular occlusion rate, tubular remineralization effect and paste structure stability.

[0297] Examples 13-14, Comparative Example 11

[0298] According to the formulation in Table 24 below, Examples 13-14 and Comparative Example 11 were prepared by conventional methods. The data in the table are all weight percentages. For ease of comparison, Comparative Example 4 is included in Table 24.

[0299] Table 24:

[0300] raw material Comparative Example 4 Comparative Example 11 Example 13 Example 14 sorbitol 30 30 30 30 polyethylene glycol 1 1 1 1 1# xanthan gum / / 0.7 0.4 Sodium carboxymethyl cellulose 0.7 0.7 / 0.3 1# Flake HAp 4 4 4 4 Zinc citrate / 2 2 2 glycerin 13 13 13 13 50% NaOH solution 0.4 0.4 0.4 0.4 Silicon dioxide 17.5 17.5 17.5 17.5 Sodium lauryl sulfate 2 2 2 2 Betaine 1.25 1.25 1.25 1.25 Sodium fluoride 0.32 0.32 0.32 0.32 Saccharin sodium 0.15 0.15 0.15 0.15 essence 1.1 1.1 1.1 1.1 water Margin to 100% Margin to 100% Margin to 100% Margin to 100%

[0301] As can be seen from Table 24, Comparative Example 4 added 4% of 1# flaky HAp and used 0.7% sodium carboxymethyl cellulose as the gelling agent system. Examples 13-14 and Comparative Example 11 all added 4% of 1# flaky HAp and 2% zinc citrate. The difference lies in the different gelling systems of the compositions, among which:

[0302] 1) Comparative Example 11 uses 0.7% cellulose gum as the gelling system;

[0303] 2) Example 13 uses 0.7% 1# xanthan gum as the gelling system;

[0304] 3) Example 14 uses 0.4% 1# xanthan gum and 0.3% cellulose gum as the gelling system;

[0305] The compositions of Examples 13-14 and Comparative Example 11 were aged at 40° C. for half a month, and the composition pastes were examined. The results are shown in Table 25 below.

[0306] Table 25:

[0307] Comparative Example 4 Comparative Example 11 Example 13 Example 14 Appearance after aging Slightly layered Layering No stratification No stratification

[0308] From Table 25 we can see that:

[0309] 1) The composition of Comparative Example 11 was aged at 40°C for half a month, and slight liquid-solid separation occurred in the paste;

[0310] 2) The composition of Comparative Example 4 was aged at 40°C for half a month, and liquid-solid separation occurred in the paste. This shows that adding a zinc ion source to a formula containing hydroxyapatite will aggravate the structural instability of the formula;

[0311] 3) The composition of Example 13 was aged at 40°C for half a month, and no liquid-solid delamination occurred in the paste; thus, when xanthan gum is used as the gelling agent in a formulation containing hydroxyapatite and a zinc ion source, the structural stability of the formulation can also be improved.

[0312] 4) The composition of Example 14 was aged at 40°C for half a month, and the paste also did not undergo liquid-solid demixing. This means that in a formulation containing hydroxyapatite and a zinc ion source, using a combination of xanthan gum and sodium carboxymethyl cellulose as a gelling agent system can also improve the structural stability of the formulation.

[0313] The compositions of Examples 13-14 and Comparative Example 11 were aged at 40° C. for one month, and the composition pastes were examined. The results are shown in Table 26 below.

[0314] Table 26:

[0315] Comparative Example 4 Comparative Example 11 Example 13 Example 14 Appearance after aging Layering Layering Slightly layered No stratification

[0316] From Table 26 we can see that:

[0317] 1) The compositions of Comparative Examples 4 and 11 were aged at 40°C for one month, and liquid-solid separation occurred in both pastes;

[0318] 2) After aging the composition of Example 13 at 40°C for one month, slight liquid-solid separation occurred in the paste;

[0319] 4) The composition of Example 14 was aged at 40°C for one month, and no liquid-solid separation occurred in the paste. This indicates that in a formulation containing hydroxyapatite and a zinc ion source, using a combination of xanthan gum and sodium carboxymethyl cellulose as the gelling agent system can further improve the structural stability of the formulation.

[0320] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" means that the specific features, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example.

[0321] In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, unless they are mutually inconsistent. The above description is merely an embodiment of the embodiment of this specification and is not intended to limit the embodiment of this specification. For those skilled in the art, various changes and modifications may be made to the embodiment of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiment of this specification shall be included within the scope of the claims of the embodiment of this specification.

Claims

1. An oral care composition, characterized in that include: 1) flaky hydroxyapatite, 2) Xanthan gum, and 3) an orally acceptable carrier; The average molecular weight of the xanthan gum is 2.5 to 5 million Daltons.

2. The oral care composition according to claim 1, wherein: The average thickness of the flaky hydroxyapatite is 30-57 nanometers.

3. The oral care composition according to claim 2, wherein: The average thickness of the flaky hydroxyapatite is 36-51 nanometers.

4. The oral care composition according to claim 1, wherein: The plate-like hydroxyapatite aggregates to form spherical particles.

5. The oral care composition according to claim 4, characterized in that: The median particle size of the spherical particles formed by agglomeration of the flaky hydroxyapatite is 2.5-12.2 microns.

6. The oral care composition according to claim 5, characterized in that: The median particle size of the spherical particles formed by agglomeration of the flaky hydroxyapatite is 3.3-10.1 microns.

7. The oral care composition according to claim 1, characterized in that: The mass proportion of the flaky hydroxyapatite in the oral care composition is 0.01-25%.

8. The oral care composition according to claim 1, wherein: The mass proportion of the flake hydroxyapatite in the oral care composition is 4-25%.

9. The oral care composition according to claim 1, wherein: The xanthan gum accounts for 0.4-1% by weight in the oral care composition.

10. The oral care composition according to claim 1, characterized in that: The oral care composition further comprises cellulose gum.

11. The oral care composition according to any one of claims 1 to 10, characterized in that: The oral care composition further comprises zinc citrate.

12. A method for improving the paste structure stability of an oral care composition containing platelet-shaped hydroxyapatite, characterized in that: The steps include: Xanthan gum with an average molecular weight of 2.5 to 5 million Daltons is added as a gelling agent to an oral care composition containing plate-like hydroxyapatite.

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