Oral care composition

Abstract

This application relates to oral care compositions, in particular novel aqueous oral care compositions that can be used to combine and deliver poorly compatible ingredients, for example, comprising: a) short-chain polyphosphates; b) an effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form; c) a stabilizing amount of an anionic surfactant; and d) water. This application also relates to methods for preparing and using the compositions.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of August 3, 2017, an application number of "201780049340.5", and an invention title of "Oral Care Composition" (which claims the priority and benefit of US Provisional Application No. 62 / 373,567 filed on August 11, 2016, the content of which is incorporated herein by reference in its entirety). Technical Field

[0002] This application relates to oral care compositions. Background Art

[0003] This application particularly relates to novel aqueous oral care compositions for combining and delivering poorly compatible ingredients, such as delivering a combination of an effective level of a cationic antimicrobial agent and polyphosphates for preventing erosion and staining.

[0004] Biofilms form when bacteria adhere to surfaces in some form of aqueous environment and begin to secrete a sticky, gelatinous substance that can adhere to all kinds of materials - metals, plastics, soil particles, medical implant materials, biological tissues. Dental plaque is a biofilm that adheres to teeth and other oral surfaces, particularly at the gingival margin, and is associated with the development of gingivitis, periodontitis, dental caries, and other forms of periodontal disease. Dental plaque is cohesive and highly resistant to removal from teeth and / or oral surfaces. Bacteria associated with dental plaque convert sugars into dextrans, which are insoluble polysaccharides that provide the cohesion of the plaque. Anaerobic bacteria in the plaque metabolize sugars, producing acids that dissolve tooth minerals, thereby damaging tooth enamel and ultimately forming dental caries. Saliva can buffer the acids produced by bacteria and promote the remineralization of tooth enamel, but extensive plaque can block the contact of saliva with tooth enamel. The re-deposition of minerals in the biofilm forms a hard deposit on the teeth called calculus (or tartar), which becomes a local irritant to the gums, causing gingivitis.

[0005] Various antimicrobial agents can retard the growth of bacteria and thus reduce the formation of biofilms on oral surfaces. In many cases, these antimicrobial agents are cationic, such as quaternary ammonium surfactants like cetylpyridinium chloride (CPC), biguanides like chlorhexidine, metal cations like zinc or stannous ions, and guanidines like arginine.

[0006] Daily activities such as smoking or other oral use of tobacco products, and eating, chewing, or drinking certain foods and beverages (especially coffee, tea, cola beverages, and red wine) can cause undesirable staining of tooth surfaces. Staining can also result from microbial activity, including microbial activity associated with dental plaque. Chromogens or coloring substances in these materials will become part of the salivary film layer and can penetrate the enamel layer. Even with regular brushing and flossing, the accumulation of chromogens over the years can cause significant tooth discoloration.

[0007] Teeth are composed of an inner dentin layer and an outer hard enamel layer, and the outer hard enamel layer is a protective layer of the teeth. The enamel layer of teeth is inherently opaque and appears white or slightly grayish white. The enamel layer is composed of hydroxyapatite mineral crystals that produce a somewhat porous surface. These hydroxyapatite crystals form fine hexagonal rods or prisms to compose the enamel surface. Thus, there are fine spaces or pores between the prisms on the surface of the enamel. Without limiting the mechanisms, functions, or utilities of the present disclosure, it is believed that this porosity of the enamel is the reason for discoloring substances to penetrate the enamel and discolor the teeth.

[0008] Since the compounds that stain teeth are generally anionic materials, cationic antibacterial agents may cause or enhance staining by promoting the deposition of chromophores or by forming salts with minerals.

[0009] One method for reducing staining and erosion and for reducing biofilm formation is to use dentifrices, such as mouthwashes, that contain mineral agents useful for stain removal. For example, polyphosphates have shown significant anti-staining ability, and when used in oral care products, they deposit on the tooth surface and protect the tooth surface, as well as chelate free calcium, thereby starving bacteria and reducing calculus deposition. However, when phosphates are combined with cationic antibacterial agents, especially in high-moisture formulations where the two can readily interact in solution, the phosphates and cationic antibacterial agents can complex to form insoluble precipitates, thereby inactivating both components.

[0010] Accordingly, there is a need for novel oral compositions and methods that inhibit staining and biofilm formation and that, in particular, can provide the anti-fouling and anti-calculus benefits of phosphates and the antibacterial and anti-biofilm benefits of cationic antibacterial agents. SUMMARY OF THE INVENTION

[0011] Surprisingly, it has been found that adding a stabilizing amount of an anionic surfactant, such as sodium lauryl sulfate, to a formulation containing short-chain polyphosphates and a cationic antibacterial agent inhibits the association of these components and enhances delivery to the teeth.

[0012] For example, quaternary ammonium antimicrobials such as cetylpyridinium chloride (CPC) are generally incompatible with anionic polyphosphates because precipitation of the two components occurs. However, we have found that adding an anionic surfactant, such as sodium lauryl sulfate, provides the desired stability and competition between the phosphate, the sulfate groups of the surfactant, and CPC - the result being the release of CPC and making it more available to interact with bacteria. In some embodiments, adding a nonionic surfactant, such as poloxamer, such as poloxamer 407, further improves the availability of CPC via an additional competition pathway between water, the sulfate groups of the anionic surfactant, and CPC. In the absence of an anionic surfactant (and optionally a nonionic surfactant), formulations having CPC and phosphate may have little better efficacy than a material or media control without CPC.

[0013] Similarly, due to their high charge density and entropy-driven precipitation reactions, biguanide antimicrobials such as chlorhexidine will generally complex with anionic polyphosphates regardless of the steps taken. Chlorhexidine also reacts with anionic surfactants such as sodium lauryl sulfate and is thus generally considered incompatible with SLS. See, e.g., Barkvoll et al., "Interaction between chlorhexidine digluconate and sodium lauryl sulfate in vivo", J Clin Periwedtol. (1989) 16(9):593 - 5).

[0014] But we have found that chlorhexidine and short-chain polyphosphates can be formulated in a way that prevents precipitation (or redissolves precipitates) by including a low content of an anionic surfactant such as sodium lauryl sulfate (SLS). In addition to the anionic surfactant, additional surfactants, particularly nonionic surfactants such as poloxamer, can be used and aid in dissolving the components of the formulation.

[0015] Cationic antimicrobials that can be stabilized in a formulation having a short-chain linear polyphosphate and an anionic surfactant can alternatively be selected from or can further include, for example, antimicrobial guanidine polymers, such as, as disclosed in WO2010134904 A1, the contents of which are incorporated herein by reference, for example, polymers or copolymers of allyl guanidine compounds and their salts; and cationic amino acids and / or metal cations.

[0016] In one embodiment, the present disclosure thus provides an oral care composition comprising:

[0017] (i) Short-chain linear polyphosphates, such as phosphates containing pyrophosphate or triphosphate anions and alkali metal cations (such as potassium or sodium), such as those selected from sodium tripolyphosphate, potassium tripolyphosphate, tetrasodium pyrophosphate, tetrapotassium pyrophosphate, and mixtures thereof;

[0018] (ii) An effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form, such as one or more selected from the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)); biguanides (such as orally acceptable salts of chlorhexidine, such as chlorhexidine digluconate, or orally acceptable salts of poly(hexamethylene biguanide), such as polyhexanide); cationic amino acids (such as arginine in free or salt form); antimicrobial guanidine polymers; metal cations (such as zinc ions, calcium ions, or stannous ions; for example, where the cation source is a metal salt or oxide, such as those containing stannous chloride, stannous fluoride, zinc citrate, zinc lactate, zinc phosphate, zinc oxide, or combinations thereof) or combinations thereof;

[0019] (iii) A stabilizing amount of an anionic surfactant, such as linear C 8 -C 18 alkyl sulfates or C 8 -C 18 alkyl ether sulfates in the form of sodium, potassium, ammonium, and ethanolammonium salts, such as sodium lauryl ether sulfate, sodium lauryl sulfate, ammonium lauryl sulfate; and

[0020] (iv) Optionally, an orally acceptable nonionic surfactant, such as those selected from poloxamers, polyoxyethylene, and combinations thereof; and

[0021] (v) Water.

[0022] The present disclosure also provides a method for inhibiting dental erosion, staining, and / or biofilm formation, which includes administering to the oral cavity a composition as described.

[0023] Other applicable fields of the present invention will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for illustrative purposes only and are not intended to limit the scope of the invention. Detailed Description

[0024] The following description of the preferred embodiments is exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0025] As used throughout, ranges are used as a shorthand for describing every value within the range. Any value within the range can be selected as the range endpoint. Additionally, all references cited herein are hereby incorporated by reference in their entirety. If there is a conflict between the definitions in the present disclosure and those of the cited references, the present disclosure shall prevail.

[0026] Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in this specification are to be understood as being weight percentages. The given amounts are based on the active weight of the substance.

[0027] As is common in the art, the compositions described herein are sometimes described in terms of their components, although the components may dissociate, combine, or react in the formulation. For example, ions are typically provided to the formulation in the form of salts, which may dissolve and dissociate in an aqueous solution. It is understood that the present invention encompasses both mixtures of the components and the products obtained therefrom.

[0028] In a first embodiment, the present disclosure provides an oral care composition (Composition 1) comprising:

[0029] (i) Short-chain polyphosphates;

[0030] (ii) An effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form;

[0031] (iii) A stabilizing amount of an anionic surfactant; and

[0032] (iv) Water.

[0033] For example, the present disclosure provides the following embodiments of Composition 1:

[0034] 1.1 Composition 1, wherein the short-chain polyphosphates comprise a phosphate chain of three or fewer phosphates and a monovalent cation.

[0035] 1.2 Any of the foregoing compositions, wherein the short-chain polyphosphates comprise pyrophosphate or triphosphate anions and an alkali metal cation, for example, selected from sodium, potassium, and combinations thereof.

[0036] 1.3 Any of the foregoing compositions, wherein the short-chain polyphosphates comprise sodium tripolyphosphate, tetrasodium pyrophosphate, tetrapotassium pyrophosphate, or combinations thereof.

[0037] 1.4 Any of the foregoing compositions, wherein the short-chain polyphosphates comprise sodium tripolyphosphate.

[0038] 1.5 Any of the foregoing compositions, wherein the short-chain polyphosphates are present in an amount of 0.01 wt% to 5.0 wt%, 0.1 wt% to 5.0 wt%, 0.1 wt% to 3 wt%, 0.5 wt% to 1.5 wt%, or 1.0 wt% based on the total weight of the composition.

[0039] 1.6 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is selected from one or more of the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)), biguanides (such as chlorhexidine digluconate), cationic amino acids (such as arginine), metal cations (such as zinc ions, calcium ions or stannous ions), guanidine polymers or combinations thereof.

[0040] 1.7 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is selected from one or more of the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)); biguanides (such as an orally acceptable salt of chlorhexidine, such as chlorhexidine digluconate, or poly(hexamethylene biguanide), such as polyhexanide); cationic amino acids (such as arginine in free form or in salt form); antimicrobial guanidine polymers; metal cations (such as zinc ions, calcium ions or stannous ions; for example, wherein the cation source is a metal salt or oxide, such as comprising stannous chloride, stannous fluoride, zinc citrate, zinc lactate, zinc phosphate, zinc oxide or combinations thereof) or combinations thereof.

[0041] 1.8 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is selected from one or more of the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)) and biguanides (such as an orally acceptable salt of chlorhexidine, such as chlorhexidine digluconate, or poly(hexamethylene biguanide), such as polyhexanide).

[0042] 1.9 Any of the foregoing compositions, wherein the orally acceptable cationic active agent comprises a pyridinium salt surfactant, such as cetylpyridinium chloride (CPC).

[0043] 1.10 Any of the foregoing compositions, wherein the orally acceptable cationic active agent comprises chlorhexidine in free base or orally acceptable salt form, such as chlorhexidine digluconate.

[0044] 1.11 Any of the foregoing compositions, wherein the orally acceptable cationic active agent comprises arginine.

[0045] 1.12 Any of the foregoing compositions, wherein the orally acceptable cationic active agent comprises zinc ions.

[0046] 1.13 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is provided by an orally acceptable salt selected from zinc salts, stannous salts, pyridinium salts and biguanide salts.

[0047] 1.14 Any of the foregoing compositions, wherein the orally acceptable cationic active agent comprises metal ions supplied by one or more of stannous chloride, stannous fluoride, zinc citrate, zinc lactate, zinc phosphate and zinc oxide.

[0048] 1.15 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is provided by an orally acceptable salt selected from cetylpyridinium chloride and chlorhexidine digluconate.

[0049] 1.16 Any of the foregoing compositions, wherein the orally acceptable cationic active agent is provided by an orally acceptable zinc salt, stannous salt, or a combination thereof.

[0050] 1.17 Any of the foregoing compositions, wherein the effective amount of the cationic active agent in free or salt form is present in an amount of 0.05 to 0.1%, such as about 0.075%, and comprises cetylpyridinium chloride.

[0051] 1.18 Any of the foregoing compositions, wherein the effective amount of the cationic active agent in free or salt form is present in an amount of 0.1 to 0.2%, such as about 0.12%, and comprises chlorhexidine digluconate.

[0052] 1.19 Any of the foregoing compositions, wherein the anionic surfactant comprises an alkyl sulfate or alkyl ether sulfate in free or orally acceptable salt form.

[0053] 1.20 Any of the foregoing compositions, wherein the anionic surfactant includes sodium, potassium, ammonium, and ethanolammonium salts of linear C8-C18 alkyl sulfates or C8-C18 alkyl ether sulfates.

[0054] 1.21 Any of the foregoing compositions, wherein the anionic surfactant comprises sodium lauryl ether sulfate (SLES), sodium lauryl sulfate, and ammonium lauryl sulfate.

[0055] 1.22 Any of the foregoing compositions, wherein the anionic surfactant comprises sodium lauryl sulfate.

[0056] 1.23 Any of the foregoing compositions, wherein the anionic surfactant is present in an amount sufficient to substantially interfere with the interaction between the cationic active agent and the short-chain polyphosphate, such as an amount sufficient to inhibit precipitate formation or reduce the efficacy of the cationic active agent.

[0057] 1.24 Any of the foregoing compositions, wherein the anionic surfactant is present in an amount of 0.01 to 5.0%, 0.1 to 2.0%, 0.1 to 1.0%, 0.2 to 0.4%, or about 0.33%.

[0058] 1.25 Any of the foregoing compositions, which further comprises a nonionic surfactant.

[0059] 1.26 Any of the foregoing compositions, which comprises a nonionic surfactant selected from poloxamer or polyoxyethylene, such as poloxamer 407.

[0060] 1.27 Any of the foregoing compositions that comprises a nonionic surfactant that is a block copolymer of polyethylene glycol and polypropylene glycol.

[0061] 1.28 Any of the foregoing compositions that comprises from about 0.01 to 5.0%, 0.1 to 2.0%, 0.1 to 0.6%, 0.2 to 0.4%, about 0.2% or about 0.5% of a nonionic surfactant.

[0062] 1.29 Any of the foregoing compositions that comprises a nonionic surfactant, wherein the ratio of anionic surfactant to nonionic surfactant is from about 5:1 to about 1:5; about 2:1 to about 1:2; about 1.5:1 to about 1:1.5; about 1.6:1; or about 1:1.5.

[0063] 1.30 Any of the foregoing compositions that further comprises an amino acid or polyamine in free or orally acceptable salt form.

[0064] 1.31 Any of the foregoing compositions that comprises a polyamine in free or orally acceptable salt form, which is selected from lysine or arginine in free or orally acceptable salt form.

[0065] 1.32 Any of the foregoing compositions, wherein the composition comprises 0.01% - 5% lysine, such as 0.5% - 1.0% lysine, in free or orally acceptable salt form.

[0066] 1.33 Any of the foregoing compositions, wherein the composition comprises 0.01% - 5% arginine, such as 0.4% - 0.8% arginine, in free or orally acceptable salt form.

[0067] 1.34 Any of the foregoing compositions, wherein the composition comprises lysine in hydrochloride form.

[0068] 1.35 Any of the foregoing compositions, wherein the composition comprises 0.01% - 2.0% of lysine hydrochloride.

[0069] 1.36 Any of the foregoing compositions, wherein the composition comprises more than 50% water.

[0070] 1.37 Any of the foregoing compositions, wherein the composition comprises 70% to 95% water.

[0071] 1.38 Any of the foregoing compositions, wherein the composition comprises one or more of the following: a thickening agent, a buffering agent, a humectant, a surfactant, an abrasive, a sweetening agent, a flavoring agent, a pigment, a dye, an anticaries agent, an antibacterial agent, a whitening agent, a desensitizing agent, a preservative, or a mixture thereof.

[0072] 1.39 Any of the foregoing compositions, wherein the composition comprises a phosphate buffer.

[0073] 1.40 Any of the foregoing compositions, wherein the composition comprises a buffer, and the buffer comprises sodium hydroxide.

[0074] 1.41 Any of the foregoing compositions, which further comprises a pH regulator selected from lactic acid, citric acid, hydrochloric acid, glycolic acid, sodium hydroxide, potassium chloride, sodium citrate monohydrate, disodium citrate, monosodium malate, sodium carbonate, bicarbonate, sesquicarbonate, borate, silicate, sodium dihydrogen phosphate, trisodium phosphate, pyrophosphate, imidazole, or a combination thereof; for example, citric acid.

[0075] 1.42 Any of the foregoing compositions, which comprises a pH regulator in an amount of 0.01% to 5.0%, 0.01% to 2.0%, 0.1% to 1.0%, or about 0.5%.

[0076] 1.43 Any of the foregoing compositions, wherein the pH of the composition is about 1 to 7, about 3 to 6, about 5 to 6, or about 5.25 to 5.75.

[0077] 1.44 Any of the foregoing compositions, wherein the composition comprises a humectant selected from, for example, sorbitol, propylene glycol, glycerol, and combinations thereof

[0078] 1.45 Any of the foregoing compositions, wherein the composition comprises a humectant, and the humectant is a mixture of glycerol, sorbitol, and propylene glycol.

[0079] 1.46 Any of the foregoing compositions, wherein the composition comprises an abrasive.

[0080] 1.47 Any of the foregoing compositions, wherein the composition comprises an abrasive, and the abrasive comprises silica.

[0081] 1.48 Any of the foregoing compositions, wherein the composition comprises a sweetener.

[0082] 1.49 Any of the foregoing compositions, wherein the composition comprises a sweetener, and the sweetener is sodium saccharin.

[0083] 1.50 Any of the foregoing compositions, wherein the composition comprises a flavoring agent.

[0084] 1.51 Any of the foregoing compositions, wherein the composition comprises a dye, such as FD&C Blue No. 1.

[0085] 1.52 Any of the foregoing compositions, wherein the composition comprises an anti-caries agent.

[0086] 1.53 Any of the foregoing compositions, wherein the composition comprises a fluoride ion source.

[0087] 1.54 Any of the foregoing compositions, wherein the composition comprises a fluoride ion source, and wherein the fluoride ion source is stannous fluoride, sodium fluoride, potassium fluoride, sodium monofluorophosphate, sodium fluorosilicate, ammonium fluorosilicate, a fluorinated amine (e.g., N'-octadecyltrimethylenediamine-N,N,N'-tris(2-ethanol)-dihydrofluoride), ammonium fluoride, titanium fluoride, hexafluorosulfate, or a mixture thereof.

[0088] 1.55 Any of the foregoing compositions, wherein the composition comprises a whitening agent.

[0089] 1.56 Any of the foregoing compositions, wherein the composition comprises a whitening agent, and wherein the whitening agent is hydrogen peroxide.

[0090] 1.57 Any of the foregoing compositions, wherein the composition comprises a desensitizing agent, a vitamin, a preservative, an enzyme, or a mixture thereof.

[0091] 1.58 Any of the foregoing compositions, wherein the composition is a mouthwash, toothpaste, tooth gel, tooth powder, non-abrasive gel, mousse, foam, oral spray, lozenge, oral tablet, dental appliance, or pet care product.

[0092] 1.59 Any of the foregoing compositions, wherein the composition is a mouthwash.

[0093] 1.60 Any of the foregoing compositions, which is biphasic, e.g., wherein the solution comprises two different aqueous phases having different compositions and densities.

[0094] 1.61 Any of the foregoing compositions, which comprises less than 5%, e.g., less than 2%, of a hydrophobic component.

[0095] 1.62 Any of the foregoing compositions, except for flavoring agents, which is substantially oil-free.

[0096] 1.63 Any of the foregoing compositions, wherein there is no discernible precipitation or reaction between the short-chain polyphosphate and the orally acceptable cationic surfactant after storage at room temperature for three months.

[0097] 1.64 Any of the foregoing compositions, which is for use in any of Methods A - E.

[0098] 1.65 Any of the foregoing compositions, which is obtained or obtainable by Method F below.

[0099] 1.66 Any of the foregoing compositions, wherein the composition is a mouthwash, wherein

[0100] (i) the short-chain polyphosphate is present in an amount of about 0.1 to 5%, e.g., 0.5 - 3%, e.g., 1 - 2%, of sodium tripolyphosphate;

[0101] (ii) The amount of the orally acceptable cationic active agent in free or orally acceptable salt form is 0.1 to 0.2% chlorhexidine;

[0102] (iii) The amount of the anionic surfactant is 0.1 to 2.0% sodium lauryl sulfate; and

[0103] (iv) The amount of water is 70 - 95%, such as 75 - 85%;

[0104] wherein the composition further comprises 0.05 - 1%, such as 0.1 - 0.3%, of poloxamer, such as poloxamer 407, poloxamer 335 or a combination thereof, such as poloxamer 407;

[0105] wherein the composition further comprises 10 - 30%, such as 15 - 25%, of a humectant, the humectant comprising sorbitol, propylene glycol, glycerol or a combination thereof; and

[0106] wherein all amounts are based on the weight of the total composition.

[0107] Also claimed is the use of an anionic surfactant in free or orally acceptable salt form to stabilize an oral care preparation comprising a short-chain polyphosphate and an effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form; for example, use in any of the foregoing compositions 1 and the like.

[0108] As used herein, "oral care composition" means a composition whose intended use may include oral care, oral hygiene or oral appearance or whose intended method of use may include administration to the oral cavity. The term "oral care composition" thus expressly excludes compositions that are highly toxic, have a poor taste or are otherwise unsuitable for administration to the oral cavity. In some embodiments, the oral care composition is not intended to be swallowed, but rather is retained in the oral cavity for a sufficient time to achieve the intended utility. The oral care compositions disclosed herein can be used in non-human mammals such as pets (e.g., dogs and cats) as well as for human use. In some embodiments, the oral care compositions disclosed herein are for human use. Oral care compositions include, for example, dentifrices and mouthwashes. In some embodiments, the present disclosure provides mouthwash formulations.

[0109] As used herein, "orally acceptable" means a material that is safe and palatable at the relevant concentrations for use in oral care preparations such as mouthwashes or dentifrices.

[0110] As used herein, "orally acceptable carrier" refers to any carrier that can be used to formulate the oral care compositions disclosed herein. An orally acceptable carrier is harmless to a mammal in the amounts disclosed herein when retained in the mouth for a time sufficient to allow effective contact with tooth surfaces as required herein without being swallowed. Generally, an orally acceptable carrier is harmless even if inadvertently swallowed. Suitable orally acceptable carriers include, for example, one or more of the following: water, thickeners, buffering agents, humectants, surfactants, abrasives, sweeteners, flavoring agents, pigments, dyes, anti-caries agents, antibacterial agents, whitening agents, desensitizing agents, vitamins, preservatives, enzymes, and mixtures thereof.

[0111] As used herein, "short-chain polyphosphates" encompasses orally acceptable monophosphates and polyphosphates, such as P 1-6 phosphates, such as mono-, di- or tri-basic orthophosphates; and diphosphates, such as sodium hexametaphosphate. For example, short-chain polyphosphates can include alkali metal dibasic orthophosphates and alkali metal pyrophosphates, such as selected from disodium hydrogen phosphate, dipotassium hydrogen phosphate, dicalcium phosphate dihydrate, calcium pyrophosphate, tetrasodium pyrophosphate, tetrapotassium pyrophosphate, sodium tripolyphosphate, and mixtures of any two or more thereof. In one specific embodiment, for example, the composition comprises a mixture of tetrasodium pyrophosphate (Na 4 P 2 O 7 ), calcium pyrophosphate (Ca 2 P 2 O 7 ), and disodium hydrogen phosphate (Na 2 HPO 4 ). In some embodiments, tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), tetrapotassium pyrophosphate (TKPP), or mixtures thereof are used. In another embodiment, the composition comprises a mixture of tetrapotassium pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) (Na 5 P 3 O 10 ). Such phosphates are provided in an amount effective to reduce stains on tooth surfaces, enamel erosion, aid in cleaning teeth, and / or reduce the accumulation of tartar on teeth, for example, in an amount of 0.01 wt% to 5.0 wt%, 0.1 wt% to 5.0 wt%, 0.1 wt% to 3 wt%, 0.5 wt% to 1.5 wt%, or 1.0 wt% based on the total weight of the composition.

[0112] As used herein, "orally acceptable cationic active agent" refers to an agent that is cationic in aqueous solution at neutral pH and provides some beneficial effect to the teeth or oral cavity, such as antimicrobial, anti-gingivitis, and / or anti-erosion activity. Although in an aqueous formulation, the agent will generally be in solution, it can be introduced into a formulation prepared in the free or orally acceptable salt form. In certain embodiments, the orally acceptable cationic active agent is selected from one or more of the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)), biguanides (such as chlorhexidine digluconate), cationic amino acids (such as arginine), metal cations (such as zinc, calcium, or stannous ions), or combinations thereof.

[0113] As used herein, "anionic surfactant" refers to those surfactants or detergent compounds that contain an organic hydrophobic group and typically contain 8 to 26 carbon atoms or typically 10 to 18 carbon atoms and at least one water-solubilizing group selected from sulfonate, sulfate, and carboxylate in their molecular structure to form a water-soluble detergent. Generally, the hydrophobic group will contain C 8 -C 22 alkyl or acyl groups. Such surfactants are used in the form of water-soluble salts, and the salifying cation is typically selected from sodium, potassium, ammonium, magnesium, and mono-, di-, or tri-C 2 -C 3 alkanolammonium (where sodium, magnesium, and ammonium cations are also commonly selected cations). Some examples of suitable anionic surfactants include, but are not limited to, linear C 8 -C 18 alkyl ether sulfates, ether sulfates, and their sodium, potassium, ammonium, and ethanolammonium salts. Suitable anionic ether sulfates have the formula R(OC 2 H 4 ) n OSO 3 M, where n is 1 to 12 or 1 to 5, and R is an alkyl, alkylaryl, acyl, or alkenyl group having 8 to 18 carbon atoms (such as C 12 -C 14 or C 12 -C 16 alkyl), and M is a solubilizing cation selected from sodium, potassium, ammonium, magnesium, and monoethanolammonium, diethanolammonium, and triethanolammonium ions. Exemplary alkyl ether sulfates contain 12 to 15 carbon atoms in their alkyl group, such as sodium lauryl polyoxyethylene ether (2EO) sulfate. Some preferred exemplary anionic surfactants that can be used in the compositions of the present disclosure include sodium lauryl ether sulfate (SLES), sodium lauryl sulfate, and ammonium lauryl sulfate. In certain embodiments, the anionic surfactant is present in an amount of 0.01 to 5.0%, 0.1 to 2.0%, 0.2 to 0.4%, or about 0.33%.

[0114] As used herein, "nonionic surfactant" generally refers to a compound produced by condensing an alkylene oxide group (which is hydrophilic in nature) with an organic hydrophobic compound which can be aliphatic or alkyl aromatic in nature. Examples of suitable nonionic surfactants include poloxamers (sold under the trade name ), polyoxyethylene, polyoxyethylene sorbitan esters (sold under the trade name ), polyethylene glycol 40 hydrogenated castor oil, fatty alcohol ethoxylates, poly(ethylene oxide) condensates of alkylphenols, condensation products derived from the reaction product of ethylene oxide with propylene oxide and ethylenediamine, ethylene oxide condensates of aliphatic alcohols, alkyl polyglycosides (e.g., fatty alcohol ethers of polyglycosides, such as fatty alcohol ethers of polyglucosides, such as decyl ether of glucose, lauryl ether of glucose, octyl ether of glucose, octanoyl ether of glucose, myristyl ether of glucose, stearyl ether of glucose and other ethers, and polyglucoside polymers, including, for example, octyl / octanoyl ((C 8-10 )) glucoside, cocoalkyl (C 8-16 ) glucoside and a mixed ether of lauryl (C 12-16 ) glucoside), long-chain tertiary amine oxides, long-chain tertiary phosphine oxides, long-chain dialkyl sulfoxides, and mixtures of these substances.

[0115] In some embodiments, the nonionic surfactant includes amine oxides, fatty acid amides, ethoxylated fatty alcohols, block copolymers of polyethylene glycol and polypropylene glycol, glycerol alkyl esters, poly(ethylene glycol) octylphenol ethers, sorbitan alkyl esters, poly(ethylene glycol) sorbitan alkyl esters, and mixtures thereof. Examples of amine oxides include, but are not limited to, lauramidopropyl dimethylamine oxide, myristamidopropyl dimethylamine oxide, and mixtures thereof. Examples of fatty acid amides include, but are not limited to, coco monoethanolamide, lauramide monoethanolamide, coco diethanolamide, and mixtures thereof. In certain embodiments, the nonionic surfactant is a combination of an amine oxide and a fatty acid amide. In certain embodiments, the amine oxide is a mixture of lauramidopropyl dimethylamine oxide and myristamidopropyl dimethylamine oxide. In certain embodiments, the nonionic surfactant is a combination of lauryl / myristamidopropyl dimethylamine oxide and coco monoethanolamide. In certain embodiments, the nonionic surfactant is present in an amount of from 0.01 to 5.0%, from 0.1 to 2.0%, from 0.1 to 0.6%, from 0.2 to 0.4%, about 0.2% or about 0.5%.

[0116] As used herein, "polyamine compound" refers to a molecule having at least two primary or secondary amine groups, such as having an isoelectric point above pH 8.5, such as pH 9 - 10. Examples of polyamines include ethylenediamine, lysine or histidine, and polymers such as Lupasol P which is polyethyleneimine. The polyamine must be safe for its intended use. When the composition is an oral care composition, the polyamine must be orally acceptable. The polyamine may be provided in free or acid addition salt form. In certain embodiments, the polyamine compound is lysine.

[0117] As used herein, "biphasic" refers to a stable liquid composition containing at least two different homogeneous phases, the at least two different homogeneous phases having different densities such that the phases are separated at rest. These phases can be easily mixed by shaking but then re - separate within a short time, such as in less than half an hour. In certain embodiments, the term does not include gels, emulsions, microemulsions and homogeneous solutions. In certain embodiments, these formulations differ from conventional biphasic formulations in that both phases are aqueous, rather than one phase being hydrophobic and the other being hydrophilic.

[0118] As used herein, "dental calculus control agent" refers to a compound or mixture of compounds that will inhibit the formation of dental calculus (calcium phosphate mixture) on an organic matrix and / or the deposition of dental plaque on teeth to form dental calculus (tartar).

[0119] As used herein, "chemical staining" refers to the discoloration of the tooth surface caused by the adsorption or absorption of a coloring agent onto or into the surface or by a chemical reaction of the tooth surface (e.g., enamel) material with a coloring or non - coloring agent in contact with the surface. "Chemical staining" herein refers to the formation and / or development of chemical staining.

[0120] As used herein, "tooth surface" refers to the surface of a natural tooth or the hard surface of an artificial dentition, including the crown, dental cap, filling, dental bridge, dental implant, etc. In some embodiments, the tooth surface is a natural tooth.

[0121] The composition is, for example, an oral care composition such as a mouthwash according to Composition 1 and the like. Any composition of Composition 1 and the like is suitable for oral care use as long as the ingredients are orally acceptable. In some embodiments, the mouthwash of Composition 1 contains an effective amount of an orally acceptable cationic active agent, which is an antimicrobial, anti-gingivitis, anti-erosion, and / or anti-caries agent, such as a cationic active agent selected from one or more of the following: quaternary ammonium surfactants (such as cetylpyridinium chloride (CPC)), biguanides (such as chlorhexidine digluconate), cationic amino acids (such as arginine), metal cations (such as zinc, calcium, or stannous ions), or combinations thereof. The orally acceptable cationic active agent may be present in an effective amount, such as an antimicrobial, anti-gingivitis, anti-erosion, and / or anti-caries amount. The exact amount will depend on the specific active agent and the condition to be treated or prevented, but in various embodiments, the antimicrobial effective level of CPC in the mouthwash includes an amount of 0.05 to 0.1%, such as about 0.075%; the antimicrobial effective level of chlorhexidine digluconate in the mouthwash includes an amount of 0.1 - 0.2%, such as about 0.12%; the anti-erosion or antimicrobial level of metal cations such as zinc (e.g., zinc citrate or other soluble salts) or stannous (e.g., stannous fluoride and / or stannous chloride) will be about 100 - 1500 ppm.

[0122] The oral care compositions used in the present disclosure contain a significant level of water. The water used for the preparation of commercial oral compositions should be deionized and free of organic impurities. The amount of water in the composition includes the added free water plus the amount of water introduced with other materials.

[0123] Mouthwashes typically contain a significant level of ethanol, which is often required to dissolve essential oils and prevent bacterial contamination. High levels of ethanol may be undesirable because, in addition to the possibility of abuse by ingestion, ethanol may also exacerbate conditions such as dry mouth. Thus, in some embodiments, the oral care compositions of the present invention are substantially free of ethanol, such as containing less than 1% ethanol.

[0124] Humectants can increase the viscosity, mouthfeel, and sweetness of the product and can also help preserve the product from degradation or microbial contamination. Suitable humectants include edible polyhydric alcohols, such as glycerol, sorbitol, xylitol, propylene glycol, and other polyols, and mixtures of these humectants. Sorbitol can be provided in some cases as a syrup form of hydrogenated starch hydrolysate, which mainly contains sorbitol (the product if starch is completely hydrolyzed to glucose and then hydrogenated), but may also contain other sugar alcohols such as mannitol, maltitol, and long-chain hydrogenated sugars due to incomplete hydrolysis and / or the presence of non-glucose saccharides, and in such cases these other sugar alcohols can also be used as humectants. In some embodiments, the humectant is present at a level of 5 wt% to 30 wt%, such as 10 wt% to 20 wt%.

[0125] The flavoring agents used in the present invention may include: extracts or oils from flavoring plants such as mint, spearmint, cinnamon, wintergreen, and combinations thereof; coolants such as menthol, methyl salicylate, and commercial products such as OptaCool from Symrise; and sweeteners, which may include polyols (which may also be used as humectants), saccharin, acesulfame potassium, aspartame, neotame, stevia, and sucralose. OptaCool; and sweeteners, which may include polyols (which may also be used as humectants), saccharin, acesulfame potassium, aspartame, neotame, stevia, and sucralose.

[0126] There is also provided a method (Method A) for treating and / or inhibiting chemical staining, dental plaque, and / or tartar on the tooth surface, which comprises contacting the tooth surface with any of the aforementioned oral care compositions.

[0127] The present invention also provides Method A as follows:

[0128] A.1 Method A, wherein the composition is Composition 1, for example, any one selected from Compositions 1.1 - 1.63.

[0129] A.2 Method A or A.1, wherein the method is used for treating chemical staining, dental plaque, and / or tartar on the tooth surface.

[0130] A.3 Method A.2, wherein the method is used for treating chemical staining on the tooth surface.

[0131] A.4 Method A.2, wherein the method is used for treating dental plaque on the tooth surface.

[0132] A.5 Method A.2, wherein the method is used for treating tartar on the tooth surface.

[0133] A.6 Method A or A.1, wherein the method is used for inhibiting chemical staining, dental plaque, and / or tartar on the tooth surface.

[0134] A.7 Method A.6, wherein the method is used for inhibiting chemical staining on the tooth surface.

[0135] A.8 Method A.6, wherein the method is used for inhibiting dental plaque on the tooth surface.

[0136] A.9 Method A.6, wherein the method is used for inhibiting tartar on the tooth surface.

[0137] A.10 Method A or A.1 - A.9, wherein the tooth surface is a human tooth.

[0138] A.11 Method A or A.1 - A.10, wherein the composition contacts the tooth surface by brushing.

[0139] A.12 Any of the foregoing Method A and the like, wherein the preparation is biphasic and shaken before use.

[0140] There is also provided a method for treating and / or inhibiting gum diseases (Method B), which comprises contacting the oral cavity with any of the foregoing oral care compositions.

[0141] The present invention also provides the following Method B:

[0142] B.1 Method B, wherein the composition is Composition 1, such as any one of 1.1 - 1.63.

[0143] B.2 Method B or B.1, wherein the method is used for treating gum diseases.

[0144] B.3 Method B, B.1 or B.2, wherein the gum disease is gingivitis.

[0145] B.4 Method B, B.1 or B, wherein the gum disease is periodontitis.

[0146] B.5 Method B or B.1, wherein the method is used for inhibiting gum diseases.

[0147] B.6 Method B, B.1 or B.5, wherein the gum disease is gingivitis.

[0148] B.7 Method B, B.1 or B.5, wherein the gum disease is periodontitis.

[0149] B.8 Method B or B.1 - B.7, wherein the oral cavity is a human oral cavity.

[0150] B.9 Method B or B.1 - B.8, wherein the composition contacts the oral cavity by brushing teeth.

[0151] B.10 Any of the foregoing Method B and the like, wherein the preparation is biphasic and shaken before use.

[0152] There is also provided a method for treating and / or inhibiting bad breath (Method C), which comprises contacting the oral cavity with any of the foregoing oral care compositions.

[0153] The present invention also provides the following Method C:

[0154] C.1 Method C, wherein the composition is Composition 1, such as any one of 1.1 - 1.63.

[0155] C.2 Method C or C.1, wherein the oral cavity is a human oral cavity.

[0156] C.3 Method C, C.1 or C.2, wherein the composition contacts the oral cavity by brushing teeth.

[0157] C.4 Any of the foregoing methods C and the like, wherein the preparation is biphasic and shaken before use.

[0158] There is also provided a method of inhibiting biofilm formation on tooth surfaces (Method D), which comprises contacting the tooth surfaces with any of the foregoing oral care compositions.

[0159] There is also provided herein Method D as follows:

[0160] D.1 Method D, wherein the composition is Composition 1, such as any one of 1.1 - 1.63.

[0161] D.2 Method D or D.1, wherein the tooth surfaces are human teeth.

[0162] D.3 Method D, D.1 or D.2, wherein the composition contacts the tooth surfaces by brushing.

[0163] D.4 Any of the foregoing methods D and the like, wherein the preparation is biphasic and shaken before use.

[0164] There is also provided a method of treating and / or inhibiting bacteria from aggregating and forming larger colonies in the oral cavity (Method E), which comprises contacting the oral cavity with any of the foregoing oral care compositions.

[0165] There is also provided herein Method E as follows:

[0166] E.1 Method E, wherein the composition is Composition 1, such as any one of 1.1 - 1.63.

[0167] E.2 Method E or E.1, wherein the oral cavity is the human oral cavity.

[0168] E.3 Method E, E.1 or E.2, wherein the composition contacts the oral cavity by brushing.

[0169] E.4 Any of the foregoing methods E and the like, wherein the preparation is biphasic and shaken before use.

[0170] There is also provided Composition 1 and the like for use in any of Methods A - E.

[0171] As used herein, "inhibit" means to reduce the staining that would otherwise form or develop after the treatment time. Such inhibition can range from a small but observable or measurable reduction to complete inhibition of subsequent staining as compared to untreated or placebo - treated tooth surfaces.

[0172] In the case where there is substantially no chemical staining on the tooth surface, after treatment according to the method, Method A (e.g., A.1 - A.12) will effectively inhibit the formation and development of new chemical staining that may occur, for example, due to the oral use of tobacco products (including smoking) or due to drinking tea, coffee, red wine, or cola. In the case where there is already a certain degree of chemical staining on the tooth surface, Method A (e.g., A.1 - A.12) will effectively inhibit the further development of the existing staining. In some embodiments, Method A (e.g., A.1 - A.12) can partially or completely remove the existing chemical staining and inhibit subsequent staining.

[0173] We further found that the formation of a precipitation complex between phosphate and cationic antimicrobials is affected by the order of addition of the components. If the components are not added in the correct order, a precipitate that will not redissolve is formed. Thus, in another embodiment, the present disclosure provides a method (Method F) for preparing an oral care composition, the composition comprising (i) short-chain polyphosphates [e.g., selected from, for example, tripolyphosphates, pyrophosphates, and mixtures thereof in the form of sodium and / or potassium salts, e.g., selected from sodium tripolyphosphate, potassium tripolyphosphate, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, and mixtures of any two or more of these]; (ii) an effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form [e.g., 0.1 - 1% chlorhexidine or chlorhexidine digluconate]; (iii) a stabilizing amount of an anionic surfactant [e.g., 0.1 - 1% sodium lauryl sulfate]; (iv) water; and optionally one or more of an alkaline amino acid in free or salt form [e.g., 0.5 - 1% lysine or 0.4 - 0.8% arginine, e.g., in solid form], a humectant, a nonionic polymer, a flavoring agent, and / or a dye (e.g., a method for preparing an oral care composition according to Composition 1 and any one of the following, etc.); the method comprises the following steps in the following order:

[0174] a) Add a stabilizing amount of an anionic surfactant to water;

[0175] b) Add a dilution solution of an effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form to the product of step a) [e.g., add an aqueous solution having a concentration of 0.1% to 5%, e.g., 0.5% to 2%, e.g., about 1% of the active substance];

[0176] c) Add short-chain polyphosphates in solid form to the product of step b);

[0177] d) Optionally, mix one or more of an alkaline amino acid in free or salt form [e.g., 0.5 - 1% lysine or 0.4 - 0.8% arginine, e.g., in solid form], a humectant, a nonionic polymer, a flavoring agent, and / or a dye into the solution thus obtained;

[0178] During steps a), b) and c) of the addition, for example, a pH regulator such as citric acid is used to maintain the pH between pH 5 and 6, for example between pH 5.25 - 5.75.

[0179] In another embodiment, the present disclosure provides an oral care composition or oral composition premix obtainable or obtained by a process of method F, comprising (i) short-chain polyphosphate; (ii) an effective amount of an orally acceptable cationic active agent in free or orally acceptable salt form; (iii) a stabilizing amount of an anionic surfactant; and (iv) water (e.g., an oral care composition according to any one of Composition 1 and the like).

[0180] Examples

[0181] Example 1 - Chlorhexidine and anti-staining polyphosphates

[0182] Chlorhexidine (CHX) mouthwash is very effective against gingivitis. However, after CHX is adsorbed onto the tooth surface, it often causes staining after drinking coffee, tea or red wine, which mainly occurs through the charge interaction between positively charged CHX and negatively charged stains. This means that people using chlorhexidine must avoid dark foods and beverages, or get used to yellower and stained teeth.

[0183] Sodium tripolyphosphate (STPP) exhibits significant anti-staining ability and deposits onto the tooth surface when used in oral care products. However, when STPP and CHX are combined, the complex formed by the two may cause precipitation of both STPP and CHX, thus inactivating both components.

[0184] However, we have found that CHX and STPP can be formulated in a way that prevents precipitation (or redissolves the precipitate) by introducing sodium lauryl sulfate. Additionally, the non-ionic surfactant poloxamer 407 can be used to supplement part of the SLS. The following formulations were tested:

[0185] Table 1: Test formulations

[0186]

[0187] Preparation method: Sodium lauryl sulfate is added to water in solid form, and a clear solution is produced when sodium lauryl sulfate dissolves. Then a 1% diluted solution of chlorhexidine is added to the solution. Chlorhexidine is added dropwise over a period of about 1 minute. Then sodium tripolyphosphate is dissolved into the solution. The pH is maintained between 5.25 - 5.75 using a pH regulator (such as citric acid). Then poloxamer 407 can be added to the solution to enhance solution clarity.

[0188] Color reduction: The efficacy of the test preparation against staining was tested on commercially available 0.12% chlorhexidine digluconate (CHX) mouthwash. Table 2 below compares the color change (△W) of hydroxyapatite (HAP) discs treated with various solutions. Each HAP disc was soaked in centrifuged saliva at 37 °C for at least two hours. After this time, the discs were rinsed with water and then transferred to the solutions listed at 37 °C for 15 minutes. This was repeated twice for a total of three CHX treatments. The discs were rinsed one last time and then placed in a coffee / tea / wine solution at 37 °C with shaking for 15 minutes. The discs were removed, rinsed, and the color change (△W) was measured.

[0189] The results are as follows:

[0190] Table 2: Stain protection of various preparations

[0191]

[0192] CHX = chlorhexidine digluconate; SLS = sodium lauryl sulfate (anionic surfactant); P407 = poloxamer 407 (nonionic surfactant); STPP = sodium tripolyphosphate.

[0193] As expected, discs treated with commercially available chlorhexidine mouthwash and red wine showed significant staining. Combining CHX with the surfactants SLS and P407 consistently provided a degree of stain protection. However, when STPP was included in the preparation, △W decreased by approximately 50%, which is a significant increase in stain protection ability.

[0194] Bacterial killing: A short-term killing test (SIKT) of 20 seconds measures the efficacy of various treatment solutions in killing oral pathogens. Fluorescent SIKT uses a live / dead BacLight fluorescent viability staining system to measure the permeabilization of bacteria by a single active ingredient or liquid formulation. The mixed-species inoculum culture contains: Lactobacillus casei, Streptococcus oralis, Actinomyces viscosus, Veillonella parvula, and Fusobacterium nucleatum with an optical density of 0.5 at 610 nm were centrifuged. The supernatant was then aspirated and the remaining salivary film was resuspended in sterile phosphate-buffered saline (PBS). Then, 100 μl of this solution was treated with 100 μl of the test sample for 30 or 60 seconds. Immediately after treatment, the exposure was neutralized by adding 1.3 ml of sterile D / E neutralizing broth. The neutralizing broth was then rinsed off by centrifugation and resuspension in PBS. Then, 50 μl of the sample was transferred in triplicate to a 96-well microplate. The fluorescent dye was then prepared according to the manufacturer's instructions and added to the samples. Fluorescence was then measured in a fluorescence plate reader. The data from this assay were presented as the percentage of remaining viable bacteria relative to a control sample treated with PBS. The formulation containing poloxamer 407 and STPP reduced bacterial viability by approximately 70%, while a commercial formulation lacking these components reduced it by approximately 50%. The viability percentages of different formulations are listed in Table 3, where lower viability percentages correspond to higher bactericidal activity.

[0195] Table 3: SIKT with different formulations

[0196]

[0197] Example 2

[0198] Stain deposition: As used in Example 1, saliva-coated hydroxyapatite (HAP) discs were treated with a commercial CHX mouthwash formulation or Formulation 1, and then the discs were attacked with a staining solution containing a mixture of coffee, tea, and wine. Briefly, the HAP discs were incubated overnight in 1 mL of saliva in an oscillator bath at 37 °C. After rinsing with distilled water, baseline spectrophotometer measurements were taken. 2 mL of the test formulation was added, and the discs were incubated in an oscillator bath at 37 °C for 30 seconds. After rinsing with distilled water, spectrophotometer measurements were repeated. Then, 2 mL of the stain solution was added, and the discs were incubated in an oscillator bath at 37 °C for 15 minutes. After rinsing with distilled water, spectrophotometer measurements were taken again. This treatment / staining procedure was repeated for a total of three staining cycles. Spectrophotometer measurements were used to evaluate changes in color values (abL). According to known methods, the anti-stain efficacy was measured as ΔE (Et - Ei) and / or ΔW* (W*t - W*i). The results are shown in Table 4 below. The results indicate that Formulation 1 is significantly more effective than the commercial CHX formulation in preventing stain deposition.

[0199] Table 4

[0200]

[0201] Bactericidal efficacy: A five-day biofilm assay was conducted to compare the efficacy of Formulation 1 with and without chlorhexidine in the presence of sodium lauryl sulfate. An active attachment biofilm model (Extrecate et al., Caries Research 2010; 44:372-379) was used to measure the antibacterial efficacy of the mouthwash formulations. In this model, 24 hydroxyapatite (HAP) discs were clamped between sterile metal caps. Then, under anaerobic conditions, the caps were inoculated in a 24-well plate in McBain medium containing 2% unstimulated saliva at 37 °C for 24 hours. After initial attachment, the biofilms were transferred to fresh growth medium for maturation. Treatments were performed after the 24-hour biofilm formation stage. The HAP discs were treated in 1.6 ml of the mouthwash formulation at room temperature for 10 minutes. Subsequently, the caps were transferred to a new plate to be washed with 1.7 ml of 25% tryptic soy buffer and moved up and down 10 times. The washing step was repeated three times. Then, the biofilms were transferred to McBain medium and incubated anaerobically at 37 °C. The discs were treated seven times over a 5-day period, and the resulting biofilms were harvested using sonication. The harvested biofilms were subjected to an ATP metabolism assay (Life Technology) and plated on 5% sheep blood agar plates to determine the total colony count. The results were reported as log(CFU / ml) for four replicates of each sample. The results are shown in Table 5 below. These results indicate that, despite the presence of sodium lauryl sulfate, the chlorhexidine present in Formulation 1 is effective in killing bacteria.

[0202] Table 5

[0203] Formulation Log CFU / ml Untreated control 9.59 Formulation 1, without CHX 8.02 Formulation 1 6.06

Claims

1. An oral care composition comprising: a) a short-chain polyphosphate, wherein the short-chain polyphosphate comprises pyrophosphate or triphosphate anions and alkali metal cations, and wherein the short-chain polyphosphate is present in an amount of 0.01 wt% to 5.0 wt% based on the total weight of the composition; b) chlorhexidine digluconate at a concentration of 0.1 wt% to 0.2 wt%; c) an anionic surfactant, wherein the anionic surfactant comprises sodium lauryl ether sulfate, sodium lauryl sulfate, ammonium lauryl sulfate or a combination thereof, and wherein the anionic surfactant is present in an amount of 0.01 to 5.0%; and d) water, wherein there is no discernible precipitation or reaction between the short-chain polyphosphate and the chlorhexidine digluconate after storage at room temperature for three months.

2. The composition according to claim 1, wherein the short-chain polyphosphate comprises sodium tripolyphosphate or potassium pyrophosphate.

3. The composition according to claim 1 or 2, wherein the short-chain polyphosphate comprises sodium tripolyphosphate at a concentration of 0.1 wt% to 5.0 wt%.

4. The composition according to claim 1 or 2, further comprising one or more orally acceptable cationic active agents selected from quaternary ammonium surfactants, biguanides, cationic amino acids, metal cations and combinations thereof.

5. The composition according to claim 4, wherein the orally acceptable cationic active agent is provided by an orally acceptable salt selected from zinc salts, stannous salts and cetylpyridinium chloride.

6. The composition according to claim 1 or 2, wherein the anionic surfactant comprises sodium lauryl sulfate at a concentration of 0.1 wt% to 1.0 wt%.

7. The composition according to claim 1 or 2, further comprising a nonionic surfactant.

8. The composition according to claim 1 or 2, wherein the composition comprises 70% to 95% water.

9. The composition according to claim 1 or 2, wherein the composition comprises one or more of the following: a thickening agent, a buffering agent, a humectant, an abrasive, a flavoring agent, a pigment, an anticaries agent, a whitening agent, a desensitizing agent, a preservative or a mixture thereof.

10. The composition according to claim 1 or 2, wherein the composition comprises one or more of the following: a sweetening agent, a dye, an antibacterial agent or a mixture thereof.

11. The composition according to claim 1 or 2, wherein the composition is a mouthwash.

12. The composition according to claim 1 or 2, which is biphasic, wherein the composition comprises two different aqueous phases having different compositions and densities.

13. A method for preparing an oral care composition, the composition comprising (i) a short-chain polyphosphate, wherein the short-chain polyphosphate comprises pyrophosphate or triphosphate anions and alkali metal cations, and wherein the short-chain polyphosphate is present in an amount of 0.01 wt% to 5.0 wt% based on the total weight of the composition; (ii) chlorhexidine digluconate at a concentration of 0.1 wt% to 0.2 wt%; (iii) an anionic surfactant, wherein the anionic surfactant comprises sodium lauryl ether sulfate, sodium lauryl sulfate, ammonium lauryl sulfate or a combination thereof, and wherein the anionic surfactant is present in an amount of 0.01 to 5.0%; (iv) water; and optionally, one or more of a basic amino acid, a humectant, a nonionic polymer, a flavoring agent and / or a dye in free or salt form, wherein the method comprises the following steps in the following order: a) adding the anionic surfactant to the water; b) adding a diluted solution of the chlorhexidine digluconate to the product of step a); c) adding the short-chain polyphosphate in solid form to the product of step b); d) optionally mixing one or more of a basic amino acid, a humectant, a nonionic polymer, a flavoring agent and / or a dye in free or salt form into the solution thus obtained; wherein during the addition of steps a), b) and c), the pH is maintained between pH 5 and pH 6.

14. The oral care composition according to claim 1 or 2, obtained by the method according to claim 13.

Images