Peroxymonosulfate oral whitening compositions

Abstract

The present disclosure provides tooth whitening oral care compositions comprising potassium peroxymonosulfate having improved stability and methods of using the same.

Description

[0001] Cross - Reference to Related Applications

[0002] This application is an international application claiming priority and the benefit of U.S. Provisional Application Serial No. 63 / 436,352, filed on December 30, 2022, the content of which is hereby incorporated by reference in its entirety. Background Art

[0003] There are numerous consumer products for tooth whitening and they come in various forms, but one of the more popular forms is as a dentifrice, such as toothpaste. Toothpaste generally must be in a semi - solid form that can hold its shape well enough to be dispensed from a tube and stay on the toothbrush bristles, but also be fluid enough to be easily extruded from the tube. Toothpaste must also be sticky enough to adhere to the teeth to some extent and yet soluble enough to disperse in the oral cavity. These different objectives are typically met by formulating toothpaste with a mixture of liquid polar humectants (such as glycerol, polypropylene glycol, and sorbitol) in a high - water base (e.g., 10% to 40% water). Various polymers are commonly used to provide the gel - like consistency required for toothpaste.

[0004] Unfortunately, many whitening agents have stability problems in the presence of water, humectants, and some polymers. Other inorganic substances (such as fluoride sources and surfactants) may also interact negatively, resulting in the instability and loss of activity of the active whitening agent. Therefore, it has become necessary to formulate whitening toothpaste with various ingredients aimed at improving the stability and activity of the whitening agent active substance.

[0005] Due to the high surface area, hygroscopicity, and acidity of many abrasives, abrasives can be particularly difficult to formulate into whitening toothpaste. However, abrasives can be a key component of a whitening composition because many stains adhere firmly but superficially to the tooth surface, and abrasives help remove such stains both through their inherent abrasive action and by providing better access of the whitening agent to the stains.

[0006] Currently available products for tooth whitening include a variety of different ingredients, and the most common main active ingredient is a peroxide source, such as hydrogen peroxide. The use of peroxide reagents generally presents many difficulties both in the formulation of the resulting composition and in its long - term stability. In addition, hydrogen peroxide can cause strong irritation to the teeth and gums at high concentrations or upon prolonged contact with the oral mucosa. Therefore, alternative oxidants with improved stability are needed, especially for whitening products that provide long - term contact with oral tissues.

[0007] Peroxymonosulfuric acid (H2SO5, also known as permonosulfuric acid) and its salts (peroxymonosulfates) are powerful oxidizing agents and detergents. They are currently used for various industrial and consumer purposes, including swimming pool treatment and denture cleaning. Compared to having an anion [HS2O8] –Regarding persulfates, peroxymonosulfates typically have the anion [HSO5] – . Peroxymonosulfate whitening products have been explored for some oral care applications, including whitening dental strips, mouthwashes, and toothpastes. A common peroxymonosulfate oxidant is potassium peroxymonosulfate (KHSO5), also known as potassium monopersulfate, and abbreviated as KMPS or MPS, and is sold as part of a composition and (each of which is a potassium peroxymonosulfate trihydrate having about 45 wt% to 50 wt% potassium peroxymonosulfate).

[0008] The use of potassium peroxymonosulfate in oral care applications is very limited due to its instability in aqueous solution (especially in aqueous solutions near or above neutral pH). Potassium peroxymonosulfate is known to degrade even in the presence of small amounts of water and heat. Thus, potassium peroxymonosulfate whitening compositions face special difficulties in formulation.

[0009] When combined with other common oral care excipients (especially polar compounds such as humectants, and anionic or neutral hydroxy polymers and surfactants), potassium peroxymonosulfate may also react and decompose. These excipients may render potassium peroxymonosulfate unstable, resulting in loss of whitening efficacy. Thus, it becomes necessary to formulate preparations with potassium peroxymonosulfate to avoid or reduce the amount of such ingredients, which still poses a challenge in formulating a composition with a desired taste (e.g., foaming), appearance, viscosity, and other important properties. In addition, potassium peroxymonosulfate may also negatively interact with any common flavoring agent that tends to have unstable or oxidizable functional groups. This may make it challenging to formulate flavoring agents into such compositions.

[0010] As described above, non-aqueous formulations have been investigated to address the aforementioned persulfate stability issues. However, such formulations may face their own formulation difficulties, such as maintaining an appropriate viscosity during aging, ensuring sufficient foaming in the absence of water, and interactions between the ingredients introduced in place of water. For example, formulation scientists have employed combinations of polyol humectants, polar and non-polar polymers in place of water in toothpaste or gels, and added different surfactants to ensure adequate stability, viscosity, and foaming. The inventors and others have found that polyol humectants commonly used as water replacements typically promote persulfate degradation. For example, propylene glycol, sorbitol, glycerin, and xylitol are very common oral care humectants, but their high polarity and hygroscopicity (due to their hydroxyl functional groups) promote MPS degradation both directly and indirectly (by retaining water). In addition, the inventors have unexpectedly found that some anhydrous toothpaste compositions in which potassium monopersulfate is stabilized by calcium pyrophosphate in a poloxamer / polyethylene glycol / PEG-PPG random copolymer carrier have an unusually low freezing point. Such compositions may solidify at temperatures of 20 °C or below (68 °F or below), or may have an unacceptably low viscosity and thus insufficient extrudability (squeeza-bility) if they do not solidify on their own.

[0011] There remains a need for teeth whitening dentifrice products based on persulfate whitening agents that have improved stability, taste, appearance, viscosity, flavor, and consumer acceptability without an adverse effect on the freezing point (e.g., improved squeezability or extrudability). SUMMARY OF THE INVENTION

[0012] The present disclosure provides a teeth whitening oral care composition comprising potassium monopersulfate by weight of the composition, stabilized with a combination of calcium pyrophosphate (Ca2P2O7) by weight of the composition, 5% to 25% propylene glycol by weight of the composition, and 5% to 50% poloxamer (polyoxyethylene / polyoxypropylene triblock copolymer) by weight of the composition. In other embodiments, the composition may further comprise one or more of the following: polyvinylpyrrolidone, polyethylene glycol / polypropylene glycol random copolymer, polyethylene glycol, alkali metal polyphosphates, anionic surfactants, zwitterionic surfactants, cationic surfactants, and amphoteric surfactants. In at least one aspect, the teeth whitening oral care composition of the present disclosure is low-water or anhydrous. Compared to prior art compositions, the compositions of the present disclosure provide a higher freezing point and thus improved extrudability (squeeza-bility).

[0013] Other applicable fields of the present disclosure 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

[0014] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0015] As used throughout, ranges are used as shorthand for describing each and every value within the range. Any value within the range can be selected as the range's endpoint. Additionally, all references cited herein are hereby incorporated by reference in their entirety. In the event of a conflict between the definitions in the present disclosure and those of the cited references, the present disclosure shall control.

[0016] Unless otherwise indicated, all percentages and amounts expressed herein and elsewhere in the specification are to be understood as being by weight percentage. The amounts given are based on the active weight of the materials.

[0017] Open-ended terms such as "comprising," "including," "containing," "having," etc. mean "including." In this specification, unless otherwise indicated, the use of the singular also includes the plural. For example, "a lubricant" also includes cases where more than one lubricant is used.

[0018] "About" means plus or minus 20% of the stated value. Thus, for example, "about 5%" means 80% to 120% of 5%, or 4.0% to 6.0%, including the end values of the range.

[0019] It has previously been found that the combination of calcium pyrophosphate (Ca2P2O7) and poloxamer (a polyoxyethylene / polyoxypropylene triblock copolymer) is very effective in stabilizing potassium monopersulfate against degradation, while also providing favorable rheological properties. Preferably, such a composition also contains an anionic surfactant and an amphoteric surfactant (such as sodium lauryl sulfate and cocamidopropyl betaine) to optimize the foaming properties of the composition. However, the inventors have unexpectedly found that such a composition (which is stable in aging studies and has good whitening and foaming properties) has too high a freezing point. At temperatures that a consumer may encounter or during product transportation, the composition may solidify or become too viscous. Thus, the composition has insufficient extrudability, which severely affects consumer acceptability. Without being bound by theory, it is believed that a higher content of poloxamer can lower the freezing point of the composition. Therefore, there is a need to find different components to replace all or part of the poloxamer to provide a composition with a freezing point below 15°C, preferably above 10°C.

[0020] It has previously been reported that propylene glycol and similar hydroxy humectants destabilize potassium peroxymonosulfate and cause rapid degradation and loss of reactive oxygen species. Thus, it was thought that propylene glycol could not be used in tooth whitening oral care compositions containing potassium peroxymonosulfate. However, the present disclosure unexpectedly shows that while compositions with about 30% or more propylene glycol are unstable, compositions with about 5% to 25% propylene glycol and 5% to 50% poloxamer have good stability and an acceptable freezing point, resulting in improved extrudability.

[0021] In a first aspect, the present disclosure provides a tooth whitening oral care composition (Composition 1) comprising potassium peroxymonosulfate, calcium pyrophosphate (Ca2P2O7), 5% to 25% propylene glycol by weight of the composition, and 5% to 50% polyoxyethylene / polyoxypropylene triblock copolymer (poloxamer). In some other embodiments, the present disclosure provides:

[0022] 1.1. Composition 1, wherein the potassium peroxymonosulfate is provided as a triple salt of potassium peroxymonosulfate, potassium bisulfate, and potassium sulfate, optionally wherein the triple salt comprises about 45 wt% to 50 wt% potassium peroxymonosulfate, such as 47 wt% or 49 wt% potassium peroxymonosulfate;

[0023] 1.2. Composition 1 or 1.1, wherein the composition comprises the potassium peroxymonosulfate in an amount of 0.01% to 10% by weight of the composition, such as 0.01% to 5% by weight of the composition, or 0.05% to 5% by weight of the composition, or 0.1% to 5% by weight of the composition, or 0.5% to 3% by weight of the composition, or 0.5% to 2.5% by weight of the composition, or 0.5% to 2% by weight of the composition, or 0.5% to 1.5% by weight of the composition, or 0.75% to 1.25% by weight of the composition, or 1% to 5% by weight of the composition, or 1% to 4% by weight of the composition, or 1% to 3% by weight of the composition, or 1% to 2% by weight of the composition, or 1.5% to 3% by weight of the composition, or 2% to 3% by weight of the composition, or 1.5% to 2% by weight of the composition, or 2% to 2.5% by weight of the composition, or about 0.5% by weight of the composition, or about 1% by weight of the composition, or about 1.5% by weight of the composition, or about 2% by weight of the composition, or about 2.5% by weight of the composition;

[0024] 1.3. Any of the foregoing compositions, wherein the inorganic peroxymonosulfate is not granulated (e.g., not pelletized);

[0025] 1.4. Any of the foregoing compositions, wherein the composition does not contain hydrogen peroxide;

[0026] 1.5. Any one of the foregoing compositions, wherein the composition does not contain any of the following: hydrogen peroxide, carbamide peroxide, peroxide salts (e.g., sodium peroxide, potassium peroxide, lithium peroxide, calcium peroxide), peroxyacids (e.g., peracetic acid, perbenzoic acid, or their salts or derivatives), organic peroxides (e.g., urea hydrogen peroxide, glycerol hydrogen peroxide, peroxy esters, diacyl peroxides, monoperoxyphthalate esters or their salts), perborates, persilicates, percarbonates, chlorine-containing oxidants (e.g., hypochlorites, chlorites, chlorates, perchlorates, chlorine dioxide), or peroxydisulfuric acid or peroxydisulfates;

[0027] 1.6. Any one of the foregoing compositions, wherein the potassium monopersulfate is the only oxidant present in the composition;

[0028] 1.7. Composition 1 or any one of 1.1 to 1.6, wherein the composition contains 5% to 60% by weight of the composition of calcium pyrophosphate (Ca2P2O7);

[0029] 1.8. Composition 1 or any one of 1.1 to 1.6, wherein the composition is stabilized by 10% to 40% by weight of the composition of calcium pyrophosphate (Ca2P2O7);

[0030] 1.9. Composition 1 or any one of 1.1 to 1.6, wherein the composition is stabilized by 20% to 30% by weight of the composition of calcium pyrophosphate (Ca2P2O7);

[0031] 1.10. Composition 1 or any one of 1.1 to 1.9, wherein the composition contains the calcium pyrophosphate in an amount of 1% to 60% by weight of the composition, such as 5% to 60% by weight of the composition, or 5% to 50% by weight of the composition, or 10% to 60% by weight of the composition, or 10% to 50% by weight of the composition, or 10% to 40% by weight of the composition, or 15% to -------------- 60% by weight of the composition, or 15% to 40% by weight of the composition, or 20% to 60% by weight of the composition, or 20% to 40% by weight of the composition, or 21% to 40% by weight of the composition, 22% to 40% by weight of the composition, or 22% to 35% by weight of the composition, or 25% to 40% by weight of the composition, or 25% to 35% by weight of the composition, or 25% to 30% by weight of the composition, or 21% to 30% by weight of the composition, or 22% to 30% by weight of the composition, or 22.5% to 27.5% by weight of the composition, or 23% to 27% by weight of the composition, or 24% to 26% by weight of the composition, or about 25% by weight of the composition;

[0032] 1.11. Composition 1 or any one of 1.1 to 1.10, wherein the polyoxyethylene / polyoxypropylene triblock copolymer is a triblock copolymer having the following formula:

[0033] HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O]a -H,

[0034] wherein a is an integer from 1 to 30 and b is an integer from 10 to 60;

[0035] 1.12. Composition 1.11, wherein in said formula, a is an integer from 5 to 20, and b is an integer from 10 to 40;

[0036] 1.13. Composition 1.11, wherein in said formula, a is an integer from 10 to 15, and b is an integer from 10 to 20;

[0037] 1.14. Composition 1.11, wherein in said formula, a is an integer from 10 to 12 (e.g., 11), and b is an integer from 15 to 20 (e.g., 16);

[0038] 1.15. Composition 1 or any one of 1.1 to 1.14, wherein the average molecular weight of the polyoxyethylene / polyoxypropylene triblock copolymer is from 1000 to 7000 daltons, such as from 1000 to 6000 daltons, or from 1000 to 5000 daltons, or from 1000 to 4000 daltons, or from 1000 to 3000 daltons, or from 1000 to 2000 daltons, or from 1500 to 3000 daltons, or from 1500 to 2000 daltons, or from 1800 to 2000 daltons, or about 1900 daltons, optionally wherein the average molecular weight is the number-average molecular weight or the weight-average molecular weight;

[0039] 1.16. Composition 1.11, wherein the polyoxyethylene / polyoxypropylene triblock copolymer is Pluronic L35;

[0040] 1.17. Composition 1 or any one of 1.1 to 1.16, wherein the composition contains the polyoxyethylene / polyoxypropylene triblock copolymer in an amount of 10% to 50%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30% to 25%, 10% to 20%, 10% to 15%, 15% to 50%, 15% to 45%, 15% to 40%, 15% to 35%, 15% to 30%, 15% to 25%, 15% to 20%, 20% to 50%, 20% to 45%, 20% to 40%, 20% to 35%, 20% to 30%, 20% to 25%, or about 23%, or about 24% by weight of the composition;

[0041] 1.18. Any of the foregoing compositions, wherein the composition further comprises one or more of the following: polyvinylpyrrolidone, polyethylene glycol / polypropylene glycol random copolymer, polyethylene glycol, polyphosphates (e.g., alkali metal polyphosphates), and surfactants (e.g., anionic surfactants and / or zwitterionic surfactants);

[0042] 1.19. Composition 1.18, wherein the composition further comprises polyvinylpyrrolidone;

[0043] 1.20. Composition 1.19, wherein the polyvinylpyrrolidone is cross-linked polyvinylpyrrolidone;

[0044] 1.21. Composition 1.19 or 1.20, wherein the polyvinylpyrrolidone is not complexed or bound with hydrogen peroxide;

[0045] 1.22. Any one of Compositions 1.19 to 1.21, wherein the composition comprises the polyvinylpyrrolidone in an amount of 1% to 50%, or 1% to 40%, or 1% to 30%, or 1% to 25%, or 1% to 22%, or 1% to 20%, or 1% to 18%, or 1% to 15%, or 1% to 12%, or 1% to 10%, or 1% to 8%, or 1% to 6%, or 3% to 15%, or 3% to 12%, or 3% to 10%, or 3% to 8%, or 3% to 6%, or 4% to 8%, or 4% to 6%, or about 5% by weight of the composition;

[0046] 1.23. Any one of Compositions 1.18 to 1.22, wherein the composition further comprises a polyethylene glycol / polypropylene glycol random copolymer (PEG / PPG copolymer);

[0047] 1.24. Composition 1.23, wherein the average molar ratio of ethylene glycol units (EG) to propylene glycol units (PG) of the PEG / PPG random copolymer is about 75 to 150 EG to 45 to 95 PG, or about 95 to 135 EG to 50 to 80 PG, or about 105 to 125 EG to 55 to 75 PG, or about 110 to 120 EG to 60 to 70 PG, or about 116 EG to 66 PG (i.e., PEG / PPG 116 / 66);

[0048] 1.25. Composition 1.23, wherein the PEG / PPG random copolymer is Pluracare L1220;

[0049] 1.26. Any one of Compositions 1.23 to 1.25, wherein the composition comprises the PEG / PPG random copolymer in an amount of 1% to 50%, or 1% to 40%, or 1% to 30%, or 1% to 25%, or 1% to 20%, or 1% to 18%, or 1% to 15%, or 1% to 12%, or 1% to 10%, or 6% to 40%, or 6% to 30%, or 6% to 25%, or 6% to 20%, or 6% to 15%, or 6% to 10%, or 8% to 30%, or 8% to 25%, or 8% to 20%, or 8% to 15%, or 8% to 12%, or 10% to 30%, or 10% to 25%, or 10% to 20%, or 10% to 15%, or 10% to 12%, or about 10% by weight of the composition;

[0050] 1.27. Any one of Compositions 1.18 to 1.26, wherein the composition further comprises polyethylene glycol;

[0051] 1.28. Composition 1.27, wherein the polyethylene glycol is selected from PEG-200, PEG-300, PEG-400, PEG-500, PEG-600, PEG-800, PEG-1000, PEG-1600, and PEG-2000;

[0052] 1.29. Composition 1.27, wherein the polyethylene glycol is PEG 600;

[0053] 1.30. Composition 1.29, wherein the polyethylene glycol is PEG 400 (e.g., in an amount of 5% to 20% by weight of the composition, e.g., 6% to 18%, or 10% to 15%, or about 12.5%);

[0054] 1.31. Any one of Compositions 1.28 to 1.30, wherein the composition comprises the polyethylene glycol in an amount of 1% to 50%, or 1% to 40%, or 1% to 30%, or 1% to 25%, or 1% to 20%, or 1% to 18%, or 1% to 15%, or 5% to 40%, or 5% to 30%, or 5% to 25%, or 5% to 20%, or 5% to 15%, or 8% to 40%, or 8% to 30%, or 8% to 25%, or 8% to 20%, or 8% to 15%, or 10% to 30%, or 10% to 25%, or 10% to 20%, or 10% to 15%, or 12% to 25%, or 12% to 20%, or 12% to 15%, or about 12% (e.g., about 12.5%) by weight of the composition;

[0055] 1.32. Any of the foregoing compositions, wherein the composition further comprises one or more additional polymers, such as any one or more of the following: polypropylene glycol, polysaccharides (e.g., cellulose derivatives, such as carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, microcrystalline cellulose; or polysaccharide gums, such as xanthan gum, guar gum or carrageenan, pectin, karaya gum); chitosan; dextran; hyaluronic acid and sodium hyaluronate; synthetic anionic polymer polycarboxylate, such as a copolymer of maleic anhydride or maleic acid and another polymerizable ethylenically unsaturated monomer, preferably methyl vinyl ether (e.g., a copolymer with a ratio of maleic anhydride / maleic acid to methyl vinyl ether of 1:4 to 4:1); polyphosphonic acids and polyphosphonates (i.e., polyphosphates); crosslinked carboxyvinyl copolymers; polyacrylic acid or polyacrylate polymers (e.g., carbomer); polyacrylamide, such as (2-hydroxypropyl) methacrylamide; other polyoxyethylene-polyoxypropylene copolymer (PEG-PPG) triblock copolymers, such as poloxamer 105, 108, 122, 123, 124, 182, 183, 184, 185, 188, 212, 215, 217, 234, 235, 237, 238, 288, 333, 334, 335, 338, 402, 403 or 407); PEG-PPG tetrablock copolymers; other PEG / PPG random copolymers, such as PEG / PPG-38 / 8; polyamines; polyvinyl alcohol; poly oxazolines, such as poly(2-alkyl-2- oxazolines), such as poly oxazolines substituted with methyl, ethyl or isopropyl; and quaternary ammonium polymers;

[0056] 1.33. Composition 1 or any one of Compositions 1.1 to 1.32, wherein the composition does not contain any one or more of the following: polyacrylic acid or polyacrylate polymer (PAA), polyvinylpyrrolidone-vinyl acetate copolymer (PVP-VA), poly oxazoline polymer (PO) and mixtures thereof;

[0057] 1.34. Composition 1 or any one of Compositions 1.1 to 1.32, wherein the composition comprises 30 wt% to 70 wt% of a polymer (e.g., PEG / PPG random copolymer, PEG / PPG triblock copolymer, PVP and PEG), such as 30 wt% to 60 wt%, or 40 wt% to 60 wt%, or 50 wt% to 60 wt%, or 55 wt% to 60 wt%, or 55 wt% to 59 wt%, or 58 wt% to 59 wt%;

[0058] 1.35. Any of the foregoing compositions, wherein the composition further comprises a polyphosphate or an organic cyclic polyphosphate, such as an alkali metal pyrophosphate, an alkali metal tripolyphosphate, an alkali metal tetraphosphate, an alkali metal metaphosphate, an alkali metal insoluble metaphosphate, an alkali metal phytate, or a mixture thereof;

[0059] 1.36. The composition of 1.35, wherein the composition comprises sodium pyrophosphate or potassium pyrophosphate, sodium tripolyphosphate or potassium tripolyphosphate, sodium tetraphosphate or potassium tetraphosphate, sodium phytate or potassium phytate, or a mixture thereof;

[0060] 1.37. The composition of 1.35, wherein the composition comprises a tetra-alkali metal pyrophosphate, such as sodium pyrophosphate or potassium pyrophosphate;

[0061] 1.38. The composition of 1.35, wherein the composition comprises a di-alkali metal pyrophosphate, such as disodium pyrophosphate or dipotassium pyrophosphate;

[0062] 1.39. The composition of 1.35, wherein the composition comprises a tetra-alkali metal pyrophosphate and a di-alkali metal pyrophosphate, such as sodium pyrophosphate and disodium pyrophosphate;

[0063] 1.40. Any one of the compositions of 1.35 to 1.39, wherein the composition comprises 0.1 wt% to 5 wt% of a polyphosphate, such as 0.5 wt% to 5 wt%, or 1 wt% to 5 wt%, or 2 wt% to 5 wt%, or 3 wt% to 5 wt%, or 3.5 wt% to 5 wt%, or 4 wt% to 5 wt%, or 3.5 wt% to 4.5 wt%, or about 4 wt% of a polyphosphate, optionally 1% to 5% or 2% to 4% of a tetra-alkali metal pyrophosphate and 0.5% to 2% of a di-alkali metal pyrophosphate, such as about 3% of sodium pyrophosphate and about 1% of disodium pyrophosphate;

[0064] 1.41. Any of the foregoing compositions, wherein the composition further comprises one or more surfactants, such as anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and / or zwitterionic surfactants;

[0065] 1.42. The composition of 1.41, wherein the composition comprises a mixture of an anionic surfactant and a zwitterionic surfactant;

[0066] 1.43. Composition 1.41 or 1.42, wherein the anionic surfactant is selected from: sodium lauryl sulfate, sodium laureth sulfate, sodium myreth sulfate, sodium lauroyl sarcosinate, sodium cocomonoglyceride sulfonate, sodium lauryl benzene sulfonate, sodium lauryl sulfoacetate, sodium N-methyl-N-cocoyl taurate, sodium cocoyl isethionate, sodium dioctyl sulfosuccinate, and sodium cocomonoglyceride sulfate and their ammonium analogs;

[0067] 1.44. Composition 1.41 or 1.42, wherein the zwitterionic surfactant is selected from: cocamidopropyl betaine (CAPB), cocamidopropyl sulfobetaine, cocamidopropyl hydroxysulfobetaine, lauramidopropyl betaine, lauramidopropyl sulfobetaine, lauramidopropyl hydroxysulfobetaine, oleamidopropyl betaine, oleamidopropyl sulfobetaine, oleamidopropyl hydroxysulfobetaine, tallowamidopropyl betaine, tallowamidopropyl sulfobetaine, tallowamidopropyl hydroxysulfobetaine, lauryl betaine, lauryl sulfobetaine, lauryl hydroxysulfobetaine, lauryl dimethylamine oxide, and myristamine oxide;

[0068] 1.45. Composition 1.41, wherein the cationic surfactant is selected from: cetylpyridinium chloride (CPC), cetrimonium bromide, benzalkonium chloride, benzethonium chloride (1-hexadecylcarbamoylethyl)-trimethylammonium halide, (1-hexadecylcarbamoyl-2-phenylethyl)-trimethylammonium halide, 1-hexadecylcarbamoyl-1,1-dimethyl-pyrrolidine halide and [2-(1H-indol-3-yl)-1-hexadecylcarbamoylethyl)]-trimethylammonium halide, wherein the halide is optionally chloride, fluoride or bromide, or lauroyl arginine, ethyl lauroyl arginate hydrochloride, or disodium sebacoyl bislauramide lysinate;

[0069] 1.46. Composition 1.41, wherein the nonionic surfactant is selected from: coconut monoethanolamide, coconut diethanolamide, lauramidopropyl dimethylamine oxide, myristamidopropyl dimethylamine oxide, and decyl glucoside;

[0070] 1.47. Any one of Compositions 1.41 to 1.46, wherein the composition contains sodium lauryl sulfate;

[0071] 1.48. Any one of Compositions 1.41 to 1.46, wherein the composition contains cocamidopropyl betaine;

[0072] 1.49. Composition 1.40 or 1.41, wherein the composition contains a mixture of sodium lauryl sulfate and cocamidopropyl betaine;

[0073] 1.50. Any one of the compositions of 1.41 to 1.49, wherein the composition comprises 0.1% to 5% by weight of the composition of a surfactant, such as 0.5% to 5%, or 1% to 5%, or 1.5% to 5%, or 2% to 5%, or 3% to 5%, or 4% to 5%, or 1% to 4%, or 2% to 4%, or 3% to 4%, or 2% to 5%, or 3% to 5%, or 1% to 3%, or 2% to 3%, or 2% to 2.5%, or 2.5% to 3%, or 2.25% to 2.75%, or 2.25% to 2.5%, or about 2.3% of a surfactant;

[0074] 1.51. Any one of the compositions of 1.41 to 1.50, wherein the composition comprises 0.1% to 5% by weight of the composition, such as 0.1% to 4%, or 0.1% to 3%, or 0.1% to 2.5%, or 0.1% to 2%, or 0.1% to 1.5%, or 0.1% to 1%, or 0.1% to 0.5%, or 1% to 4%, or 2% to 4%, or 1% to 3%, or 2% to 3%, or 1.5% to 2.5%, or 2% to 2.5%, or about 0.3%, or about 2% of any one or more surfactants in a separate amount;

[0075] 1.52. Any one of the compositions of 1.41 to 1.51, wherein the composition comprises 0.1% to 5%, or 1% to 5%, or 2% to 4%, or 1% to 3%, or 2% to 3%, or 1.5% to 2.5%, or 2% to 2.5%, or about 2% of sodium lauryl sulfate, and 0.1% to 1%, or 0.1% to 0.5%, or about 0.3% of cocamidopropyl betaine;

[0076] 1.53. Any one of the compositions of 1.41 to 1.52, wherein the composition comprises an anionic surfactant (such as sodium lauryl sulfate) and an amphoteric surfactant (such as cocamidopropyl betaine) in a weight ratio of about 20:1 to 1:1, such as about 20:1 to 2:1, or about 15:1 to 3:1, or about 12:1 to 4:1, or about 10:1 to 5:1, or about 8:1 to 5:1, or about 7:1 to 5:1, or about 6:1;

[0077] 1.54. Any of the foregoing compositions, wherein the composition further comprises an antioxidant, such as an antioxidant selected from butylated hydroxyanisole, butylated hydroxytoluene, vitamin A, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid, and mixtures thereof;

[0078] 1.55. The composition of 1.54, wherein the antioxidant is butylated hydroxyanisole or butylated hydroxytoluene;

[0079] 1.56. Composition 1.54, wherein the antioxidant is butylated hydroxytoluene;

[0080] 1.57. Any one of Compositions 1.54 to 1.57, wherein the composition contains any one or more antioxidants in an amount of 0.001% to 1%, for example 0.01% to 0.5%, or 0.01% to 0.3%, or 0.01% to 0.1%, or 0.01% to 0.05%, or about 0.03% by weight of the composition;

[0081] 1.58. Any of the foregoing compositions, wherein the composition further comprises a thickening agent, such as magnesium aluminum silicate or pyrogenic silica, optionally in an amount of 0.1% to 10% by weight of the composition, for example 1% to 10%, or 2.5% to 10%, or 3% to 10%, or 2.5% to 7.5%, or 3% to 8%, or 3% to 6%, or 3% to 5%, or about 4% by weight of the composition;

[0082] 1.59. Any of the foregoing compositions, wherein the composition further comprises a fluoride source;

[0083] 1.60. Composition 1.59, wherein the fluoride source is selected from sodium fluoride, sodium monofluorophosphate, and stannous fluoride, or a mixture thereof;

[0084] 1.61. Composition 1.59 or 1.60, wherein the composition contains a fluoride source in an amount of 0.1% to 5% by weight of the composition, for example 0.5% to 5%, or 0.5% to 3%, or 0.5% to 2%, or 0.5% to 1%, or about 0.75% by weight of the composition;

[0085] 1.62. Any of the foregoing compositions, wherein the composition further comprises an additional abrasive (i.e., in addition to the calcium pyrophosphate and / or insoluble metaphosphate), optionally wherein the composition does not contain hydrated silica or precipitated silica abrasives (e.g., synthetic high detergency silica);

[0086] 1.63. Composition 1.62, wherein the additional abrasive is selected from silica (e.g., hydrated silica, precipitated silica), calcium carbonate, calcium orthophosphate, dicalcium orthophosphate, tricalcium phosphate, and arginine carbonate, for example, in an amount of 0.1% to 10%, or 0.1% to 5%, or 1% to 5%, or 2.5% to 5%;

[0087] 1.64. Any of the foregoing compositions, wherein the composition further comprises a desensitizing agent, for example, in an amount of 0.1% to 5% by weight, such as potassium nitrate;

[0088] 1.65. Any of the foregoing compositions, wherein the composition further comprises an enamel strengthener, for example, the enamel strengthener is included in an amount of 0.1% to 5% by weight, such as zinc phosphate;

[0089] 1.66. Any of the foregoing compositions, wherein the composition further comprises one or more flavoring agents and sweetening agents, for example, in an amount of 0.1% to 5%, or 0.5% to 5%, or 1% to 5%, or 2% to 5%, or 2% to 3%;

[0090] 1.67. Any of the foregoing compositions, wherein the composition is substantially anhydrous (for example, less than 4%, or less than 3%, or less than 2%, or less than 1% water by weight of the composition);

[0091] 1.68. Any of the foregoing compositions, wherein the composition does not contain any acetate, for example, wherein the composition does not contain any of the following: glyceryl triacetate, glyceryl acetate, propylene glycol diacetate, ethylene glycol diacetate, and diethylene glycol diacetate;

[0092] 1.69. Any of the foregoing compositions, wherein the composition comprises the propylene glycol in an amount of 5% to 25%, or 10% to 25%, or 15% to 25%, or 2% to 25%, or 5% to 20%, or 10% to 20%, or 15% to 20%, or 5% to 15%, or 10% to 15%, or 5% to 10%, or about 7.5% by weight of the composition;

[0093] 1.70. Any of the foregoing compositions, wherein the composition does not contain any humectant other than the propylene glycol, for example, wherein the composition does not contain any of glycerol, sorbitol, or xylitol;

[0094] 1.71. Composition 1 or any one of 1.1 to 1.70, wherein the composition comprises 1% to 3% by weight of sodium lauryl sulfate and 0.1% to 0.5% by weight of cocamidopropyl betaine;

[0095] 1.72. Composition 1 or any one of 1.1 to 1.70, wherein the composition comprises 1.5% to 2.5% by weight of sodium lauryl sulfate and 0.2% to 0.4% by weight of cocamidopropyl betaine;

[0096] 1.73. Composition 1 or any one of 1.1 to 1.70, wherein the composition comprises about 2% by weight of sodium lauryl sulfate and about 0.3% by weight of cocamidopropyl betaine;

[0097] 1.74. Composition 1 or any one of Compositions 1.1 to 1.73, wherein the composition contains sodium lauryl sulfate and cocoamidopropyl betaine in a weight ratio of about 8:1 to 5:1, such as about 6:1;

[0098] 1.75. Any of the preceding compositions, wherein the composition contains potassium monopersulfate in an amount of 1% to 5%, calcium pyrophosphate in an amount of 20% to 40%, propylene glycol in an amount of 5% to 20%, and a polyoxyethylene / polyoxypropylene triblock copolymer in an amount of 15% to 40%, each based on the weight of the composition, and the polyoxyethylene / polyoxypropylene triblock copolymer has the formula HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H, where a is an integer from 10 to 12 (e.g., 11), and b is an integer from 15 to 20 (e.g., 16), for example, the polymer is Pluronic L35;

[0099] 1.76. Any of the preceding compositions, wherein the composition contains potassium monopersulfate in an amount of 1% to 3%, calcium pyrophosphate in an amount of 20% to 30%, propylene glycol in an amount of 5% to 15%, and a polyoxyethylene / polyoxypropylene triblock copolymer in an amount of 15% to 25%, each based on the weight of the composition, and the polyoxyethylene / polyoxypropylene triblock copolymer has the formula HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H, where a is an integer from 10 to 12 (e.g., 11), and b is an integer from 15 to 20 (e.g., 16), for example, the polymer is Pluronic L35;

[0100] 1.77. Any of the preceding compositions, wherein the composition further contains polyvinylpyrrolidone in an amount of 1% to 10%, and a PEG / PPG random copolymer with an average molar ratio of ethylene glycol units (EG) to propylene glycol units (PG) of about 105 to 125 EG to 55 to 75 PG (e.g., Pluracare L1220 polymer) in an amount of 6% to 15%, and polyethylene glycol 600 in an amount of 5% to 20%, each based on the weight of the composition;

[0101] 1.78. Any of the preceding compositions, wherein the composition further contains sodium pyrophosphate tetrabasic in an amount of 2% to 5% and sodium pyrophosphate dibasic in an amount of 0.5% to 1.5% based on the weight of the composition;

[0102] 1.79. Any of the foregoing compositions, wherein the composition further comprises a blue dye or pigment, such as Pigment Blue 15 (also known as CI 74160), optionally in an amount of from 0.001% to 0.1% by weight of the composition, such as from 0.01% to 0.08% by weight of the composition, or from 0.03% to 0.07% by weight of the composition, or about 0.05%;

[0103] 1.80. Any of the foregoing compositions, wherein the composition further comprises from 1% to 15% by weight of the composition of propylene glycol, such as from 5% to 15% by weight of the composition, or from 5% to 10% by weight of the composition, or about 7.5% by weight of the composition of propylene glycol;

[0104] 1.81. Any of the foregoing compositions, wherein the composition further comprises from 2% to 10% by weight of the composition of one or more of the following: potassium nitrate, zinc nitrate, potassium sulfate, potassium chloride, calcium chloride, sodium chloride or aluminum nitrate, such as from 5% to 10% by weight of the composition, or from 10% to 15% by weight of the composition, or from 2% to 5% by weight of the composition, or from 3% to 8% by weight of the composition, or about 5% (e.g., potassium nitrate or zinc nitrate);

[0105] 1.82. Composition 1 or any one of 1.1 to 1.81, wherein the composition comprises or consists of the following:

[0106]

[0107] or

[0108]

[0109] 1.83. Any of the foregoing compositions, wherein the composition is an oral care product, such as toothpaste or dental gel;

[0110] 1.84. Any of the foregoing compositions, wherein the composition has the consistency of a paste or gel (e.g., not a free-flowing liquid nor a solid, such as a solid powder or granule);

[0111] 1.85. Any of the foregoing compositions, wherein the extrusion pressure of the composition is from 0.03 bar to 0.2 bar, such as from 0.03 bar to 0.15 bar, or from 0.03 bar to 0.10 bar, or from 0.03 bar to 0.07 bar, or from 0.04 bar to 0.06 bar, or about 0.05 bar;

[0112] 1.86. Any of the foregoing compositions, wherein the viscosity (measured at 1 rpm) of the composition is from 50,000 cP to 300,000 cP, such as from 100,000 cP to 300,000 cP, or from 150,000 cP to 250,000 cP, or from 175,000 cP to 225,000 cP, or about 200,000 cP;

[0113] 1.87. Any of the foregoing compositions, wherein after aging at 40 °C / 65% relative humidity for up to 3 months, the composition maintains an extrusion pressure of less than 0.1 bar and / or a viscosity (at 1 rpm) of less than 300,000 cP;

[0114] 1.88. Any of the foregoing compositions, wherein the composition loses no more than 10% of its initial active oxygen (AO) content after aging at 60 °C / 75% relative humidity for up to 1 week, or 2 weeks, or 3 weeks, or 1 month, or 2 months, or 3 months;

[0115] 1.89. Any of the foregoing compositions, wherein the composition loses no more than 5% of its initial active oxygen (AO) content after aging at 60 °C / 75% relative humidity for up to 1 week, or 2 weeks, or 3 weeks, or 1 month, or 2 months, or 3 months;

[0116] 1.90. Any of the foregoing compositions, wherein the composition loses no more than 15% of its initial active oxygen (AO) content after aging at 40 °C / 60% relative humidity for up to 1 month, or 2 months, or 3 months;

[0117] 1.91. Any of the foregoing compositions, wherein the composition loses no more than 10% of its initial active oxygen (AO) content after aging at 40 °C / 60% relative humidity for up to 1 month, or 2 months, or 3 months;

[0118] 1.92. Any of the foregoing compositions, wherein the composition loses no more than 5% of its initial active oxygen (AO) content after aging at 40 °C / 60% relative humidity for up to 1 month, or 2 months, or 3 months;

[0119] 1.93. Any of the foregoing compositions, wherein the composition has a foam volume of at least 100 mL, such as at least 120 mL, or at least 130 mL, or at least 140 mL after stirring at 4000 rpm for 120 seconds;

[0120] 1.94. Any of the foregoing compositions, wherein the composition forms a foam with a bubble size (R 32 ) not greater than 50 μm, such as less than 45 μm, after stirring at 4000 rpm for 120 seconds;

[0121] 1.95. Any of the foregoing compositions, wherein the freezing point of the composition is below 15 °C, such as below 10 °C, or below 5 °C, or below 0 °C, for example, from 0 °C to 15 °C, or from 0 °C to 10 °C, or from 0 °C to 5 °C;

[0122] 1.96. Any of the foregoing compositions, wherein the composition has an extrudability greater than 0.1 mL / second, for example, as measured using a Texture-Analyzer with tube extrusion (TA-TR), for example, as described in Example 8 herein, for example, 0.1 ml / second to 5 ml / second, 0.1 mL / second to 4 mL / second, or 0.1 mL / second to 3 mL / second, or 0.1 mL / second to 2 mL / second, or 0.5 mL / second to 5 mL / second, or 0.5 mL / second to 4 mL / second, or 0.5 mL / second to 3 mL / second, or 0.5 mL / second to 2 mL / second, or 1 mL / second to 5 mL / second, or 1 mL / second to 4 mL / second, or 1 mL / second to 3 mL / second, or 1 mL / second to 2 mL / second, or 1.5 mL / second to 2 mL / second, or 2 mL / second to 5 mL / second, or 3 mL / second to 5 mL / second, or 4 mL / second to 5 mL / second, or greater than 0.5 mL / second, or greater than 1 mL / second, or greater than 2 mL / second, or greater than 3 mL / second, or greater than 4 mL / second, or greater than 5 mL / second;

[0123] 1.97. Any of the foregoing compositions, wherein the composition has an extrusion pressure less than 0.1 bar, for example, as measured using the "extrusion pressure" method as described in Example 8 herein, for example, less than 0.07 bar, less than 0.06 bar, less than 0.05 bar, less than 0.04 bar, less than 0.03 bar, less than 0.02 bar, less than 0.01 bar, 0.001 bar to 0.1 bar, 0.001 bar to 0.07 bar, 0.001 bar to 0.06 bar, 0.001 bar to 0.05 bar, 0.001 bar to 0.04 bar, 0.001 bar to 0.03 bar, 0.001 bar to 0.02 bar, 0.001 bar to 0.01 bar, 0.005 bar to 0.07 bar, 0.005 bar to 0.06 bar, 0.005 bar to 0.05 bar, 0.005 bar to 0.04 bar, 0.005 bar to 0.03 bar, 0.005 bar to 0.02 bar, or 0.005 bar to 0.001 bar;

[0124] 1.98. Any of the foregoing compositions, wherein the composition has a static viscosity less than 300 Pa*s (e.g., at 1 second -1at the shear rate of), e.g., as measured using the low shear rate viscosity method as described in Example 8 herein, e.g., less than 250 Pa*s, less than 200 Pa*s, less than 150 Pa*s, less than 100 Pa*s, less than 50 Pa*s, from 1 Pa*s to 300 Pa*s, from 1 Pa*s to 250 Pa*s, from 1 Pa*s to 200 Pa*s, from 1 Pa*s to 150 Pa*s, from 1 Pa*s to 100 Pa*s, from 1 Pa*s to 50 Pa*s, from 10 Pa*s to 300 Pa*s, from 10 Pa*s to 250 Pa*s, from 10 Pa*s to 200 Pa*s, from 10 Pa*s to 150 Pa*s, from 10 Pa*s to 100 Pa*s, from 10 Pa*s to 50 Pa*s, from 20 Pa*s to 300 Pa*s, from 20 Pa*s to 250 Pa*s, from 20 Pa*s to 200 Pa*s, from 20 Pa*s to 150 Pa*s, from 20 Pa*s to 100 Pa*s, or from 20 Pa*s to 50 Pa*s of static viscosity;

[0125] 1.99. Any of the foregoing compositions, wherein the composition has a hardening point below 13 °C, e.g., as measured using the method as described in Example 8 herein, e.g., below 12 °C, below 10 °C, below 8 °C, below 6 °C, below 4 °C, below 2 °C, below 1 °C, below 0 °C, from -10 °C to 13 °C, from -10 °C to 12 °C, from -10 °C to 10 °C, from -10 °C to 8 °C, from -10 °C to 6 °C, from -10 °C to 4 °C, from -10 °C to 2 °C, from -10 °C to 1 °C, from -10 °C to 0 °C, from -5 °C to 13 °C, from -5 °C to 12 °C, from -5 °C to 10 °C, from -5 °C to 8 °C, from -5 °C to 6 °C, from -5 °C to 4 °C, from -5 °C to 2 °C, from -5 °C to 1 °C, from -5 °C to 0 °C, from 0 °C to 13 °C, from 0 °C to 12 °C, from 0 °C to 10 °C, from 0 °C to 8 °C, from 0 °C to 6 °C, from 0 °C to 4 °C, from 0 °C to 2 °C, from 0 °C to 1 °C, from 2 °C to 13 °C, from 2 °C to 12 °C, from 2 °C to 10 °C, from 2 °C to 8 °C, from 2 °C to 6 °C, from 4 °C to 13 °C, from 4 °C to 12 °C, from 4 °C to 10 °C, from 4 °C to 8 °C, from 6 °C to 13 °C, from 6 °C to 12 °C, from 6 °C to 10 °C, or from 6 °C to 8 °C of hardening point.

[0126] Potassium peroxymonosulfate (also known as MPS, KMPS, monopersulfate of potash or potassium monopersulfate) as or is commercially available, and both are triple salts of potassium peroxymonosulfate, potassium bisulfate and potassium sulfate (2KHSO5·KHSO4·K2SO4).

[0127] Potassium peroxymonosulfate has limited stability in aqueous solution and may be unstable due to other common toothpaste ingredients (even small amounts of water). Therefore, contact with water should be avoided or minimized during processing and storage. The composition is preferably packaged in a moisture-free environment.

[0128] The compositions of the present disclosure do not contain water or have a low water content. As used herein, the term "low water content" means the total concentration of water, including any free water and all water contained in any ingredient. In various embodiments of the composition, the amount of water is less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.1 wt%, or from about 0.0001 wt% to about 4 wt%, or from about 0.0001 wt% to about 0.5 wt%, or from about 0.0001 wt% to about 0.1 wt%. Preferably, the composition does not have added water.

[0129] Compared to a control composition without a persulfate, when used once or twice daily for about three months, the amount of potassium peroxymonosulfate in the compositions of the present invention is effective in producing improved tooth whitening. The amount of persulfate is generally from about 0.1% to about 10% by weight of the composition, preferably about 1% or 2%.

[0130] In some embodiments, the compositions of the present disclosure contain a buffering agent. Examples of buffering agents include anhydrous carbonates such as sodium carbonate, sesquicarbonates, bicarbonates such as sodium bicarbonate, silicates, bisulfates, phosphates such as potassium dihydrogen phosphate and dipotassium hydrogen phosphate, citrates, pyrophosphates (sodium and potassium salts), and combinations thereof. When the strip is hydrated, the amount of buffering agent is sufficient to provide a pH of about 5 to about 9, preferably about 6 to about 8, and more preferably about 7. The typical amount of buffering agent is from about 0.1% to about 5% by weight of the total composition, about 1% to about 3% in one embodiment, and about 0.5% to about 1% in another embodiment.

[0131] The compositions of the present disclosure contain a polyoxyethylene - polyoxypropylene triblock copolymer, also known as poloxamer. The term "poloxamer" or "poloxamer copolymer" refers to a nonionic triblock copolymer consisting of a central polyoxypropylene unit (also known as a poly(propylene oxide) unit) hydrophobic chain flanked by two polyoxyethylene units (e.g., poly(ethylene oxide) units) hydrophilic chains. Poloxamer has the following chemical structure:

[0132] HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H,

[0133] wherein a and b are integers, each typically from 10 to 200. Poloxamers are named according to conventional practice based on their molecular weight and ethoxy content, and include Poloxamer 407, Poloxamer 338, Poloxamer 237, Poloxamer 188, and Poloxamer 124. Pluronic is the name of a series of poloxamer polymers manufactured by BASF. For example, Pluronic F-127 is Poloxamer 407. Poloxamers differ from other polyethylene glycol / polypropylene glycol copolymers (PEG / PPG copolymers or EO / PO copolymers) having a structure different from the triblock structure (e.g., a random copolymer structure). Such copolymers different from poloxamers include PEG / PPG copolymers sold by BASF as and series polymers, which are random PEG / PPG copolymers.

[0134] For example, suitable poloxamers can include one or more of the following: L35, L43, L64, L10, L44, L62, 10R5, 17R4, L25R4, P84, P65, PI 04 and PI 05. Dispersants of the brand are commercially available from BASF, Florham Park, NJ.

[0135] In some embodiments, the compositions of the present disclosure can include polyvinylpyrrolidone (optionally crosslinked), also known as poly-N-vinyl-poly-2-pyrrolidone, and commonly abbreviated as "PVP" (optionally crosslinked PVP). PVP generally refers to polymers containing vinylpyrrolidone (also known as N-vinylpyrrolidone, N-vinyl-2-pyrrolidone, and N-vinyl-2-pyrrolidone) as monomer units. The monomer units can include polar imide groups, four nonpolar methylene groups, and a nonpolar methane group. Crosslinked PVP includes those commercially available as and and POLYPLASDONE INF-10 sold by Ashland, Covington, KY, USA.

[0136] The compositions of the present disclosure may optionally include a whitening (oxidizing) agent other than potassium monopersulfate, but preferably do not include additional whitening agents. Whitening agents are generally materials that effectively provide whitening to the tooth surface to which they are applied via oxidation, and include reagents such as hydrogen peroxide and carbamide peroxide. In various embodiments, the compositions of the present disclosure may optionally include a peroxide whitening agent (including peroxide compounds), but preferably do not include a peroxide whitening agent or do not include a peroxide compound. A peroxide compound is an oxidation compound containing a divalent oxygen-oxygen group. Peroxide compounds include peroxides and hydroperoxides, such as hydrogen peroxide, peroxides of alkali metals and alkaline earth metals, organic peroxides, peroxyacids, pharmaceutically acceptable salts thereof, and mixtures thereof. Peroxides of alkali metals and alkaline earth metals include lithium peroxide, potassium peroxide, sodium peroxide, magnesium peroxide, calcium peroxide, barium peroxide, and mixtures thereof. Organic peroxides include carbamide peroxide (also known as urea hydrogen peroxide), glycerol peroxide, alkyl hydroperoxides, dialkyl peroxides, alkyl peroxyacids, peroxy esters, diacyl peroxides, benzoyl peroxide, and monoperoxyphthalate esters, and mixtures thereof. Peroxyacids and their salts include organic peroxyacids such as alkyl peroxyacids and monoperoxyphthalate esters, and mixtures thereof, and inorganic peroxysalts such as persulfates, dithiosulfates, percarbonates, perphosphates, perborates, and persilicates of alkali metals and alkaline earth metals (such as lithium, potassium, sodium, magnesium, calcium, and barium), and mixtures thereof. In various embodiments, the peroxide compound includes hydrogen peroxide, carbamide peroxide, sodium percarbonate, and mixtures thereof. In some embodiments, the peroxide compound includes hydrogen peroxide. In some embodiments, the peroxide compound consists essentially of hydrogen peroxide. In some embodiments, the composition may include a non-peroxide whitening agent. Whitening agents among those useful herein include non-peroxide compounds, such as chlorine dioxide, chlorites, and hypochlorites. Chlorites and hypochlorites include those of alkali metals and alkaline earth metals (such as lithium, potassium, sodium, magnesium, calcium, and barium). One or more additional whitening agents are optionally present in a tooth-whitening effective total amount. In some embodiments, the composition additionally includes an activator, such as tetraacetylethylenediamine. In some embodiments, the compositions of the present invention do not contain all of the additional whitening agents listed above.

[0137] In some embodiments, the composition may include a non-oxidizing whitening agent. Non-oxidizing whitening agents include colorants (such as titanium dioxide and blue pigments or dyes) and hydroxyapatite. These agents make the appearance of the teeth whiter by masking or covering the stains, rather than chemically removing or destroying the stains.

[0138] The compositions of the present disclosure may optionally further comprise other ingredients such as flavoring agents; fillers; surfactants; preservatives such as sodium benzoate and potassium sorbate; colorants including, for example, dyes and pigments; and sweeteners. In some embodiments, the compositions of the present disclosure comprise one or more surfactants such as anionic surfactants, cationic surfactants, zwitterionic surfactants or nonionic surfactants.

[0139] As used herein, "anionic surfactant" means those surface-active compounds or detergent compounds that contain an organic hydrophobic group and at least one water-solubilizing group in their molecular structure to form a water-soluble detergent, the organic hydrophobic group usually containing 8 to 26 carbon atoms or usually containing 10 to 18 carbon atoms, and the at least one water-solubilizing group being selected from sulfonate, sulfate and carboxylate. Generally, the hydrophobic group will include a C8-C 22 alkyl or acyl group. Such surfactants are used in the form of water-soluble salts, and the salifying cations are usually selected from sodium, potassium, ammonium, magnesium and mono-C2-C3 alkanolammonium, di-C2-C3 alkanolammonium or tri-C2-C3 alkanolammonium, among which sodium cations, magnesium cations and ammonium cations are again the commonly selected cations. Some examples of suitable anionic surfactants include, but are not limited to, the sodium salts, potassium salts, ammonium salts and ethanolammonium salts of linear C8-C 18 alkyl ether sulfates, ether sulfates and their salts. Suitable anionic ether sulfates have the formula R(OC2H4) n OSO3M, where n is 1 to 12, or 1 to 5, and R is an alkyl group, alkylaryl group, acyl group or alkenyl group having 8 to 18 carbon atoms, such as C 12 -C 14 or C 12 -C 16 alkyl groups, and M is a solubilizing cation selected from sodium ions, potassium ions, ammonium ions, magnesium ions and monoethanolammonium ions, diethanolammonium ions and triethanolammonium ions. Exemplary alkyl ether sulfates (such as sodium lauryl ether (2EO) sulfate) contain 12 to 15 carbon atoms in their alkyl groups. 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%.

[0140] As used herein, "nonionic surfactant" generally refers to compounds produced by the condensation of an alkylene oxide group (essentially hydrophilic) with an organic hydrophobic compound that can be aliphatic or alkylaryl in nature. Examples of suitable nonionic surfactants include poloxamers (under the trade name for sale), polyethylene oxide, polyoxyethylene sorbitan esters (under the trade name for sale), polyoxyethylene 40 hydrogenated castor oil, fatty alcohol ethoxylates, poly(ethylene oxide) condensates of alkylphenols, condensation products derived from the reaction products of ethylene oxide with propylene oxide and ethylenediamine, ethylene oxide condensates of aliphatic alcohols, alkyl polyglycosides (e.g., fatty alcohol ethers of polyglycosides, e.g., fatty alcohol ethers of polyglucosides, e.g., decyl ethers, lauryl ethers, octyl ethers, octanoyl ethers, myristyl ethers, stearyl ethers, and other ethers of glucose and polyglucoside polymers, including, for example, octyl / octanoyl (C 8-10 ) glucoside, cocoalkyl (C 8-16 ) glucoside, and mixed ethers of lauryl (C 12-16 ) glucoside), long-chain tertiary amine oxides, long-chain tertiary phosphine oxides, long-chain dialkyl sulfoxides, and mixtures of such substances.

[0141] 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, coconut monoethanolamide, lauramide monoethanolamide, coconut 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 coconut monoethanolamide. In certain embodiments, the nonionic surfactant is present in an amount of 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%.

[0142] As used herein, the term "cationic surfactant" includes the cationic surfactants disclosed in WO 2007 / 011552A2, the content of which is incorporated herein by reference in its entirety.

[0143] Examples of surfactants that can be used are sodium lauryl sulfate, sorbitan fatty acid esters, polyoxyethylene (20) sorbitan monooleate (polysorbate 80 or Tween 80), polyethylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene block copolymers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitol fatty acid esters, and polyoxyethylene glycerol fatty acid esters. In the present invention, each of them can be used alone, or two or more of them can be used in combination. A typical amount of the surfactant is about 0.1% to about 3% by weight of the total composition, about 0.1% to about 2% in one embodiment, and about 0.1% to about 1% in another embodiment.

[0144] Examples of fillers are crystalline cellulose, ethyl cellulose, dextrin, various cyclodextrins (α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin), sodium sulfate, and its derivatives and pullulan.

[0145] Acceptable flavoring agents include natural and synthetic flavor sources, including, for example, volatile oils, synthetic flavor oils, flavoring aromatics, oils, liquids, oleoresins, and extracts from plants, leaves, flowers, fruits, stems, and combinations thereof. Suitable flavoring agents include, for example: lemon oils, such as lemon, orange, grape, lime, and grapefruit; fruit flavors, including, for example, apple, pear, peach, grape, strawberry, raspberry, cherry, plum, pineapple, apricot, and other fruit flavorings. Other acceptable flavoring agents include, for example, aldehydes and esters (e.g., benzaldehyde (cherry, almond)); citral, i.e., α-citral (lemon, lime); neral, i.e., β-citral (lemon, lime); decanal (orange, lemon); aldehyde C-8 (citrus fruits); aldehyde C-9 (citrus fruits); aldehyde C-12 (citrus fruits); tolualdehyde (cherry, almond); 2,6-dimethyloctanal (immature fruit); 2-dodecenal (2-dodedenal) (citrus, tangerine); and mixtures thereof.

[0146] Suitable colorants include, for example, food, drug, and cosmetic (FD&C) pigments, including, for example, dyes, lakes, and certain natural and derived colorants. Acceptable lakes include dyes absorbed on aluminum hydroxide and other suitable carriers.

[0147] Suitable sweeteners include stevia; sugars such as sucrose, glucose, invert sugar, fructose, ribose, tagalose, sucralose, maltitol, erythritol, xylitol, and mixtures thereof; saccharin and its various salts (e.g., sodium and calcium salts of saccharin); cyclohexanesulfamic acid and its various salts; dipeptide sweeteners (e.g., aspartame); acesulfame potassium; dihydrochalcones; glycyrrhizin; and sugar alcohols, including, for example, sorbitol, sorbitol syrup, mannitol, and xylitol, and combinations thereof.

[0148] It should be understood that although the general properties of each of the materials in the above categories may be different, there may be some common properties within two or more of such categories of materials, and any given material may be used for multiple purposes. All ingredients in a composition may have functions in addition to their primary function and may contribute to the overall properties of the composition, including its stability, efficacy, consistency, texture, taste, odor, etc. For example, a binder may also act as a disintegrant, and vice versa.

[0149] In a second aspect, the present disclosure provides a method for whitening teeth, comprising the steps of: (a) applying any one of Composition 1, or 1.1, and the like to teeth, and (b) keeping the composition in contact with the teeth for a sufficient period of time (e.g., 0.1 minute to 60 minutes, or 0.1 minute to 30 minutes, or 0.1 minute to 10 minutes, or 0.1 minute to 5 minutes, or 0.1 minute to 2 minutes, or 0.1 minute to 1 minute) to effect whitening of the teeth contacted by the composition. In some embodiments, a toothbrush may be used to apply the composition, and the composition is kept in contact with the teeth by utilizing a brushing motion. In some embodiments, a dental tray may be used to apply the composition to the teeth, and the composition is kept in contact with the teeth by placing the dental tray in the mouth until whitening is complete.

[0150] In other embodiments, the present disclosure provides the use of any one of Composition 1, or 1.1, and the like, or any other embodiment thereof for whitening teeth.

[0151] Examples

[0152] Exemplary embodiments of the present disclosure will be described with reference to the following examples, including that these examples are for illustration and not for limiting the scope of the invention.

[0153] In the Examples and elsewhere in the specification of the present invention, chemical symbols and terms have their usual and customary meanings. Unless otherwise indicated, temperatures are in degrees Celsius. Amounts of components are weight percentages based on the described standard; if no other standard is described, it is inferred as the total weight of the composition. Various names of chemical components include those listed in the CTFA International Cosmetic Ingredient Dictionary (Cosmetics, Toiletry and Fragrance Association, Inc., 7th Edition, 1997).

[0154] Example 1: Exemplary Whitening Dentifrice Based on MPS

[0155] Potassium peroxymonosulfate is combined and mixed with calcium pyrophosphate and other excipients to provide a homogeneous product.

[0156] The composition may have the following formulation:

[0157]

[0158] Testing of formulations within the scope of the present disclosure has shown that, compared to comparative formulations outside the scope of the present disclosure, they provide improved stability and retained active oxygen activity.

[0159] Example 2: MPS Stability

[0160] To evaluate the effect of replacing calcium pyrophosphate abrasive with a high detergency silica abrasive, four compositions were prepared according to the following table:

[0161]

[0162] Compositions A, B, C, and D were compared in an accelerated aging study. Samples were placed in tubes and stored at 60 °C / 75% RH (relative humidity) for 2 weeks. The levels of active oxygen (AO) at the initial time and at weeks 1 and 2 were determined by iodometric titration. The results are shown in the following table (expressed as a percentage of the initial theoretical AO):

[0163] Formulation Initial AO AO at 1 Week AO at 2 Weeks Composition A 100％ 94％ 94％ Composition B 100％ 95％ 92.3％ Composition C 95％ 53％ 41％ Composition D 110％ 44％ 26％

[0164] The results showed that compositions A and B stabilized by calcium pyrophosphate abrasive and PEG / PPG triblock copolymer retained almost all of the active oxygen during the 2-week study. In contrast, with highly cleaning silica abrasives (compositions F, G), there was a rapid loss of active oxygen due to the decomposition of potassium monopersulfate. Without being bound by theory, it is believed that trace heavy metals in precipitated silica (such as highly cleaning silica) promoted the catalytic decomposition of MPS (different from pyrogenic silica lacking such impurities). It was also noted that highly cleaning silica is a more effective abrasive than calcium pyrophosphate (for example, the RDA (relative dentin abrasivity) of highly cleaning silica is about 160, but the RDA of calcium pyrophosphate is about 90). Therefore, this loss of abrasivity is the result of improved MPS stability.

[0165] Example 3: Rheology

[0166] During the aging study, compositions A and B were compared using a Brookfield programmable viscometer. All tests were performed with toothpaste in a solid container (120 ml sample cup). The samples were stored at 40 °C / 65% RH (relative humidity) for 2 or 3 months. New locations were chosen at least 1 cm from the walls of the jar and from previously tested locations. The viscometer rotor was slowly lowered into the sample jar, disturbing the sample as little as possible. Then, the v74 rotor with blades on the shaft of the viscometer was slowly lowered into the sample. The thixotropy loop test was performed according to the programmed software. The extrusion pressure (bar) is a measure used to evaluate the ability of the toothpaste or gel to be extruded from the tube. The acceptable range of extrusion pressure is from 0.03 bar to 0.1 bar, with about 0.05 bar being ideal. If the extrusion pressure is too low, the toothpaste will ooze out of the tube or be expelled too violently from the tube under slight pressure. If the extrusion pressure is too high, the toothpaste will be difficult to extrude from the tube. The viscosity was measured at 1 rpm (in centipoise (cP)). The viscosity of the toothpaste is preferably maintained between 70,000 cP and 300,000 cP during aging, most preferably maintained at about 200,000 cP.

[0167] The results are shown in the table below (N.M. = not measurable because the toothpaste could not be extruded from the tube):

[0168] Extrusion Pressure Initial 1 Month 2 Months 3 Months Composition A 0.048 0.052 0.052 0.057 Composition B 0.080 N.M. (>0.2 bar) N.M. (>0.2 bar) N.M. (>0.2 bar)

[0169] Viscosity (1 rpm) Initial 1 Month 2 Months 3 Months Composition A 205,883 258,726 282,788 298,990 Composition B 368,676 N.M. N.M. N.M.

[0170] The results showed that the compositions of the present invention maintained stable rheological properties compared to similar compositions outside the scope of the present disclosure.

[0171] Example 4: Whitening efficacy

[0172] The whitening efficacy of Composition A was tested relative to Composition E. Composition E is a commercial whitening toothpaste composition with high detergency silica. Composition E contains (in decreasing order of concentration): glycerol, hydrated silica, sodium hexametaphosphate, water, PEG-6, flavor, silica, sodium lauryl sulfate, cocamidopropyl betaine, trisodium phosphate, mica, chondrus crispus powder, PEG-20M, sodium fluoride, xanthan gum, and sodium chloride, as well as small amounts of flavoring agents, pigments, and preservatives.

[0173] The head of a soft-bristled toothbrush was cut off from the handle and mounted on a brushing machine for use. Bovine teeth were mounted and stained with coffee and tea. Each toothpaste slurry was poured onto each tray, and brushing of the teeth was immediately started. The teeth were brushed for 2 minutes under an applied pressure of 250 grams. The brushing machine was set at 120 strokes per minute. After 2 minutes, brushing was stopped, the slurry was removed, and the teeth were rinsed with deionized water and then dried. The brushing treatment was repeated a total of 14 times to simulate twice-daily use of each product for 7 days.

[0174] Software from Medical High Technology (MHT) was used to measure the L*, a*, and b* values of each tooth before and after treatment. The L*, a*, and b* values were used to calculate the change in whiteness index of each tooth compared to the baseline after 14 treatments. The whiteness index is reported as ΔW*, where:

[0175] W* = (a* 2 + b* 2 +(L* - 100) 2 ) 1 / 2

[0176] ΔW* = W* 经处理的 – W* 基线

[0177] The absolute value of ΔW* was reported. It should be noted that the larger the positive value of ΔW*, the closer the tooth color is to white.

[0178] Analysis of variance tests were used to compare the mean ΔW* values of each product after 14 treatments. Subsequent Tukey multiple comparison tests were performed to evaluate pairwise comparisons of the products. A p-value less than 0.05 indicates a statistically significant difference between the products.

[0179] The results are shown in the table below:

[0180]

[0181] At the 14th treatment, the whitening result of composition A was statistically significantly improved compared to that of composition E (p-value 0.0023). The results indicate that the whitening compositions according to the present disclosure are very effective and more significant than current commercial whitening compositions.

[0182] Example 5: Enhancing Whitening Efficacy with Blue Pigment

[0183] Tooth whitening is typically performed using abrasives (such as high-cleaning silica) to remove stain molecules from the tooth surface, or oxidizing agents to bleach the color of stain molecules on the teeth, or both. The inventors further found that using blue pigments can mask the presence of stains by making the teeth appear whiter. This is important because both abrasives and oxidizing agents take some time (usually 1 to 2 weeks) to start showing significant whitening effects, while the masking effect of blue pigments is much more immediate.

[0184] These compositions were compared in a whitening study. Composition A from Example 1, composition A with 0.05% Blue 15 pigment (CI 74160) added, and a commercial whitening composition (composition F) containing 0.1% hydrogen peroxide and 0.05% Blue 15 pigment.

[0185] Intact human molars were obtained from Thermametric Technologies, Inc. The crowns and roots were separated, and the separated crowns were longitudinally bisected using a Buehler IsoMet low-speed saw. The bisected crown portions were mounted in a methacrylate resin such that only the enamel was exposed. Twenty-seven teeth were selected and three teeth were mounted in each tray using a thermosetting impression compound. All nine trays were used to evaluate each product in a random order.

[0186] All measurements were performed using a Spectroshade Micro instrument manufactured by Medical High Technology (MHT). The instrument was calibrated according to the manufacturer's instructions before measuring the baseline optical properties of the teeth. To perform the measurement, the instrument was positioned such that one tooth was in the field of view of the instrument, and then an image was captured. This process was repeated for each measurement in the study.

[0187] A paste of toothpaste and artificial saliva in a 1:2 (weight / weight) ratio (e.g., approximately 250 g of toothpaste and 500 g of artificial saliva) was prepared for each sample. The paste was mixed by hand to completely homogenize the solution before adding it to the trays.

[0188] The head of a soft-bristled toothbrush is cut off from the handle and used on a brushing machine. 9 mL of a standard toothpaste slurry is poured onto each tray and brushing is immediately started. The teeth are brushed for 10 minutes under an applied pressure of 250 grams. The brushing machine is set at 120 strokes per minute. After 10 minutes, brushing is stopped, the slurry is removed, and the teeth are rinsed with deionized water and then dried. Then baseline spectrophotometer measurements are taken. Then the teeth are immersed in artificial saliva (9 mL / tray) and aged for 15 minutes with stirring at 37 °C. Then, the test toothpaste slurry is added to the tray and the teeth are brushed for 2 minutes under an applied pressure of 250 grams. The brushing machine is set at 120 strokes per minute. After 2 minutes, brushing is stopped, the slurry is removed, and the teeth are rinsed with deionized water and then dried. Then post-treatment spectrophotometer measurements are taken. Data analysis is as described in Example 4.

[0189] The results are shown in the table below.

[0190] Average ΔW Composition A (1% MPS) 7.20 Composition A (1% MPS) + Blue 15 15.83 Composition F (0.1% HP) + Blue 15 12.01

[0191] The results show that the addition of Blue 15 pigment enhances the immediate whitening effect (1 brushing cycle) of the MPS toothpaste according to the present disclosure. Additionally, the whitening effect of MPS in combination with Blue 15 is greater than that of the same amount of Blue 15 added to a comparable hydrogen peroxide-based toothpaste composition (0.1% HP has an active oxygen content equivalent to 1% MPS).

[0192] Example 6: Synergistic effect of SLS and CAPB on foaming properties

[0193] Foaming properties are measured using a Dynamic Foam Analyzer (DFA) from Kruss. The DFA is equipped with a cylinder with a prism attached on one side, which allows measurement of the bubble size and bubble count on the surface of the cylinder. Immediately before testing, 50 mL of each toothpaste slurry is made by mixing the toothpaste sample and water in a 1:3 weight ratio. The slurry is delivered to the DFA cylinder. To measure the foaming rate, a flash foam test is conducted. In this test, since the foam height cannot be measured during stirring, stirring is occasionally stopped midway during foam growth to measure the foam height. Specifically, the slurry is stirred at 4000 rpm for 10 seconds and stirring is stopped for 15 seconds, during which the foam height is measured. This stirring-stop procedure is repeated 12 times. After this flash foam test, the slurry is kept unstirred for an additional 20 seconds and the final foam height, bubble size, and bubble count are measured. The bubble count is determined as both area count (bubbles per square millimeter on a flat surface) and volume count (bubbles per cubic millimeter). For each tested composition, the test is repeated three times. Analysis is performed using Kruss's Advance software.

[0194] Composition A is the MPS whitening toothpaste described above, and for comparison, compositions G and H were prepared, which correspond to composition A except that they do not contain CAPB (composition G) or SLS (composition H). Composition J is a commercial fluoride tooth cream for comparison. The formulations of the compositions are shown in the table below (all values are weight percentages of the composition):

[0195]

[0196] The test results are shown in the table below:

[0197]

[0198]

[0199] These results show that the use of a combination of anionic surfactants (SLS) and zwitterionic surfactants (CAPB) in an MPS-based anhydrous toothpaste provides significantly improved foaming properties compared to using either anionic surfactants (SLS) or zwitterionic surfactants (CAPB) alone. For this synergistic combination, total foam volume increased at all time points, and the increase in foam volume was faster and more significant. For example, between 10 and 110 seconds, the foam volume of composition G increased by only 25%, and the foam volume of composition H increased by only 14%, but the foam volume of composition A increased by 45%. Moreover, most of this increase was achieved quickly, with the foam volume of composition A increasing by 35% from 10 to 40 seconds. In contrast, during this time period, the foam volumes of compositions G and H increased by only 11% and 6%, respectively. The results for composition A were also greatly improved compared to commercial toothpaste composition J.

[0200] Furthermore, the individual bubble size of the SLS / CAPB surfactant combination was found to be significantly smaller, resulting in a greater number of bubbles formed per unit area and per unit volume. These results lead to an improved mouthfeel when brushing teeth with the composition.

[0201] Example 7: Stability in the presence of propylene glycol

[0202] It was desirable to evaluate whether a small amount of propylene glycol could replace a portion of the poloxamer in the above formulation while maintaining stability and improving the freezing point of the composition. Without being bound by theory, it is believed that the high freezing point of the poloxamer polymer significantly contributes to the high freezing point of the final toothpaste composition. Therefore, replacing a portion of the poloxamer with propylene glycol should lower the freezing point of the composition. However, propylene glycol has previously been reported to promote the degradation of MPS potassium. Therefore, it was first necessary to evaluate whether a small amount of propylene glycol could be incorporated into the composition without adversely affecting the stability of the composition.

[0203] To study this, an accelerated aging study was conducted to evaluate the active oxygen (AO) content of various compositions as described in Example 2. Three compositions were compared: Composition A (as above, having approximately 31% poloxamer L35 but no propylene glycol), Composition K (having approximately 32% propylene glycol but no poloxamer), and Composition L (having approximately 7.5% propylene glycol and 24% poloxamer L35). Compositions K and L were otherwise identical to Composition A as shown in the previous composition table. The study was conducted at 60 °C and 75% relative humidity (RH) for 2 weeks, at 40 °C and 60% RH for 3 months, and at 30 °C and 75% RH for 3 months. The results are shown in the table below:

[0204]

[0205] The results showed that replacing poloxamer with 32% propylene glycol led to MPS instability and loss of active oxygen. However, compared to using approximately 31% poloxamer (Composition A), using a combination of 7.5% propylene glycol and 24% poloxamer (Composition L) provided almost the same AO stability results. Thus, unexpectedly, it was shown that MPS stability could be maintained at a sufficiently low concentration of propylene glycol.

[0206] In addition, it was found that using a smaller amount of poloxamer caused an improvement in the taste of the composition as evaluated by a consumer or professional tasting panel. Moreover, propylene glycol is significantly cheaper than poloxamer L35, making this substitution highly cost - beneficial for product manufacturing.

[0207] Example 8: Effect of salts on extrudability

[0208] Extrudability Measurements Using a Texture Analyzer

[0209] A texture analyzer (TA) measures the response of a material when subjected to a force (e.g., compression or tension). Due to its adaptability, texture analysis has become commonplace in many industries for measuring a specific range of characteristics or properties related to material behavior, fracture, flow, adhesion, or bending. There are many fixtures that allow the texture analyzer to be used for various tests simulating specific processes. One of them is the tube extrusion fixture (TA - TR), which can be used to test the extrusion of a material from a package (e.g., a toothpaste tube). See, for example, Ahuja et al., "Rheological measurements for prediction of pumping and squeezing pressures of toothpaste", Journal of Non - Newtonian Fluid Mechanics, 258:1 - 9 (2018).

[0210] In a typical experiment, the TA probe travels downward at a speed of 20 mm / second and applies a constant force of 1.5 kg to the toothpaste tube for 5 seconds. During the experiment, the amount of paste discharged is collected and weighed. All of the tested pastes have similar densities (about 1.3 g / mL), and the mass is converted to volume and reported as the flow rate in mL / second (“extrudability”). A force of 1.5 kg was chosen because, based on recent studies of toothpaste tubes, it closely represents the typical force exerted by a human hand on a toothpaste tube. See, for example, J. Cepriá-Bernal et al., “Grip force and force sharing in two different manipulation tasks with bottles”, Ergonomics, 60:957-966 (2017); J. Cepriá-Bernal and A. Pérez González, “Dataset of Tactile Signatures of the Human Right Hand in Twenty-One Activities of Daily Living Using a High Spatial Resolution Pressure Sensor”, Sensors (Basel), 21:2594 (2021).

[0211] The extrudability results determined using this TA-TR method were found to be closely related to the data from a panel of human testers. The preferred compositions were found to have an extrudability greater than 0.1 mL / second, typically in the range of 0.1 mL / second to 2 mL / second, but compositions with higher extrudability are achievable.

[0212] Extrudability Based on Rheological Characterization

[0213] Rheological measurements were performed using a DHR rheometer. A standard 15 mm diameter 4 vane impeller was used in a standard rheometer cup, where the shear rate was scanned from 0.1 / second to 30 / second and returned at 10 points per decade in logarithmic mode, with 10 seconds per point. This roughly corresponds to an RPM range of 0.5 to 200.

[0214] Two parameters were extracted from these rheological measurements: “extrusion pressure” as calculated by FitFlow; and a specific shear rate of 1 second -1"Rest" viscosity under. The extrusion pressure is calculated by integrating the flow curve and represents the pressure required to push the paste through a tapered tube (roughly simulating a toothpaste tube). This measurement and data analysis can be performed on a rheometer or using the FitFlow method on a Brookfield viscometer, but using a rheometer is preferred. For viscosity measurement, tests are conducted starting from rest at a low shear rate (e.g., 1 second -1 ).) because this best represents normal toothpaste tube extrusion conditions. This measurement is very different from the usual Brookfield "viscosity" measurement, which is typically performed at 1 RPM after high-shearing the sample at 200 RPM.

[0215] It was found that the extrudability (both "extrusion pressure" and "rest" viscosity metrics) is closely related to the TA-TR results. The preferred compositions were found to have an extrusion pressure of less than 0.1 bar, typically in the range of 0.001 bar to 0.07 bar (more preferably 0.001 bar to 0.04 bar), and a "rest" viscosity of less than 400 Pa*s (Pascal*seconds), typically in the range of 10 Pa*s to 200 Pa*s (more preferably 10 Pa*s to 150 Pa*s).

[0216] Extrudability inferred from the hardening point <(

[0217] Another way to estimate extrudability is by determining the "hardening point" of the composition, which is the temperature at which the viscosity derivative curve (i.e., the slope of the viscosity curve) of the composition reaches a minimum. By cooling the composition at a constant shear rate of 1 second -1 .), the viscosity curve (viscosity in Pa*s versus temperature, e.g., within 0 °C to 20 °C) can be quickly and easily determined using a rheometer. The first derivative can be obtained from this graph, which provides a graph of the viscosity slope (Pa*s / °C) versus temperature (°C), and the hardening point is the minimum of this graph. Generally, the lower the hardening point (the temperature at which the viscosity increases sharply), the higher the extrudability of the paste at low temperatures.

[0218] The above methods were applied to the following toothpaste compositions:

[0219]

[0220] The results showed that the formulations containing propylene glycol provided a significant improvement in extrudability, especially at low temperatures. For example, the hardening point measurements were as follows:

[0221]

[0222] For the MPS formulation containing PG, the viscosity slope plot versus temperature shows a decline starting at approximately 5 °C, but the minimum value is not reached at the lowest temperature measured (0 °C). The results obtained from the texture analyzer and rheological characterization are comparable.

[0223] Preferably, the hardening point value is less than 13 °C, especially less than 10 °C, to ensure sufficient extrudability at lower temperatures.

[0224] Additional data shows that adding PEG-400, or using PEG-400 in place of PEG-600 also confers significant improvements in the hardening point, freezing point, and extrudability.

[0225] Additional data shows that including salt additives (such as potassium nitrate, zinc nitrate, potassium sulfate, potassium chloride, calcium chloride, sodium chloride, aluminum nitrate) also provides a significant reduction in the hardening temperature, freezing point, and improved extrudability.

[0226] The present invention has been described above with reference to illustrative embodiments, but it should be understood that the present invention is not limited to the disclosed embodiments. Variations and modifications that occur to those skilled in the art upon reading this specification are also within the scope of the present invention, which is defined in the appended claims.

Claims

1. A tooth whitening oral care composition comprising potassium monopersulfate, calcium pyrophosphate (Ca2P2O7), propylene glycol in an amount of 5% to 25% by weight of the composition, and 5% to 50% of a polyoxyethylene / polyoxypropylene triblock copolymer.

2. The composition according to claim 1, wherein the potassium monopersulfate is the only oxidizing agent present in the composition.

3. The composition according to claim 1 or 2, wherein the composition comprises calcium pyrophosphate (Ca2P2O7) in an amount of 10% to 40% by weight of the composition.

4. The composition according to any one of claims 1 to 3, wherein the composition comprises the propylene glycol in an amount of 5% to 25%, or 10% to 25%, or 15% to 25%, or 20% to 25%, or 5% to 20%, or 10% to 20%, or 15% to 20%, or 5% to 15%, or 10% to 15%, or 5% to 10%, or about 7.5% by weight of the composition.

5. The composition according to any one of claims 1 to 4, wherein the polyoxyethylene / polyoxypropylene triblock copolymer is a triblock copolymer having the following formula: HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H, wherein a is an integer from 1 to 30 and b is an integer from 10 to 60.

6. The composition according to any one of claims 1 to 5, wherein the composition further comprises one or more of the following: polyvinylpyrrolidone, polyethylene glycol / polypropylene glycol random copolymer, polyethylene glycol, polyphosphates (e.g., alkali metal polyphosphates), and surfactants (e.g., anionic surfactants and / or zwitterionic surfactants).

7. The composition according to any one of claims 1 to 6, wherein the composition comprises a mixture of an anionic surfactant and a zwitterionic surfactant.

8. The composition according to claim 7, wherein the composition comprises a mixture of sodium lauryl sulfate and cocamidopropyl betaine.

9. The composition according to claim 8, wherein the composition comprises sodium lauryl sulfate in an amount of 2% to 4%, or 1% to 3%, or 2% to 3%, or 1.5% to 2.5%, or 2% to 2.5%, or about 2% by weight of the composition, and cocamidopropyl betaine in an amount of 0.1% to 1%, or 0.1% to 0.5%, or about 0.3% by weight of the composition.

10. The composition according to any one of claims 1 to 9, wherein the composition further comprises an antioxidant, such as an antioxidant selected from butylated hydroxyanisole, butylated hydroxytoluene, vitamin A, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid, and mixtures thereof.

11. The composition according to any one of claims 1 to 10, wherein the composition comprises an amount of 1% to 5% of the potassium peroxymonosulfate, 20% to 40% of calcium pyrophosphate, 5% to 20% of propylene glycol, and 15% to 40% of a polyoxyethylene / polyoxypropylene triblock copolymer, each by weight of the composition, and the polyoxyethylene / polyoxypropylene triblock copolymer has the formula HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H, where a is an integer from 10 to 12 (e.g., 11), and b is an integer from 15 to 20 (e.g., 16), and for example, the polymer is Pluronic L35.

12. The composition according to any one of claims 1 to 11, wherein the composition comprises the potassium monopersulfate in an amount of 1% to 3%, and the composition comprises 20% to 30% of calcium pyrophosphate, 5% to 25% of propylene glycol, and 15% to 25% of a polyoxyethylene / polyoxypropylene triblock copolymer, each based on the weight of the composition, and the polyoxyethylene / polyoxypropylene triblock copolymer has the formula HO-[CH2CH2O] a [-CH(CH3)CH2O-] b [CH2CH2O] a -H, where a is an integer from 10 to 12 (e.g., 11), and b is an integer from 15 to 20 (e.g., 16), for example, the polymer is Pluronic L35.

13. The composition according to any one of claims 1 to 12, wherein the composition further comprises polyvinylpyrrolidone in an amount of 1% to 10%, and a PEG / PPG random copolymer (e.g., Pluracare L1220 polymer) having an average molar ratio of ethylene glycol units (EG) to propylene glycol units (PG) of about 105 to 125 EG to 55 to 75 PG in an amount of 6% to 15%, and polyethylene glycol 600 in an amount of 5% to 20%, each based on the weight of the composition.

14. The composition according to any one of claims 1 to 13, wherein the composition further comprises tetrasodium pyrophosphate in an amount of 2% to 5% and disodium pyrophosphate in an amount of 0.5% to 1.5% based on the weight of the composition.

15. The composition according to any one of claims 1 to 14, wherein the composition further comprises a blue dye or pigment, such as Blue 15 pigment (also known as CI 74160), optionally in an amount of 0.001% to 0.1% based on the weight of the composition, such as 0.01% to 0.08% or 0.03% to 0.07% or about 0.05% based on the weight of the composition.

16. The composition according to any one of claims 1 to 15, wherein the composition further comprises PEG 400 (e.g., in an amount of 5% to 20% based on the weight of the composition, such as 6% to 18% or 10% to 15% or about 12.5%).

17. The composition according to any one of claims 1 to 16, wherein the composition further comprises one or more of the following in an amount of 2% to 10% based on the weight of the composition: potassium nitrate, zinc nitrate, potassium sulfate, potassium chloride, calcium chloride, sodium chloride or aluminum nitrate, such as 5% to 10% or 10% to 15% or 2% to 5% or 3% to 8% or about 5% (e.g., potassium nitrate or zinc nitrate).

18. The composition according to any one of claims 1 to 17, wherein the composition comprises: or 19. The composition according to any one of claims 1 to 18, wherein the composition is a dentifrice, such as toothpaste or tooth gel.

20. A method for whitening teeth, comprising the following steps: (a) applying the composition according to any one of claims 1 to 18 to the teeth, and (b) keeping the composition in contact with the teeth for a sufficient period of time (e.g., 0.1 minute to 60 minutes or 0.1 minute to 30 minutes or 0.1 minute to 10 minutes or 0.1 minute to 5 minutes or 0.1 minute to 2 minutes or 0.1 minute to 1 minute) to achieve whitening of the teeth contacted by the composition.

21. Use of the composition according to any one of claims 1 to 18 in a method for whitening teeth.

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