WO2023031026A1

WO2023031026A1 - Oral care composition

Info

Publication number: WO2023031026A1
Application number: PCT/EP2022/073743
Authority: WO
Inventors: Katherine Mary Thompson
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Priority date: 2021-09-01
Filing date: 2022-08-26
Publication date: 2023-03-09
Anticipated expiration: 2024-03-01

Abstract

An oral care composition comprising: • flavour • bleach; and • aminopolycarboxylate comprising one or more coordinate covalent bound iron-(Fe), Manganese-(Mn) and/or cobalt-(Co) cations.

Description

ORAL CARE COMPOSITION

Technical Field of the Invention

The present invention relates to an oral care composition in particular an oral care whitening composition.

Background of the Invention

White teeth are considered to be cosmetically desirable. Oral care compositions comprising peroxide sources are useful for cleaning and whitening teeth. The peroxide may be present as hydrogen peroxide, or as a source of bound hydrogen peroxide. Sources of bound hydrogen peroxide include, urea peroxide, calcium peroxide and sodium percarbonate. The peroxide can bleach teeth, remove stains, and kill cariogenic bacteria. However, peroxide compounds are highly reactive with common ingredients found in oral care. Moreover, hydrogen peroxide can spontaneously decompose to form oxygen gas and water, so that on storage, the composition containers may bloat, burst or leak. Consequently, the remaining formulation will have a reduced whitening and cleaning efficacy.

WO 96/05802 teaches an oral care composition for whitening teeth. The activity is achieved by inclusion in the oral care compositions of certain organic peroxy acids as teeth whitening/bleaching agents, particularly peroxyamidophthalamides and cationic peroxycarboxylic acids such as N-phthalimido per hexanoic acid and quaternary benzylperoxyacid. A more effective use of peracids in a whitening/bleaching agent for use on teeth would be an advantage.

It is an object of the present invention to provide an oral care composition which has effective whitening with improved biodegradability. It is a further object of the invention to provide such a composition while using commonly known ingredients in oral care compositions which are suitable for long-term storage without a significant loss of whitening and cleaning efficacy.

Summary of the Invention

The present invention relates to an oral care composition comprising:

• flavour bleach; and aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations.

In another aspect the invention relates to the use of aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations to provide an oral care composition with a bleach system for whitening and/or storage.

A further aspect of the invention relates to a method of whitening the teeth by application of a composition comprising bleach and aminopolycarboylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/on cobalt- (Co) cations.

Detailed Description of the Invention

Weight percentage (wt.%) is based on the total weight of the oral care composition unless otherwise indicated or as made clear from the context. It will be appreciated that the total weight amount of ingredients will not exceed 100 wt. %. Whenever an amount or concentration of a component is quantified herein, unless indicated otherwise, the quantified amount or quantified concentration relates to said component per se, even though it may be common practice to add such a component in the form of a solution or of a blend with one or more other ingredients. It is furthermore to be understood that the verb "to comprise" and its conjugations is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. Finally, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one". Unless otherwise specified all measurements are taken at standard conditions. Whenever a parameter, such as a concentration or a ratio, is said to be less than a certain upper limit it should be understood that in the absence of a specified lower limit the lower limit for said parameter is 0. Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use may optionally be understood as modified by the word “about”.

All amounts are by weight of the composition, unless otherwise specified.

It should be noted that in specifying any ranges of values, any upper value can be associated with any particular lower value.

Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

Any ingredients mentioned in this application that are natural or naturally derived have been sourced from Europe.

The composition of the invention is used to preferably used to clean and/or whiten the surfaces of the oral cavity particularly the teeth and is known as an oral care composition.

The present invention relates to an oral care composition comprising: An oral care composition comprising:

• flavour

• bleach; and

• free acid equivalent of aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations;

Concentrations expressed in wt. % of ‘free acid equivalent’ refer to the concentration of the compound expressed as wt. %, assuming it would be in fully protonated from. The following table shows how the free acid equivalent concentrations can be calculated for some (anhydrous) aminopolycarboxylates and (anhydrous) acid salts. 1.

Aminopolycarboxylate

Aminopolycarboxylates are well known in the detergent industry and sometimes referred to as aminopolycarboxylic acids chelants. Suitable aminopolycarboxylic acids include glutamic acid N,N-diacetic acid (GLDA), methylglycinediacetic acid (MGDA), ethylenediaminedisuccinic acid (EDDS), iminodisuccinic acid (IDS), iminodimalic acid (IDM), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), hydroxyethyliminodiacetic acid (HEIDA) aspartic acid diethoxysuccinic acid (AES) aspartic acid-N,N-diacetic acid (ASDA) , hydroxyethylene-diaminetetraacetic acid (HEDTA), hydroxyethylethylenediaminetriacetic acid (HEEDTA) , iminodifumaric (IDF), iminoditartaric acid (IDT), iminodimaleic acid (IDMAL), ethylenediaminedifumaric acid (EDDF), ethylenediaminedimalic acid (EDDM), ethylenediamineditartaric acid (EDDT), ethylenediaminedimaleic acid and (EDDMAL).

Preferred aminopolycarboxylates are GLDA, MGDA, EDDS, IDS, IDM or a mixture thereof, more preferred are GLDA, MGDA, EDDS or a mixture thereof and even more preferred are GLDA and MGDA or a mixture thereof. Of these GLDA is especially preferred as it can be made from bio-based materials (e.g. monosodium glutamate, which itself can be made as by-product from corn fermentation). Also, GLDA itself is highly biodegradable. MGDA is more preferred in view of it being somewhat less hygroscopic, which improves detergent stability during storage. Preferred salts are alkali-based salts and more preferred are sodium-based salts.

2.

Aminopolycarboxylate with coordinate covalent bound Fe, Mn and/or Co cations A coordinate covalent bond, also known as a dative bond, dipolar bond, or coordinate bond is a type of two-centre, two-electron covalent bond in which the two electrons derive from the same atom. The bonding of metal ions to ligands generally involves this type of bond. The preferred complexes have the following formulae: [M_mL_n]^pY^p.qH2O where, M is iron, manganese or cobalt, L is an aminocarboxylate ligand, m = 1-3, n = 1-3, p = 0-3, q = 0- 3. If p <1 >, Y is counterion.

General methods to prepare aminopolycarboxylate metal ion complexes are known in the art (e.g. V. Springer et. al. Preparation and study of the solid complexes of the racemic ethylenediamine-N,N'-disuccinic acid with iron(lll), cobalt(lll), and bismuth(lll) ions. Chem. Zvesti 34(2), pages 184-189, 1980; US5,559,261).

The preferred method of manufacture aminopolycarboxylate coordination complexes comprising one or more iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations comprises the following steps: a) providing an aqueous solution comprising aminopolycarboxylate and Fe, Mn and/or Co cations, wherein the molar ratio of the aminopolycarboxylate and the cations is from 100:1 to 1 :3; and b) optionally adjusting the pH of the aqueous solution to the range of from 6 to 11 ; and c) removing water from the aqueous solution to provide a composition comprising aminopolycarboxylate with coordinate covalent bound Fe, Mn and/or Co cations and the composition having water content of at most 60 wt.% and/or precipitating the complexes from aqueous solution by adding a non-aqueous solvent (preferably an organic solvent such as ethanol).

Preferably at step c) water is removed until a solid is provided or a precipitated solid formed on addition of an organic solvent is separated from the supernatant solution by filtration and then air dried. This is especially advantageous when the aminopolycarboxylates comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations is part of the ingredients to make a tablet or powder detergent.

Suitable examples of such water-soluble salts are the chloride salts of Fe, Mn and/or Co. The Fe²⁺, Fe³⁺, Mn²⁺, Mn³⁺, Mn⁴⁺, Mn⁵⁺, Mn⁶⁺, Mn⁷⁺ and Co²⁺, Co³⁺ are the preferred cations. Advantageously the cation is a Fe²⁺, Fe³⁺, Mn²⁺ and/or Mn⁴⁺ cation and particularly preferred are the Fe³⁺ and Mn²⁺ oxidation states. Preferred aminopolycarboxylate coordination complexes comprising a bound Fe, Mn and/or Co cation are MGDA, GLDA, EDDS and IDS, whereof MGDA and GLDA are the more preferred.

As indicated in the method, the molar ratio of aminopolycarboxylate and the cations can be from 100:1 to 1 :3. Lower ratios will lead to only a part of the aminopolycarboxyate comprising coordinate covalent bound Fe, Mn and/or Co ions. This can be beneficial since such an aminopolycarboxylate mixture can both contribute to effective bleaching as well as providing strong builder and chelating functionality in one go. Higher ratios are beneficial to provide a more targeted bleach catalyst activity and can allow for more than one Fe, Mn and/or Co cation to be coordinate covalent bound to the aminopolycarboxylate. In this respect it is noted that many aminopolycarboxylates are capable of coordinate covalent binding more than one Fe, Mn and/or Co cations.

Preferred coordination complexes include Mn" (GLDA)^2-, Mn"₂ (GLDA), Fe^IH (GLDA)", Fe^IH (GLDA) (OH)²; Fe^IH (GLDA) (OH)₂ ³ Co" (GLDA)²", Co"₂ (GLDA), Co¹" (GLDA)", Co¹" (GLDA) (OH)²; Co¹" (GLDA) (OH)₂ ³’ Mn" (MGDA)", Fe¹" (MGDA), Co" (MGDA)", Co¹" (MGDA), Mn" (EDDS)²; Fe¹" (EDDS)", Co" (EDDS)²; Co¹" (EDDS). The negatively charged complexes may be isolated as the acid, sodium, potassium or ammonium salts depending on the identity of the base used in the synthesis. The positively charged complexes may be preferably isolated as sulphate or halide salts, preferably chloride salts. All complexed may be isolated as their respective hydrates.

Besides the aminopolycarboylate coordinate covalent bound to one or more Fe, Mn and/or Co cations, further aminopolycarboxylate may be present which does not comprise such coordinate covalent bound Fe, Mn and/or Co cations. The detergent composition according to the invention preferably comprises from 0.5 to 40 wt. % free acid equivalent of total aminopolycarboxylate which does not comprise coordinate covalent bound Fe, Mn and/or Co cations. A particularly of aminopolycarboxylate which does not comprise coordinate covalent bound Fe, Mn and/or Co cations is from 0.5 to 20 wt. %, more preferably from 1 .0 to 15 wt. %, even more preferably from 2.0 to 10 wt. % and still even more preferably from 3.0 to 8 wt.%. An optimal balance of aminopolycarboxylate comprising one or more coordinate covalent bound Fe, Mn or Co cations versus aminopolycarboxylate not comprising such, is considered to be from 1:4000 to 100:1 , more preferably from 1 :100 to 20:1, even more preferably from 1 :50 to 1 :1 and still even more preferably from 1:20 to 1:10.

Preferably the oral care composition of the invention does not comprise further poorly biodegradable bleach catalyst and beneficially comprises essentially no further bleach catalyst (biodegradable or not). pH profile

The oral care composition of the invention provides a pH of a solution of 1 wt.% of the oral care composition in water as measured at 25 degrees Celsius of from 6.0 to 12.0, preferably from 6.5 to 11.5, more preferably 7.0 to 11.0, even more preferably from 8.5 to 10.5 and still even more preferably from 9.0 to 10.0.

Bleach

The oral care composition of the invention preferably comprises from 0.01 to 15 wt. % of the total composition of bleach. Inorganic and/or organic bleaches can be used. Bleach may be selected from peroxides, organic peracids, salts of organic peracids and combinations thereof.

Advantageously the bleach is selected from peroxides (including peroxide salts such as sodium percarbonate), organic peracids, salts of organic peracids and combinations thereof. More preferably, the bleach is a peroxide. Most preferably, the bleach is a percarbonate particularly preferred is sodium percarbonate.

Preferably the level of bleach, more preferably the level of peroxide precursor is from 0.01 to 10 wt. %, preferably from 0.05 to 5 wt. % most preferably from 0.1 to 3 wt% of the total composition.

Further ingredients

In one preferred embodiment the dentifrice/toothpaste is in the form of an extrudable semi-solid such as a cream, paste or gel (or mixture thereof). A composition according to the invention (such as a dentifrice/toothpaste) will generally contain further ingredients to enhance performance and/or consumer acceptability, in addition to the ingredients specified above.

Compositions according to the invention, particularly toothpastes, preferably comprise particulate abrasive materials such as silicas, aluminas, calcium carbonates, and so on, including agglomerated particulate abrasive materials, usually in amounts between 3 and 60% by weight of the oral care composition.

Preferably the composition, particularly a toothpaste, comprises a silica based abrasive. The preferred abrasive silicas used in the present invention is a silica with a low refractive index. It may be used as the sole abrasive silica, or in conjunction with a low level of other abrasive silicas, e.g. those according to EP 236070. The low refractive index silicas, used as abrasives in the present invention are preferably silicas with an apparent refractive index (R.l.) in the range of 1.41 - 1.47, preferably 1.435 - 1.445, preferably having a weight mean particle size of between 5 and 15 mm, a BET (nitrogen) surface area of between 10 and 100 m²/g and an oil absorption of about 70 - 150 cm³/100 g, but abrasive silicas with a lower apparent refractive index may also be used. Typical examples of suitable low refractive index abrasive silicas (e.g. having an R.l. of between 1.435 and 1.445) are Tixosil 63 and 73 ex Rhone Poulenc; Sident 10 ex Degussa; Zeodent 113 ex Zeofinn; Zeodent 124 ex Evonik, Sorbosil AC 77 ex PQ Corporation (having an R.l. of approximately 1.440). The amount of these silicas in the composition generally ranges from 5-60% by weight, usually 5-20% by weight.

The composition, particularly if a toothpaste preferably comprises an inorganic or a natural or synthetic thickener or gelling agent in proportions of about 0.10 to about 15% by weight depending on the material chosen. These proportions of thickeners in the dentifrice compositions of the present invention form an extrudable, shape-retaining product which can be squeezed from a tube onto a toothbrush and will not fall between the bristles of the brush but rather, will substantially maintain its shape thereon. Suitable thickeners or gelling agents useful in the practice of the present invention include inorganic thickening silicas such as amorphous silicas available from Huber Corporation under the trade designation Zeodent 165, Irish moss, iota-carrageenan, gum tragacanth, and polyvinylpyrrolidone. Compositions according to the invention preferably comprise a polymeric deposition aid. Preferably the composition comprises acid anhydride polymers, particularly preferred are co-polymers of maleic anhydride with methyl vinylether, in which the anhydride moiety may be in a partially or fully hydrolysed or alcoholysed form. Preferred copolymers include Gantrez(R) polymers such as: Gantrez S-95: molecular weight 216,000; free acid;

Gantrez S-96: molecular weight 700,000; free acid;

Gantrez S-97: molecular weight 1,500,000; free acid; and

Gantrez MS-955: molecular weight 1,060,000; calcium/sodium salt.

Particularly preferred co-polymers of maleic acid and methyl vinylether have a molecular weight of 1,000,000 or greater and an especially preferred material is Gantrez S-97.

Compositions according to the invention may comprise a further tooth whitening agent. The whitening agent preferably comprises a green and/or a blue pigment. In the context of the present invention a pigment is generally understood to be a shade/material which is insoluble in the relevant medium, at the relevant temperature. This is in contrast to dyes which are soluble. In the context of this invention, the "relevant medium" is human saliva, the liquid medium in which the composition is used, at the temperature of the oral cavity during brushing of the teeth, i.e. up to 37 Degrees C. As a reasonable approximation, the relevant medium may be considered to be water and the relevant temperature to be 25 Degrees C.

Preferably the blue pigment is Pigment Blue 15, more preferably Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:5 or 15:6, most preferably 15:1. A preferred pigment is blue pigment is Phthalocyanine Blue Pigment, Cl No. 74160, blue covarine.

The preferred Green pigment is Phthalocyanine Green, preferably Phthalocyanine Green CI-74260.

Preferably the total level of pigment in the composition is from 0.01 wt% to 3 wt, more preferably from 0.02 to 2 wt%.

If the composition is a toothpaste it is preferably a dual phase paste, with the aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations and preferably the whitening pigments present in one phase and separate from the bleach.

Compositions according to the invention may comprise water-soluble or sparingly water-soluble sources of metal salts. Preferred are zinc ions such as zinc chloride, zinc acetate, zinc gluconate, zinc sulphate, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglycerolate, zinc tartrate, zinc pyrophosphate and zinc maleate; also preferred are stannous ions such as stannous fluoride and stannous chloride.

Compositions according to the invention may comprise oral care enzyme systems such as hydrogen peroxide producing enzyme systems (e.g. the oxidoreductase enzyme glucose oxidase), amyloglucosidase, dextranase and/or mutanase, (optionally in the presence of zinc ion providing compounds and/or 8- hydroxyquinoline derivatives), lactoperoxidase, lactoferrin, lysozyme and mixtures thereof.

Compositions of the invention may comprises fluoride sources such as sodium fluoride, stannous fluoride, sodium monofluorophosphate, zinc ammonium fluoride, tin ammonium fluoride, calcium fluoride, cobalt ammonium fluoride and mixtures thereof.

In one embodiment a preferred class of oral care active for inclusion in the compositions of the invention includes agents for the remineralisation of teeth. The term “remineralisation” in the context of the present invention means the in situ generation of hydroxyapatite on teeth.

Mixtures of any of the above described materials may also be used.

The composition according to the invention will comprise further ingredients which are common in the art, such as: antimicrobial agents, e.g. chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds, such as cetylpyridinium chloride; cetylpyridium chloride clay complex bis-guanides, such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenolic compounds, such as 2,2’ methylenebis-(4-chloro-6-bromophenol); anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin etc.; anti-caries agents such as sodium- and stannous fluoride, aminefluorides, sodium monofluorophosphate, sodium trimeta phosphate and casein; plaque buffers such as urea, calcium lactate, calcium glycerophosphate and strontium polyacrylates; vitamins such as Vitamins A, C and E; plant extracts; plant-derivable antioxidants such as flavonoid, catechin, polyphenol, and tannin compounds and mixtures thereof; desensitising agents, e.g. potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate and strontium salts; anti-calculus agents, e.g. alkali-metal pyrophosphates, hypophosphite-containing polymers, etc.; biomolecules, e.g. bacteriocins, antibodies, enzymes, etc.; flavours, e.g. peppermint and spearmint oils; proteinaceous materials such as collagen; preservatives; opacifying agents; hyaluronic acid; amino acids such as arginine; colouring agents; pH-adjusting agents; sweetening agents; pharmaceutically acceptable carriers, e.g. starch, sucrose, water or water/alcohol systems etc.; surfactants, such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants;

Humectants such as glycerol, sorbitol, propyleneglycol, xylitol, lactitol etc.; binders and thickeners such as sodium carboxymethyl-cellulose, hydroxyethyl cellulose (Natrosol®), xanthan gum, gum arabic etc. as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®; polymeric compounds which can enhance the delivery of active ingredients such as antimicrobial agents can also be included; buffers and salts to buffer the pH and ionic strength of the oral care composition; and other optional ingredients that may be included are e.g. bleaching agents such as peroxy compounds e.g. potassium peroxydiphosphate, effervescing systems such as sodium bicarbonate/citric acid systems, colour change systems, and so on.

The oral care composition is preferably comprises at most 1.0 wt. %, preferably at most 0.8 wt.%, more preferably at most 0.5 wt. %, of phosphate . The oral care composition is preferably also phosphonate-free i.e. , contains at most 0.2 wt. % of phosphonate, preferably at most 0.1 wt. %, more preferably at most 0.05 wt. %, still even more preferably contains essentially no phosphonate.

Form of the oral care composition

The oral care composition of the invention may be in any suitable form, the compositions may be provided as a dentifrice, a whitening gel, a mouthwash or a mouthrinse, a spray, an oral strip, a chewing gum or a lozenge.

An oral strip comprises a flexible material with the composition applied to the surface or impregnating the surface.

Unless stated otherwise or is apparent from the context of the description, preferred embodiments mentioned for one aspect of the invention applies mutated mutandis to the other aspects of the invention as well. The below examples are meant to be illustrative and not limiting.

EXAMPLES

Example 1

A base solution was made by dispersing 0.005 wt. % of naphthol blue black dye (available from Sigma-Aldrich) in water and adjusting the pH to 10 (using 0.1 M bicarbonate). To this solution hydrogen peroxide was added to provide a level of 20mM. For testing either 25ppm of bleach catalyst according to the invention was added, or (not according to the invention) bare Mn²⁺ (as water soluble MnSOt) as control. The final solution was incubated at 20 degrees Celsius for 20 hours after which the light absorbance was measured at 629nm using a UV-VIS spectrophotometer. The results are given in the Table 1 below. Tablel : dye-bleaching results at pH 10 at 20 degrees Celsius

The results show that aminopolycarboxylate complexes of Mn²⁺ substantially improve dye bleaching at 20 degrees Celsius and a pH of 10, where complexes with GLDA and MGDA perform best. These conditions are relevant for machine dishwash wash liquor conditions when operating at low temperatures.

The experiment was repeated, at pH of 7.0 by adjusting the pH with phosphate in place of the bicarbonate. The results are shown in Table 2 below.

Table 2: dye-bleaching results at pH 7.0 at 20 degrees Celsius

The results show that for the manganese (II) aminopolycarboxylate complexes at 20 degrees Celsius there is no appreciable improvement on dye bleaching at a pH of 7.0 and that hence the pH profile of the wash liquor as claimed is relevant.

Claims

1 . An oral care composition comprising:

• flavour

• bleach; and

• aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations.

2. An oral care composition according to claim 1 , wherein the wherein the aminopolycarboxylate comprises GLDA, MGDA, EDDS or a combination thereof, preferably GLDA, MGDA or a combination thereof and even more preferably comprises GLDA.

3. An oral care composition according to claim 1 or claim 2, wherein the cation comprises Fe²⁺, Fe³⁺, Mn²⁺, Mn³⁺, Mn⁴⁺, Mn⁵⁺, Mn⁶⁺, Mn⁷⁺ and Co²⁺, Co³⁺ or mixtures thereof, preferably comprises Fe²⁺, Fe³⁺, Mn²⁺, Mn⁴⁺, Co²⁺, Co³⁺ or mixtures thereof and even more preferably comprises Fe³⁺, Mn²⁺ or mixtures thereof.

4. An oral care composition according to any preceding claim, wherein the composition comprises further aminopolycarboxylate not comprising coordinate covalent bound Fe, Mn or Co cations, wherein the ratio of aminopolycaroboxylate comprising one or more coordinate covalent bound Fe, Mn and/or Co cations to aminopolycaroboxylates not comprising coordinate covalent bound Fe, Mn or Co cations is from 1 :4000 to 100:1 , preferably from 1 :100 to 20:1 , more preferably from 1 :50 to 1 : 1 and even more preferably from 1 :20 to 1 : 10.

5. An oral care composition according to any preceding claim, wherein the pH of a solution of 1 wt. % of the oral care composition in water as measured at 25 degrees Celsius is from 6. to 12, preferably 7.0 to 11.0, more preferably from 8.5 to 10.5 and even more preferably from 9.0 to 10.0.

6. An oral care composition according to claim 6, wherein the amount of bleach is from 0.01 to 10 wt. % of the total composition, preferably from 0.05 to 5 wt. % most preferably from 0.1 to 3 wt% of the composition.

7. An oral care composition according to any preceding claim comprising less than 0.2 wt. % of the total composition of phosphonate; preferably less than 0.1 wt% phosphonate.

8. An oral care composition according to any preceding claim that is in the form of a toothpaste.

9. An oral care composition according to any preceding claim that further comprises an abrasive.

10. An oral care composition according to any preceding claim that further comprises a surfactant.

11. An oral care composition according to any preceding claim that is applied to a flexible substrate.

12. An oral care composition according to any preceding claims, wherein the composition does not comprise further poorly biodegradable bleach catalyst and preferably comprises essentially no further bleach catalyst.

13. Use of aminopolycrboxylate comprising one or more coordinate covalent bound Fe, Mn and/or Co cations to provide an oral care composition for whitening the teeth.

14. A method of whitening the teeth by application of a composition comprising bleach and a aminopolycarboxylate comprising one or more coordinate covalent bound iron- (Fe), Manganese- (Mn) and/or cobalt- (Co) cations.