Compositions

~ot ~22~ 01 - 1 - J2012 02 03NOVEL COMPOSITIONS 04 05The present invention relates to oral hygiene 06 compositions, ln particular compositions comprising a 07 tripolyphosphate salt, which compositions are useful in 08 the inhibition of dental calculus.

09 Several proposals for oral hygiene compositions 11 comprising a tripolyphosphate salt as an anti-calculus 12 agent have been made.

For instance, EP-A-0 236 290 (to 13 Monsanto) discloses dentifrices comprising inter alia a 14 tripolyphosphate salt in combination with an abrasive which ls calcium pyrophosphate, the pH of which is 16 preferably less than 8. EP-A-0 295 116 ( to unilever) 17 discloses anti-calculus compositions comprising a 18 combination of a tripolyphosphate salt and zinc citrate 19 as the anti-calculus agent whilst EP-A-0 254 452 (to Lion Corporation) discloses anti-calculus compositions 21 comprising a combination of a tripolyphosphate salt and 22 anethol as the anti-calculus agent.

Each of the two 23 latter applications describes an example comprising a 24 silica abrasive, with sodium tripolyphosphate included at 5% and 1.5% by weight of the composition, 26 respectively.

In neither case is any teaching provided 27 with respect to the pH of the composition.

28 29 US 4 627 977 ~to Colgate-Palmolive) discloses anti-calculus compositions comprising a linear 31 molecularly dehydrated polyphosphate salt such as a 32 tripolyphosphate in which the otherwise observed 33 enzymatic hydrolysis of the anti-calculus agent by 'f'~ r/~ ~ 01 - 2 - J2012 02 03 phosphatase enzymes present in saliva is reduced by 04 including a mixture of a source of fluoride ions and a 05 synthetic anionic linear polymeric carboxylate.

The 06 preferred pH of such compositions is in the rante 5.5 07 to 8.

The patent includes an example comprising sodium 08 tripolyphosphate at s% by weight of the composition.

09 In addition, GB-A-2 200 551 ~to Colgate-Palmolive) 11 discloses compositions having anti-calculus and 12 anti-plaque activity, the former being provided by a 13 linear molecularly dehydrated polyphosphate salt which 14 is preferably a pyrophosphate salt, and the latter being provided by a non-cationic anti-bacterial agent 16 such as a hydroxydiphenylether, and preferably 17 triclosan.

The preferred pH for such compositions is 18 in the range 5.5 to 8.

No examples comprising a 19 tripolyphosphate are provided.

21 In spite of the various proposals referred to above, as 22 far as we are aware, no anti-calculus dentifrice 23 comprising a tripolyphosphate salt such as sodium 24 tripolyphosphate has yet been marketed. one particular problem to be overcome in developing a commercially 26 viable composition is that of the storage stability of 27 the composition.

28 29 This problem is addressed in EP-A-0 236 290.

This application provides storage stability data on two 31 toothpastes comprising a calcium polyphosphate abrasive 32 and sodium tripolyphosphate at 5% by weight of the 33 composition, but which differ in having pHs of 8.5 and 34 7.1.

Under accelerated aging conditions, both toothpastes suffer a similar loss of about one third in 36 the amount of sodium tripolyphosphate present, 2 ~ 01 - 3 - J2012 02 03 suggesting that a higher pH per se is not a critical 04 factor.

This loss is considered to be unsatisfactory 05 for a commercial product. JP-A-50161/88 (to Lion 06 Corporation) suggests that storage stability may be 07 improved by selecting as the abrasive certain silicas 08 characterised by their surface area.

There is however 09 no discussion of the influence of pH or the amount of tripolyphosphate salt on storage stability.

No storage 11 stability data is provided in the other patent 12 applications or patents referred to above.

13 14 It has now been found that the problem of storage stability may be remedied by providing a relatively 16 large amount of the tripolyphosphate salt at a high pH, 17 contrary to the teachings of the prior art.

18 19 Accordingly, in a first aspect, the present invention provides a toothpaste composition which comprises: an 21 anti-calculus agent comprising at least about 4% by 22 weight, based on the total weight of the toothpaste, of 23 a water-soluble alkali metal tripolyphosphate salt; a 24 dental abrasive other than calcium pyrophosphate; and 2s an orally acceptable vehicle; the toothpaste having a 26 pH of from about 8 to about 10.

27 28 Such a toothpaste is found to have sufficient storage 29 stability for a commercially viable product.

31 It has been further found that an oral hygiene 32 composition may be provided having, in addition to 33 anti-calculus activity, anti-plaque activity by 34 incorporating, in addition to a tripolyphosphate salt, 3s an anti-bacterial compound.

36 201~22 t 01 - 4 - J2012 02 03 Accordingly, in a second aspect of the invention, there 04 is provided an oral hygiene composition which 05 comprises: an anti-calculus agent comprising a 06 water-soluble alkali metal tripolyphosphate salt; a 07 substantially water insoluble noncationic 08 anti-bacterial agent; and an orally acceptable vehicle.

09 Suitable noncationic anti-bacterial agents include for 11 example diphenyl ethers of the formula (I):

12 13 R3 R2 R12 R13 14 ~ ~ 165 R4 ~--Rl~ R14 17 6 1 /--~\ 18 R5 R R 6 R15 19 ~I 21 in which R1 is oxygen, sulphur, or an alkylene group of 22 from one to six carbon atoms and each of R2 to R6 and 23 R12 to R16 is hydrogen, hydroxyl or a halogen; phenolic 24 and bisphenolic compounds; benzoate esters and halogenated carbanilides 26 27 Examples of compounds of formula (I) include, for 28 example, 5,5'-dichloro-2,2'-dihydroxydiphenylmethane;

29 2,2'-dihydroxy-3,5,6,3',s',6'-hexachlorodiphenyl methane; 3,3'-dibromo-5,5'-dichloro-2,2'31 dihydroxydiphenylether and 2,4,4'-trichloro-2'-hydroxy32 diphenyl ether (triclosan)~ of which triclosan is 33 particularly preferred.

34 Examples of phenolic compounds, which include the 36 halogenated salicylanilides, include, ~or example, 37 2 ~ rS 2 ~ 01 - 5 - J2012 02 03 2-phenylphenol, 04 4-chlorophenol, 05 4-chloro-3-methylphenol, 06 4-chloro-3-methylphenol, 07 4-chloro-3,5-dimethylphenol, 08 2,4-dichloro-3,5-dimethylphenol, og 5-methyl-2-pentylphenol, 4-isopropyl-3-methylphenol, 11 5-chloro-2-hydroxydiphenylmethane, 12 4',5-dibromosalicylanilide, 13 3,4',5-tribromosalicylanilide, 14 2,3,3',5-tetrachlorosalicylanilide, 3,3',4,5'-tetrachlorosalicylanilide, 16 3,5-dibromo-3'-trifluoromethylsalicylanilide, and 17 5-n-octanoyl-3'-trifluoromethylsalicylanilide 18 19 Examples of bisphenolic compounds include, for example, 21 2,2'-methylenebis(3~4~6-trichlorophenol)~ 22 2,2'-methylenebis(4-chlorophenol)~ 23 2,2'-methylenebis(4-chloro-6-bromophenol)~ 24 bis(2-hydroxy-3,5-dichlorophenyl)sulphide, and bis(2-hydroxy-5-chlorophenyl)sulphide.

26 27 Examples of benzoate esters include, for example, 28 esters of hydroxybenzoic acid, especially the methyl, 29 ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, heptyl and benzyl esters.

31 32 Examples of halogenated carbanilides include, for 33 example, 34 3,4,4'-trichlorocarbanilide, 36 3-trifluoromethyl-4,4'-dichlorocarbanilide, and 37 3,3',4-trichlorocarbanilide.

38 201~2~ 01 - 6 - J2012 02 03 The preferred noncationic anti-bacterial agents are 04 compounds of formula (I), in particular the compound 05 triclosan.

06 07 The noncationic anti-bacterial agent is preferably 08 present in from 0.01 to 2.0%, more preferably 0.05 to og 1.0% by weight of the composition.

11 The oral hygiene composition may be presented in any of 12 the conventional formulations such as a dentifrice, 13 including toothpaste, a mouthwash or a formulation that 14 is chewed or sucked by the user such as a lozenge or a chewing gum.

Suitably the oral hygiene composition is 16 in the form of a toothpaste composition which comprises 17 an abrasive.

18 19 It will be appreciated that the alkali metal trlpolyphosphate salt is included in compositions of 21 the invention as an anti-calculus agent.

In some 22 instances, the anti-calculus agent may consist 23 essentially of the water-soluble alkali metal 24 tripolyphosphate salt.

26 Suitable water-soluble alkali metal salts include 27 sodium or potassium trlpolyphosphate which may be used 28 in the hydrated or unhydrated forms.

Preferably the 29 tripolyphosphate salt is present in at least 4%, more preferably from about 4 to about 6% by weight, based on 31 the total weight of the composition.

32 33 Preferably the pH of the composition is from about 8 to 34 10, more preferably from about 8 to about 9.

When the composition comprises a compound of formula (I), a pH 36 of above 8 is found to enhance the availability of the 2;~ o1 - 7 - J2012 02 03 compound of formula ( I ) .

All references to the pH of 04 the composition herein are references to the pH of the 05 composition measured without dilution of the 06 composition.

07 08 Suitable abrasives for use in the present invention og include silica, plastics particles, alumina, calciuim carbonate, and zinc orthophosphate, and if a 11 noncationic antibacterial agent as hereinbefore defined 12 is present, calcium pyrophosphate.

Silica is 13 especlally preferred.

14 Silica abrasives are well known and commercially 16 available, generally having an average particle size 17 ranging between about 0.1 to about 30 microns, such as 18 from about 5 to about 15 microns.

Silica dental 19 abrasives useful in the present invention include those marketed by the J.M.

Huber Corporatlon under the trade 21 name 'Zeodent' and the sillca zerogels marketed by the 22 W.R.

Grace and Company, Davison Chemlcal Division under 23 the trade name 'Sylold'. US 3 358 230 and US 3 862 307 24 describe silica dental abrasives that are useful in the toothpaste composltions according to the present 26 lnvention.

The silica abrasive may also be a naturally 27 occurring amorphous silica such as diatomaceous earth.

28 Suitable forms of diatomaceous earth are those marketed 29 under the trade mark 'Celite' by Johns - Manville Products Corporation, for instance 'Celite Superfine 31 Superfloss'.

32 33 Plastics dental abrasives are well known and are 34 described in, for example, GB 939 230, GB 995 351 and GB 1 055 784, and US 3 151 027.

36 37 Alumina abrasives are well known and commercially 38 available.

Preferably the alumina abrasive may be 39 treated with a solution of a surface-treating agent 2 0 ~ 01 - 8 - J2012 02 03 which may be an alkali metal silicate, hydrogen 04 peroxide, an acid or an organophosphorus compound, of 05 which an alkali metal silicate is especially preferred, 06 as described in US 4 781 982 (to Aluminium Company of 07 America).

08 09 A calcium carbonate abrasive is preferably used in conjunction with an ionic agent to suppress the 11 formation of free calcium ions, such as an alkali metal 12 carbonate or bicarbonate, or mixture thereof, as 13 described in EP 0 092 929 ~to BeechPm Group p.l.c.).

14 Generally, an amount of the dental abrasive suitable 16 for use in the toothpaste composition of the present 17 invention will be empirically determined to provide an 18 a~ceptable level of cleaning and polishing, in 19 accordance with the techniques well known in the art.

Suitably, the abrasive will be present in from about 5 21 to about 60%, preferably from about 5 to about 30%, by 22 weight of the toothpaste.

23 24 Advantageously, compositions of the present invention may further comprise a phosphatase enzyme inhibitor 26 comprising a fluoride ion source, to optimise the 27 anti-calculus activity of the compositions by 28 inhibiting the enzymatic hydrolysis of the 29 tripolyphosphate salt by salivary phosphatase enzymes.

The fluoride ion source may be provided by an alkali 31 metal fluoride, preferably sodium fluoride, an alkali 32 metal monofluorophosphate, stannous fluoride and the 33 like.

Preferably, however, the fluoride ion source is 34 an alkali metal fluoride, most preferably sodium fluoride, since this appears to provide enhanced 36 storage stability as compared to other fluoride ion 37 sources.

The fluoride ion source serves as a ~ o ~ 01 - 9 - J2012 02 03 phosphatase enzyme inhibitor, and in addition, the 04 fluoride ion source may also provide an anti-caries 05 effect.

Preferably, the fluoride ion source will be 06 used in an amount to provide an anti-caries effective 07 amount and a phosphatase enzyme inhibiting amount, such 08 as an amount sufficient to provide from about 25 ppm to 09 about 3500 ppm, preferably about 1100 ppm, fluoride.

It will be appreciated that the fluoride ion source may 11 be included in compositions of the invention to provide 12 a phosphatase enzyme inhibitor.

In some instances, the 13 phosphatase en~yme inhibitor may consist essentially of 14 a fluoride ion source.

16 Suitably, in compositions of the present invention, the 17 orally acceptable vehicle may comprise a thickening 18 agent, a binding agent and a humectant.

Preferred 19 thickening and binding agents include for example natural and synthetic gums such as xanthan gums, 21 carageens, alglnates, cellulose ethers and esters and 22 silica.

When the abrasive is silica, it is preferred 23 to use a thickening silica as the thickening agent.

24 Preferred humectants include glycerin, sorbitol, propylene glycol and polyethylene glycol. A preferred 26 humectant system consists of glycerin, sorbitol and 27 polyethylene glycol.

28 29 In addition, the orally acceptable vehicle may optionally comprise surfactants, sweetening agents, 31 flavouring agents, anticaries agents (in addition to 32 the fluoride ion source provided as a phosphatase 33 enzyme inhibitor)~ anti-plaque agents, anti-bacterial 34 agents such as triclosan or cetyl pyridinium chloride, tooth desensitizing agents, colouring agents and 36 pigments.

Useful surfactants include the water-soluble 37 salts of alkyl sulphates having from 10 to 18 carbon 201~22~L 01 - 10 - J2012 02 03 atoms in the alkyl moiety, such as sodium lauryl 04 sulphate, but other anionic surfactants as well as 05 non-ionic, zwitter-ionic, cationic and amphoteric 06 surfactants may also be used.

07 08 When the preferred aqueous orally acceptable dental 09 vehicle is employed, a toothpaste composition of the present invention suitably contains from about 10 to 11 about 80% humectant, from about 0.25 to about 5% 12 detergent, from o to about 2% sweeteners and flavouring 13 agents together with water and an effective amount of 14 binding and thickening agents, such as from about 0.1% to about 12%, to provide the toothpaste of the 16 invention with the desired stability and flow 17 characteristics.

18 19 Toothpaste compositions according to the present invention may be prepared by admixing according to 21 conventional practice the tripolyphosphate salt, the 22 dental abrasive and, if inciuded, the fluoride ion 23 source with the orally acceptable dental vehicle, which 24 may be anhydrous but is preferably an aqueous orally acceptable dental vehicle, to form a storage stable 26 semi-solid extrudable material useful as a toothpaste 27 The pH thereof may be ad~usted if necessary and 28 desired, by the addition of, for instance sodium 29 hydroxide.

Preferably, the tripolyphosphate salt is in powder form when incorporated into the vehicle, as this 31 tends to enhance the stability of the resulting 32 toothpaste.

33 34 Toothpaste compositions of the present invention may also be prepared in the form of a paste of a uniform 36 colour or in the form of a striped toothpaste. A 37 suitable aparatus for filling toothpaste tubes with r, _~L 01 ~ J2012 02 03 striped toothpaste is described in GB 962 757.

In 04 accordance with this patent, toothpastes of different 05 colours are fed through separate tubes of a bundle of 06 tubes that is inserted into a toothpaste container and 07 gradually moved relative to the container as the 08 container is filled.

09 In a third aspect, the present invention provides a 11 method of inhibiting dental calculus which method 12 comprises applying an anti-calculus effective amount of 13 a composition as hereinbefore defined to the oral 14 cavity; and optionally a method of also inhibiting dental plaque, when a compound of formula (I) is also 16 present in the composition.

17 18 The invention will now be illustrated by the following 19 examples:

~ Q ~ 01 - 12 - J2012 02 03 Example 1 04 05 A toothpaste was prepared from the following 06 ingredients, sodium tripolyposphate being in powder 07 form when combined with the other ingredients:

08 os % w/w 11 Polyethylene glycol ~PEG-8) 3.00 12 Xanthan Gum 0.70 13 D + C Red No. 30 Lake 0.02 14 FD + C Blue No. 1 tO.2%) 0.17 D + C Yellow No. 10 (0.20%) 0.24 16 Sodium Fluoride 0.24 17 Sorbitol (70%) 29.61 18 Sodium Saccharin 0.21 19 Thickening Silica 8.00 Abrasive Silica 14.00 21 Titanium Dioxide 0.96 22 Glycerine 99% 10.00 23 Sodium Tripolyphosphate 24 (Food Grade)* Sodium Hydroxide (25%) 1.80 26 Flavour 0.80 27 Sodium Lauryl Sulphate 1.15 28 Deionized Water to 100.00 29 * Food grade has a nominal purity of 92%.

31 Initial pH 8.4 32 2 Q ~ ~ $, ~ ~ 01 - 13 - J2012 02 03 Examples 2 - 5 - StriPed dentifrices 04 05 The preparation of striped dentrifrices is well known 06 in the art. US Patent Nos. 3 996 863, 3 980 767, 4 328 07 205 and 4 358 437 described toothpastes and methods for 08 production thereof which may be utilised for the 09 production of the dentifrices according to the present invention.

11 12 Example 2 13 14 A striped dentifrice according to the present invention and comprising a central core with red stripes and aqua 16 stripes was prepared by combining the ingredients set 17 forth below according to known conventional techniques.

18 19 % w/w Core Red A~ua 21 22 PEG* 400 3.00 3.00 3.00 23 Xanthan Gum 0.70 0.70 0.70 24 Sodium Fluoride 0.24 0.24 0.24 Sodium Saccharin 0.21 0.21 0.21 26 Triclosan 0.20 0.20 0.20 27 Sorbitol (70%) 29.0929.09 29.09 28 FD + C Blue No.l dye - - 0.0020 29 D + C Yellow No. 10 dye - - 0.0002 Titanium Dioxide 1.459 31 Abrasive Silica 14.0014.00 14.00 32 Thickening Silica 8.00 8.00 8.00 33 Sodium Tripolyphosphate 5.00 5.00 s.00 34 Glycerine 10.0010.00 10.00 NaOH 0.45 0.45 0.45 36 Flavour 0.80 0.80 0.80 37 Sodium Lauryl Sulphate1.15 1.15 1.15 38 Deionized Water to 100.00100.00 100.00 39 *PEG denotes polyethylene ~lycol.

41 ~ ~ ~5 5J ~'"'~~ 01 - 14 - J2012 02 03 ExamPle 3 04 05 As Example 2 but with triclosan at 0.3%.

06 07 Example 4 08 % w/w 09 Core Red Aqua 11 PEG* 300 3.00 3.00 3.00 12 Xanthan Gum 0.60 0.60 0.60 13 Sodium Fluoride 0.22 0.22 0.22 14 Sodium Saccharin 0.20 0.20 0.20 Triclosan 0.20 0.20 0.20 16 Sorbitol (70%) 27.7027.70 27.70 17 FD + C Blue No.l.dye - - 0.002 18 D + C Yellow No. 10 dye - - 0.001 19 D + C Yellow No. 3 dye - 0.10 Titanium Dloxide 1.45 21 Abrasive Silica 14.0014.00 14.00 22 Thickening Silica 7.00 7.00 7.00 23 Sodium Tripolyphosphate 5.00 5.00 5.00 24 Glycerine 20.0020.00 20.00 Flavour 0.80 0.80 0.80 26 Sodium Lauryl Sulphate 1.70 1.70 1.70 27 Deionized Water to100.00100.00100.00 28 29 *PEG denotes polyethylene glycol.

~ Q ~ 01 - 15 - J2012 02 03 ExamPle 5 04 05 As Example 4 but with triclosan at 0.3%.

06 07 ExamPle 6 08 09 Toothpastes A (as per Example 1), B, C, and D were prepared uslng a silica dental abrasive, sodium 11 tripolyphosphate (STP), and sodium fluoride in an 12 amount to provide llO0 ppm fluoride, in an aqueous 13 orally acceptable vehicle.

The amounts of STP and the 14 pH of the toothpastes were varied as shown in the Table below:

16 17 Table 18 19 Tooth- pH* STP% % STP As % Of Initial STP After 21 paste 22 1 year 2 year 3 year 5 year 23 24 A 9 4.3 98 96 94 91 B 7 4.3 96 93 89 85 26 C 9 3.0 90 80 69 59 27 D 7 2.8 85 70 55 39 28 29 :30 *The pH's reported are no~in~1 values.

31 32 The data presented in the Table were derived from 33 storage stability tests on actual samples of the four 34 toothpastes, with the storage stabilty data regressed to provide predicted stability over four years of 36 storage at room temperature with a confidence level of 37 95%.

38 2 ~ 01 - 16 - J2012 02 03 As can be seen from the table, toothpaste A which 04 contains a large amount of STP and has a high pH is the 05 most stable of the four toothpastes.

06 07 In comparison, either a large amount of STP (B) alone 08 or a high pH (C) alone provides inferior storage og stability.

11 Unexpectedly, the use of a large amount of STP and a 12 high pH in combination with a silica dental abrasive 13 and a fluoride ion source provides sufficient storage 14 stability for a commercial toothpaste.