GB2358584A - Oral care composition - Google Patents

Abstract

An oral care composition comprising a copolymer of N-vinylpyrrolidone and acrylic acid in a weight ratio in the range of 20-50 to 50-80 in combination with a halogenated diphenyl ether compound as antibacterial agent. The halogenated diphenyl ether is preferably Triclosan (2,4,4'-trichloro-2'-hydroxy-diphenyl ether). The composition may be in the form of a toothpaste, mouthwash or other oral composition.

Description

2358584 Novel Compositions The present invention relates to oral hygiene

compositions whose aim is to improve the effectiveness of certain antibacterial compounds used for the retardation 5 and prevention of bacterial plaque formation on the surfaces of the teeth.

Dental plaque is a soft deposit that forms on teeth and is an accumulation of bacteria and bacterial by-products. Plaque will adhere primarily to rough calculus surfaces found on the gum line of the teeth. Besides being unattractive in appearance, plaque is implicated in the formation of periodontal diseases such as gingivitis and halitosis.

Antibacterial agents are well known in the art to prevent plaque formation and associated diseases. Hitherto, halogenated hydroxy-phenyl ether compounds such as 2',4,4-trichloro-2-hydroxy-diphenyl ether, also known as Triclosan have been successfully used in oral care compositions intended to prevent plaque formation by bacterial build up in the oral cavity.

Bacterial agents such as Triclosan are highly effective in killing the bacteria that are responsible for the formation of plaque but it is difficult to maintain the levels of such agents in the oral cavity for any length of time after initial application. It is desirable for the. agent to remain in contact with the dental tissue in the oral cavity in order to prolong the effectiveness of the material.

A need has therefore arisen to provide a means whereby antibacterial agents used in oral hygiene compositions can be retained on dental tissue within the oral cavity for a period of time after initial application.

Numerous attempts have been made to achieve this by enhancing the bio adhesion of the antibacterial agents by the addition of polymers.

An example of a known polymer resulting in improved bioadhesion is Gantrez S-96, a copolymer of maleic anhydride and methoxyvinyl. Polyvinylpyrrolidone has also been used for the same purpose. Although products containing this polymer will give initial improvements in bioadhesion of the antibacterial agent, after a time the effects become reduced or diminish entirely.

It has since been found that low levels of certain N-vinylpyrrolidone and acrylic acid polymer materials are effective at enhancing the bioadhesive effect andlor the substantivity of certain antibacterial compounds, such as halogenated diphenyl ether (antibacterial) compounds by retaining the antibacterial compound on dental tissue within the oral care cavity.

Surprisingly, the use of these certain N-vinylpyrrolidone and acrylic acid polymer materials results in a dramatic improvement of the bioadhesion, retention and substantivity of the halogenated diphenyl ether compounds when compared to known polymers that are incorporated into oral hygiene products.

Preferred N-vinylpyrrolidone and acrylic acid polymer materials used in the products of the invention are known and can be prepared in a conventional manner, for example by random radical polymerisation in bulk, emulsion or suspension.

They are commercially available from International Speciality Products (ISP) of 1361 Alps Road, Wayne, NJ 07470, under the trade name Acrylidone.

Only certain of these Acrylidone polymers exhibit the desired effects of bioadhesion, retention and substantivity. The Acrylidone polymers that show these characteristics to the greatest extent are those with weight ratio of N vinylpyrrolidone and acrylic acid in the range of 20-80 to 20-80.

Preferably, Acrylidone polymers with the weight ratio of 25 to 75 are used.

Specific N-vinylpyrrolidone and acrylic acid polymers that have this weight ratio and are known to produce these unexpected effects are known as ACP 1005 and ACP 1042.

In terms of molecular weight, these Acrylidone polymers have molecular weights ranging from 50,000 to 300,000. Specifically ACP 1005 and ACP 1042 have molecular weights of 250,000 and 80,000 respectively.

Accordingly there is provided an oral care composition comprising an N vinylpyrrolidone and acrylic acid polymer in a weight ratio in the range of 20-50 to 50-95 in combination with an antibacterially effective amount of an halogenated diphenyl ether compound in an orally acceptable carrier or excipient.

Halogenated diphenyl ether compounds for use in oral care compositions of the present invention include 2,4,4'-trichloro-2'-hydroxy-diphenyl ether (Triclosan) and 2,2'-dihydroxy-5,5-dibromo-dipheny1 ether. Triclosan is a particularly preferred halogenated diphenyl (antibacterial) compound.

The amount of N-vinylpyrrolidone and acrylic acid polymer to be used in the oral care composition may range from 0.01 to 10.0% w/w, preferably between 0 - 1 to 5. 0 % w/w, more preferably between 0. 05 to 2. 0 % w/w of the product.

The amount of halogenated diphenyl ether compound to be used in the oral care composition is in an antibacterially effective amount and may be in the range of from 0. 05 to 2 % w/w, preferably between 0. 1 to 1 % w/w of the product.

The oral hygiene compositions of the present invention include all the known types of oral hygiene products, such as toothpaste or cream, abrasive and non abrasive dental gel, toothpowder, mouthwash, gargle, mouthspray, chewing gum, dental or chewing tablet or lozenge or any other suitable form. It is noted that in oral hygiene products that are in concentrated form, for example a concentrated mouthwash that must be diluted prior to use, or in tablets to be dissolved, the amount of N-vinylpyrrolidone and acrylic acid polymer and halogenated diphenyl ether compound will be that much higher. Suitable amounts of N- vinylpyrrolidone and acrylic acid polymer are in the range of from 2 to 50% w/w. Components for the orally acceptable carrier or excipient will be selected according to the particular type of presentation involved.

The N-vinylpyrrolidone and acrylic acid polymer and halogenated diphenyl ether compound are compatible with the usual oral hygiene product additives, such 20. as fluorides, bactericides, abrasives, polishing agents, thickening agents, whitening agents, surfactants, foaming agents, flavoring agents, sweeteners, preservatives, colouring agents and pigments and/or other ingredients that are commonly and conventionally found in the oral hygiene products listed above.

Oral hygiene compositions of the present invention may also usefully contain an ionic fluorine-containing compound. Suitable ionic fluorine-containing compounds include, for instance, fluoride salts such as amine fluorides and alkali metal fluoride salts, for example sodium fluoride, and monofluorophosphate salts such as alkali metal monofluorophosphate salts, for example sodium monofluorophosphate. Suitably the ionic fluorine-containing compound is incorporated into the composition to provide between 100 and 3000ppm, preferably between 500 and 2000ppm of fluoride ions.

Suitable surfactants include anionic, nonionic, amphoteric, and cationic surfactants.

Non-ionic surfactants include, for example, polyethoxylated sorbitol esters, in particular polyethoxylated sorbitol monoesters, for instance, PEG(40) sorbitan di isostearate, and the products marketed under the trade name Tween' by ICI; polycondensates of ethylene oxide and propylene oxide (poloxamers), for instance the product s marketed under the trade name Tluronic' by BASF-Wyandotte; condensates of propylene glycol; polyettioxylated hydrogenated castor oil, for instance, cremophors; and sorbitan fatty esters.

Suitable amphoteric surfactants include, for example, long chain imidazoline derivatives such as the product marketed under the trade name 'Miranol C2M' by Miranol; long chain alkyl betaines, such as the product marketed under the tradename 'Empigen BW by Albright + Wilson, and long chain alkyl amidoalkyl betaines, such as cocamidopropylbetaine, and mixtures thereof.

Suitable cationic surfactants include the D,L-2-pyrrolidone-5-carboxylic acid salt of ethyl-N-cocoyl-L-arginate, marketed under the trade name CAE by Ajinomoto Co. Inc.

Suitable anoinic surfactants include alkali metal (C12-18)alkyl sulphates, for instance sodium lauryl sulphate, and N-acyl sarcosinates and N-acyl taurines in which the acyl moiety has from 12 to 16 carbon atoms, for instance, N- lauroyl, Nmyristoyl and N-palmitoyl sarcosine alkali metal salts.

Advantageously, the surfactant is present in the range 0.005 to 20%, preferably 0. 1 to 10 %, more preferably 0. 1 to 5 % by weight of the dentifrice.

Suitable nonionic thickening agents include, for example, (Cl-6)alkylcellulose ethers, for instance methylcellulose, hydroxy(C1-6)alkylcellulose ethers, for instance hydroxypropylcellulose, (C2-6)alkylene oxide modified (Cl-6)alkylcellulose ethers, for instance hydroxypropyl methylcellulose, and mixtures thereof. Advantageously the nonionic thickening agent is present in the range 0.01 to 30 %, preferably 0. 1 to 15 %, more preferably 1 to 5 %, by weight of the composition.

Suitable sparingly soluble salts that may be used as an abrasive include calcium carbonate, calcium phosphates, magnesium carbonate, insoluble sodium metaphosphate, and suitable mixtures thereof. The agent to suppress anion formation typically comprises a water soluble salt containing a cation which may be same as the cation of the abrasive and which forms an essentially insoluble or sparingly soluble salt with the anion of the abrasive. Preferably the sparingly soluble salt used as an abrasive is calcium carbonate, advantageously used in combination with dicalcium phosphate, which also usefully buffers the pH of the formulation. Suitable types of calcium carbonate include both natural and synthetic chalks. The agent to suppress anion formation may be an alkaline earth metal salt, for instance calcium chloride. The agent is preferably present in from 0.0001 to 1 %, more preferably 0. 005 to 0. 1 % by weight of the dentifrice.

The term 'essentially insoluble compound' as used herein refers to a compound which is intrinsically insoluble in aqueous solution and includes those compounds which are listed as being 'insoluble' in cold water in the 'Handbook of Chemistry and Physics', 48th Edition, Chemical Rubber Company, Section B, Physical Constants of Inorganic Compounds. Furthermore, such compounds when used as an abrasive shall contain little if any contaminating anionic impurities. Preferably the insoluble abrasive compound should contains less than 1 %, preferably less than 0. 5 and more preferably less than 0. 25 % of anionic impurities, based on the weight of the abrasive. Suitable essentially insoluble compounds for use as alrasives include, for example, silica, zinc orthophosphate, plastics particles, alumina, hydrated alumina, and calcium pyrophosphate or mixtures thereof.

Preferably, the abrasive is silica. Suitable silicas include natural amorphous silica, for instance diatomaceous earth; and synthetic amorphous silicas, for instance a precipitated silica, or a silica gel, such as a silica xerogel; or mixtures thereof. The preferred synthetic amorphous silicas are those with a low-level of water soluble anionic impurities (hereinafter referred to as "low-anion silica"). These are obtainable from manufacturing process which are carefully controlled so that the level of anion impurities, particularly sulphate and silicate from sodium sulphate and sodium silicate, respectively, is kept to a minimum. Alternatively, or in addition, the level of anion impurities may be reduced to the required level by careful washing of the initially produced silica with, for instance, deionised or distilled water. Suitable low-anion silicas contain less than 0.5%, preferably less than 0.25 %, more preferably less than 0. 1% by weight of water soluble impurities such as sodium sulphate and/or sodium silicate. Examples of such low- anion silicas are described in EP A 0 315 503 (to Rhone-Poulenc). Suitable silica xerogels are described in US 3 538 230. Preferred precipitated silicas include the grade RP93 available from Rhone-Poulenc and those marketed under the trade name 'SIDENT' by Degussa, for instance, SIDgNT 9 silica. Preferred silica xerogels are those marketed under the trade name 'SYLOBLANC' by W.R. Grace Corporation, Davison Chemical Division. Suitable grades of precipitated silica have BET surface areas in the range 20 to 300, preferably 20 to 100 m2/g and median agglomerate sizes in the range 2 to 50 lim, preferably 5 to 30 im. Suitable forms of diatomaceous earth include those marketed under the trade name 'Celite' by Johns Manville Products Corporation, for instance 'Celite Superfine Superfloss'.

The abrasive is advantageously present in the range I to 80%, preferably 5 to 70%, more preferably 5 to 60% by weight of the dentifrice.

Suitable hurnectants for use in compositions of the invention include for instance glycerine, sorbitol, propylene glycol or polyethylene glycol, or mixtures thereof. The humectant may be present in the range from 5 to 70%, preferably 5 to 30%, more preferably 10 to 30% by weight of the dentifrice.

The pH of a composition according to the invention will be orally acceptable and typically in the range pH 5 to 11, preferably 7 to 9.

Oral care compositions according to the present invention may be prepared by mixing the ingredients thereof in the required proportions. It is advantageous to make a premix of the Triclosan and the Acrylidone polymer to ensure that a complex is made before this is added to the formulation. Thereafter and if necessary the pH may be adjusted to the required value.

Accordingly, in a further aspect, the present invention provides for an oral hygiene composition as hereiribefore defined for use in therapy, in particular anti plaque, anti-caries, anti-calculus and/or periodontal (including anti- gingivitis) therapy. The present invention also provides for the use of an N- vinylpyrrolidone and acrylic acid polymer in a weight ratio in the range of 20-80 to 20-80 and an halogenated diphenyl ether compound in the manufacture of an oral hygiene composition for use in oral hygiene.

The invention will now be illustrated by reference to the following invitro data and examples. 5 DATA To show the effect and comparison of certain N-vinylpyrrolidone and acrylic acid polymers on the uptake of Tr. iclosan onto bovine enamel. Certain N-vinylpyrrolidone and acrylic acid polymers, Gantrez S-96 and a placebo toothpaste (no Acrylidone or Gantrez) were tested in this experiment. MEETHOD Bovine incisors of a known surface area were strung-up with Reprosil and soaked overnight in filtered, pooled, human saliva at 37<bC. The toothpaste formulations to be tested in the experiment were prepared and stored overnight at 37<zC. Bovine incisors were then rinsed for 15 seconds in 25nil deionised water before being treated in 5mI of one of the solutions which were being tested, for one minute. The bovine enamel was then rinsed (60 seconds for each wash) in 25M1 deionised water three times. The Reprosil plug which was holding the cotton into -place was removed in the last rinsp step to prevent any TW bound to the Reprosil being taken into account in the final calculations. Any bound TW was then extracted from the bovine enamel by soaking the enamel in SmI methanol (HPLC grade) for one minute. A sample from this was taken and placed into a secure glass HPLC vial and stored in a fridge.

The samples were then removed and analysed by HPLC. A 10Oppm TCN standard was then prepared by adding 0.01g WN to 10OmI methanol. This 10Opprn standard was then diluted to give:

lppm WN (,--.lml 10Oppm WN + 99m], methanol) 2.5ppm WN (2.5nil 10Opprn WN + 97.5nil methanol) Sppm WN (5ml 10Oppm WN + 95mI methanol) 1Oppm WN (10nil 10Opprn WN + 90m.1 methanol) 20pprn WN (20mI 10Oppm, WN + 80m.1 methanol) Reprosil is a Trade Name of DENTSPLY of DENTSPLY Detrey GmbH, Germany and is a dental impression agent. 5 RESULTS The graph at Table I show the uptake of WN onto the emanel in the presence of certain levels of Acrylidone Polymers.

CONCLUSION

Both ACP-1005 and ACP-1042 showed greater uptake of Triclosan than Gantrez polymer.

6 TCN Bound (upicrn2) p p p p 0 1 W b.

4 1. > 1 0.05% z M -D = it Gantrez 5-95 00 4 er M cp 0 to P=1 1 to M 0 0.10% =r Gantrez 5-95 CO n E' =r 0 CD 0 1 R. 0.:E 2% Gantrez S 96 0.05% ACp IODS n 9 1 0.10% ACP- 5 1 ODS CL 1 2% ACP-1 DDS D.D5% ACP-:D 2. 4 1042 a N 0 1 2.

0.1 D% ACP 1 c 1042 2% ACP-1 D42 a N Placebo Paste The following examples further illustrate the invention:

EXAMIPLE 1 5 TOOTBIPASTE Ingredient % W/W Sorbitol 70 % Solution (non crystallising) 26. 0000 Silica 14.0000 Glycerin (98% min) 10.0000 Zeofree 153B 7.5000 PEG-6 3.0000 Detergent (Empicol 0045/V) 3.8300 Sodium Hydroxide, 10. 2 % Solution 4.4100 Titanium Dioxide (Cl 77891) 1.4500 Keltrol F 0.7000 Flavour 1.0000 Sodium Fluoride BP 0.2430 Saccharin, 30% Solution 0.7100 Polymer ACP-1042 0.0500 Triclosan 0.3000 Deionised Water to 100 4(1 EXAMPLE 2 TOOTHPASTE Ingredient % w/w Sorbitol 70 % Solution (non crystallising) 26. 0000 Silica 14.0000 Glycerin (98% min) 10.0000 Zeofree 153B 7.5000 PEG-6 3.0000 Detergent (Empicol 0045/V) 3.8300 Sodium Hydroxide, 10.2 % Solution 4.4100 Titanium Dioxide (Cl 77891) 1.4500 Keltrol F 0.7000 Flavour 1.0000 Sodium Fluoride BP 0.2430 Saccharin, 30% Solution 0.7100 Polymer ACP-1042 2.0000 Triclosan 0.3000 Deionised Water to 100 41- EXAMPLE 3 MOUTHWASH Ingredient % w/w Triclosan 0.05 Propylene Glycol 15.00 Ethanol 15.00 Glycerin 5.00 Flavour 0.15 PEG 60 Hydrogenated Castor Oil 0.25 Acrylidone Polymer 1005 2.00 Sodium Saccharin 0.06 Sodium Fluoride 0.05 Dye 0.0005 Deionised Water to 100 42-

Claims (1)

1. Claims

   1. An oral care composition comprising an N-vinylpyrrolidone, and acrylic acid polymer in a weight ratio in the range of 20-50 to 50-95 in combination with an antibacterially effective amount of an halogenated diphenyl ether compound in an orally acceptable carrier or excipient.

   2. A composition according to claim 1 wherein the halogenated diphenyl ether compound is 2,4,4'-trichloro-2'-hydroxy-diphenyl ether (Triclosan) or 2,T dihydroxy-5,5'-dibromo-diphenyl ether.

   3. A composition according to claim 2 wherein the halogenated diphenyl ether is Triclosan.

   4. A composition according to any one of claims 1 to 3 wherein the halogenated diphenyl ether is in the range of from 0.05 to 2 % w/w of the product.

   5. A composition according to claim 4 wherein the halogenated diphenyl ether is in the range of from 0. 1 to 1 % w/w of the product.

   6. A composition according to claim 1 wherein the N-vinylpyrrolidone and acrylic acid polymer is in the range from 0.01 to 10.0% w/w of the product.

   7. A composition according to claim 6 wherein the N-vinylpyrrolidone: and acrylic acid polymer is in the range from 0. 1 to 5.0 % w/w of the product.

   8. A composition according to any one of the above claims wherein the Nvinylpyrrolidone and acrylic acid polymer is present from between 0.05 to 2. 0 % w/w and the halogenated diphenyl ether is in the range of from 0. 1 to 1 % w/w of the product.

   43- 9. An oral hygiene composition according to any one of the above claims in the form of a toothpaste or cream, abrasive or non-abrasive dental gel, toothpowder, mouthwash, gargle, mouthspray, chewing gum, dental or chewing tablet or lozenge. 5 44.

   Abstract An oral care composition comprising an N-vinylpyrrolidone and acrylic acid polymer in a weight ratio in the range of 20-50 to 50-95 in combination with an antibacterially effective amount of an halogenated diphenyl ether compound in an orally acceptable carrier or excipient.

   45.