FR2684550A1 - Antibacterial composition for combating plaque, comprising a styrenephosphonic acid polymer or a copolymer of styrenephosphonic acid and an ethylenically unsaturated monomer - Google Patents

Abstract

The invention relates to an antibacterial composition for combating plaque, comprising a styrenephosphonic acid polymer or a copolymer of styrenephosphonic acid and an ethylenically unsaturated monomer. The polymer is chosen from a beta -styrenephosphonic acid polymer, an alpha -styrenephosphonic acid polymer and copolymers of one or other of these acids with at leat one other ethylenically unsaturated copolymerisable monomer. This polymer is, in particular, useful as an agent for stimulating antibacterial activity in antibacterial compositions for buccal use against dental plaque. Field of application: Dentibuccal hygiene products.

Description

 The present invention relates to styrene-phosphonic polymers which are effective in stimulating the activity against dental plaque of an anti-bacterial anti-plaque composition for oral use.

 Dental plaque is a soft deposit that forms on the teeth, unlike tartar which is a hard mineral formation deposited on the teeth.

Unlike tartar, plaque can form anywhere on the surface of the teeth, including in particular at the gingival margin. As a result, in addition to its unsightly appearance, dental plaque is involved in the appearance of gingivitis.

 It is therefore very desirable to include antimicrobial agents, which are already known to reduce plaque, in compositions for oral use. Cationic type antibacterial agents have often been proposed. In addition, in the U.S. patent NO 4,022,880 a compound providing zinc ions serving as an anti-scale agent is mixed with an effective antibacterial agent to retard the development of the bacteria responsible for dental plaque. A wide variety of antibacterial agents are described with zinc compounds, including cationic substances such as guanides and quaternary ammonium compounds, as well as non-cationic compounds such as halogenated salicylanilides and halogenated hydroxydiphenyl ethers. Antibacterial, anti-plaque, non-cationic halogenated hydroxydiphenyl ether, namely Triclosan, has also been proposed in combination with zinc citrate trihydrate in European patent publication No. 0 161 899.

Cationic antibacterial substances such as chlorhexidine, benzethonium chloride and cetylpyridinium chloride have been the subject of the most important research on antibacterial anti-plaque agents. However, they are generally ineffective when used with anionic substances. Non-cationic antibacterial substances can, on the other hand, be compatible with the anionic components of a composition for oral use.
However, compositions for oral use are typically mixtures of many components and, even typically neutral substances such as humectants, can affect the behavior of these compositions.

 An advantage of the present invention is that it makes it possible to obtain a composition for oral use containing a non-cationic antibacterial agent substantially insoluble in water and provides an antibacterial stimulating agent comprising a new styrene-phosphonic polymer which improves the distribution and retention of said antibacterial agent on the surfaces of the oral cavity to inhibit the formation of dental plaque.

 An advantage of the present invention is that said antibacterial stimulants improve the distribution and retention of antibacterial agent on teeth and soft tissues of the oral cavity.

 Another advantage of the present invention resides in that the antiplaque composition for oral use effectively reduces the appearance of gingivitis.

 Other advantages of the present invention will emerge from the description which follows.

 In certain aspects, the present invention relates to a polymer chosen from a beta-styrene-phosphonic acid polymer, an alpha-styrene-phosphonic acid polymer and copolymers of both of these styrene acids. -phosphonic with at least one polymerizable ethylenically unsaturated monomer.

 These polymers are effective in stimulating the antiplaque activity of compositions for oral use containing an antibacterial antiplaque agent substantially insoluble in water, for example in an amount of about 0.01 to 5% by weight, chosen for example from ethers of halogenated diphenyls, such as 2 ', 4,4'-trichloro-2-hydroxy (diphenyl ether) (Triclosan) or 2,2' -dihydroxy-5,5'-dibromo (diphenyl ether), as well as halogenated salicylanilides, benzol esters, halogenated carbanilides and phenolic compounds.

 The antibacterial stimulating agent (ASA) which improves the distribution and retention of said antibacterial agent on the oral surfaces, is used in amounts effective to achieve this improvement which are in the range of about 0.005% to about 4% , preferably from about 0.1% to about 3% and more preferably from about 0.5% to about -2.5% by weight in the composition for oral use.

 ASA can be a simple compound, preferably a polymerizable monomer, better still a polymer, the latter term being taken in a completely generic sense and including for example oligomers, homopolymers, copolymers of two or more monomers, ionomers , block copolymers, graft copolymers, crosslinked polymers and copolymers, etc. ASA can be natural or synthetic, and insoluble in water or, preferably, soluble or swellable (hydratable, forming a hydrogel) in water (saliva). It has an average molecular weight (by weight) of about 100 to about 1,000,000, preferably from about 1,000 to about 1,000,000 and more preferably from about 2,000 or 2,500 to about 250,000 or 500,000.

The ASA ordinarily contains at least one distribution enhancing group, which is preferably acidic, for example of a sulfonic, phosphonic, or more preferably phosphonic or carboxylic acid, or a salt thereof, for example of an alkali metal or of ammonium, and at least one organic group improving the retention, preferably several of each of the groups improving the distribution and improving the retention, the latter groups preferably corresponding to the formula - (X) R where X is O, N, S, So, S021 P, PO,
not
If, etc., R is a hydrophobic alkyl, alkenyl, acyl, aryl, alkaryl, aralkyl, heterocyclic group or one of their inert substituted derivatives, and n is zero or 1 or more. The above "inert substituted derivatives" include substituents on R which are generally non-hydrophilic and do not substantially disturb the functions which the ASA must fulfill to improve the distribution and retention of the antibacterial agent on the oral surfaces, for example halogen substituents, in particular Cl, Br, I, and carbo, etc.

Representative examples of such retention enhancing groups are presented in a table below.

n X
n 0 --- methyl, ethyl, propyl, butyl, isobutyl,
t-butyl, cyclohexyl, allyl, benzyl,
phenyl, chlorophenyl, xylyl, pyridyl,
furannyl, acetyl, benzoyl, butyryl,
terephthaloyl, etc.

1O ethoxy, benzyloxy, thioacetoxy, phenoxy,
carbethoxy, carbobenzyloxy, etc.

N ethylamino, diethylamino, propylamido,
benzylamino, benzoylamido, phenylacetamido,
etc.

S thiobutyle, thio-isobutyle, thioallyl,
thiobenzyl, thiophenyl, thiopropionyl,
phenylthioacetyl, thiobenzoyl, etc.

SO butylsufoxy, allylsulfoxy, benzylsulfoxy,
phenylsulfoxy, etc.

SO2 butylsulfonyl, allylsulfonyl, benzylsul
fonyl, phenylsulfonyl, etc.

P diethylphosphinyl, ethylvinylphosphinyl,
ethylallylphosphinyl, ethylbenzylphosphi
nyle, ethylphenylphosphinyl, etc.

PO diethylphophinoxy, dthylvinylphosphinoxy,
methylallylphosphinoxy, methylbenzylphos
phinoxy, methylphenylphosphinoxy, etc.

If trimethylsilyl, dimethylbutylsilyl,
dimethylbenzylsilyl, dimethylvinylsilyl,
dimethylallylsilyl, etc.

 As used herein, the term "distribution enhancing group" refers to a group which substantially, adhesively, adhesively, or cohesively binds or binds ASA (carrying the antibacterial agent) to the surfaces of the cavity buccal (eg teeth and gums), thereby "delivering" or "distributing" the antibacterial agent to these surfaces. The organic group improving retention, usually hydrophobic, fixes or otherwise binds the antibacterial agent to ASA, thereby improving the retention of the antibacterial agent to the IVASA and, indirectly, to the surfaces of the oral cavity. In some cases, the fixing of the antibacterial agent is effected by its physical overlapping by the ASSAI in particular when ASA is a crosslinked polymer, the structure of which naturally offers more sites suitable for such encroachment. The presence of a more hydrophobic crosslinking fragment, of higher molecular weight, in the The crosslinked polymer further promotes the physical encroachment of the antibacterial agent by the crosslinked polymer forming the ASA.

 Preferably, the ASA is an anionic polymer comprising a chain or skeleton having repeating units which each preferably contain at least one carbon atom and, preferably, at least one monovalent group improving the distribution attached laterally directly or indirectly and at least one monovalent retention improving group attached laterally directly or indirectly, which are linked in twin, vicinal or, less preferably, in other ways to atoms, preferably chaining carbon atoms. Less preferably, the polymer may contain distribution improving groups and / or retention improving groups and / or other divalent atoms or groups as links in the polymer chain in place of or in addition to carbon atoms, or as moieties crosslinkers.

 It will be understood that all of the examples or illustrations of ASAs presented herein which do not contain both distribution improving groups and retention improving groups can, and preferably should, be chemically modified in a known manner to form the Preferred ASAs containing these two types of groups, and preferably more than one of each type of these groups. In the case of preferred polymeric ASAs, it is advantageous, in order to maximize the substantivity and the distribution of the antibacterial agent to the surfaces of the oral cavity, that the recurring units of the polymer chain or skeleton comprising the acid groups improving the distribution constitute at least 10%, preferably at least about 50%, and more preferably at least about 80% to 95% or 100% by weight of the polymer.

qui, cependant, ne contient pas de groupe améliorant la rétention.Un groupe de ce dernier type est cependant présent dans un poly-(l-phosphonopropène) ayant des motifs de formule

According to a preferred embodiment of the present invention, the ASA consists of a polymer containing repeating units in which one or more distribution improving phosphonic acid groups are linked to one or more carbon atoms of the polymer chain. An example of such an ASA is a poly (vinylphosphonic acid) having units of formula

which, however, does not contain a retention enhancing group. A group of the latter type is, however, present in a poly- (l-phosphonopropene) having units of the formula

où Ph est le groupe phényle, le groupe phosphonique améliorant la distribution et le groupe phényle améliorant la rétention étant liés à des atomes de carbone vicinaux de la chaîne, ou un copolymère d'acide bêtastyrène-phosphonique avec le chlorure de vinylphosphonyle contenant les motifs de formule III en alternance ou en association statistique avec des motifs de formule I ci-dessus, ou encore un poly(acide alphastyrène-phosphonique) ayant des motifs de formule ::

où les groupes améliorant la distribution et les groupes améliorant la rétention sont liés en relation géminale à la chaîne.An ASA containing phosphonic acid which is preferred to be used here is a poly (beta-styrenephosphonic acid) having units of formula

where Ph is the phenyl group, the phosphonic group improving the distribution and the phenyl group improving the retention being linked to vicinal carbon atoms of the chain, or a copolymer of betastyrene-phosphonic acid with vinylphosphonyl chloride containing the units of formula III alternately or in statistical association with units of formula I above, or alternatively a poly (alphastyrene-phosphonic acid) having units of formula:

where the groups improving the distribution and the groups improving the retention are linked in female relation to the chain.

 These styrene-phosphonic acid polymers and their copolymers formed with other inert ethylenically unsaturated monomers generally have molecular weights in the range of about 2000 to about 30,000, preferably about 2,500 to about 10,000. These "inert" monomers do not significantly disturb the function assigned to any copolymer used here as ASA.

et une poly(allyl-bis(phosphonoéthyl)amine) ayant des motifs de formule

Other polymers containing phosphonic groups include, for example, a phosphonated ethylene polymer having units of formula:
V [CH2) 14eHP03H2] n- where n can, for example, be an integer or have a value giving the polymer a molecular weight of approximately 3000; and a poly (sodium butene-4,4-diphosphonate) having units of formula

and a poly (allyl-bis (phosphonoethyl) amine) having units of formula

Other phosphonated polymers, for example a poly (allyl-phosphono-acetate), a phosphonated polymethacrylate, etc., and the polymers with two feminine phosphonate groups described in European patent No. 321 233 can be used here as ASA, provided of course that they contain or are modified to contain the organic groups improving the retention defined above.

 The new polymers of alpha- and beta-styrene-phosphonic acids and their copolymers formed with other ethylenically unsaturated monomers can generally be prepared by heating the monomers or mixtures of monomers, preferably under nitrogen, in the presence of an amount effective, for example about 2.6 & 5 *, of a radical initiator, for example AIBN (a: obisisobutyronitrile), benzoyl peroxide, tert.-butyl hydroperoxide, a persulfate, etc., without solvent or dissolved in an inert solvent such as acetonitrile, methylene chloride or 1,2-dichioromethane, at elevated temperatures, for example up to about 125 ° C or at reflux of the solvent, for periods of about 8 & 200 hours.

The crude polymer products, after removal of any inert solvent, are mixed with water and the pH of the aqueous mixture is adjusted to about 8-11, for example with an aqueous solution of sodium hydroxide. After filtration of any solid impurities, the filtrate solution is dialyzed against water (for example at a molecular weight threshold of 3500 daltons) and the purified polymer is isolated from the solution retained, for example by lyophilization.

 According to another preferred embodiment, the ASA may contain a synthetic anionic polymeric polycarboxylate. Although not used in the present invention to act in concert with a polyphosphate type anti-scale agent, a synthetic anionic polymeric polycarboxylate having a molecular weight of from about 1000 to about 1,000,000, preferably from about 30,000 at around 500,000, has been used as an alkaline phosphatase inhibitor to optimize the anti-scale activity of linear saline polyphosphates with molecular dehydration, as described in the US patent NO 4 627 977. Indeed, in British patent publication NO 2 200 551, the polymeric polycarboxylate is proposed as an optional ingredient in compositions for oral use containing linear saline polyphosphates with molecular dehydration and a non-cationic antibacterial agent. has further observed, in the context of the present invention1 that this polycarboxylate, when it contains or is modified to contain retention-improving groups, is very effective in improving the distribution and retention of the nonionic antibacterial anti-plaque agent on dental surfaces when there is no other ingredient with which the polymeric polycarboxylate is capable of acting (i.e. a molecularly dehydrated polyphosphate); for example, when the ingredient with which the polymeric polycarboxylate acts in concert is in particular the non-cationic antibacterial agent.

 Synthetic anionic polymeric polycarboxylates and their complexes formed with various cationic germicides, zinc and magnesium have been previously proposed as scale inhibitors by themselves, for example in U.S. patents.

 NO 3,429,963, 4,152,420, 3,956,480, 4,138,477 and 4,183,914. It will be understood that the synthetic anionic polycarboxylates thus proposed in these various patents, when they contain or are modified to contain groups improving the retention, are usable in the compositions and methods of the present invention and, to that extent, the relevant disclosures of these patents are incorporated herein by reference to them.

These synthetic anionic polymeric polycarboxylates are often used in the form of their free acids or, preferably, their alkali metal (for example potassium and preferably sodium) or ammonium salts, partially or, better still, totally neutralized, water-soluble or swellable with water (hydratable, forming a gel). Preferred are the 1: 4 to 4: 1 copolymers of maleic anhydride or acid with another ethylenically unsaturated polymerizable monomer, preferably a methyl ether / vinyl / maleic anhydride copolymer having a molecular weight (PM) of about 30 000 to about 1,000,000 and better still from about 30,000 to about 500,000. These copolymers are available, for example, under the Gantrez product designations, for example
AN 139 (PM 500,000), AN 119 (PM 250,000) and, preferably, S-97 Pharmaceutical Grade (PM 70,000) from
GAF Corporation.

 Other polymeric polycarboxylates usable as ASA, containing or modified to contain retention improving groups include those proposed in the U.S. Patent. NO 3,956,480 cited above, such as 1: 1 copolymers of maleic anhydride with ethyl acrylate, hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone or ethylene, the latter type of copolymer being available, for example, under the designations EMA NO 1103, PM

10,000, and EMA Grade 61 from Monsanto, and 1: 1 copolymers of acrylic acid with methyl or hydroxyethyl methacrylate, methyl or ethyl acrylate, isobutyl vinyl ether or N-vinyl-2-pyrrolidone.

Other usable polymeric polycarboxylates proposed in the aforementioned US Pat. Nos. 4,138,477 and 4,183,914, containing or modified to contain retention improving groups, include maleic anhydride copolymers with styrene, isobutyrene or ethyl vinyl ether, polyacrylic, polyitaconic and polymaleic acids, and sulfoacrylic oligomers with PM as low as 1000, available under the designation ND-2 from
Uniroyal.

 Suitable monomers in general are the olefinically or ethylenically unsaturated carboxylic acids containing a retention-improving group, which have an activated carbon-carbon olefin double bond which easily polymerizes because it is present in the monomer molecule either in alpha-beta position relative to a carboxyl group, either as part of a terminal methylene group. Representative examples of such acids are acrylic, methacrylic, ethacrylic, alpha-chloracrylic, crotonic, beta-acryl oxypropionic, sorbic acids, alpha-chlorosorbic, cinnamic, beta-styrylacrylic, muconic, itaconic, citraconic, mesaconic, glutaconic, aconitic, alpha-phenylacrylic, 2-benzylacrylic, 2-cyclohexylacrylic, angelic, umbellic, fumaric, maleic and. Other different olefin monomers copolymerizable with these carboxylic monomers include vinyl acetate, vinyl chloride, dimethyl maleate, etc. The copolymers contain enough salified carboxylic groups to ensure their solubility in water.

 Substances also useful here are so-called carboxyvinyl polymers proposed as components of toothpaste in U.S. patents.

Nos. 3,980,767, 3,935,306, 3,919,409, 3,911,904 and 3,711,604. These polymers are available commercially, for example, under the trade names.
Carbopol 934, 940 and 941 from BF Goodrich, these products essentially consisting of a colloidally water-soluble polymer of polyacrylic acid crosslinked with approximately 0.75% to approximately 2.0% of polyallyl-sucrose or polyallyl-pentaerythritol as crosslinking agent , the crosslinked structure and the crosslinking bonds ensuring the desired retention improvement by hydrophobicity and / or physical overlapping of the antibacterial or other agent. A carbophilic polymer is quite similar, being a polyacrylic acid crosslinked with less than 0.2% of divinylglycol, the proportion, the molecular weight and / or the hydrophobicity lower of this crosslinking agent tending to offer little or no improvement in retention. 2,5dimethyl-1,5-hexadiene is an example of a more effective cross-linking agent which improves retention.

 The synthetic anionic polymeric polycarboxylate component is most often a hydrocarbon optionally containing halogenated and oxygenated bonds and substituents, such as exist for example in ester, ether and OH groups.

 The ASA may also include natural anionic polymeric polycarboxylates containing retention enhancing groups. Carboxymethylcellulose and other binding agents, gums and film-forming agents lacking the distribution improving and / or retention improving groups defined above are ineffective as ASAs.

As representative examples of ASAs containing phosphinic acid and / or sulfonic acid groups improving the distribution, mention may be made of polymers and copolymers containing units or fragments originating from the polymerization of vinyl- or allyl-phosphinic acids and / or sulfonic acids substituted, as necessary, on the carbon atom in 1 or 2 (or 3) by an organic group improving retention, corresponding for example to the formula - (X) nR defined above. Mixtures of these monomers and their copolymers formed with one or more ethylenically unsaturated inert polymerizable monomers such as those described above with respect to the usable synthetic anionic polycarboxylates can be used. As will be noted, in these polymeric ASAs as well as others usable here, there is generally only one acid group improving the distribution linked to any given atom of carbon or other of the backbone of the polymer or of a branching of the latter. Polysiloxanes containing or modified to contain side groups improving distribution and side groups improving retention can also be used here as ASA. Ionomers containing or modified to contain distribution and retention enhancing groups are also effective here as ASA. These ionomers are described on pages 546-573 of the additional volume of "Kirk
Othmer Encyclopedia of Chemical Technology ", third edition, John Wiley & Sons, Inc., copyright 1984, the description of which is incorporated herein by reference. Substances also effective here as ASA are synthetic and natural polyesters, polyurethanes and polyamides, including proteins and proteinaceous materials such as collagen, poly (arginine) and other polymerized amino acids, provided that they contain or are modified to contain retention enhancing groups.

 Without wishing to be bound by a theoretician, it is considered that ASA, in particular a polymeric ASA, is generally and advantageously a film-forming anionic substance and it is believed that it binds to dental surfaces and forms a continuous film on the surfaces, thereby preventing bacterial attachment to the surface of the teeth. It is possible that the non-cationic antibacterial agent forms a complex or some other kind of association with ASA, thereby forming a film of a complex or the like on the dental surfaces. It appears that the film-forming property of 1ASA and the better distribution and retention of the antibacterial agent on the dental surfaces under the effect of 1ASA make the dental surfaces not receptive to bacterial accumulation, in particular because the direct bacteriostatic action of the antibacterial agent inhibits bacterial growth.

Consequently, by the combination of the three modes of action, namely: 1) the best distribution, 2) the long retention time on the dental surfaces and 3) the prevention of ~ bacterial attachment to the dental surfaces, the composition for oral use is made effective in reducing dental plaque.

A similar antiplaque efficacy is obtained on the soft tissues located at or near the gingival margin.

 A vehicle acceptable for oral use, comprising an aqueous phase with a humectant, is present in the preparation for oral use. The humectant is preferably glycerol and / or sorbitol. Large quantities of polyethylene glycol, in particular with a molecular weight of 600 or more, should be avoided, since polyethylene glycol strongly inhibits the antibacterial activity of the non-cationic antibacterial agent. For example, polyethylene glycol (PEG) 600, when present with Triclosan in a weight ratio of Triclosan to PEG 600 by 25: 1, reduces the antibacterial activity of Triclosan by a factor of about 16 compared to that which occurs in the absence of polyethylene glycol.

 Substances which substantially dissolve the antibacterial agent can be used to dissolve the antibacterial agent in saliva to allow its distribution to the soft tissues of the oral cavity at or near the gingival margin.

Typical examples of solubilizing substances include humectants of the polyol type such as propylene glycol, dipropylene glycol and hexylene glycol, products of the Cellosolve type such as
Methylcellosolve and Ethylcellosolve, vegetable oils and waxes containing at least about 12 carbon atoms in a straight chain configuration, such as olive oil, castor oil, petroleum jelly and esters such as l amyl acetate, ethyl acetate, glyceryl tristearate and benzyl benzoate. Propylene glycol is preferred. As used herein, the term "propylene glycol" includes 1,2-propylene glycol and 1,3-propylene glycol.

 The pH of the oral preparation is generally in the range of from about 4.5 to about 9 or 10, and preferably from about 6.5 to about 7.5. It is interesting to note that the compositions can be applied to the oral cavity at a pH below 5 without substantially decalcifying or otherwise damaging the dental enamel. The pH can be adjusted with an acid (for example citric acid or benzolic acid) or a base (for example sodium hydroxide) or buffered (for example with citrate, benzoate, carbonate or sodium bicarbonate , disodium hydrogen phosphate, sodium dihydrogen phosphate, etc.).

 The preparation for oral use can be substantially liquid, for example being a mouthwash, or it can be a toothpaste containing a polishing agent acceptable for the teeth.

The composition of toothpaste for oral use generally contains a natural or synthetic thickening or gelling agent.

 The composition for oral use may also contain a source of fluoride ions or of component providing fluorine, as an anti-caries agent.

 It will be understood that, as is usual, preparations for oral use must be sold or otherwise distributed in suitably labeled packages. Thus, a toothpaste gel is usually packaged in a compressible tube, typically aluminum, coated lead or plastic, or in another compressible dispenser, pump or pressure, intended to deliver its content in a metered and carrying a label essentially describing it as a toothpaste gel, etc.

 Organic surfactants are used in the oral compositions to exert an increased prophylactic action, to help achieve a complete and uniform dispersion of the anti-plaque antibacterial agent throughout the oral cavity, and to make the compositions more palatable cosmetic view. The organic surface-active substance is preferably of anionic, nonionic or ampholytic character, and it is preferred to use as a surface-active agent a detersive substance which gives the composition detergent and foaming properties.

 Various other substances can be incorporated into the oral preparations of the present invention, such as preservative bleaches, silicones, chlorophyll compounds and / or ammonia substances such as urea and diammonium phosphate, and their mixtures. These adjuvants, if present, are incorporated into the preparations in proportions which do not significantly affect the desired properties and characteristics. Large proportions of generally soluble salts and substances containing zinc, magnesium and other metals which would form complexes with the active components of the preparations of the present invention should be avoided.

 Any suitable flavoring or sweetening substance may also be used.

 The composition for oral use is preferably applied at regular intervals to the dental enamel and the soft tissues of the oral cavity, in particular at or near the gingival margin, for example daily or every two or three days, or preferably 1 to 3 times a day, at a pH of about 4.5 to about 9, generally about 5.5 to about 8, preferably about 6.5 to 7.5, for at least 2 to 8 weeks or more, even for life.

 The ASA and the antibacterial agent can be incorporated into lozenges or into chewing gum or other products, for example by shaking them in a hot gum base or by applying them to the outer surface of a gum base. of which representative examples which may be mentioned are jelutong, rubber latex, vinylite resins, etc., advantageously combined with conventional plasticizers or softeners, sugar or other sweeteners or carbohydrates such as glucose , sorbitol, etc.

 The following examples further illustrate the present invention without, however, limiting it. All quantities and proportions are expressed by weight, unless otherwise indicated.

EXAMPLE A Beta-styrene-phosphonic acid)
A mixture of 18.1 g is stirred at reflux in an atmosphere of anhydrous nitrogen for 96 hours.
(0.1 mole) beta-styrene-phosphonic acid and 0.82 g
(0.005 mole) of azobisisobutyronitrile (AIBN) in 300 ml of anhydrous acetonitrile. The mixture is cooled and the precipitated crude product is isolated by filtration, washed with acetonitrile and air dried.

The crude product is mixed with water; in the mixture is dissolved an aqueous solution of sodium hydroxide (& pH 11) and the mixture is dialyzed against water with a molecular weight-threshold of 3000 daltons. The solution retained is concentrated under vacuum to a volume of 100 ml under vacuum and lyophilized to obtain 0.91 g of the purified polymer product in the form of a white powdery solid. Infrared spectrum: 1610, - 1550, 745 cm (aryl, 5 H adjacent); 1240, 1020 950 cm (phosphonate). NMR of the protons (D2O): t, 6.4 ppm (H on carbon carrying the phosphonate); m, 7.3 ppm (aryl and benzylic protons); ratio of areas 1 to 6.

Phosphorus NMR (D2O): m, 6.2 ppm (alkyl phosphonate).

EXAMPLE B
Copoly (beta-styrene-phosphonic acid / vinylphosphonic acid)
Heated, with stirring, under an atmosphere of anhydrous nitrogen, intermittently for a few hours, then at 80-900 ° C. overnight, a mixture of 10.68 g (0.058 mole) of beta-styrene-phosphonic acid, 6 , 0 ml (8.4 g, 0.058 mole) of vinylphosphonyl dichloride and 0.5 g of AIBN. The material is transferred to a beaker with 60 to 70 ml of water. A crystalline precipitate forms while the hot solution cools.

The mixture is filtered, the aqueous filtrate is diluted to 125 ml with water, and the resulting solution is dialyzed against water with a threshold molecular weight of 3000 daltons. The solution retained is evaporated under vacuum to obtain 0.600 g of the purified acid form of the copolymer. The proton NMR spectrum (D20) shows regions wide at 1.0-2.8 (allyl, lin) and 6.9-7.5 ppm (aryl, 5H). These results indicate a ratio of beta-styrene-phosphonic acid to vinylphosphonic acid of 1: 3 in the copolymer. The phosphorus NMR spectrum (D20) shows two main phosphorus signals centered at around 23.4 and 29.2 ppm respectively.

EXAMPLE C
Poly (alpha-styrene-phosphonic acid)
A mixture of 2.21 g (0.01 mole) of alphastyrene-phosphonyl dichloride and 0.01 g of AIBN is stirred at 1150cri under a nitrogen atmosphere. At intervals of 12 hours, successive portions of 0.01 g of AIBN are added to the mixture. After 96 hours, the mixture is allowed to cool and dissolve in water. The pH is adjusted to 8-10 with an aqueous solution of sodium hydroxide in a total volume of 125 ml. The solution is filtered and the filtrate is dialyzed against water in a cellulose sachet having a threshold molecular weight of 3500 daltons. The retained solution is concentrated under vacuum to a volume of approximately 50 ml, then lyophilized. The polymer is obtained in the form of a powdery solid of tan color in an amount of 0.08 g. Proton NMR (D2O): 23-25 ppm (m).

 It goes without saying that the invention is not limited to the embodiments described and that it is possible to make various variants and modifications without departing from its scope.

Claims (7)

 1. Antiplaque antibacterial composition for buccal use, characterized in that it comprises a polymer chosen from a beta-styrenephosphonic acid polymer, an alpha-styrene-phosphonic acid polymer, and the copolymers of one or the other of these styrene-phosphonic acids with at least one other ethylenically unsaturated polymerizable monomer.  2. anti-bacterial anti-plaque composition for buccal use according to claim 1, characterized in that the molecular weight of said polymer is approximately 2000 to 10 000.  3. anti-bacterial anti-plaque composition for oral use according to claim 1, characterized in that said polymer is a polymer of alphastyrene-phosphonic acid.  4. Anti-bacterial anti-plaque composition for oral use according to claim 1, characterized in that said polymer is a polymer of betastyrene-phosphonic acid.  5. Antiplaque antibacterial composition for oral use according to claim 1, characterized in that said styrene-phosphonic acid copolymer is copolymerized with at least one other ethylenically unsaturated monomer.  6. A method of preparing a polymer as defined in claim 1, characterized in that it consists in polymerizing the monomer or a mixture of monomers at high temperature in the presence of a radical initiator, in mixing the crude polymer product with water, adjust the pH of the resulting solution to about 8-11, dialyze the solution against water and isolate the purified polymer.  7. Method according to claim 6, characterized in that the molecular weight of said purified polymer is approximately 2000 to 10 000.