Oral Composition

This invention relates to oral antiplaque compositions such as dentifrice's, mouthwashes, lozenges, chewing gums and the like. The use of nisin, or of related anthionine-containing bacteriocins, in mouthwash and toothpaste is suggested in Blackburn et al, PCT International patent application WO 89/12399, published Dec. 28, 1989.

In accordance with one aspect of this invention, the oral composition contains the nisin together with an azacycloalkane-2,2-diphosphonate ion, such as azacycloheptane-2,2-diphosphonate ("AHP").

In broader aspects of the invention, other polyphosphonates may be used in place of the AHP. These include the known polyphosphonates which inhibit crystallization of hydroxyapatite and are inhibitors of the formation of dental claculus. Examples of such agents include pharmaceutically acceptable ions of azacycloalkane-2,2-phosphonic acids, such as those in which the alkane moiety has five, six or seven carbon atones, in which the nitrogen atom is unsubstituted (as in AHP) or carries a lower alkyl substitutent (e.g. methyl), such as those disclosed in Ploger et al U.S. Pat. No. 3,941,772. Other examples are ions of germinal diphosphonic acids such as ethanehydroxy-1,1,-diphosphonate (EHDP), ethane-1-amino-1,1-diphosphonate or dichloromethane-diphosphonate, as well as polymeric phosphonates such as water-soluble polymers and copolymers of vinylphosphonic acid (e.g. of molecular weight about 5000 to 30,000), including phosphonic polymers disclosed in Gaffar et al U.S. Pat. No. 5,032,386.

In place of the nisin, other lanthionine-containing peptide bacteriocins (e.g. subtilin, epidermin, cinnamycin, duramycin, anconvenin and Pep 5) may be employed, alone or in combinations of two or more such bacteriocins.

The proportion of the bacteriocin such as nisin is preferably such as to exert an antiplaque effect and the proportion of the phosphonate such as AHP is preferably such as to increase the antiplaque effectiveness of the bacteriocin. For a mouthrinse the proportion of the phosphonate may, for instance, be in the range of about 0.01% to 3%, preferably less than about 1%, e.g. within the range of about 0.05% to 0.5% such as about 0.2% or 0.3% and the proportion of the bacteriocin may, for instance, be in the range of about 0.01% to 1%, preferably about 0.03% to 0.5%. For a toothpaste (or other oral composition which, unlike a mouthrinse, becomes considerably diluted by saliva during use) the proportion of the phosphonate may, for instance, be in the range of about 0.03% to 15%, preferably within the range of about 0.15% to 6%, such as about 0.5% or 1%, and the proportion of the bacteriocin may, for instance, be in the range of about 0.01% to 5%, preferably about 0.5% to 2%.

Some aspects of the invention are illustrated in the following Examples.

A mouth rinse is prepared by mixing the following ingredients in the following proportions:

Tween 80, Pluronic F87 (Ex. 1) and Pluronic F127 (Ex. 2 and 3) are nonionic surfactants. Tween 80 is polyoxyethylene (20) sorbitan mono-oleate. The Pluronics are polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers; F87 has an average molecular weight of 7700, an HLB of more than 24 and a cloud point in aqueous 1% or 10% solution above 100.degree. C.; F 127 has an average molecular weight of 12600, an HLB of 18-23 and a cloud point in aqueous 1% or 10% solution of above 100.degree. C.

The pHs of the mixtures are 4.42 (Ex. 1), 4.16 (Ex. 2) and 4.06 (Ex. 3). Example 1 gives an initially clear mixture which becomes cloudy on standing for a few hours. Examples 2 and 3 give mixtures which remain clear. Each formulation shows superior activity against plaque formation when tested in an "artificial mouth" apparatus. In that test, diluted whole human saliva is pumped continuously, at a rate of 1 ml/minute, through a chamber containing two germanium plates. This forms a pellicle on the plates. After 20 minutes the saliva flow is stopped and the mouthrinse is pumped into the chamber for 30 seconds at a flowrate of 10 ml/min., after which the saliva flow, at 1 ml/min., is resumed for 30 minutes to wash out residual mouthrinse. Then the diluted saliva, together with 10% of its volume of trypticase soy broth, is continuously pumped through the chamber at the rate of 1 ml/min. After 24 and 48 hours the same procedure (involving a 30-second mouthrinse treatment) is repeated. After 72 hours the saliva treatment is discontinued and distilled water is circulated through the chamber at a rate of 5 ml/min. for 10 minutes. The resulting washed plates are removed and allowed to air dry, and the amount of plaque formed thereon is measured by infrared spectroscopy.

In the foregoing formulations the sodium acetate and acetic acid are present to provide a pH buffer, the Tween and Pluronic components are nonionic surfactants which aid in dispersing the ingredients, the flavor is added in solution in the ethanol (which helps to solubilize it in the composition), the glycerol (a conventional humectant ingredient in mouthwashes) gives increased viscosity and a moist feel in the mouth and the saccharin is, of course, a sweetening agent.

Generally, a mouthrinse according to this invention may contain, for instance, up to about 20% of ethyl alcohol, about 0% to about 50% of humectant, about 0.1 to 5% of an emulsifying agent (surfactant), about 0% to 0.5% of a sweetening agent, about 0.03% to 0.3% of a flavoring agent.

The pH values of the oral compositions of this invention are preferably in the range of about 4 to 8, such as about 4, 4.5, 5, 5.5, 6, 6.5 or 7. The compositions are preferably acidic; e.g. the pit is below about 6 or below about 5.

The oral compositions of this invention preferably contain surfactants, such as nonionic, cationic, zwitterionic and amphoteric surfactants. Many of the suitable surfactants (surface-active agents) are disclosed in Gaffar et al U.S. Pat. No. 4,889,712; the disclosures of such agents, and their proportions (e.g. up to about 10%), in that patent are incorporated herein by reference.

Zwitterionic surfactants include quaternary ammonium, phosphonium and sulfonium compounds having an 8 to 18 carbon atom aliphatic substituent and an aliphatic substituent having an anionic water-solubilizing group (e.g. carboxy, sulfonate, sulfate, phosphate or phosphonate); one example is 4-(N,N-di(2-hydroxyethyl)-N-octadecylammonio)-butane-1-carboxylate.

Cationic surfactants include quaternary ammonium compounds having an 8 to 18 carbon atom alkyl substituent, e.g. cetyl pyridinium chloride.

Amphoteric surfactants include secondary and tertiary amines having an 8 to 18 carbon atom aliphatic substituent and an aliphatic substituent having an artionic water-solubilizing group (e.g. carboxy, sulfonate, sulfate, phosphate or phosphonate); examples are N-alkyltaurines (e.g. reaction product of dodecylamine and sodium isethionate), Miranol, etc.

The compositions of this invention may contain fluoride ion, e.g. in the form of sodium fluoride, sodium fluorophosphate, or other fluoride ion source, such as those listed in Gaffar et al U.S. Pat. No. 4,889,712; the disclosures of such fluoride ion sources, and their proportions, in that patent are incorporated herein by reference.

A toothpaste is prepared according to the following formula:

In this toothpaste formulation, the glycerol and 70% sorbitol are conventional humectants, the hydroxyethylcellulose is a conventional binder or gelling agent, and the precipitated silica is a conventional amorphous silica dental abrasive. Other humectants, binders (thickeners or gelling agents), abrasives (polishing agents), surfactants and flavoring agents may be used, such as those listed in Gaffar et al U.S. Pat. No. 4,889,712, in the proportions described in that patent, whose disclosures thereof are incorporated herein by reference.

A clear mouthrinse having a pH of 4.25 is prepared from the following ingredients: water 84.625%; sodium acetate 0.6%; aqueous 10% solution of acetic acid 2.6%; Tego Betain L5351 1%; Pluronic F127 1%; sodium sacharin 0.075%; nisin 0.1%; aqueous 5% solution of polyvinyl phosphonic acid (of molecular weight about 300) 10%. The Tego Betain L5351 is an aqueous solution, containing about 33% of cocamidopropyl betain, a zwitterionic surfactant commercially available from Goldschmidt Chemical Corp.

The composition of this invention are preferably substantially free of strong chelating agents such as EDTA or citrate ions.

As indicated in the Examples the compositions of this invention contain water, e.g. 2% to 95% water. For mouthrinses the proportion of water may be, for instance, in the range of about 10 to 95% preferably about 40% to 85%. For toothpastes the water content may be, for instance, in the range of about 5 to 50% preferably about 10 to 30%.

This invention has been disclosed with respect to preferred embodiment and it will be understood that modifications and variations thereof are to be included within the spirit and purview of this application.