WO1999036048A1

WO1999036048A1 - Stable dental and oral preparations for removing tobacco tar and common food stains, as well as refreshing the mouth

Info

Publication number: WO1999036048A1
Application number: PCT/US1998/027760
Authority: WO
Inventors: Jin Xu; Marissa K. Mercado; Bala C. Nayar; Kuo-Chen Yeh
Original assignee: Block Drug Company, Inc.
Priority date: 1998-01-15
Filing date: 1998-12-24
Publication date: 1999-07-22
Also published as: AU1949199A

Abstract

A formulation for removing deposits on surfaces found in the oral cavity comprising at least one material for removing hydrophobic deposits from surfaces found in the oral cavity, wherein said material is subject to degradation over time in an aqueous environment; and a buffering agent to retard degradation of said material.

Description

STABLE DENTAL AND ORAL PREPARATIONS FOR REMOVING TOBACCO TAR AND COMMON FOOD STAINS, AS WELL AS REFRESHING

THE MOUTH

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to formulations for maintaining oral hygiene. The invention can solubilize, disperse and remove tobacco tar and other common stains, such as coffee, tea and blueberry stains, from the oral cavity, including teeth (or dentures) . The invention also relates to methods for making and using such formulations.

2. Description of Related Art

Staining of teeth and dentures by foods, beverages and tobacco products is a common problem. Unfortunately, good solutions to the staining problem are not as common. Generally, it is difficult to remove tobacco tar and food stains from the teeth (and dentures) , gums and other surfaces of the oral cavity.

As an example, the major constituent of deposits caused by smoking is commonly known as "tar". Tobacco tar is loosely defined as a dark, oily, viscid blend of polycyclic aromatic and aliphatic hydrocarbons, although tar also contains other compounds .

As a smoker smokes a cigarette, pipe, or cigar, he or she brings tar, along with the other tobacco combustion products, into the oral cavity. After inhaling, the smoke passes through the mouth of the smoker once again while exhaling. The -smoke can thus pass through the mouth of the smoker twice, which provides ample opportunity for the compounds in the tar to come into contact with the teeth, gums, tongue, and other surfaces in the oral cavity and to be deposited thereon.

Due to the hydrophobic nature of the compounds contained within the tar, the tar is not easily dissolved or dispersed by commonly available over-the-counter mouth treatments such as toothpastes, gels, and oral rinses. As a result, tar can build up on the teeth, dentures, denture plates, artificial teeth and other surfaces of the smoker's mouth causing, among other things, staining of plaque and calculus and an aesthetically displeasing appearance of the smoker's teeth and mouth. Additionally, since the compounds in tar have an unpleasant aroma, deposition of these compounds in the oral cavity can cause halitosis.

Many other compounds contained within food and other substances that come into the oral cavity can also be deposited on the surfaces of the oral cavity and cause problems similar to those caused by tobacco tar.

Various products, such as toothpastes and gels, attempt to remove tar and other deposits from teeth by physical abrasion. These products usually include an aluminum or silicon based abrading material to remove deposits from surfaces in the oral cavity. Unfortunately, the abrading materials in these products do not differentiate between the deposits and other, beneficial materials, such as the actual surface of the teeth. In addition to removing tobacco tar, these materials can also remove enamel from the teeth themselves, causing scratches and other damage to the tooth surface and irritation to soft tissues in the oral cavity.

These scratches can make the teeth more susceptible to decay and endanger the softer interior layers of the teeth. Also, the scratches can act to increase the surface area of the teeth, thereby increasing the number of places where bacteria can attach to the surface of the tooth and potentially cause tooth decay.

These abrasive cleaners are also not capable of removing deposits from areas in the oral cavity that are either too small for the abrasives to enter or that are not reached by mechanical brushing, such as the interproximal spaces between teeth and some gingival spaces between the teeth and gums .

One attractive alternative to abrasive products is found in U.S. Patent No. 5,514,366 to Diamond, issued May 7, 1996. That patent describes an oral preparation for removing tar and other hydrophobic materials from surfaces in the oral cavity. The preparation comprises a nonionic surfactant, an anionic surfactant, ethyl alcohol, methyl salicylate and another essential oil. The disclosure of U.S. Patent No. 5,514,366 to Diamond is hereby incorporated by reference herein.

Diamond states that its oral preparation removes tar from all surfaces in the mouth of a smoker and does not physically harm the tooth surface. It acts by dissolving and/or dispersing the tobacco tar, thereby removing it from the surface without any of the adverse effects associated with abrasive materials.

While the Diamond formulation offers many advantages, it may not be fully stable in all circumstances. Products in aqueous environments, such as water-based dentifrices and mouthwashes, may require special precautions to prevent interactions among the various ingredients in the formulation. Such interactions occur even more readily in a homogeneous aqueous solution. For example, hydrolysis of methyl salicylate or various esters mentioned in Diamond can lower the tar-removal and anti-bacterial efficacy of the formulation and degrade the taste profile of the product .

SUMMARY OF THE INVENTION

The principal object of the invention therefore is to provide a stabilized oral health care formulation for the removal of hydrophobic materials from surfaces found in the oral cavity. Another object of the invention is to provide methods for using such oral health care formulations.

It is an advantage of the invention that such formulations may also comprise ingredients to improve the overall oral health of a user of the formulation.

It is another advantage of the invention that such formulations may also contain ingredients to clean the oral cavity.

It is still another advantage of the invention that such formulations may provide excellent organoleptic qualities to enhance the attractiveness of the product.

Additional objects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from this description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims . To achieve the foregoing objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a formulation comprising at least one material for dissolving or dispersing hydrophobic deposits from surfaces found in the oral cavity. The material is subject to degradation over time in an aqueous environment, so the formulation also comprises a buffering agent to retard degradation of the material.

To further achieve the foregoing objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a method of removing deposits from a surface found in the oral cavity, comprising the steps of: exposing the surface to a formulation comprising: (a) at least one material for dissolving or dispersing hydrophobic deposits from surfaces found in the oral cavity, wherein the material is subject to degradation over time in an aqueous environment; and (b) a buffering agent to retard degradation of the material, for a time sufficient to dissolve or disperse the deposit; and removing the dissolved or dispersed deposit from the surface. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the presently preferred embodiments of the invention.

The formulations of the invention remove deposits on the teeth, gums, tongue, and other surfaces in the oral cavity. The formulations of the invention preferably include at least one surfactant and at least one cyclic, preferably aromatic, essential oil. At least one of these ingredients should be susceptible to degradation over time in an aqueous environment.

It will be understood by those skilled in the art that the properties and weight percentages set forth herein are directed to mouthwashes and mouth rinses. The formulation of the present invention may be included in a mouthwash or oral rinse, but it may also be part of a dentifrice, gel, or powder, or in any other effective form. Those skilled in the art will recognize that different weight percentages of ingredients will be required for an effective dentifrice, because less dentifrice material is used in each application by the user than is found with mouthwashes . The invention may comprise a nonionic surfactant component. The nonionic surfactant may act as a tar solubilizer and/or flavor solubilizer, among other things. Any pharmaceutically or orally acceptable nonionic surfactant may be used in the invention.

Examples of nonionic surfactants that may be used in the present invention include, but are not limited to, glycerol- polyethylene glycol oxystearate (PEG 40, Cremophor^® RH40 and 60 available from BASF) , polyoxyethylene esters or sorbitol laurate esters, such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monoisostearate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene or sorbitol laurate esters including polysorbates, and block polymers of polyoxyethylene, polyoxypropylene (Pluronic^® 127) and polyoxyethylene hydrogenated castor oil. The amount of nonionic surfactants included in the formulations of the invention is from about 0.1% to about 8% by weight, preferably 0.2% to about 7% by weight and most preferably from about 0.3% to about 6.5% by weight of the overall formulation. The invention may also include at least one anionic surfactant. The anionic surfactant component of the invention may act as a sudsing agent and tar co-solubilizer, among other things. Any pharmaceutically or orally acceptable anionic surfactant may be used in the invention. Examples of anionic surfactants that may be used in the present invention include, but are not limited to, sodium lauryl sulfate and a pharmaceutical or oral grade of sodium ether lauryl sulfate. The anionic surfactant is present in formulations of the invention at from about 0.1% to about 6.0% by weight, preferably from about 0.2% to about 5.0% by weight, and most preferably from about 0.3% to about 4.5% by weight of the overall formulation.

The invention also comprises at least one aromatic essential oil such as methyl salicylate. In a preferred embodiment of the invention, however, at least two, and preferably more, essential oils are used. The aromatic essential oil component of the invention may act as a tar solubilizer, among other things. Any pharmaceutically or orally acceptable aromatic essential oil may be used in the invention. Examples of aromatic essential oils which may be used in the present invention include, in addition to methyl salicylate, anise, anethole, bergamot, camphor, cinnaminic anhydrides, clove, eucalyptol, peppermint, spearmint, and thyme, among others. Preferably, all the aromatic essential oils included in the present invention comprise from about 0.01% to about 5% by weight of the formulation, preferably from about 0.02% to about 4% by weight, and most preferably from about 0.03% to about 3.75% by weight of the overall formulation.

The overall amount of tar solubilizing agents, including surfactants and essential oils, comprises from about 0.1% to about 20% by weight of the overall formulation, preferably from about 0.2% to about 15% by weight, and most preferably from about 0.3% to about 11.0% by weight. The invention also preferably includes a combination of anionic and nonionic surfactants, including at least one of each.

The stabilizing portion of the formulation preferably includes a pH buffering system comprising from about 0.01% to about 6% by weight of the overall composition, preferably from about 0.05% to about 5% by weight, and most preferably from about 0.2% to about 0.5% by weight of the overall composition. The pH buffering system comprises at least one acid such as citric, benzoic, acetic, lactic, phosphoric, tartaric, oxalic and ethylenediamine N, N, N' ,N' tetraacetic acids. The pH buffering system also comprises at least one base such as mono-, di- and tri- sodium, ammonium and potassium salts of phosphoric acid; sodium, ammonium and potassium hydroxides; calcium hydroxide; sodium, ammonium and potassium carbonates and hydrogen carbonates; sodium, ammonium and potassium salts of acetic, citric, benzoic, lactic, tartaric, oxalic and ethylenediamine-N, N, N' , N' tetraacetic acids. Preferably the acids are citric, benzoic, and acetic acids. Preferably the bases are di- and trisodium phosphate, sodium hydroxide, and sodium carbonate . The buffering system should be used in proportions sufficient to stabilize the formulation at a pH from about 6.5 to about 7.5, preferably from about 6.8 to about 7.2 and most preferably about 7.0.

Other ingredients useful in the invention include a vehicle for the formulation, solvents, humectants, sweeteners, flavors, and preservatives. The preferred vehicle for an oral rinse prepared according to the present invention is water or a water/alcohol mixture. When water is used as the vehicle to prepare such a rinse, the water comprises from about 50% to about 85% by weight of the overall composition. Additional vehicles include pastes and gels, which allow the invention to be formulated as a tooth paste or other solid or semi-solid form. The relative amounts of vehicle and active ingredients will be easily adjusted by those skilled in the art to account for the differing amounts and conditions of use.

The invention may also include a solvent in a concentration range of from about 3.0% to about 30.0% by weight. Ethanol is a preferred solvent, but any pharmaceutically or orally acceptable solvent may be used.

Humectants may also be included in the invention from about 3% to about 15% by weight. Humectants help to stabilize the water content of the solution. Humectants which may be used in the present invention include, among others, glycerine and sorbitol. However, any pharmaceutically or orally acceptable humectant may be used in the invention. The humectant also helps to give the invention a better mouthfeel.

The invention may also include additional essential oils as flavoring components in addition to the methyl salicylate and, optionally, at least one other essential oil discussed above as tar solubilizers . Preferably, flavoring essential oils should also aid in solubilizing tar and other hydrophobic materials, but any essential oils known in the art for flavoring may be used.

The invention may include a preservative at from about 0.05% to about 2.0% by weight of the overall formulation. Such preservatives include benzoic acid and sodium benzoate, among others. Any pharmaceutically or orally acceptable preservative may be used to prepare the invention.

The invention may include a sweetener, such as sodium saccharin, in a concentration from about 0.01% to about 0.7% by weight. A color may also be added to the preparation of the invention in a concentration range of from about 0.001% to about 0.5% by weight.

In addition to the oral rinse form of the product, as discussed above, the preparation of the present invention may be included in gels or pastes utilizing thickening or gelling agents. Such agents include, among others, silica aerogels, pyrogenic silica, silica precipitates, carboxymethyl cellulose, carboxyvinyl polymers, xanthan gum, and carrageenan. In addition, such gels or pastes may contain other conventional dentifrice ingredients. Even though these ingredients may include some abrasives and polishing agents, the invention will provide additional cleaning for areas not reached by conventional toothbrushes .

Generally, an oral rinse form of the invention is prepared by adding the following ingredients in the following sequence. The vehicle is provided, and any sudsing agent in the formulation is added. The surfactants and other hydrophobic materials are added to the solvent. Then, any flavoring is added to the solvent/surfactant mixture. Finally, the vehicle and solvent solutions are mixed together.

The formulations of the invention are also suitable for use on denture material . The ingredients set forth herein may be incorporated into effervescent denture tablets or powders or may be formulated as a denture cream or paste . In addition to being useful for dissolving tar from tobacco, formulations of the invention can also dissolve and/or disperse food oils and other hydrophobic materials found in the oral cavity. Examples include essential oils from onions and garlic.

Example 1

An oral rinse in accordance with the invention was prepared by placing 13,179.7 Kg water into a first tank. 32.385 Kg disodium phosphate (anhydrous) and 7.62 Kg sodium saccharin were added to the water with mixing.

In a second tank, 3,288 Kg of 190 proof denatured ethyl alcohol containing premixed flavor oils and methyl salicylate were mixed with 133.35 Kg PEG 40 hydrogenated castor oil, 19.05 Kg benzoic acid, 57.15 Kg sodium lauryl sulfate and 2,286 Kg glycerin. The ingredients were all mixed until completely dissolved.

The contents of the second tank were added to the contents of the first tank and mixed until a homogeneous solution was obtained.

45 Kg of water and a colorant were mixed in a third tank and the contents of the third tank were then added to the first tank. The final mixture (about 5,000 gallons or 19,050 Kg) was then sent to a bottle filling line through a 10 micron filter. The final formulation (in weight percent) is set forth in Table

This formulation is expected to show significant improvement in slowing the loss of methyl salicylate during shelf storage of the formulation.

The purpose of the above description is to illustrate some embodiments of the present invention without implying a limitation. It will be apparent to those skilled in the art that various modifications and variations may be made in the apparatus or procedure of the invention without departing from the scope or spirit of the invention.

Claims

CLAIMS :What is claimed is:

1. A formulation comprising:

(a) at least one material for removing hydrophobic deposits from surfaces found in the oral cavity, wherein said material is subject to degradation over time in an aqueous environment; and

(b) a buffering agent to retard degradation of said material .

2. The formulation of claim 1, wherein said material comprises an essential oil.

3. The formulation of claim 2, wherein said essential oil comprises an ester.

4. The formulation of claim 1, wherein said material comprises a surfactant .

5. The formulation of claim 3, wherein said surfactant comprises an ester.

6. The formulation of claim 1, wherein said formulation further comprises at least one anionic surfactant .

7. The formulation of claim 6, wherein said formulation further comprises a solvent, a vehicle, at least one humectant, at least one flavoring, and at least one preservative.

8. The formulation of claim 1, wherein said buffering agent maintains the pH of said formulation from about 6.5 to about 7.5.

9. The formulation of claim 1, wherein in the form of a mouthwash.

10. The formulation of claim 2, in the form of a dentifrice .

11. A method of removing deposits from a surface found in the oral cavity, comprising the steps of: (a) exposing said surface to the formulation of claim 1 time sufficient to solubilize said deposit; and

(b) removing said solubilized deposit from said surface.