Drug – bio-affecting and body treating compositions – Dentifrices – Fluorine or fluorine compound containing
Reexamination Certificate
2002-11-22
2004-02-24
Rose, Shep K. (Department: 1614)
Drug, bio-affecting and body treating compositions
Dentifrices
Fluorine or fluorine compound containing
C424S049000, C424S057000
Reexamination Certificate
active
06696045
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to dentifrice compositions comprising a low water phase comprising polyphosphate and ionic active ingredients including fluoride and/or metal ions such as stannous, zinc, and copper ions.
BACKGROUND OF THE INVENTION
The compositions of the present invention are dentifrices comprising a phase that provides effective amounts of polyphosphate and ionic actives such as fluoride ion and/or metal ions such as stannous, zinc, and copper ions, such a phase having a low level of water in which the components are stable, and also comprising a binder system that provides adequate gellation in a low water, non-polar humectant system.
While such actives have previously been used in dentifrices to promote oral health, for several reasons it has proven challenging to provide these actives together in a stable single phase. Certain polyphosphates effective as antitartar agents are known to be unstable in high aqueous systems and are also known to react with ionic fluoride in oral compositions at ambient temperature and produce monofluorophosphate ions, in addition to altering the pH of the composition. This reaction compromises the efficacy of the oral composition and its ability to provide stable ionic fluoride and polyphosphate to the oral surfaces.
Metal ions such as stannous, copper and zinc ions are known to be effective anti-microbial agents. These metal ions provide anti-gingivitis and anti-plaque benefits and may also improve breath and reduce sensitivity. However, dentifrices containing metal ions are also known to be astringent. Stannous and copper are also known to cause staining on the tooth surfaces.
Previous attempts to provide dentifrice compositions that contain these actives in efficacious amounts and in efficacious forms have provided the dentifrice in dual compartmented packaging wherein the reactive ingredients are kept physically separate until the time of brushing. (See, e.g., WO98/22079, “Dentifrice Compositions Containing Polyphosphate and Fluoride.”) However, such dual-compartmented packages are typically considerably more expensive than the conventional laminate tubes that have been used for many years to contain and dispense dentifrices. They may also be problematic in terms of ease of consumer use and uniform dispensing of approximately equal amounts of each composition during each consumer use. Therefore it remains desirable to provide single phase compositions that can be packaged in conventional laminate squeeze tubes.
Other attempts to provide such efficacious dentifrice compositions have reduced the amount of water present in the composition. Reducing the amount of water would theoretically reduce or eliminate the stability issues associated with the fluoride, polyphosphate and other ionic actives. However, reducing the level of water, and optionally replacing some or all of the removed water with a humectant, creates problems in obtaining acceptable rheology and thickening properties in the composition. When water, which is a highly polar solvent, is removed, conventional thickening agents such as carboxymethylcellulose (“CMC”) tend to inadequately gel up. Attempts to reduce water content in dentifrice have included the dentifrices described in, e.g., EP 0 638 307 B1; U.S. Pat. No. 4,647,451; and U.S. Pat. No. 5,670,137.
Carageenan, a polysaccharide and a natural derivative of seaweed, has been used in dentifrice compositions as a replacement for lower cost thickeners such as CMC. See, e.g., U.S. Pat. No. 6,187,293 B1, “Process For Making Toothpaste Using Low Levels of Carageenan,” and U.S. Pat. No. 6,162,418, “Non-Stringy Toothpaste.” However, the relatively higher cost of carageenan and the thixotropic properties of carageenen-containing toothpastes have been seen as limiting the widespread use of carageenen in dentifrices.
Therefore, it remains desirable to provide dentifrice compositions that provide efficacious delivery of water-unstable actives and/or actives that are reactive with respect to each other in a stable single phase. None of the existing art provides all of the advantages and benefits of the present invention.
SUMMARY OF THE INVENTION
The present invention relates to dentifrice compositions comprising in a single phase: (a) from about 0.1% to about 30% of one or more linear polyphosphates having an average chain length of about 4 or more; (b) an ionic active ingredient selected from the group consisting of a fluoride ion source, a stannous ion source, a zinc ion source, a copper ion source, and mixtures thereof, wherein the ionic active ingredient is present as a solid dispersion in the composition and delivers an effective amount of ionic active when solubilized; (c) a binder system comprised of (i) from about 0.05% to about 3% of a thickening agent selected from the group consisting of polysaccharides, carbomers, poloxamers, modified celluloses, and mixtures thereof; and (ii) from about 0.1% to about 70% of at least one humectant; wherein the dentifrice composition has a total water content of less than about 10%. The present invention further relates to methods for stabilizing dentifrice compositions by providing such a binder system. These and other features, aspects, and advantages of the invention will become evident to those of skill in the art from a reading of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed that the present invention will be better understood from the following description of preferred embodiments.
All percentages used herein are by weight of the dentifrice composition, unless otherwise specified. The ratios used herein are molar ratios of the overall composition, unless otherwise specified. All measurements are made at 25° C., unless otherwise specified.
All publications, patent applications, and issued patents mentioned herein are hereby incorporated in their entirety by reference. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
Herein, “comprising” means that other steps and other components which do not affect the end result can be added. This term encompasses the terms “consisting of” and “consisting essentially of.”
Herein, “effective amount” means an amount of a compound or composition sufficient to significantly induce a positive benefit, preferably an oral health benefit, but low enough to avoid serious side effects, i.e., to provide a reasonable benefit to risk ratio, within the sound judgment of a skilled artisan.
The dentifrice composition of the present invention may be in the form of a toothpaste or dentifrice. The term “dentifrice”, as used herein, means paste or gel formulations unless otherwise specified. The dentifrice composition may be in any desired form, such as deep striped, surface striped, multi-layered, having the gel surrounding the paste, or any combination thereof.
The dentifrice composition is a product, which in the ordinary course of administration, is not intentionally swallowed for purposes of systemic administration of particular therapeutic agents, but is rather retained in the oral cavity for a time sufficient to contact substantially all of the tooth surfaces and/or oral tissues for purposes of oral activity.
The term “aqueous carrier” as used herein means any safe and effective materials for use in the compositions of the present invention. Such materials include thickening agents, humectants, ionic active ingredients, buffering agents, anticalculus agents, abrasive polishing materials, peroxide sources, alkali metal bicarbonate salts, surfactants, titanium dioxide, coloring agents, flavor systems, sweetening agents, antimicrobial agents, herbal agents, desensitizing agents, stain reducing agents, and mixtures thereof.
The present compositions comprise essential components, as well as optional components. The essential and optional components of the compositions of the present invention are described
Chen Li
Cheng Ying
Wang Ying
Weller Andrew Damian
Xu Tao
Emelyn Deleon Hiland
Rose Shep K.
The Procter & Gamble & Company
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