HK1119967B - Stannous salt and sodium tripoly-phosphate oral care compositions and methods - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present invention relates to oral care compositions and their uses in maintaining systemic health of a human or mammal.

BACKGROUND OF THE INVENTION

Stannous salts such as stannous fluoride are used in dentifrices as agents for preventing plaque. However, some disadvantages of stannous salts include instability, tendency to stain teeth, astringency and unpleasant taste for users. For that reason, oral care compositions containing stannous salts such as stannous fluoride are often presented as dual phase compositions, in which the stannous salt is kept separate from the other components in order to reduce its negative effects on the oral cavity, such as astringency and unpleasant taste. See, e.g., U.S. Patent No. 6,521,216 and U.S. Patent No. 7,063,833, both to Glandorf et al.

Sodium tripolyphosphate is an effective anticalculus (anti-tartar) agent, but the compound is not generally compatible with stannous salts in long term storage (such as that normally sustained in the lifetime of a tube of toothpaste between time of packaging and time of discard after use). In particular, the combination of sodium tripolyphosphate with stannous salts such as stannous fluoride can lead to undesirable stannous tripolyphosphate intermediates.

Accordingly, there is an ongoing need for oral care compositions that have improved efficacy in combating plaque and tooth discoloration and are still able to retain long-term stability.

BRIEF SUMMARY OF THE INVENTION

US2005/112070 describes oral care compositions comprising a stannous ion source.

The present invention provides an oral care composition comprising:

1. (a) 0.01 to 5% stannous salt;
2. (b) 0.01 to 15% sodium tripolyphosphate,
3. (c) less than 10% water, and
4. (d) 0.1 to 5% of a methylvinyl ether-maleic anhydride copolymer;

wherein the stannous salt, sodium tripolyphosphate and methylvinyl ether maleic anhydride are blended in the composition.

The invention further provides an oral care composition as defined above for use in a method of maintaining systemic health of a human or mammal, the method comprising applying the composition to the oral surfaces of the human or mammal.

The description provides a method for making an oral care composition, comprising blending: (a) 0.01 to 5% stannous salt; (b) 0.01 to 15% sodium tripolyphosphate; and (c) 0.1 to 5% of a methylvinyl ether-maleic anhydride copolymer.

The description further provides an oral care kit comprising a container containing a mixture of: (a) 0.01 to 5% stannous salt; (b) 0.01 to 15% sodium tripolyphosphate; and (c) less than 10% by weight water; wherein the mixture comprises less than 1% stannous tripolyphosphate ionic intermediates.

DETAILED DESCRIPTION OF THE INVENTION

Where there is any conflict between definitions in the disclosures of the references cited and the present disclosure, the present disclosure is controlling.

In certain aspects, the description provides a dual phase composition and oral care kit wherein stannous salt and sodium tripolyphosphate are formulated to be physically separated in two separate aqueous mixtures. Each of the two aqueous mixtures is stored in a physically separate chamber (such as in a dual-compartment tube of toothpaste), and the two aqueous mixtures are blended together into a mixture when the anticipated time between mixture formation and application of the mixture to the teeth is sufficiently minimal such that the reaction time needed for migration of the stannous ion and the tripolyphosphate ionic complex into an ionic intermediate configuration for the stannous tripolyphosphate is not sufficient for stannous tripolyphosphate ionic intermediate formation prior to use.

The present invention specifically provides an oral care composition comprising:

1. (a) 0.01 to 5% stannous salt;
2. (b) 0.01 to 15% sodium tripolyphosphate,
3. (c) less than 10% water, and
4. (d) 0.1 to 5% of a methylvinyl ether-maleic anhydride copolymer;

wherein the stannous salt, sodium tripolyphosphate and methylvinyl ether maleic anhydride are blended in the composition.

In certain embodiments, at least one of tetrasodium pyrophosphate, and a silica oral polishing agent may be optionally mixed into the formulation. In certain embodiments, the methylvinyl ether-maleic anhydride copolymer has the structural formula wherein n is an integer that provides molecular weight in the agent of about 60,000 to about 500,000. Examples of suitable methylvinyl ether-maleic anhydride copolymers for the present invention are copolymers of methyl vinyl ether and maleic anhydride available under the trade name Gantrez® (for example, Gantrez® S-96, Gantrez® S-97, Gantrez® MS and MS-955, Gantrez® ES, ES-225 and ES-425 available from International Specialty Products, Wayne, NJ, USA).

In certain embodiments, the present invention provides compositions comprising an orally acceptable carrier or vehicle. As used herein, an "orally acceptable carrier" and "orally acceptable vehicle" are used interchangeably, and refer to a material or combination of materials that is safe for use in the present compositions, commensurate with a reasonable benefit/risk ratio, with which the other ingredients may be associated while retaining significant clinical efficacy. Such carrier materials should be selected for compatibility with the other ingredients of the compositions, and preferably do not substantially reduce the efficacy of the other ingredients. Selection of specific carrier components is dependent on the desired product form, including dentifrices, rinses, gels, and paints.

Materials useful in carriers include but are not limited to: adhesion agents, viscosity modifiers, diluents, surfactants, foam modulators, peroxide activators, peroxide stability agents, abrasives, pH modifying agents, humectants, mouth feel agents, sweeteners, flavorants, colorants, and combinations thereof. As used herein, an "adhesion agent" is a material or combination of materials that enhances the retention of an ingredient to an oral cavity surface onto which it is applied. Such adhesion agents include without limitation: adhesives, film forming materials and viscosity enhancers; for example, hydrophilic organic polymers, hydrophobic organic polymers, silicone gums, silicone adhesives, silicas, and combinations thereof.

In certain embodiments, any of tetrasodium pyrophosphate, and/or a silica oral polishing are independently mixed into the oral care composition. In certain embodiments, the silica oral polishing agent is high cleaning silica. In certain embodiments, the stannous salt comprises a stannous halide such as stannous fluoride, stannous chloride dehydrate; organic stannous carboxylate salts such as stannous formate, acetate, gluconate, lactate, tartrate, oxalate, malonate and citrate; stannous ethylene glyoxide, and mixtures thereof. One or more stannous salts are present in a total amount of 0.01% to 5%, optionally 0.05 to 4%, 0.1 to 3%, 0.5 to 2% or 0.1 to 1%.

In certain aspects of the description, the oral care composition comprises a mixture having:

1. (a) a first phase comprising a first orally acceptable aqueous vehicle; and
2. (b) a second phase comprising a second orally acceptable aqueous vehicle; where a stannous salt is mixed into the first orally acceptable aqueous vehicle, sodium tripolyphosphate is mixed into the second orally acceptable aqueous vehicle; and the first phase provides at least one first portion of the mixture, the second phase provides at least one second portion of the mixture, and at least one of the first portion is in fluid interface with at least one of the second portion in the mixture.

In certain aspects of the description, any of tetrasodium pyrophosphate and/or a silica oral polishing agent (such as high cleaning silica) may be independently mixed in at least one phase of the first phase and the second phase. In certain embodiments of the mixture, a methylvinyl ether-maleic anhydride copolymer, such as that of Formula I, is mixed in the second phase.

In certain aspects, the description provides methods comprising:

1. (a) mixing 0.01 to 5% stannous salt into a first orally acceptable aqueous vehicle to provide a first phase;
2. (b) mixing 0.01 to 15% sodium tripolyphosphate into a second orally acceptable aqueous vehicle to provide a second phase;
3. (c) storing the first phase in a first enclosure;
4. (d) storing the second phase in a second enclosure; and
5. (e) removing the first phase from the first enclosure and removing the second phase from the second enclosure so that the first phase and the second phase together provide the mixture.

In certain aspects, the description further provides a first type of oral care kit as a container containing a mixture of

1. (a) 0.01 to 5% stannous salt; and
2. (b) 0.01 to 15% sodium tripolyphosphate;

wherein the mixture comprises less than about 1% stannous tripolyphosphate ionic intermediates and comprises less than about 10% water.

In certain aspects, the description provides a second type of oral care kit, comprising:

1. (a) a first chamber having a first outlet in fluid communication with the first chamber for discharge of a first dentifrice from the first chamber; and
2. (b) a second chamber having a second outlet in fluid communication with the second chamber for discharge of a second dentifrice from the second chamber;

to the first outlet so that, during simultaneous discharge of the first dentifrice from the first chamber through the first outlet and of the second dentifrice from the second chamber through the second outlet, the discharged first dentifrice interfaces with discharged second dentifrice to form a mixture.

Thickening agents useful for the present invention include, without limitation:

• carboxyvinyl polymers, carrageenans (also known as Irish moss and more particularly iota-carrageenan), cellulosic polymers such as hydroxyethylcellulose, carboxymethylcellulose (carmellose) and salts thereof (e.g., carmellose sodium), natural gums such as karaya, xanthan, gum arabic and tragacanth, colloidal magnesium aluminum silicate, colloidal silica, and mixtures thereof.

Viscosity modifiers useful for the present invention include, without limitation:

• mineral oil, petrolatum, clays and organomodified clays, silica, and mixtures thereof. In various embodiments, the viscosity modifiers are able to inhibit settling or separation of ingredients, or to promote redispersibility upon agitation of a liquid composition.

Diluents useful for the present invention include, without limitation, materials or combinations of materials that can solubilize and/or suspend other components. In various embodiments, diluents can adjust the viscosity of the composition, optionally in conjunction with viscosity modifiers as discussed herein and other components of the composition.

Surfactants useful for the present invention include, without limitation: anionic, nonionic, and amphoteric surfactants. Surfactants may be used, for example, to provide enhanced stability of the formulation, to help in cleaning the oral cavity surfaces through detergency, and to provide foam upon agitation, e.g., during brushing. Suitable anionic surfactants include, e.g., watersoluble salts of C_8-20 alkyl sulfates, sulfonated monoglycerides of C_8-20 fatty acids, sarcosinates, taurates; e.g., sodium lauryl sulfate, sodium coconut monoglyceride sulfonate, sodium lauryl sarcosinate, sodium lauryl isoethionate, sodium laureth carboxylate and sodium dodecyl benzenesulfonate, and mixtures thereof. Suitable nonionic surfactants include, e.g., poloxamers, polyoxyethylene sorbitan esters, fatty alcohol ethoxylates, alkylphenol ethoxylates, tertiary amine oxides, tertiary phosphine oxides, dialkyl sulfoxides, and mixtures thereof.

Foam modulators useful for the present invention include, without limitation:

• materials operable to increase amount, thickness or stability of foam generated by the composition (e.g., dentifrice compositions) upon agitation. Any orally acceptable foam modulator can be used, including polyethylene glycols (PEGs), also known as polyoxyethylenes. High molecular weight PEGs are suitable, including those having an average molecular weight of about 200,000 to about 7,000,000, for example about 500,000 to about 5,000,000 or about 1,000,000 to about 2,500,000. One or more PEGs are optionally present in a total amount of about 0.1% to about 10%, for example about 0.2% to about 5% or about 0.25% to about

Humectants useful for the present invention include, without limitation: polyhydric alcohols such as glycerin, sorbitol, xylitol or low molecular weight PEGs. In various embodiments, humectants can prevent hardening of paste or gel compositions upon exposure to air. In various embodiments humectants also function as sweeteners.

In certain aspects, the description provides a two-phase oral care composition having a stannous salt in a first phase and sodium tripolyphosphate in a second phase, the measured pH of the first phase is sustained at 2 to 8, and the measured pH of the second phase is sustained at 5 to 11. The embodiments, therefore, provide an effectively acid pH (a chemical pH of 7 or less) in the first phase with a measured pH (the pH measured when a pH probe is inserted into the phase) of between 2 and 8 and an effectively alkaline pH (a chemical pH of between 7 and 11) in the second phase with a measured pH (again, the pH measured when a pH probe is inserted into the phase) of between 5 and 11.

Any other desired components may be added to the compositions, including, for example, mouth-feel agents, pH modifying agents, flavorants, sweeteners, additional anticalculus and antiplaque agents, abrasives, polishing agents, antimicrobial (e.g., antibacterial) agents such as those described in U.S. Patent No. 5,776,435 , saliva stimulants, anti-inflammatory agents, H₂ antagonists, nutrients, vitamins, proteins, antioxidants, colorants, or additional active materials useful for the prevention or treatment of a condition or disorder of hard or soft tissue of the oral cavity, the prevention or treatment of a physiological disorder or condition, or to provide a cosmetic benefit.

Certain aspects of the description provide oral care compositions having stannous salt and sodium tripolyphosphate in a first phase comprising a first orally acceptable aqueous vehicle and in a second phase comprising a second orally acceptable aqueous vehicle. The first and second phases may be independently formulated such that the stannous salt is mixed into the first orally acceptable aqueous vehicle and such that the sodium tripolyphosphate is mixed into the second orally acceptable aqueous vehicle. The first phase may be maintained at a measured pH of about 2 to about 8, and the second phase may be maintained at a measured pH of about 5 to about 11. The first and second phases may be kept from physical chemical interaction prior to a brief period prior to application to a tooth surface. At that time, the first and second phases may be combined together (e.g., on a toothbrush) as a mixture (a combination of different components) where the first phase provides at least one first portion of the mixture, the second phase provides at least one second portion of the mixture, and the at least one first portion is in fluid interface with the at least one second portion in the mixture. This may be achieved by, for example, use of a dual-compartment toothpaste tube where two approximately equivalent volumetric portions from each of the two compartments are simultaneously extruded onto a toothbrush under the presumption that the resulting mixture dentifrice is to be immediately applied to the teeth by the user.

In certain aspects, the description provides an oral care composition comprising a two-phase mixture having stannous fluoride as the stannous salt and sodium tripolyphosphate in differentiated phases where the first phase is mixed to comprise a measured pH of 2 to 8. In various embodiments, this first phase and the second phase each may additionally comprise one or more ingredients chosen from citric acid, trisodium citrate dihydrate, glycerine, a cellulosic polymer such as, e.g., sodium carboxymethyl cellulose (Sodium CMC 2000), a gum such as xanthan gum or carrageenan gum (e.g., iota carrageenan), a flavorant (such as, e.g., the sweeteners sodium saccharin or sorbitol) an additional salt such as, e.g., tetrasodium pyrophosphate, polymer such as, e.g., polyoxypropylene-polyoxyethylene block polymer (PLURONIC® F127), titanium dioxide, an oil such as, e.g., castor oil, silicon dioxide, precipitated silica, synthetic amorphous silica, or sodium lauryl sulfate.

In various aspects of the description, the compositions comprise, further to the first phase described in (a) above, a second phase (b) which is mixed to comprise a measured pH about 5 to about 11.

The compositions of the present invention optionally comprise silica oral polishing agent ("silica abrasive") in at least one of the phases. In various embodiments, silica may be mixed at, for example, 10 to 50%, 15 to 40% or 20 to 30% dental type precipitated amorphous hydrated silicon dioxide; and at 10 to 15%, 11 to 14 and 12 to 13% synthetic amorphous silica.

In the dual phase mixtures as provided by the description, having at least two portions where each is extruded from an independently stored phase, silica may be provided in the first phase as 10 to 50% dental type precipitated amorphous hydrated silicon dioxide, less than 8% synthetic amorphous precipitated silica, less than 15% synthetic amorphous silica. In the second phase, in various embodiments silica may be provided in an amount of 10 to 50% precipitated synthetic amorphous silica, less than 15% synthetic amorphous silica, or less than 8% synthetic amorphous precipitated silica.

In various embodiments, the compositions comprise silica in the form of silica gel, hydrated silica or precipitated silica, alumina, insoluble phosphates, calcium carbonate, resinous abrasives such as urea-formaldehyde condensation products, and mixtures thereof. Insoluble phosphates useful as abrasives include, for example, orthophosphates, polymetaphosphates and pyrophosphates; e.g., dicalcium orthophosphate dihydrate, calcium pyrophosphate, dicalcium pyrophosphate, tricalcium phosphate, calcium polymetaphosphate and insoluble sodium polymetaphosphate or mixtures thereof. One or more abrasives are optionally present in an abrasive effective total amount of, in various embodiments, 5% to 70%, 10% to 50%, or 15% to 30% by weight of the composition. Average particle size of an abrasive, if present, is generally 0.1 to 30 microns, for example 1 to 20 microns or 5 to 15 microns. The use of silica as previously noted is preferred to reduce staining of the teeth due to the stannous fluoride.

In various embodiments, the present methods include adding and mixing the ingredients in a suitable vessel such as a stainless steel tank provided with a mixer. In certain aspects of the description, the stannous salt is mixed into a first orally acceptable aqueous vehicle to provide a first phase of a dentifrice; the sodium tripolyphosphate is mixed into a second orally acceptable aqueous vehicle to provide a second phase of the dentifrice; the first phase is stored in a first enclosure; the second phase is stored in a second enclosure; sodium tripolyphosphate is mixed into a second orally acceptable aqueous vehicle to provide a second phase of the dentifrice; the first phase is stored in a first enclosure; the second phase is stored in a second enclosure; and the first phase is expelled from the first enclosure and the second phase is expelled from the second enclosure just prior to application to the teeth so that the first phase and the second phase together provide a mixture. In various aspects of the description, the resultant mixture has at least one first portion comprising the first phase, the mixture has at least one the second portion comprising the second phase, and each first portion is in fluid interface with at least one second portion.

In various aspects of the description, the mixture may be provided to the consumer in the form of an oral care kit providing (a) a first chamber (the first storage enclosure for storing the first phase of the mixture) having a first outlet in fluid communication with the first chamber for discharge of a first dentifrice from the first chamber; and (b) a second chamber (the second storage enclosure for storing the second phase of the mixture) having a second outlet in fluid communication with the second chamber for discharge of a second dentifrice from the second chamber. In various aspects, the second outlet is proximate to the first outlet so that, during simultaneous discharge of the first dentifrice from the first chamber through the first outlet and of the second dentifrice from the second chamber through the second outlet, discharged first dentifrice fluidly interfaces with discharged second dentifrice to form the mixture. In certain aspects, equal amounts of each phase are delivered into the mixture so that the consumer has a convenient basis for ascertaining that both phases are being delivered and that rapid intermixing of the phases will occur as the mixture is brushed against the teeth.

Additional ingredients such as flavorant, coloring or sweeteners are added at any point during the mixing process but in various embodiments such ingredients are preferably added last or close to last.

The present invention also provides an oral care composition as defined herein for use in a method of maintaining systemic health of a human or mammal, the method comprising applying the composition to the oral surfaces of the human or mammal. As referred to herein, "applying" refers to any method by which a compositional embodiment is placed in contact with the tooth surface. Such uses, in various embodiments, comprise direct application of a composition by such methods as painting and brushing. Suitable application devices include, e.g., toothbrushes.

In one prophetic example, a composition according to the present invention comprises less than 10% water, and further comprises:

• 0.4 to 0.8% stannous salt,
• 0.20 to 24% polyhydric alcohol,
• 10.0 to 17% amorphous silica,
• 0.5 to 4% tetrasodium pyrophosphate; and
• 1 to 15% sodium tripolyphosphate.

In another prophetic example, a composition according to the present invention comprises:

• 0.4 to 0.8% stannous salt,
• 1 to 9% water,
• 0.2 to 24% polyhdric alcohol,
• 0.5 to 4% tetrasodium pyrophosphate,
• 1 to 15% sodium tripolyphosphate,
• 10 to 50% dental type precipitated amorphous hydrated silicon dioxide; and
• 10 to 17% amorphous silica.

In one prophetic example, outside the scope of the invention the composition comprises stannous fluoride as the stannous salt, and

1. (i) the first phase is mixed to comprise:
   • 0.9 to 1.8% stannous fluoride,
   • 0.3 to 1% stannous chloride dihydrate,
   • 0.5 to 4% tetrasodium pyrophosphate,
   • 10 to 50% precipitated amorphous hydrated silicon dioxide,
   • less than 8% synthetic amorphous precipitated silica,
   • less than 15% synthetic amorphous silica; and
2. (ii) the second phase is mixed to comprise:
   • 0.5 to 4% tetrasodium pyrophosphate,
   • 0.1 to 15% methylvinyl ether-maleic anhydride copolymer,
   • 1 to 15% sodium tripolyphosphate,
   • 10 to 50% precipitated synthetic amorphous silica, and
   • less than 15% synthetic amorphous silica.

By way of further example, and not limitation, specific embodiments of the present invention are illustrated in the following Examples.

EXAMPLE 1

A dual component composition outside the scope of the invention may be prepared by independently combining the ingredients of "Side 1" and "Side 2" of Table I:

q.s.	Purified Water
0.01-2	Citric Acid Anhydrous
0.5-5	Trisodium Citrate Dihydrate
0.2-1	Stannous Fluoride
0.2-2	Stannous Chloride Dihydrate
20-40	Glycerin
0.1-5	Sodium Carboxymethyl Cellulose
0.1-10	Xanthan Gum
0.1-5	Sodium Saccharin
0.1-5	Tetrasodium Pyrophosphate
0.5-10	Pluronic F127 Polyoxypropylene - Polyoxyethylene Block Polymer
0.1-5	Titanium Dioxide
0.5-20	Oil
1-15	Dental Type Precipitated Amorphous Hydrated Silicon Dioxide
1-10	Synthetic Amorphous Precipitated Silica
1-15	Synthetic Amorphous Silica
1-15	Sodium lauryl sulfate 30% Solution
0.01-10	Flavor

q.s.	Purified Water
0.1-1	Sodium Saccharin
5-60	Sorbitol
0.01-5	Tetrasodium Pyrophosphate
1-15	Gantrez S-97 13% Liquid
0.5-5	Sodium Hydroxide 50%
0.01-5	Titanium Dioxide
1-20	Glycerine
1-15	Sodium Tripolyphosphate
0.01-5	Sodium CMC 2000S-12 Sodium Carboxymethyl Cellulose
0.1-10	Iota Carrageenan
1-30	Precipitated Synthetic Amorphous Silica
1-20	Synthetic Amorphous Silica
1-10	Sodium lauryl sulfate
0.01-10	Flavor

Claims (4)

1. An oral care composition comprising:

   (a) 0.01 to 5% stannous salt;

   (b) 0.01 to 15% sodium tripolyphosphate,

   (c) less than 10% water, and

   (d) 0.1 to 5% of a methylvinyl ether-maleic anhydride copolymer;

   wherein the stannous salt, sodium tripolyphosphate and methylvinyl ether maleic anhydride are blended in the composition.
2. The composition of claim 1, further comprising a compound chosen from tetrasodium pyrophosphate and a silica polishing agent.
3. The oral care composition of claim 1 or claim 2 wherein the methylvinyl ether-maleic anhydride copolymer is represented by formula (I): wherein n is an integer that provides molecular weight in the agent of 60,000 to 500,000.
4. An oral care composition according to any preceding claim for use in a method of maintaining systemic health of a human or mammal, the method comprising applying the composition to the oral surfaces of the human or mammal.