WO2021067683A1

WO2021067683A1 - Carbomer based tooth paste composition comprising crosslinked polyvinylpyrrolidone for building viscosity

Info

Publication number: WO2021067683A1
Application number: PCT/US2020/053923
Authority: WO
Inventors: Philip John OTHS; Shafiq Sahar WAHIDI; Petros Gebreselassie; Hani M. Fares
Original assignee: Isp Investments Llc
Priority date: 2019-10-02
Filing date: 2020-10-02
Publication date: 2021-04-08

Abstract

An anhydrous earhomer based tooth paste composition comprising: (i) about 0. 1 to about 10 wt.% of a strongly sweliable, lightly to moderately erosslinked polyvinyl pyrrolidone; (ii) about 10 to about 80 wt.% of one or more polyol or glycol selected from the group consisting of glycerin, sorbitol, polyethylene glycol, propylene glycol, butylene glycol and mixtures thereof; (iii) about 0.001 to about 5 wt.% of a carbomer;.(tv) about 0.001 to about 60 wt.% of an excipient and, (v) about 0 to about 3% of water based on total weight of the composition. Also disclosed is a method of use thereof.

Description

CARBOMER BASED TOOTH PASTE COMPOSITION COMPRISING

CROSSLINKED POLYVINYLPYRROLIDONE FOR BUILDING VISCOSITY

FIELD OF THE INVENTION

[0001 ] The present application relates to a tooth paste composition, and more particularly, to an anhydrous carbomer based tooth paste composition comprising strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone for building viscosity.

BACKGROUND OF THE INVENTION

[0002] Anhydrous oral care products are useful to protect water sensitive compounds such as stannous fluoride, calcium sodium phosphosilicate (bio-glass), higher order polyphosphates such as sodium hexametaphosphate and solid peroxides. Currently, there are relatively few polymeric thickening agents which are used in commercial toothpastes that can adequately structure an anhydrous toothpaste.

[0003] Carbomer polymers are often used to thicken anhydrous toothpastes and can impart desirable characteristics to toothpaste formulations such as viscosity, yield value, shear thinning and clarity. The problems associated with anhydrous toothpastes thickened with carbomer are related to toothpaste structure (poor toothpaste ribbon stand-up, stringiness) and phase separation (syneresis). In addition, forming adequate structure with carbomer in non-aqueous solvent systems can be problematic. Problems associated with trying to build structure with carbomer in non- aqueous toothpaste formulations include variable viscosity from batch to batch and poor process robustness. The carbomers’ thickening ability is often affected by the following: other ingredients in the formula, at which stage it is introduced in the process and, processing parameters. Often heat and/or long mixing times are needed to help build and maintain structure in anhydrous formulations thickened with carbomer.

[0004] We have unexpectedly found that the addition of strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone to anhydrous toothpastes thickened with carbomer provides enhanced, synergistic viscosity, improved toothpaste structure and rheology and showed no phase separation (syneresis) upon storage. We have also found that the addition of strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone to a carbomer based toothpaste formula is capable of improving processing and process robustness.

[0005] In accordance with the methods described herein, levels of the carbomer and Polymer I up to about 5% based on the weight of the toothpaste unexpectedly can be used to provide a toothpaste with a desired toothpaste viscosity and structure - ribbon ‘stand-up’ as measured by the Cuban rack test (in the range of 3 to 12units).

[0006] US20070189983 A 1 describes an anhydrous liquid tooth whitening composition comprising a peroxide-containing compound and an orally acceptable carrier wherein the carrier includes a humectant, a bioadhesive agent selected from xanthan gum, a carbomer and polyvinyl pyrrolidone and its copolymers and mixtures thereof, and a film-forming agent.

[0007] EP3370691A1 describes oral care whitening compositions comprising a non-aqueous phase comprising a peroxysulfate whitening agent, a hydrophobic base and at least one hydrophilic polymer of the aqueous phase comprises linear polyvinylpyrrolidone or cross-linked polyvinylpyrrolidone and polycarboxymethylene polymer, e.g., a carbopol.

[0008] US10092482B2 describes an oral care composition comprising: (a) an oral care active; and (b) an acrylic film forming polymer and additionally comprising a hydrophilic polymer selected from the group consisting of polyethyelene glycols, nonionic polymers of ethylene oxide, block copolymers of ethylene oxide and propylene oxide, carboxymethylene polymers, polyvinyl pyrrolidone, and mixtures thereof.

[0009] Low stringiness is important not only to the consumer but also in high volume manufacturing where high-speed filling lines require that the toothpaste ribbon cuts off sharply from the tube. Toothpastes having good rheology will be easy to dispense from the tube yet stand up well on the brush.

[0010] Significant viscosity enhancements can be obtained from the carbomer/Polymer I combination vs. each polymer alone at the same overall polymer loading in the non-aqueous solvent system. The addition of Polymer I to carbomer based toothpaste provides higher viscosities at each stage during manufacture. In accordance with the methods described herein, low levels of Polymer I down to about 0.1 to 10% with carbomer, based on the weight of the toothpaste, can be used to provide a toothpaste with a desired Cuban rack test values in the range of 3 to 12 and moreover, such toothpaste formulations showed improved toothpaste ribbon stand-up and stringiness, increased thixotropy and elastic behavior, viscosity building properties and no syneresis on-storage in comparison to benchmark formulation.

SUMMARY OF THE INVENTION

[0011] A primary objective of the present application is to provide an anhydrous, carbomer based tooth paste composition comprising: (i) about 0. 1 to about 10 wt.% of a strongly swellable, lightly to moderately crosslinked polyvinyl pyrrolidone; (ii) about 10 to about 80 wt.% of at least one polyol or glycol selected from the group consisting of glycerin, sorbitol, polyethylene glycol, propylene glycol, 1,3-butylene glycol and mixtures thereof; and (iii) about 0.001 to about 60 wt.% of at least one excipient.

[0012] According to one aspect of the present application, there is provided an anhydrous carbomer based tooth paste composition that has a viscosity of greater than about 425,000 cP.

[0013] Yet another aspect of the present application discloses an anhydrous carbomer based toothpaste composition used for (i) improving toothpaste ribbon stand-up and stringiness, (ii) increased thixotropy and elastic behavior, and (iii) viscosity building properties and shows no syneresis on-storage.

[0014] Another aspect of the present application provides an anhydrous carbomer based toothpaste composition comprising a (i) about 0.1 to about 5 wt.% of a strongly swellable, lightly to moderately crosslinked polyvinyl pyrrolidone; (ii) about 10 to about 80 wt.% of at least one polyol or glycol selected from the group consisting of glycerin, sorbitol, polyethylene glycol, propylene glycol, 1,3-butylene glycol and mixtures thereof; (iii) about 0.001 to about 5 wt.% of a carbomer; and (iv) about 0.001 to about 25 wt.% of at least one excipient, wherein the composition has a Cuban value of about 3 to 12 and a viscosity of about 200,000 to about 1 ,400,000 cP at room temperature after it has been allowed to quiescently cool. BRIEF DESCRIPTION OF THE FIGURES

[0015] Further embodiments of the present application can be understood with the appended figures.

[0016] Figures 1 represents viscosity of polymers in toothpaste liquid phase glycerin/PEG 400.

[0017] Figure 2 shows the viscosity of polymers in toothpaste at accelerated conditions (45°C) of storage.

[0018] Figure 3 represents the effect of Polymer I on ribbon stand-up.

[0019] Figure 4 shows linear or crosslinked grades of polyvinylpyrrolidone vs Polymer I building viscosity providing structure to carbomer-based toothpastes.

[0020] Figure 5 shows finished toothpaste viscosity after addition of SnFz at various mixing times at high impeller speed.

[0021] Figure 6 represents the effect of Polymer I during processing of carbomer-based, anhydrous toothpastes showing viscosity after various stages of addition during process.

[0022] Figure 7 represents the effect of Polymer I on toothpaste thixotropy.

[0023] Figure 8 represents the effect of Polymer I on toothpaste viscoelasticity.

DETAILED DESCRIPTION OF THE INVENTION

[0024] Before explaining at least one aspect of the disclosed and/or claimed inventive concepts) in detail, it is to be understood that the disclosed and/or claimed inventive concepts) is not limited in its application to the details of construction and the arrangement of the components or steps or methodologies set forth in the following description or illustrated in the drawings. The disclosed and/or claimed inventive concept(s) is capable of other aspects or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0025] As utilized in accordance with the disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings.

[0026] Unless otherwise defined herein, technical terms used in connection with the disclosed and/or claimed inventive concept(s) shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0027] The singular forms "a," "an," and "the" include plural forms unless the context clearly dictates otherwise specified or clearly implied to the contrary by the context in which the reference is made. The term “Comprising” and “Comprises of" includes the more restrictive claims such as “Consisting essentially of’ and “Consisting of’.

[0028] For purposes of the following detailed description, other than in any operating examples, or where otherwise indicated, numbers that express, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". The numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties to be obtained in carrying out the invention.

[0029] All percentages, parts, proportions and ratios as used herein, are by weight of the total composition, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the active level and, therefore; do not include solvents or by-products that may be included in commercially available materials, unless otherwise specified. [0030] All publications, articles, papers, patents, patent publications, and other references cited herein are hereby incorporated herein in their entirety for all purposes to the extent consistent with the disclosure herein.

[0031 ] The use of the term “at least one” will be understood to include one as well as any quantity more than one, including but not limited to, 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term “at least one” may extend up to 100 or 1000 or more depending on the term to which it is attached. In addition, the quantities of 100/1000 are not to be considered limiting as lower or higher limits may also produce satisfactory results.

[0032] As used herein, the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has"), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0033] The term “each independently selected from the group consisting of’ means when a group appears more than once in a structure, that group may be selected independently each time it appears.

[0034] The term “polymer” refers to a compound comprising repeating structural units (monomers) connected by covalent chemical bonds. Polymers may be further derivatized, crosslinked, grafted or end-capped. Non-limiting examples of polymers include copolymers, terpolymers, tetrapolymers, quaternary polymers, and homologues. The term “copolymer" refers to a polymer consisting essentially of two or more different types of monomers polymerized to obtain said copolymer.

[0035] As used herein, the term “anhydrous” means non-aqueous or substantially free of water. To someone skilled in the art, this means that water is not intentionally added, however, a small amount may be present due to the water content found in the individual components of the formula. The individual components of the non-aqueous composition may contain limited amounts of water usually up to or equal to or less than about 2%, or equal to or less than about 1%, as long as the overall composition remains below about 3% water content. [0036] As used herein, the term “carbomer” refers to a group of cross linked polyacrylic acid polymers commonly used as a rheological modifier to create suspending, stabilizing, or thickening properties in products like hand sanitizers, sunscreens, creams, body lotions, cosmetics, toothpaste, hair products, eye gels, and pain gels, and includes, without limitation, various commercially available products sold by The Lubrizol Company (Wickliffe, Ohio) under the trade name Caibopol®. Accordingly, the terms “carbomer based products,” “carbomer based fluid,” “carbomer based composition,” as used herein, are used interchangeably to refer to any formulation where a carbomer has been used as a rheological modifier to create suspending, stabilizing, or thickening properties, and includes without limitation certain, toothpaste, oral spray or a mouth wash/oral rinse formulation. In some embodiments, the carbomer used in the carbomer gel based products acted upon by dispenser components according to embodiments of the present application may include, polyacrylic acid, crosslinked polyacrylic acid, a low viscosity carbomer, a carbomer copolymer, a carbomer interpolymer, a hydrophobically modified carbomer, or combinations without limitation, Carbopol® Aqua CC Polymer, Carbopol® Ultrez 10 Polymer, Carbopol® Ultrez 20 Polymer, Carbopol® Ultrez 21 Polymer, Carbopol® Ultrez 20 Polymer, Carbopol^® EDT 2020 Polymer, Carbopol^® EDT 2050 Polymer, Carbopol^® 980 Polymer, Carbopol^® 981 Polymer, Carbopol® 1342 Polymer, Carbopol^® 1382 Polymer, Carbopol® 2984 Polymer, Carbopol^® 5984 Polymer, or combinations thereof. Numerous grades of carbomer are available. Examples are the carbomers available from the Lubrizol Company, USA, under the trade names Carbopol^® 934 Polymer, Carbopol^® 940 Polymer, Carbopol® 941 Polymer, Carbopol®956 and Carbopol^® 974P or combinations thereof. Carbomer cross linked polyacrylic acid polymers can be used in toothpastes and an array of oral care products including gels, mouthwash, desensitizing and whitening products. They primarily function as efficient thickeners and binders and facilitate suspension of non-soluble actives or excipients.

[0037] In some embodiments, the carbomer is present in an amount of suitable range in the present application can be varied from about 0.001 wt.% to about 0.01 wt.%, from about 0.01 wt.% to about 0.1 wt.%, or from about 0.1 wt.% to about 1 wt.%, or from about 1 wt.% to about 5wt.%, or from about 5 wt.% to about 10 wt.% based on the total weight of the toothpaste composition. [0038] The term “viscosity” as used herein refers to dynamic viscosity, measured at 23°C using a Brookfield™ Model DV2T viscometer fitted with suitable spindle. As reported, toothpaste viscosities are measured at 23°C at 2 RPM using a TD (#94) spindle in the Heli-path mode with the measurement taken after 1 -minute (unless otherwise indicated).

[0039] According to one embodiment of the present application, the toothpaste composition is provided with strongly swellable, lightly to moderately crosslinked PVP (polyvinylpyrrolidone) polymer obtained directly as fine powders by precipitation polymerization of vinyl pyrrolidone in the presence of predetermined amount of a multifunctional crosslinking agent and a free radical initiator in an organic solvent, and wherein the crosslinked PVP has a Brookfield viscosity at least about 500 to about 50,000 cP in 4% aqueous solution. The viscosity ranges of the crosslinked PVP in the present application can be varied from about 500 to about 50,000 cP or from about 800 to about 20,000 cP or from about 1000 to about 10,000 cP. The Brookfield viscosity can be measured at 2.5, 5, 10, 12, 20, 30, or 50 RPM and at 25°C.

[0040] The crosslinked PVP polymer of the present application can be prepared according to US Patent No. 5,073,614, and US Patent No. 5,130,388 assigned to ISP Investments Inc. and used as a thickening agent as described in US20130209376A1 assigned to ISP Investments Inc. The disclosures of these references are incorporated herein in their entirety.

[0041] In another embodiment of the present application, the thickening agent comprising strongly swellable, lightly to moderately crosslinked polyvinylpyrrolidone as described in commonly owned U.S. Pat. Nos. 5,312,619 and 5,139,770, the contents of which are hereby incorporated by reference. The term “ strongly swellable, lightly to moderately crosslinked PVP", unless otherwise noted, specifically refers to polymer essentially consisting of lightly-to moderately-crosslinked poly(N-vinyl-2-pyrrolidone) having at least one of the following nonlimiting characteristics: (1) an aqueous swelling parameter defined by its gel volume from about 15 mL/g to about 300 mL/g, more particularly from about 15 mL/g to about 250 mL/g, and in other cases from about 15 mL/g to about 150 mL/g, or (2) a Brookfield viscosity of 5% crosslinked PVP in a liquid carrier comprising water at 25°C of at least 2,000 cP, more particularly of at least about 5,000 cP, and in certain cases of at least about 10,000 cP. Disclosure for these parameter ranges is provided in U.S. Pat. No. 5,073,614 (incorporated herein by reference) and in Shih, J. S., et al. (1995). Synthesis methods for the crosslinked PVP are disclosed in a number of references, including U.S. Pat. Nos. 5,073,614; 5,654,385; and 6,177,068, the contents of which are hereby incorporated by reference. It is appreciated by a polymer scientist skilled in the art that the method of synthesis is immaterial, in as much as the produced polymer achieves at least one of the above defined parameters.

[0042] It is contemplated to employ any other possible polymerization methods known in the art for a skilled artisan, which can provide strongly swellable, moderately crosslinked PVP as fine white powder. Such polymerization methods can include, but are not limited to, precipitation polymerization, inverse emulsion polymerization, gel polymerization, dispersion polymerization, solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, Liquid dispersion polymerization (LDP) and ionic polymerization.

[0043] Other polymerization techniques employed to prepare the polymer of the present application are duly disclosed in (1) "Principles of Polymerization" 4^th edition, 2004, Wiley by George Odian and (2) W02012061147A1 assigned to ISP Investments Inc., which are incorporated herein by reference in their entirety. Further, the polymerization of the present application can optionally require suitable catalysts or initiators, stabilizers, salts, pH adjusting agents, co-dispersants, thickeners, solvents, acidic agents, basic agents, and/or photo initiators depending on type of polymerization technique being employed, and one skilled in the art can easily derive such information from the relevant literature known in the art or from "Principles of Polymerization" 4th edition, 2004, Wiley by George Odian, which is incorporated herein by reference in its entirety.

[0044] The poly-N-vinyl-poly-2-pyrrolidone is also commonly known as polyvinylpyrrolidone or "PVP". PVP refers to a polymer containing vinylpyrrolidone (also referred to as N- vinylpyrrolidone, N-vinyl-2-pyrrolidione and N-vinyl-2-pyrrolidinone) as a monomeric unit. Suitable vinyl-pyrrolidone polymers include poly(vinyl-pyrrolidone) (PVP), Plasdone® K-90, and Plasdone® K-120.

[0045] Crosslinked polyvinylpyrrolidones are commercially available, for example, as Kollidon® CL types from BASF or as Polyplasdone® from Ashland. [0046] Commercially available examples of strongly swellable, lightly to moderately crosslinked PVP include, but are not limited to, FLEXITHIX™, PVP, available from Ashland.

[0047] In an embodiment, the present application provides toothpaste composition containing strongly swellable, lightly to moderately crosslinked PVP polymers (Polymer I) directly as fine powders obtained by precipitation polymerization of vinyl pyrrolidone in the presence of a predetermined amount of a multifunctional crosslinking agent and a free radical initiator in an organic solvent.

[0048] In another embodiment, the composition of the present application is provided with strongly swellable, moderately crosslinked PVP polymer based fine powders characterized by an aqueous gel volume of about 15-150 ml/g of polymer and a Brookfield viscosity in 5% aqueous solution of at least 1000-10,000 cP.

[0049] In some embodiments, the crosslinked PVP is present in an amount of suitable range can be varied from about 0.001 wt.% to about 0.01 wt.%, from about 0.01 wt.% to about 0.1 wt.%, or from about 0.1 wt.% to about 1 wt.%, or from about.1 wt.% to about 5wt.%, or from about 5 wt.% to about 10 wt.% based on the total weight of the toothpaste composition.

[0050] According to one embodiment of the present application, glycol can be selected from compounds having 2-8 carbon atoms, for example 1, 2-propylene glycol, 1, 3-propylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,3-bulylene glycol, and mixtures thereof. As polyols, for example glycerol, erythritol, diglycerol, sorbitol and polyethylene glycols can be included. The polyols can be selected from the group of glycerin, sorbitol, polyethylene glycol, and mixtures thereof.

[0051 ] In some embodiments, the glycols or polyols is/are present in an amount of suitable range can be varied from about 10 wt. % to about 20 wt. %, or from about 20 wt.% to about 30 wt.%, or from about 30 wt.% to about 40 wt.%, or from about 40 wt.% to about 50 wt.% or from about 50 wt.% to about 60 wt.% or from about 60 wt.% to about 70wt.% or from about 70 wt.% to about 80wt.% based on the total weight of the toothpaste composition of the present application.

[0052] In some embodiments, the excipients of the present application can be chosen to provide an appropriate mode of delivery, for example, solutions, colloidal dispersions, emulsions, suspensions, gels, powders, solids, and the like, and can include conventional components typically associated with toothpastes, and the like. Excipients suitable for the preparation of components of the present application are well known in the art. Their selection will depend on secondary considerations like taste, cost, shelf stability and the like.

[0053] According to one embodiment of the present application, the excipients can be selected from the group consisting of a humectant, flavoring agent, a colorant, a sweetener, an abrasive, a surfactant, a binder, a thickener, a vehicle, an antimicrobial agent a fragrance, a sensate, a polyphosphate, one or more solids, a fluoride-providing compound and mixtures thereof.

[0054] In some embodiments, the excipients is/are present in an amount of suitable range can be varied from about 0.001 wt.% to about 0.01 wt.%, from about 0.01 wt.% to about 0.1 wt.%, or from about 0.1 wt.% to about 1 wt.%, or from about.1 wt.% to about 5 wt.%, or from about 5 wt.% to about 10 wt.% , from about 10 wt % to about 15 wt. %, or from about 15 wt.% to about 20 wt.%, or from about 20 wt.% to about 25 wt.%, from about 25 wt. % to about 30 wt. %, or from about 30 wt.% to about 35 wt.%, or from about 35 wt.% to about 40 wt.% or from about 40 wt.% to about 45 wt.% , from about 45 wt. % to about 50 wt. % or from about 50 wt.% to about 55 wt.% , from about 55 wt. % to about 60 wt. % based on the total weight of the toothpaste composition of the present application.

[0055] According to one embodiment of the present application, suitable humectants for use in the toothpaste compositions include edible polyhydric alcohols such as glycerin, soibitol, xylitol, polyethylene glycol, and propylene glycol.

[0056] In another embodiment, the composition of the present application is provided with flavoring agents, which can include, but not limited to, volatile oils distilled or expressed from plants and constituents of these volatile oils. Typical essential oils and their main constituents are those obtained for example from anise (anethole, safrol), clove (eugenol, eugenyl acetate, caryophyllene), peppermint (menthol, menthyl esters), spearmint (carvone, limonene, pinene); wintergreen (methyl salicylate), cinnamon (cinnamaldehyde, cinnamyl acetate, eugenol), sassafras (safrole), thyme (thymol, carvacrol), oregano (carvacrol, terpenes), lemon (limonene, terpinene, phellandrene, pinene, citral), lemongrass (citral, methylheptenone, citronellal, geraniol), orange flower (linalool, β-pinene, limonene), orange (limonene, citral), rose (geraniol, citronellol), rosemary (bomeol, bomyl esters, camphor), geranium (geraniol, citronellol, linalool), lavender (linalyl acetate, linalool), citronella (geraniol, citronellol, citronellal, camphene), eucalyptus (eucalyptol); camphor (safrole, acetaldehyde, camphor), bay (eugenol, myrcene, chavicol), tea tree (terpinen-4-ol, cineole), and cedar leaf (α-thujone, β-thujone, fenchone). Suitable flavoring agents include wintergreen oil, peppermint oil, spearmint oil, clove bud oil, menthol, anethole, methyl salicylate, eucalyptol, cassia, 1-menthyl acetate, sage, eugenol, parsley oil, oxanone, alpha-irisone, marjoram, lemon, orange, propenyl guaethol, cinnamon, vanillin, thymol, linalool, cinnamaldehyde glycerol acetal known as CGA, and mixtures thereof.

[0057] In another embodiment, the composition of the present application is provided with a colorant which can include, but is not limited to, dyes and pigments, talc, mica, magnesium carbonate, magnesium silicate, silica, titanium dioxide, zinc oxide, red, yellow, brown and black iron oxides, ferric ammonium ferrocyanide, manganese violet, ultramarine, titanated mica, bismuth oxychloride, and mixtures thereof.

[0058] In another embodiment, composition of the present application comprises sweetening agents which can include but not limited to sucrose, glucose, saccharin, levulose, lactose, mannitol, sorbitol, fructose, maltose, xylitol, saccharin salts, thaumatin, aspartame, dihydrochalcones, acesulfame, sucralose and cyclamate salts, especially sodium cyclamate and sodium saccharin, and mixtures thereof. A composition contains from about 0.1% to about 10% of these agents, from about 0.1% to about 1 %, by weight of the composition.

[0059] In another embodiment, the composition of the present application further comprises suitable abrasives which include, but are not limited to, silica abrasives, such as standard cleaning silicas, high cleaning silicas or any other suitable abrasive silicas. Additional examples of abrasives that can be used in addition to or in place of the silica abrasives include, for example, a calcium phosphate abrasive, e.g., tricalcium phosphate (Ca3(PO₄)2), hydroxyapatite (Ca10(P04)6(OH)2), or dicalcium phosphate dihydrate CaHPO₄.2H2O or calcium pyrophosphate; calcium carbonate abrasive; or abrasives such as sodium metaphosphate, potassium metaphosphate, aluminum silicate, calcined alumina, bentonite or other siliceous materials, or combinations thereof. The silica component of the present silica substrate is an amorphous precipitated silica. Precipitated silicas include the following products available from the Evonik Corporation, Havre de Grace, MD.: Zeodent® 103, Zeodent® 113, Zeodent® 114, Zeodent® 115, Zeodent® 118, Zeodent® 119, Zeodent® 165, and Zeodent® 9175.

[0060] In another embodiment, the composition of the present application further comprises surfactants which are reasonably stable and foam throughout a wide pH range. The surfactant can be anionic, nonionic, amphoteric, zwitterionic, cationic, or mixtures thereof.

[0061 ] In another embodiment, the composition of the present application contains one or more anionic surfactants which includes water-soluble salts of alkyl sulfates having from 8 to 20 carbon atoms in the alkyl radical (e.g., sodium alkyl sulfate) such as sodium lauryl sulfate and the water- soluble salts of sulfonated monoglycerides of fatty acids having from 8 to 20 carbon atoms, such as sodium coconut monoglyceride sulfonate. Other suitable anionic surfactants are sarcosinates, such as sodium lauroyl sarcosinate, taurates, sodium lauryl sulfoacetate, sodium lauroyl isethionate, sodium lauryl carboxylate, and sodium dodecyl benzenesulfonate, and mixtures thereof.

[0062] Another suitable surfactant is selected from the group consisting of sarcosinate surfactants, isethionate surfactants and taurate surfactants. Surfactants are alkali metal or ammonium salts of these surfactants, sodium and potassium salts of lauroyl sarcosinate, myristoyl sarcosinate, palmitoyl sarcosinate, stearyl sarcosinate, and oleoyl sarcosinate.

[0063] Cationic surfactants are derivatives of aliphatic quaternary ammonium compounds having one long alkyl chain containing from about 8 to 18 carbon atoms such as lauryl trimethylammonium chloride; cetyl pyridinium chloride; cetyl trimethylammonium bromide; di- isobutylphenoxyethyl-dimethylbenzylammonium chloride; coconut alkyltrimethylammonium nitrite; cetyl pyridinium fluoride; etc.

[0064] Nonionic surfactants useful in the tooothpaste compositions include compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound which can be aliphatic or alkylaromatic in nature. Examples of suitable nonionic surfactants include the Pluronics™, polyethylene oxide condensates of alkyl phenols, products derived from the condensation of ethylene oxide with the reaction product of propylene oxide and ethylene diamine, ethylene oxide condensates of aliphatic alcohols, long chain tertiary amine oxides, long chain tertiary phosphine oxides, long chain dialkyl sulfoxides and mixtures of such materials.

[0065] Zwitterionic are derivatives of aliphatic quaternary ammonium compounds, in which the aliphatic radicals can be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate or phosphonate.

[0066] The toothpaste composition may further comprise surfactants including, but not limited to alkyl dimethyl betaines. The alkyl dimethyl betaines include decyl betaine or 2-(N-decyl-N,N- dimethylammonio) acetate, coco betaine or 2-(N-coc-N, N -dimethyl ammonio) acetate, myristyl betaine, palmityl betaine, lauryl betaine, cetyl betaine, cetyl betaine, stearyl betaine, etc. The amido-betaines are exemplified by cocoamidoethyl betaine, cocoamidopropyl betaine, lauramidopropyl betaine and the like.

[0067] The toothpaste composition can further comprise thickening agents which are water- soluble cellulose ethers such as sodium carboxymethylcellulose, sodium carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose and PVP which generally refers to a polymer containing vinylpyrrolidone (also referred to as N-vinylpyrrolidone, N-vinyl-2-pyrrolidone and N- vinyl-2-pyrrolidinone) as a monomeric unit. Other suitable thickening agents include; carboxyvinyl polymers, carrageenan, laponite and other natural gums such as gum karaya, xanthan gum, guar gum, gum arabic, and gum tragacanth. Colloidal magnesium aluminum silicate or finely divided silica can be used as part of the thickening agent to further improve texture. A class of thickening or gelling agents includes a class of homopolymers of acrylic acid cross-linked with an alkyl ether of pentaeiythritol or an alkyl ether of sucrose.

[0068] The toothpaste composition may further comprise suitable anti-microbial agents which include, but are not limited to, halogenated diphenyl ether, 2,4,4'-trichloro-2’-hydroxy-diphenyl ether, 2,2'-dihydroxy-5,5'-dibromo-diphenyl ether, 2,2'-methylenebis-4(4-chloro-6- bromo- phenol), halogenated salicylanilides and halogenated cabanilides, stannous chloride, zinc lactate, zinc citrateand zinc oxide. [0069] As used herein the term "sensate" means refers to a material in which its predominant effect in the oral cavity is to impart a sensation, for example, a taste, moisturization, warming, cooling, and/or tingling sensation. A sensate can be, but is not limited to, a flavor, a sweetener, a coolant, a saliva stimulant, or a TRPV1 activator.

[0070] In another embodiment, polyphosphates including tripolyphosphates, tetrapolyphosphates, and hexametaphosphates, can also be included in the toothpaste compositions. The phosphate source suitable for use in this application includes monosodium phosphate, orthophosphoric acid such as sodium dihydrogen phosphate, disodium hydrogen phosphate and trisodium phosphate, alkali metal salts of polyphosphates such as tetrasodium pyrophosphate, pentasodium tripolyphosphate or sodium hexametaphosphate. Also, di-sodium pyrophosphate, potassium dihydrogenphosphate, tripotassium phosphate, and mixtures thereof or the like.

[0071] As used herein the term “solids” can include, but is not limited to, alumina, calcium carbonate, calcium pyrophosphate, and dicalcium phosphate, precipitated silica, titanium dioxide, sodium carboxymethyl cellulose, pigment, colorant, mica, coated mica, talc, fumed silica, microencapsulated pigment, microencapsulated fragrance, an orthophosphate and mixtures thereof.

[0072] As used herein the term “fluoride-providing compound" can include, but is not limited to, sodium fluoride, potassium fluoride, amine fluoride, ammonium fluoride, manganese fluoride, a copper fluoride such as cuprous fluoride, zinc fluoride, barium fluoride, sodium fluorosilicate, ammonium fluorosilicate, sodium fluoroziiconate, sodium monofluorophosphate, potassium fluorozirconates, sodium monofluorophosphate, and a tin fluoride such as stannous fluoride, stannic fluoride or stannous chlorofluoride, and sodium hexafluorostannate.

[0073] In accordance with various aspects of this embodiment, the composition is designed to maintain the active ingredient(s) in contact with a surface for an extended period of time. Exemplary compositions have a viscosity greater than about 20,000 centipoise (cP), preferably greater than about 30,000 cP, and more desired greater than about 35,000 cP. The viscosity of the compositions can be in range from about 20,000 to about 250,000 cP, about 25,000 to about 100,000 cP, or about 200,000 to about 1,400,000 cP. [0074] The viscosity increase observed using this application will depend on the type and amount of Polymer I used and on the temperature from which the composition is allowed to quiescently cool. A viscosity for a toothpaste of this application will generally be in the range of about 200,000 to about 1,400,000 cP when measured at 23°-25° C. Toothpaste viscosities are expressed in centipoise(cP) and were measured at 23° C using a Brookfield™ Model DV2T viscometer.

[0075] The following examples are presented for purposes of demonstrating, but not limiting, the preparation and use of the polymers. In the examples, the following abbreviations are used: wt% or % (w/w) Weight percent centipoise cP

PVP Polyvinylpyrrolidone

Polymer I Lightly to moderately crosslinked polyvinyl pyrrolidone Crosslinked PVP Self-crosslinked polyvinyl pyrrolidone

Carbomer Homopolymer Type B (Carbopol^® 974P, crosslinked polyacrylic acid

Carbomer available from the Lubrizol Company

: Polyvinyl pyrrolidone powder average molecular weight of 1 ,300,000 in Daltons

PVP K-90 PVP K-15 : Polyvinylpyrrolidone powder average molecular weight of 8,000 in Daltons

PEG : Polyethylene glycol

SLS : Sodium Lauryl sulfate

[0076] Further, certain aspects of the present application are illustrated in detail by way of the following examples. The examples are given herein for illustration of the application and are not intended to be limiting thereof.

EXAMPLES

Example 1 : Toothpaste Manufacture-Gel Phase Manufacture

[0077] To a suitably sized vessel, charge the glycerin and PEG-400 and disperse the Polymer I using an overhead propeller mixing blade with strong agitation (800-1,000 RPM) for 25-minutes. Carbomer is then added into the vortex and mixed under strong agitation (800- 1 ,000 RPM) for 20- minutes. Next add sodium tripolyphosphate and sodium saccharin to the gel and mix under strong agitation (800-1,000 RPM) for 25-minutes. Transfer the gel phase to a Ross™ 1QT double planetary mixer fitted with a vacuum pump and add the silicas and titanium dioxide powders. Mix in the Ross™ double planetary mixer at high speed (80 RPM) for 20-25 minutes under a minimum of 28” Hg vacuum. Sodium lauryl sulfate, cocamidopropyl betaine and flavor are added and mixed at low speed ( 10 RPM) for 15-minutes under a minimum of 28” Hg vacuum. Add stannous fluoride and mix at low speed (10 RPM) for 20-25 minutes under a minimum of 28” vacuum.

Example 2: Cuban test method for toothpaste ribbon stand-up

[0078] Full toothpaste formulations were packaged into tubes and the toothpaste integrity (stand- up) was measured using the Cuban rack test. In this test, the paste is squeezed from the bottom of the tube through a fixed orifice across a grid of parallel rods, increasingly spaced apart. The test results are expressed as the bar number furthest away from the starting point (numbers are from 1- 12) that is still able to support the dentifrice ribbon (e.g. the bar where the ribbon breaks). Higher Cuban rack test values indicate better toothpaste ribbon stand-up. The Cuban rack test is run as follows: The nozzle of the toothpaste tube is held at a 45° angle to the rack device, pressure is applied, and the toothpaste bead is quickly drawn down the entire length of the rack in a straight line. Generally, this is accomplished in approximately 2- seconds. If the ribbon breaks before the entire rack is traversed, the procedure is repeated. The ribbon is allowed to stand for 30 seconds and the rod number corresponding to the highest bar value still able to support the toothpaste ribbon is recorded as the Cuban value. The test was performed four times and the averaee readme recorded, rounding the number off to the nearest whole number. Example 3: Viscosity Measurements

[0079] Viscosity measurements were taken at 23°C using a Brookfield™ Model DV2T viscometer fitted with suitable spindle. All finished toothpastes were measured at 2 RPM using a TD (#94) spindle in the Heli-path mode with the measurement taken after 1 -minute.

Example 4: Viscosity of polymers in toothpaste liquid phase glvcerin/PEG

[0080] Experiments were conducted for polymers of Polymer I (0.95 parts), Carbomer Homopolymer Type B) (0.95 parts) alone and their combination (Polymer I and Carbomer Homopolymer Type B with ratio 0.2:0.75 parts) of polymers in a non-aqueous solvent liquid phase glycerin/PEG 400 (55:20) for viscosity measurements. Synergistic viscosity is observed with the carbomer/ Polymer I combination vs. each polymer, alone at the same overall polymer loading. Non-additive increase in viscosity was seen upon the addition of 0.25% Polymer I to 1% Carbomer Homopolymer Type B vs. each polymer at 1.25%, alone in the non-aqueous, liquid phase solvent system. This indicates a high degree of interaction/association between Polymer I (0.95) and Carbomer Homopolymer Type B. (Table 1 and Fig 1).

Table 1: Polymer I and carbomer show viscosity synergy in a glycerin/PEG 400 anhydrous solvent system

Example 5: Carbomer-based anhydrous toothpaste with and without Polymer I

[0081 ] Carbomer-based anhydrous toothpaste were made at room temperature, in a single vessel (see procedure example 1) and stored at accelerated temperature condition of 45°C for a stability study. The addition of a small amount of Polymer I to Carbomer Homopolymer Type B based anhydrous toothpaste dramatically increased toothpaste viscosity and improved toothpaste structure. It shows that a small (0.2%) addition of Polymer I essentially doubles the viscosity of a 0.75% carbomer-thickened anhydrous toothpaste and that this formulation is stable at accelerated conditions of storage (12-weeks at accelerated temperature conditions is usually what is needed to show that the product is stable). The addition of a small amount of Polymer I approximately doubled the toothpaste viscosity of an anhydrous toothpaste thickened with Carbomer Homopolymer Type B due to the viscosity synergy seen between the two polymers (Fig 2 and Table 2).

Table 2: Carbomer-based anhydrous toothpaste with and without Polymer I

Example 6: Toothpaste ribbon stand-up

[0082] Carbomer-based anhydrous toothpaste were made at room temperature with addition of a small amount (0.2%) of Polymer I to the carbomer-based toothpaste and resulted in significantly better toothpaste ribbon body (‘stand-up’) upon dispensing. Addition of Polymer I improves the toothpaste structure (stand-up and stringiness) of an anhydrous toothpaste formula thickened with Carbomer Homopolymer Type B which was also smooth and creamy with good gloss (Fig 3). Example 7: Linear or stronelv-crosslinked grades of PVP vs Polymer I

[0083] Experiments showed that Polymer I (lightly crosslinked PVP) was unique amongst other PVP homopolymers both linear and crosslinked PVP in that it very efficiently thickened the anhydrous 0.75%, Carbomer Homopolymer Type B formulation, whereas the linear PVP K-90 and crosslinked PVP did not thicken the toothpaste to any appreciable degree above carbomer, alone. Linear and Crosslinked PVP’s were significantly poorer than Polymer I at providing structure to carbomer-based toothpastes at the same level (Fig 4 and Table 3).

Table 3: Linear or crosslinked grades of PVP and Polymer 1 tooth paste formulations

Example 8: Finished toothpaste viscosity after addition of SnF2

[0084] Finished toothpaste viscosity after the addition of stannous fluoride (SnF2) at various mixing times at high impeller speed of 1-QT Ross double planetary mixer (80 RPM) were measured for formulas with and without Polymer I. The results show the instability (shear-induced viscosity loss after stannous fluoride addition) during manufacture of the carbomer-only formula and the preservation of formula viscosity with the addition of lightly crosslinked PVP (Polymer I). The addition of Polymer I protects carbomer-based toothpaste from shear-induced viscosity loss making it a more robust formula (Fig. 5 and Table 4).

Table 4: Toothpaste formulas used to measure viscosity after addition of SnFa at various mixing times at high impeller speed

Example 9: Effect of Polymer I - Viscosity after various stages of addition during process

[0085] The effect of Polymer I during various processing stages of carbomer-based, anhydrous toothpaste was studied. The results show that the addition of Polymer I provides higher viscosities at each stage during manufacture studied (Fig 6 and Table 5).

Table 5: Formulas used to study the effect of Polymer I at various manufacturing stages

Example 10: Toothpaste thixotropy loop measurements and LAOS plots

[0086] Method: AR-G2 rheometer (TA Instruments) with 40 mm sand blasted stainless steel parallel plates with solvent trap was used at 25°C temperature. After loading and trimming, a solvent trap was placed, and the samples were equilibrated at 25°C temperature for 30 minutes as a conditioning step for all measurements. Measurements were conducted using a continuous shear ramp up and down test between 0 to 4 1/s (Fig 7 and Fig 8).

[0087] Toothpaste thixotropy loop measurements for the 0.75% carbomer toothpaste formulas, with and without 0.2% Polymer I are shown in Fig 7 and Table 2. The caibomer-only toothpaste has negligible thixotropy as seen by the up and down portions of the loop nearly coinciding. The formula with both carbomer and Polymer I (Formula B in Table 2) shows thixotropic behavior, as seen by the hysteresis loop and shows increased shear stress.

[0088] Large Amplitude Oscillatory Flow (LAOS) experiments is a sinusoidal oscillatory flow experiment where the amplitude of the strain input is large enough to deform the material beyond the linear viscoelastic limit A special form of plotting shear rate versus stress data from LAOS experiments is named as Lissajous-Bowditch curves and can be used to compare non-linear viscoelastic behavior of formulations. Comparison of the Lissajous plots in Figure 8 shows that the addition of Polymer I to the carbomer containing formula (Formula B in Table 2) increased the corresponding absolute stress values for the same shear rate values and the shape of the ellipses became closer to that of a circle, which is an indication of increased viscoelasticity in the nonlinear deformation region.

[0089] While the compositions and methods of the disclosed and/or claimed inventive concepts) have been described in terms of particular aspects, it will be apparent to those of ordinary skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the disclosed and/or claimed inventive concept(s). AH such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosed and/or claimed inventive concepts).

Claims

What is Claimed is

1. An anhydrous carbomer based tooth paste composition comprising: i. about 0. 1 to about 10 wt.% of a strongly swellable, lightly to moderately crosslinked polyvinyl pyrrolidone (PVP); ii. about 10 to about 80 wt.% of one or more polyols or glycols selected from the group consisting of glycerin, sorbitol powder, polyethylene glycol, propylene glycol, 1,3-butylene glycol and mixtures thereof; iii. about 0.001 to about 5 wt.% of a carbomer; iv. about 0.001 to about 60 wt.% of an excipient; and v. about 0 to about 3 wt.% of water.

2. The composition of claim 1, wherein the crosslinked polyvinyl pyrrolidone is present in an amount of from about 0.1 wt. % to about 5.0 wt. %.

3. The composition of claim 1, wherein the glycol or polyols further comprise one or more glycols or polyols selected from the group consisting of 1 , 2-propylene glycol, 1 , 3-propylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, eiythritol, diglycerol and polyol powders selected from the group consisting of sorbitol, mannitol, maltitol, xylitol, erythritol and mixtures thereof.

4. The composition of claim 1, wherein the polyol or glycol is present in an amount of from about 35 wt. % to about 80%.

5. The composition of claim 1, wherein the carbomer is selected from the group consisting of polyacrylic acid, crosslinked polyacrylic acid, a low viscosity carbomer, a carbomer copolymer, a carbomer interpolymer, a hydrophobically modified carbomer, or combinations thereof.

6. The composition of claim 1 , wherein the carbomer is present in an amount of from about 0.1 wt. % to about 5.0 wt. % based on the weight of the tooth paste composition.

7. The composition of claim 1, wherein said composition is used for (i) improving toothpaste ribbon stand-up and stringiness, (ii) increasing thixotropy and elastic behavior and, (iii) building viscosity, and shows no syneresis on-storage.

8. The composition of claim 1 further comprising about 0.001 to about 50 wt.% of an excipient selected from the group consisting of a humectant, a flavoring agent, a colorant, a sweetener, an abrasive, a surfactant, a binder, a thickener, a vehicle, an antimicrobial agent a fragrance, a sensate, a polyphosphate, one or more solids, a fluoride-providing compound and mixtures thereof.

9. The composition of claim 8, wherein the excipient comprises one or more solids selected from the group consisting of precipitated silica, titanium dioxide, sodium carboxymethyl cellulose, PVP-hydrogen peroxide complexes (Peroxydones), carbamide peroxide, sodium percarbonate, sodium perphosphate, calcium peroxide, bio-glasses, stannous chloride, potassium nitrate, tin oxide, zinc oxide, zinc citrate, arginine, citric acid, sodium citrate, pigment, colorant, mica, coated mica, talc, fumed silica, microencapsulated pigment, microencapsulated fragrance, an orthophosphate and mixtures thereof.

10. The composition of claim 8, wherein the abrasive is selected from the group consisting of precipitated silica, calcium carbonate, calcium pyrophosphate, dicalcium orthophosphate dihydrate, tricalcium phosphate, hydrated alumina and mixtures thereof.

11. The composition of claim 8, wherein the fluoride-providing compound is selected from the group consisting of sodium fluoride, stannous fluoride, manganese fluoride, potassium fluoride, amine fluoride, sodium hexafluorostannate, stannous chlorofluoride, sodium fluorozirconate, potassium fluorozirconates and sodium monofluorophosphate.

12. The composition of claim 8, wherein the surfactant is selected from the group consisting of alkyl phosphate surfactants, alkyl phosphate ethoxylated surfactants, alkyl sulfate surfactants, betaine surfactants, sarcosinate surfactants, sulfonated monoglycerides of fatty acids surfactants, amine oxide surfactants, non-ionic surfactants, ethylene oxideZpropylene oxide block polymers, poly-ethoxylated fatty acid sorbitan esters, ethoxylated fatty acids, esters of polyethylene glycol, cocoamidopropyl betaine, sodium lauryl sulfate, sodium lauroyl sarcosinate, cetyl phosphate, oleth-5 phosphate, poloxamer 407, polysorbate 20, lauryldimethylamine oxide, and sodium coconut monogiyceride sulfonate and mixtures thereof.

13. The composition of claim 8, wherein the sweetener is selected from the group consisting of saccharin, sucralose, acesulfame potassium, aspartame, cyclamate, xylitol, sorbitol, mannitol, dextrose and mixtures thereof.

14. The composition of claim 8 wherein the flavoring oil is selected from the group consisting of anise oil, clove oil, sassafras oil, spearmint oil, peppermint oil, oil of wintergreen, eugenol and mixtures thereof.

15. The composition of claim 8, wherein the phosphate source is selected from the group consisting of alkali metal salts of orthophosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, alkali metal salts of polyphosphates, tetrasodium pyrophosphate, di-sodium pyrophosphate, pentasodium tripolyphosphate, sodium hexametaphosphate and mixtures thereof.

16. The composition of claim 1 , wherein the anhydrous carbomer based tooth paste has a viscosity of greater than about 425,000 cP.

17. An anhydrous carbomer based toothpaste composition comprising: i. about 0.1 to about 5 wt.% of a strongly swellable, lightly to moderately crosslinked polyvinyl pyrrolidone; ii. about 10 to about 80 wt.% of a polyol or glycol selected from the group consisting of glycerin, sorbitol, polyethylene glycol, polyglycerols, propylene glycol, butylene glycol and mixtures thereof; iii. about 0.001 to about 5 wt.% of a carbomer; iv. about 0.001 to about 60 wt.% of an excipient, and v. about 0 to about 3 wt. % of water wherein the composition has a Cuban value of 3 to 12 or viscosity of about 200,000 to about 1,400,000 cP at room temperature after it has been allowed to quiescently cool.