Methods for visualizing and quantifying the presence of fluoride

Abstract

Disclosed herein are methods for detecting the presence of fluoride deposited on a substrate from an oral care composition, kits for detecting fluoride deposition on a substrate, oral care compositions comprising fluoride, an antibacterial agent such as cetylpyridinium chloride, a thickener such as xanthan gum, and optionally a pearlescent agent that may comprise glycol distearate, laureth-4 and cocamidopropyl betaine, and methods for detecting and quantifying the presence of fluoride in a liquid oral care composition.

Description

1077927-00- WO-Ol-OCMETHODS FOR VISUALIZING AND QUANTIFYING THE PRESENCE OF FLUORIDECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 63 / 748,215, filed January 22, 2025, the contents of which are hereby incorporated herein by reference in their entirety.BACKGROUND

[0002] Constant bacterial activity in the mouth releases acids that erode the enamel and essential minerals, weakening the teeth. Fluoride promotes the remineralization of the weakened enamel and the replacement of the minerals, making the teeth stronger. Weak teeth enamel without enough replacement of essential minerals is susceptible to developing dental caries that may lead to cavities. Fluoride helps resist cavities by promoting remineralization and strengthening the enamel. Remineralization also provides teeth with a harder deposit of the lost minerals, thereby reversing the early signs of tooth decay. The benefits of fluoride also extend to soft tissues such as the gums. Fluoride can prevent the growth of cavity-forming bacteria in the mouth that contribute to cavities and gum disease.

[0003] Dental fluoride provided in oral care compositions such as toothpastes, mouthwashes, and films helps to maintain oral health. The efficacy of fluoride treatment with such products varies and depends on such factors as the form of the compositions and their ingredients. Compositions that provide greater deposition and retention of fluoride on hard and soft tissues in the oral cavity may offer improved benefits by virtue of the extended contact of fluoride with the tissues.

[0004] It would therefore be beneficial to provide methods for visualizing and quantifying the presence of fluoride on hard or soft tissue-mimicking substrates or in neat solutions, and to provide compositions comprising fluoride that are more retentive to hard and soft tissues for improved deposition of fluoride in the oral cavity.BRIEF SUMMARY

[0005] This summary is intended merely to introduce a simplified summary of some embodiments of one or more implementations of the present disclosure. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. This summary is not an extensive overview, nor is it intended to identify all elements of the present1077927-00- WO-Ol-OCteachings, nor to delineate the scope of the disclosure. Rather, its purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description below.

[0006] An embodiment of the disclosure is a method for detecting the presence of fluoride deposited on a substrate from an oral care composition, which comprises:contacting a surface of the substrate with the oral care composition to form a treated surface of the substrate;contacting the treated surface of the substrate with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;assessing the color of the treated surface of the substrate: anddeducing from the color of the treated surface of the substrate whether fluoride is deposited on the substrate.

[0007] The substrate can be a hard or soft tissue-mimicking substrate, such as hydroxyapatite. The oral care composition can be a liquid oral care composition, for instance.

[0008] In some embodiments, contacting the surface of the substrate with the liquid oral care composition comprises immersing at least a portion of the substrate in the oral care composition. This may comprise immersing at least a portion of the substrate in the oral care composition for 1 minute or longer, 5 minutes or longer, or 10 minutes or longer.

[0009] The reagent solution may comprise iron (III) chloride, iron (III) nitrate, or both. Various embodiments comprise contacting the treated surface of the substrate with the reagent solution by immersing at least a portion of the substrate in a colorless aqueous solution then adding the reagent to the aqueous solution.

[0010] In embodiments of the disclosure, assessing the color of the treated surface of the substrate comprises detecting the presence or absence of a color change of the treated surface of the substrate upon contact with the reagent solution. For example, some embodiments comprise detecting the absence of a color change of the treated surface of the substrate upon contact with the reagent solution; and deducing that fluoride is deposited on the substrate.

[0011] Further embodiments of the disclosure comprise:contacting a surface of a comparative substrate with a comparative oral care composition to form a treated surface of the comparative substrate;1077927-00- WO-Ol-OCcontacting the treated surface of the comparative substrate with the reagent solution; assessing the color of the treated surface of the comparative substrate; anddeducing from the colors of the treated surfaces of the substrate and of the comparative substrate whether more or less fluoride is deposited on the substrate than on the comparative substrate.

[0012] This method of comparison may comprise detecting less of a color change of the treated surface of the substrate than of the treated surface of the comparative substrate; and deducing that more fluoride is deposited on the substrate than on the comparative substrate. Such a method may comprise:detecting the absence of a color change of the treated surface of the substrate and a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface of the comparative substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.

[0013] The method of comparison may alternatively comprise detecting less of a color change of the treated surface of the comparative substrate than of the treated surface of the substrate; and deducing that less fluoride is deposited on the substrate than on the comparative substrate. Such a method may comprise:detecting the absence of a color change of the treated surface of the comparative substrate and a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface of the substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.

[0014] A further embodiment of the disclosure is a kit for detecting fluoride deposition on a substrate, which comprises:iron (III) chloride or iron (III) nitrate;potassium thiocyanate; and1077927-00- WO-Ol-OCa hard or soft tissue-mimicking substrate, such as hydroxyapatite.

[0015] An additional embodiment of the disclosure is a liquid oral care composition, such as a mouthwash or mouth rinse, which comprises:a fluoride source;an antibacterial agent;a thickener; andoptionally a pearlescent agent.

[0016] Exemplary fluoride sources include, for example, sodium fluoride, stannous fluoride, potassium fluoride, sodium fluorosilicate, ammonium fluorosilicate, potassium monofluorophosphate, sodium monofluorophosphate, ammonium monofluorophosphate, indium fluoride, an amine fluoride, ammonium fluoride, titanium fluoride, hexafluorosulfate, or a combination thereof. The oral care composition may comprise, for instance, from about 25 ppm to about 25,000 ppm of fluoride.

[0017] An exemplary antibacterial agent is cetylpyridinium chloride. The antibacterial agent may be present in the oral care composition, for example, in an amount ranging from about 0.01 wt% to about 2 wt%, such as from about 0.05 wt% to about 0.1 wt%, based on the total weight of the oral care composition.

[0018] An exemplary thickener is xanthan gum. The thickener may be present in the oral care composition, for example, in an amount ranging from about 0.1 wt% to about 1 wt%. such as from about 0.3 wt% to about 0.5 wt%, based on the total weight of the oral care composition.

[0019] In some embodiments, the oral care composition comprises a pearlescent agent, such as a pearlescent agent that comprises glycol distearate, laureth-4 and cocamidopropyl betaine. The pearlescent agent may be present in the oral care composition, for example, in an amount ranging from about 0.1 wt% to about 5 wt%, such as from about 1 wt% to about 3 wt%, based on the total weight of the oral care composition.

[0020] A yet further embodiment of the disclosure is a method for detecting the presence of fluoride in a liquid oral care composition, which comprises:combining a sample of the liquid oral care composition with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;1077927-00- WO-Ol-OCassessing the color of the combined solution; anddeducing from the color of the combined solution whether the aqueous oral care composition comprises fluoride.

[0021] In such an embodiment, combining the sample of the liquid oral care composition with the reagent solution may comprise first providing the reagent solution then adding the sample of the liquid oral care composition to the reagent solution. Assessing the color of the combined solution may comprise, for instance, detecting the presence or absence of a color change in the reagent solution upon combination with the sample of the liquid oral care composition. Some embodiments of this method can include detecting a color change of the reagent solution upon combination with the sample of the liquid oral care composition, wherein the color change is of from red to orange, from orange to yellow, or from yellow to colorless; and deducing that the aqueous oral care composition comprises fluoride.

[0022] In some embodiments, the method for detecting the presence of fluoride in the liquid oral care composition includes assessing the color of the combined solution by measuring light absorbance of the combined solution. This may include, for instance, quantifying the concentration of fluoride in the combined solution from the measured light absorbance. The concentration of fluoride in the combined solution may be quantified, for example, from a calibration equation derived from measured calibration data, wherein the calibration equation expresses the concentration of fluoride as a function of the measured light absorbance.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The features and advantages of the disclosure will be apparent from the following more detailed description of certain embodiments and as illustrated in the accompanying Figures in which:

[0024] FIG. 1 is a standard curve of fluoride concentration in solution vs. absorbance (445 nm wavelength) based on sodium fluoride concentrations ranging from 0 wt% to 0.25 wt%.

[0025] FIG. 2 is a bar graph illustrating absorbance of liquid solutions in which HAp disks were placed.

[0026] It should be understood that the disclosure is not limited to the particular compositions and results shown in the Figures.1077927-00- WO-Ol-OCDETAILED DESCRIPTION

[0027] For illustrative purposes, the principles of the present disclosure are described by referencing various exemplary embodiments thereof. Although certain embodiments of the disclosure are specifically described herein, one of ordinary skill in the art will readily recognize that the same principles are equally applicable to, and can be employed in, other compositions and methods. Before explaining various embodiments of the present disclosure in detail, it is to be understood that the disclosure is not limited in its application to the details of any particular embodiments disclosed herein. The terminology used herein is for the purpose of description and not of limitation.

[0028] As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context dictates otherwise. The singular form of any class of the ingredients refers not only to one chemical species within that class, but also to a mixture of those chemical species. The terms “a” (or “an”), “one or more” and “at least one” may be used interchangeably herein. The terms “comprising”, “including”, and “having” may be used interchangeably. The term “include” should be interpreted as “include, but are not limited to”. The term “including” should be interpreted as “including, but are not limited to”.

[0029] As used throughout, ranges are used as shorthand for describing each and every value that is within the range. It should be appreciated and understood that the description in a range format is merely for convenience and brevity, and should not be construed as an inflexible limitation on the scope of any embodiments or implementations disclosed herein. Accordingly, the disclosed range should be construed to have specifically disclosed all the possible subranges as well as individual numerical values within that range. Any value within the range can be selected as the terminus of the range. Thus, a range from 1-5, includes specifically 1, 2, 3, 4 and 5, as well as subranges such as 2-5, 3-5, 2-3. 2-4, 1-4, etc.

[0030] The term “about” when referring to a number means any number within a range of 10% of the number. For example, the phrase “about 2 wt%” refers to a number between and including 1.8 wt% and 2.2 wt%.

[0031] The abbreviations and symbols as used herein, unless indicated otherwise, take their ordinary meaning. The abbreviation “wt%” means percent by weight with respect to the oral care composition. The symbol “mL” refers to milliliters. The expression HAp refers to hydroxyapatite.The expressions “USP” and “EP” refer to the United States Pharmacopoeia and European Pharmacopoeia, respectively.

[0032] Any member in a list of species that are used to exemplify or define a genus may be mutually different from, or overlapping with, or a subset of, or equivalent to, or nearly the same as, or identical to, any other member of the list of species. Further, unless explicitly stated, such as when reciting a Markush group, the list of species that define or exemplify the genus is open, and it is given that other species may exist that define or exemplify the genus just as well as, or better than, any other species listed.

[0033] The phrases, “a mixture thereof,” “a combination thereof,” or a combination of two or more thereof’ do not require that the mixture include all of A, B, C, D, E, and F (although all of A, B, C. D, E, and F may be included). Rather, it indicates that a mixture of any two or more of A, B, C, D, E, and F can be included. In other words, it is equivalent to the phrase “one or more elements selected from the group consisting of A, B, C, D, E, F, and a mixture of any two or more of A, B, C. D, E, and F.” Likewise, the term “a salt thereof’ also relates to “salts thereof.” Thus, where the disclosure refers to “an element selected from the group consisting of A, B, C, D, E, F, a salt thereof, and a mixture thereof,” it indicates that that one or more of A, B, C, D, E and F may be included, one or more of a salt of A, a salt of B, a salt of C, a salt of D, a salt of E, and a salt of F may be included, or a mixture of any two of A, B, C, D, E, F, a salt of A, a salt of B, a salt of C, a salt of D, a salt of E, and a salt of F may be included.

[0034] All components and elements positively set forth in this disclosure can be negatively excluded from the claims. In other words, the oral care compositions of the instant disclosure can be free or essentially free of all components and elements positively recited throughout the instant disclosure. In some instances, the oral care compositions of the present disclosure may be substantially free of non-incidental amounts of the ingredient(s) or compound(s) described herein. A non-incidental amount of an ingredient or compound is the amount of that ingredient or compound that is added into the oral care composition by itself. For example, an oral care composition may be substantially free of a non-incidental amount of an ingredient or compound, although such ingredient(s) or compound(s) may be present as part of a raw material that is included as a blend of two or more compounds.

[0035] Some of the various categories of components identified may overlap. In such cases where overlap may exist and the oral care composition includes both components (or the composition1077927-00- WO-Ol-OCincludes more than two components that overlap), an overlapping compound does not represent more than one component. For example, certain compounds may be characterized as both a humectant and a sweetener. If a particular oral care composition includes both a humectant and a sweetener (e.g., xylitol), the compound will serve only as either a humectant or a sweetener — not both.

[0036] One embodiment of the disclosure is a method for detecting the presence of fluoride deposited on a substrate from an oral care composition, which comprises:contacting a surface of the substrate with the oral care composition to form a treated surface of the substrate;contacting the treated surface of the substrate with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;assessing the color of the treated surface of the substrate: anddeducing from the color of the treated surface of the substrate whether fluoride is deposited on the substrate.

[0037] This method allows for conveniently visualizing the presence of fluoride on a substrate. The method could be used, for instance, to monitor the retention of fluoride on a substrate under aging conditions.

[0038] When iron (III) chloride or iron (III) nitrate and potassium thiocyanate are mixed in solution, an equilibrium mixture of Fe3+, SCN- and the complex ion FeSCN2+is formed. The full reaction is shown in Equation 1 with the use of iron (III) nitrate:<Equation 1The net ionic equation is illustrated in Equation 2:" <Equation 2

[0039] The complex ion FeSCN2+is blood red in color while Fe3+is pale yellow. The addition of fluoride (such as from NaF) to the FeSCN2+equilibrium mixture allows the fluoride ions to react1077927-00- WO-Ol-OCwith Fe3+, thereby decreasing the amount of Fe3+, and rendering the solution colorless or at least a lighter color shade due to a reactant shift to the left in the equations above. A net back reaction therefore occurs to compensate for the addition of fluoride, resulting in a colorless or lighter solution. Reactions that take place on a substrate with deposited fluoride can provide a visual indication of the extent of fluoride deposition. This in turn can indicate how well an oral care composition deposits fluoride on a substrate and ultimately on the hard and soft tissues in the oral cavity.

[0040] The term “fluoride” as used herein refers to the fluoride ion. The fluoride ion may be associated, for example, with an inorganic or organic cation. A fluoride ion source, such as sodium fluoride, may dissociate in an aqueous solution into the fluoride ion and cation.

[0041] In some embodiments, the substrate is a tooth of a mammal that comprises enamel, such as bovine teeth or human teeth. In further embodiments, the substrate is a hard or soft tissuemimicking substrate, such as hydroxyapatite (HAp). Other tissue-mimicking materials include, for example, substrates made from agar, gelatine, polyvinyl alcohol (PVA), polyacrylamide (PAA), polyvinyl chloride (PVC), paraffin gel, copolymers such as styrene-ethylene / butylene-styrene (SEBS), and mixtures of agar or gelatine gel with safflower oil,. Additional substrates include polymethyl methacrylate (PMMA), VitroSkin, and polydimethylsiloxane (PDMS) for soft tissues and enamel / bovine surfaces for hard tissues.

[0042] As used herein, the term “oral care composition” means a composition that is delivered to the oral surfaces. In certain embodiments, the oral care composition is further defined as a product which, during the normal course of usage, is not for the purposes of systemic administration of particular therapeutic agents, and not intentionally swallowed but rather is retained in the oral cavity for a time sufficient to contact oral tissues. Methods of the disclosure allow for evaluating the extent of fluoride deposition from oral care compositions onto hard and soft tissues of the oral cavity.

[0043] The oral care composition may be in the form of a liquid oral care composition, including aqueous compositions such as mouthwashes or mouth rinses, a toothpaste or a dentifrice, a lozenge, mint, cream, patch, strip or gum (e.g„ chewing gum), a topical oral gel, a denture cleanser, sprays, and the like. In embodiments where the oral care composition is a liquid, contacting the surface of the substrate with the liquid oral care composition may comprise immersing at least a portion of the substrate in the oral care composition, such as for a duration of 30 seconds or longer,1077927-00- WO-Ol-OC1 minute or longer, 5 minutes or longer, 10 minutes or longer, or from about 30 seconds to about 10 minutes, from about 30 seconds to about 5 minutes, or from about 1 minute to about 5 minutes. In embodiments where the oral care composition is a toothpaste or dentifrice, contacting the surface of the substrate with the composition may comprise brushing for such periods of time. Other forms of oral care compositions can be otherwise contacted or adhered to the surface of the substrate for an appropriate period of time.

[0044] Embodiments of the disclosure include contacting the treated surface of the substrate with a reagent solution, wherein the reagent solution comprises a) iron (III) chloride or iron (III) nitrate and b) potassium thiocyanate. This may comprise, for example, first combining a) iron (III) chloride or iron (III) nitrate with b) potassium thiocyanate, then contacting the treated surface of the substrate with the reagent. Further embodiments comprise contacting the treated surface of the substrate with a) iron (III) chloride or iron (III) nitrate then adding b) potassium thiocyanate to form the reagent, or contacting the treated surface of the substrate with b) potassium thiocyanate then adding a) iron (III) chloride or iron (III) nitrate to form the reagent. In some embodiments, contacting the treated surface of the substrate with the reagent solution comprises immersing at least a portion of the substrate in a colorless aqueous solution then adding the reagent to the aqueous solution.

[0045] Embodiments of the disclosure include assessing the color of the treated surface of the substrate after contact with the reagent. The color of the treated surface of the substrate is indicative of the extent of fluoride deposition on the substrate. In some embodiments, assessing the color of the treated surface of the substrate comprises detecting the presence or absence of a color change of the treated surface of the substrate upon contact with the reagent solution. Assessing the color of the treated surface of the substrate can be performed, for example, by eyesight. Some embodiments of the disclosure include detecting the absence of a color change of the treated surface of the substrate upon contact with the reagent solution; and thus deducing that fluoride is deposited on the substrate.

[0046] Further embodiments of the disclosure include a qualitative comparison of the relative amounts of fluoride deposited on substrates by different oral care compositions. One such embodiment comprises:contacting a surface of a comparative substrate with a comparative oral care composition to form a treated surface of the comparative substrate;1077927-00- WO-Ol-OCcontacting the treated surface of the comparative substrate with the reagent solution; assessing the color of the treated surface of the comparative substrate; anddeducing from the colors of the treated surfaces of the substrate and of the comparative substrate whether more or less fluoride is deposited on the substrate than on the comparative substrate.

[0047] In some embodiments, the qualitative comparison of fluoride deposition may comprise detecting less of a color change of the surface of the substrate treated with a first oral care composition than of the surface of the comparative substrate treated with a second oral care composition; and thus deducing that more fluoride is deposited on the substrate by the first oral care composition than on the comparative substrate by the second oral care composition. Such a comparison may comprise, for example:detecting the absence of a color change of the treated surface of the substrate and a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface of the comparative substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.

[0048] In other embodiments, the qualitative comparison of fluoride deposition may comprise detecting less of a color change of the surface of the comparative substrate treated with a second oral care composition than of the surface of the substrate treated with a first oral care composition; and thus deducing that less fluoride is deposited on the substrate by the first oral care composition than on the comparative substrate by the second oral care composition. Such a comparison may comprise, for example,detecting the absence of a color change of the treated surface of the comparative substrate and a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface of the substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.1077927-00- WO-Ol-OC

[0049] A further embodiment of the disclosure includes a kit for detecting fluoride deposition on a substrate, which comprises:iron (III) chloride or iron (III) nitrate;potassium thiocyanate; anda hard or soft tissue-mimicking substrate.

[0050] The hard or soft tissue-mimicking substrates may be selected, for example, from any of those mentioned in embodiments discussed above. One exemplary hard tissue-mimicking substrate is hydroxyapatite, which simulates enamel. The a) iron (III) chloride or iron (III) nitrate and b) potassium thiocyanate may be combined in the form a reagent in the kit or, alternatively, may be maintained separate from one another until the time of use when they are combined to form the reagent. The hard or soft-tissue-mimicking substrate may, for example, be maintained in a compartment or container in the kit that is separate from the reagent or reagent components. The kit may be used according to methods of the disclosure, for instance, by contacting the hard or soft- tissue-mimicking substrate with an oral care composition then using the reagent to visualize the extent of fluoride deposition on the substrate.

[0051] A further embodiment of the disclosure includes a liquid oral care composition, such as a mouthwash or mouth rinse, which comprises:a fluoride source;an antibacterial agent;a thickener; andoptionally a pearlescent agent.

[0052] Such a composition provides both hard and soft tissue benefits. A thickener such as xanthan gum thickens the liquid, provides texture and makes the composition more retentive to the hard and soft tissues for improved release of actives. For instance, Examples 6 and 7 illustrate improved retention of fluoride on HAp disks using a composition comprising xanthan gum. The antibacterial agent such as cetylpyridinium chloride provides antibacterial activity. The optional pearlescent agent provides improved consumer perception benefits and aesthetics. One exemplary pearlescent agent is EUPERLAN® PK 3000 AM. One exemplary oral care composition of the disclosure is Formulation 3 in Example 1.

[0053] In some embodiments, the fluoride ion source in the oral care composition is sodium fluoride, stannous fluoride, potassium fluoride, sodium fluorosilicate, ammonium fluorosilicate,1077927-00- WO-Ol-OCpotassium monofluorophosphate, sodium monofluorophosphate, ammonium monofluorophosphate, indium fluoride, an amine fluoride, ammonium fluoride, titanium fluoride, hexafluorosulfate, or a combination thereof.

[0054] The fluoride source may be present in an amount providing a clinically efficacious amount of total soluble fluoride ion to the oral care composition. In some embodiments, the fluoride source may be present in the oral care composition in an amount ranging from about 0.005 wt% to about 5 wt%, based on the total weight of the oral care composition. The oral care composition may comprise any suitable concentration of fluoride, such as from about 25 ppm to about 25,000 ppm, from about 100 to about 10,000 ppm, or about 500 ppm of fluoride in the oral care composition.

[0055] Antibacterial agents that may be used in the oral care compositions disclosed herein include, for example, halogenated diphenyl ether (e.g. triclosan), herbal extracts and essential oils (e.g., rosemary extract, tea extract, magnolia extract, thymol, menthol, eucalyptol, geraniol, carvacrol, citral, hinokitol, catechol, methyl salicylate, epigallocatechin gallate, epigallocatechin, gallic acid, miswak extract, sea-buckthorn extract), bisguanide antiseptics (e.g., chlorhexidine, alexidine or octenidine), quaternary ammonium compounds (e.g., cetylpyridinium chloride (CPC), benzalkonium chloride, tetradecylpyridinium chloride (TPC), N-tetradecyl-4-ethylpyridinium chloride (TDEPC)), phenolic antiseptics, hexetidine, octenidine, sanguinarine, povidone iodine, delmopinol, salifluor, other metal ions (e.g., stannous salts, copper salts, iron salts), sanguinarine, propolis and oxygenating agents (e.g., hydrogen peroxide, buffered sodium peroxyborate or peroxycarbonate), phthalic acid and its salts, monoperthalic acid and its salts and esters, ascorbyl stearate, oleoyl sarcosine, alkyl sulfate, dioctyl sulfosuccinate, salicylanilide, domiphen bromide, delmopinol, octapinol, and other piperidino derivatives, nicin preparations, chlorite salts; and combinations of any of the foregoing.

[0056] In some embodiments, the oral care composition comprises cetylpyridinium chloride as an antibacterial agent. Embodiments include oral care compositions where an antibacterial agent such as cetylpyridinium chloride is present in the oral care composition in an amount ranging from about 0.01 wt% to about 2 wt%, such as from about 0.05 wt% to about 0.1 wt%, based on the total weight of the oral care composition.

[0057] Thickeners that may be used in the oral care compositions disclosed herein include, for example, carboxyvinyl polymers, carrageenan (also known as carrageenan gum), hydroxyethyl cellulose (HEC), natural and synthetic clays (e.g., Veegum and laponite), water soluble salts of1077927-00- WO-Ol-OCcellulose ethers (e.g., sodium carboxymethylcellulose (CMC) and sodium carboxymethyl hydroxyethyl cellulose), natural gums (e.g., gum karaya, xanthan gum, gum arabic, and gum tragacanth), colloidal magnesium aluminum silicate, silica (e.g., finely divided silica), cross-linked poly(vinyl)pyrrolidone, carbowaxes, fatty acids and salts thereof (e.g., stearic acid and palmitic acid), fatty alcohols (e.g., stearyl alcohol), and mixtures thereof. In certain embodiments, the thickener is xanthan gum. In some embodiments, the oral care compositions comprise a thickener such as xanthan gum in an amount ranging from about 0.1 wt% to about 1 wt%, such as from about 0.3 wt% to about 0.5 wt%, based on the total weight of the oral care composition.

[0058] The optional pearlescent agent may comprise, for example, glycol distearate, laureth-4 and cocamidopropyl betaine. An exemplary pearlescent agent is EUPERLAN® PK 3000 AM, which may be present in the oral care composition in an amount ranging from, for example, about 0.1 wt% to about 5 wt%, such as from about 1 wt% to about 3 wt%, based on the total weight of the oral care composition.

[0059] In some embodiments, the oral care compositions further comprise additional ingredients as known in the art and as disclosed below. These additional ingredients may include, but are not limited to, one or more metal ion sources, humectants, emulsifiers, flavoring agents, sweeteners, anti-calculus agents, surfactants, anti-bacterial agents, whitening agents, colorants, pH adjusters, foam modulators, viscosity modifiers, anti- sensitivity agents, antioxidants, water, and combinations thereof. Such ingredients would be known to those skilled in the art of oral care. However, non-limiting examples of these ingredients are provided herein. Suitable components, such as those listed herein, may be included or excluded from the formulations for the oral care compositions depending on the specific combination of other ingredients and the form of the oral care compositions. In other embodiments, the oral care composition of the disclosure does not comprise one or more of the recited additional ingredients.

[0060] The ingredients for use in the compositions described herein should be orally acceptable. As used herein, “orally acceptable” may refer to any ingredient that is present in a composition as described in an amount and form which does not render the composition unsafe for use in the oral cavity.

[0061] In some embodiments, the oral care compositions further comprise one or more soluble or partially soluble metal ion sources, such as a stannous ion source, a zinc ion source or a copper ion source. For example, in certain embodiments, the oral care composition comprises a zinc ion1077927-00- WO-Ol-OCsource selected from zinc oxide, zinc citrate, zinc citrate trihydrate, zinc lactate, zinc phosphate, and combinations thereof, or a stannous ion source selected from stannous fluoride, stannous chloride, stannous acetate, stannous tartrate, stannous oxalate, sodium stannous citrate, stannous gluconate, stannous phosphate, stannous pyrophosphate, stannous sulfate, and combinations thereof. The oral care composition may comprise, for instance, from about 0.01 wt% to about 10 wt%, such as from about 0.1 wt% to 0.5 wt%, of the metal ion source by weight of the oral care composition.

[0062] In some embodiments, the oral care compositions further comprise one or more humectants. A humectant keeps oral care compositions from hardening upon exposure to air by reducing evaporation and / or contributing to preservation by lowering water activity. Certain humectants can also impart desirable sweetness or flavor to oral care compositions. In certain exemplary embodiments, the one or more humectants are selected from glycerin, sorbitol, xylitol, propylene glycol, as well as other polyols and combinations thereof. The one or more humectants may be present in the oral care composition in a combined total amount of, for example, from about 10 wt% to about 40 wt%, based on the total weight of the oral care composition.

[0063] In some embodiments, the oral care compositions further comprise one or more emulsifiers. Any emulsifier known in the art for oral care use may be incorporated, including for example, polyglyceryl-4 caprate, polyethylene glycol (PEG), PEG-40 hydrogenated castor oil, alkyl polyglucosides, polysorbates, and combinations thereof. In certain embodiments, the emulsifier may be chosen from poloxamers (e.g., PLURONICS®) and other non-ionic emulsifiers. In certain embodiments, the emulsifier is polyglyceryl-4 caprate (TEGOSOFT® PC). The one or more emulsifiers may be present in the oral care composition in a combined total amount of, for example, from about 0.01 wt% to about 2 wt%, based on the total weight of the oral care composition.

[0064] In some embodiments, the oral care compositions further comprise one or more flavoring agents. Suitable flavoring agents include essential oils and various flavoring aldehydes, esters, alcohols, and similar materials. Examples of the essential oils include oils of spearmint, peppermint, Wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, lemon, lime, grapefruit, and orange. Also useful are such chemicals as menthol, carvone, and anethole. Additional flavoring agents may include, but are not limited to menthol, artificial vanilla, cinnamon derivatives, and various fruit flavors, spearmint oil, peppermint oil, cinnamon oil, oil of1077927-00- WO-Ol-OCWintergreen (methylsalicylate), clove oil, bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, oil of nutmeg, oil of sage, oil of bitter almonds, cassia oil, and a combination of two or more thereof. The one or more flavoring agents may be present in the oral care composition in a combined total amount of, for example, from about 0.01 wt% to about 5 wt%, based on the total weight of the oral care composition.

[0065] In some embodiments, the oral care compositions further comprise one or more sweeteners useful, for example, to enhance taste of the composition. Sweeteners may include, but are not limited to, sucralose, maltodextrin, dextrose, polydextrose, sucrose, maltose, dextrin, dried invert sugar, mannose, xylose, ribose, fructose, levulose, galactose, sugar alcohols, such as sorbitol, mannitol, xylitol, maltitol, and isomalt, aspartame, neotame, saccharin and salts thereof (e.g., sodium saccharin), gum arabic. dipeptide-based intense sweeteners, cyclamates, dihydrochalcones, or the like, or combinations thereof. The one or more sweeteners may be present in the oral care composition in a combined total amount of, for example, from about 0.1 wt% to about 5 wt%. based on the total weight of the oral care composition.

[0066] In some embodiments, the oral care compositions further comprise one or more anticalculus agents. Illustrative anticalculus agents include, but are not limited to, phosphates and polyphosphates, polyaminopropane sulfonic acid (AM PS), polyolefin sulfonates, polyolefin phosphates, diphosphonates such as azacycloalkane-2, 2-diphosphonates (e.g., azacycloheptane-2,2-diphosphonic acid), N-methyl azacyclopentane-2,3-diphosphonic acid, ethane- 1 -hydroxy -1,1-diphosphonic acid (EHDP) and ethane- 1 -amino- 1,1 -diphosphonate, and phosphonoalkane carboxylic acids. Useful inorganic phosphate and polyphosphate salts include monobasic, dibasic and tribasic sodium phosphates. Soluble pyrophosphates may be useful anti-calculus agents. The pyrophosphate salts can be any of the alkali metal pyrophosphate salts. In certain embodiments, salts include tetra alkali metal pyrophosphate, dialkali metal diacid pyrophosphate, trialkali metal monoacid pyrophosphate and mixtures thereof, wherein the alkali metals are sodium or potassium. The pyrophosphates may also contribute to preservation of the compositions by lowering water activity. Exemplary pyrophosphates may include tetrasodium pyrophosphate (TSPP), tetrapotassium pyrophosphate, sodium tripolyphosphate, tetrapolyphosphate, sodium trimetaphosphate, sodium hexametaphosphate and mixtures thereof. The salts may be useful in both their hydrated and / or unhydrated forms. An effective amount of pyrophosphate salt that may be included in the oral care compositions disclosed herein is generally enough to provide least1077927-00- WO-Ol-OCabout 0.1 wt% pyrophosphate ions, e.g., from about 0.1 wt% to about 3 wt%, based on the total weight of the oral care composition.

[0067] In some embodiments, the oral care compositions further comprise one or more surfactants. Exemplary surfactants include, but are not limited to, anionic, cationic, zwitterionic, and nonionic surfactants, and combinations thereof. The one or more surfactants may be present in the oral care compositions in a combined total amount of, for example, from about 0.01 wt% to about 10 wt% based on the total weight of the oral care composition.

[0068] Non-ionic surfactants are known in the art and generally include surfactants that are not electrically charged. An exemplary nonionic surfactant may be poly(oxyethylene)-poly(oxypropylene) block copolymers. Such copolymers are known commercially by the nonproprietary name of poloxamers. The name poloxamer is often used in conjunction with a numeric suffix to designate the individual identification of each copolymer. Poloxamers may have varying contents of ethylene oxide and propylene oxide which results in poloxamers that have a wide range of chemical structures and molecular weights. One poloxamer that may be mentioned is Poloxamer 407, sold under the trade name PLURONIC® F127 by BASF, Inc. (Parsippany, N.J.). In certain embodiments, the oral care compositions disclosed herein may comprise poloxamer as the at least one surfactant.

[0069] Anionic surfactants that may be used in the oral care compositions disclosed herein include, for example: (i) water-soluble salts of higher fatty acid monoglyceride monosulfates, such as the sodium salt of the monosulfated monoglyceride of hydrogenated coconut oil fatty acids such as sodium N-methyl N-cocoyl taurate, sodium cocomonoglyceride sulfate; (ii) higher alkyl sulfates, such as sodium lauryl sulfate; (iii) higher alkyl-ether sulfates, such as those of formula CH3(CH2)mCH2(OCH2CH2)nOSO3X, wherein m is 6-16, e.g., 10, n is 1-6, e.g., 2, 3 or 4, and X is Na or K, for example sodium laureth-2 sulfate (CH3(CH2)ioCH2 (OCFFCIDOSChNa); (iv) higher alkyl aryl sulfonates such as sodium dodecyl benzene sulfonate (sodium lauryl benzene sulfonate); and (v) higher alkyl sulfoacetates, such as sodium lauryl sulfoacetate (dodecyl sodium sulfoacetate), higher fatty acid esters of 1,2 dihydroxy propane sulfonate, sulfocolaurate (N-2-ethyl laurate potassium sulfoacetamide) and sodium lauryl sarcosinate.

[0070] In some embodiments, the oral care compositions disclosed herein may comprise an anionic surfactant. In some embodiments, the anionic surfactant is the water soluble salt of alkyl sulfates having from 10 to 21 carbon atoms in the alkyl radical and water soluble salts of sulfonated1077927-00- WO-Ol-OCmonoglycerides of fatty acids having from 10 to 18 carbon atoms. Sodium lauryl sulfate, sodium lauryl sarcosinate, and sodium coconut monoglyceride sulfonates are examples of anionic surfactants of that type.

[0071] In some embodiments, the oral care compositions further comprise one or more preservatives, such as methylisothiazolinone (MIT), sodium benzoate, potassium sorbate, benzyl alcohol, and combinations thereof. The one or more preservative agents may optionally be present in the oral care composition in a combined total amount of, for example, from about 0.01 wt% to about 0.5 wt%. based on the total weight of the oral care composition.

[0072] In some embodiments, the oral care compositions further comprise one or more whitening agents. The one or more whitening agents can include materials or substances that are effective to, capable of, or configured to provide whitening of a tooth surface to which it is applied and can include, for example, peroxides, metal chlorites, perborates, percarbonates, peroxyacids, hypochlorites, hydroxyapatite, and combinations thereof. In some embodiments, the oral care compositions do not comprise a whitening agent.

[0073] In some embodiments, the oral care compositions further comprise one or more colorants. Colorants herein include pigments, dyes, lakes and agents imparting a particular luster or reflectivity such as pearling agents. In various embodiments, colorants are operable to provide a white or light-colored coating on a dental surface, to act as an indicator of locations on a dental surface that have been effectively contacted by the composition, and / or to modify appearance, in particular color and / or opacity, of the composition to enhance attractiveness to the consumer. Any orally acceptable colorant can be used, including FD&C dyes and pigments, talc, mica, magnesium carbonate, calcium carbonate, magnesium silicate, magnesium aluminum silicate, silica, titanium dioxide, zinc oxide, red, yellow, brown and black iron oxides, ferric ammonium ferrocyanide, manganese violet, ultramarine, titaniated mica, bismuth oxychloride, and mixtures thereof. The one or more colorants may be present in the oral care composition in a combined total amount of, for example, from about 0.001 wt% to about 20 wt%, based on the total weight of the oral care composition.

[0074] In some embodiments, the oral care composition comprises one or more pH adjusters to increase or decrease the overall pH of the oral care composition. For example, one or more acids may be included to decrease the pH of the oral care composition. Examples of suitable acids for decreasing the pH of the oral care composition include, but are not limited to, citric acid, acetic1077927-00- WO-Ol-OCacid, and the like. The oral care composition may include one or more bases, such as sodium hydroxide, potassium hydroxide and the like, to increase the pH of the oral care composition. Additional or alternative acids and bases that are suitable for adjusting the pH of the oral care composition are readily known to one of ordinary skill in the art.

[0075] The amount of the pH adjuster in the oral care composition may be based on the desired pH of the final oral care composition and / or product. For example, the total amount of the pH adjuster may range from about 0.05 wt% to about 20 wt%, based on the total weight of the oral care composition.

[0076] The oral care compositions may have a pH from 4.5 to about 10, 4.5 to about 9, 4.5 to about 8, 4.5 to about 7, 4.5 to about 6; from about 5 to about 10, about 5 to about 9, about 5 to about 8, about 5 to about 7, about 5 to about 6; from about 6 to about 10, about 6 to about 9, about 6 to about 8, or about 6 to about 7; from about 7 to about 10, about 7 to about 9, or about 7 to about 8, including any ranges and subranges therebetween.

[0077] In some embodiments, the oral care compositions further comprise at least one foam modulator, useful for example to increase amount, thickness or stability of foam generated by the composition upon agitation. Any orally acceptable foam modulator can be used, including without limitation polyethylene glycols (PEGs), also known as polyoxyethylenes. High molecular weight PEGs are suitable, including those having an average molecular weight of 200,000 to 7,000,000, for example 500,000 to 5,000,000, or 1,000.000 to 2,500,000. One or more PEGs may be present in the oral care composition in a combined total amount of, for example, from about 0.1 wt% to about 10 wt%, based on the total weight of the oral care composition.

[0078] In some embodiments, the oral care compositions further comprise at least one viscosity modifier, useful for example to help inhibit settling or separation of ingredients or to promote redispersibility upon agitation of a liquid oral care composition. Any orally acceptable viscosity modifier can be used, including without limitation, mineral oil, petrolatum, clays and organo-modified clays, silicas and the like. The one or more viscosity modifiers may be present in the oral care composition in a combined total amount of, for example, from about 0.01 wt% to about 10 wt%, based on the total weight of the oral care composition.

[0079] In some embodiments, the oral care compositions further comprise one or more antisensitivity agents, e.g., potassium salts such as potassium nitrate, potassium bicarbonate, potassium chloride, potassium citrate, and potassium oxalate; capsaicin; eugenol; strontium salts;1077927-00- WO-Ol-OCchloride salts and combinations thereof. The one or more anti sensitivity agents may be present in the oral care composition in a combined total amount of, for example, from about 1 wt% to about 20 wt%, based on the total weight of the oral care composition.

[0080] In some embodiments, the oral care compositions further comprise one or more antioxidants. Any orally acceptable antioxidant can be used, including butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), vitamin A, carotenoids, co-enzyme Q10. PQQ, Vitamin A, Vitamin C, Vitamin E, anethole-dithiothione, flavonoids, polyphenols, ascorbic acid, herbal antioxidants, chlorophyll, melatonin, and mixtures thereof.

[0081] Water commonly makes up the balance of the compositions and includes about 5 wt% to about 99 wt%, such as from about 10 wt% to about 90 wt%, from about 65 wt% to about 85 wt%, or about 70 wt% to about 80 wt%, or any range or subrange thereof, by weight based on the total weight of the oral care composition. This amount of water includes the free water that is added plus any amount of water that may be introduced with other materials, such as with sorbitol or silica or any components of the oral care composition disclosed herein. The Karl Fischer method is a one measure of calculating free water.

[0082] The oral care compositions disclosed herein may be made according to methods and procedures known to those skilled in the art. In certain embodiments, the compositions can be made by incorporating the fluoride source, an antibacterial agent such as cetylpyridinium chloride, a thickener such as xanthan gum, an optional pearlescent agent, and one or more additional components in an aqueous solution.

[0083] A further embodiment of the disclosure is a method for detecting the presence of fluoride in a liquid oral care composition, which comprises:combining a sample of the liquid oral care composition with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;assessing the color of the combined solution; anddeducing from the color of the combined solution whether the aqueous oral care composition comprises fluoride.1077927-00- WO-Ol-OC

[0084] In some embodiments, combining the sample of the liquid oral care composition with the reagent solution comprises first providing the reagent solution then adding the sample of the liquid oral care composition to the reagent solution.

[0085] Assessing the color of the combined solution may comprise, for example, detecting the presence or absence of a color change in the reagent solution upon combination with the sample of the liquid oral care composition. This may comprise detecting a color change of the reagent solution upon combination with the sample of the liquid oral care composition, wherein the color change is of from red to orange, from orange to yellow, or from yellow to colorless; and thus deducing that the aqueous oral care composition comprises fluoride.

[0086] Assessing the color of the combined solution may comprise, for example, measuring light absorbance at one or more wavelengths in the combined solution, such as with a spectrophotometer. This technique, illustrated in Examples 5 and 6, may be used to quantify the concentration of fluoride in the combined solution from the measured light absorbance. This may comprise, for instance, quantifying the concentration of fluoride from a calibration equation derived from measured calibration data, wherein the calibration equation expresses the concentration of fluoride as a function of the measured light absorbance.

[0087] The examples and other embodiments described herein are exemplary and not intended to be limiting in describing the full scope of compositions and methods of this disclosure. Equivalent changes, modifications and variations of specific embodiments, materials, compositions and methods may be made within the scope of the present disclosure, with substantially similar results.EXAMPLESExample 1: Preparation of mouthwash serums

[0088] Three neat mouthwash serum formulations were prepared for testing. All three mouthwash serums had the same backbone. Formulations 1 and 3 contained NaF while Formulation 2 did not contain NaF. Formulation 3 contained EUPERLAN PK 3000 AM pearlescent agent while Formulations 1 and 2 did not. The composition of each formulation is provided in Tables 1-3 below. All three formulations exhibited an essentially colorless appearance.1077927-00- WO-Ol-OCTable 1: Formulation 1 composition&&Table 2: Formulation 2 composition1077927-00- WO-Ol-OC&&Table 3: Formulation 3 composition&&Example 2: Preparation of stock solutions for reagent

[0089] Two stock solutions for the reagent were prepared. For the first stock solution, Erlenmeyer flask #1 was filled with 25 mL of 0.05M Fe (III) chloride (FeCh) solution. For the second stock solution, Erlenmeyer flask #2 was filled with 25 mL of 0.05M Potassium thiocyanate (KSCN) solution. A stock solution of 0.1 wt% NaF (aq) was also prepared. The iron (III) chloride solution exhibited a yellow color. The solutions of KSCN (aq) and NaF (aq) appeared essentially colorless.Example 3: Preparation of combined solutions of reagent and serums

[0090] Three other Erlenmeyer flasks were filled with about 3 mL of respective mouthwash serum (Formulation 1, 2 and 3, respectively), about 9 mL of FeCh solution and 1 mL of KSCN. The solutions were mixed with a magnetic stir bar for about 5 minutes and then photographed. The combined solutions of Formulations 1 and 3 with reagent exhibited a yellow color. The combined solution of Formulation 2 with reagent exhibited a red color. The red color of the combined solution of Formulation 2 with reagent indicated that Formulation 2 did not comprise fluoride. The yellow color of the combined solutions of Formulations 1 and 3 with reagent indicated that Formulations 1 and 3 contained fluoride.Example 4: Visualizing fluoride on HAp Disks

[0091] A qualitative comparison was conducted of Formulations 2 (no fluoride) and 1 (with fluoride) on a hard tissue mimicking substrate (HAp disks). The HAp disks were soaked in their respective Formulations for 1 minute, 5 minutes and 10 minutes. The disks were then placed in equal volumes of water and gently agitated. The reagent solution comprising FeSCN2+(aq) solution was added drop wise (1 or 2 drops to each sample). At as early as the 1 minute time point, the disks treated with Formulation 2 exhibited a color change of from white to yellow as assessed1077927-00- WO-Ol-OCby eyesight. In contrast, the disks treated with Formulation 3 exhibited either no color change or less of a color change from white to yellow as assessed by eyesight.Example 5: Quantitative assessment of fluoride in solution

[0092] A dosing experiment was performed with fluoride concentrations (from NaF) ranging from 0% (dark red visible color) to 0.25% (light yellow). FIG. 1 illustrates a calibration curve of sodium fluoride concentration vs. absorbance (445 nm wavelength) throughout the fluoride concentration range.

[0093] The method was then validated by means of a blinded study where the fluoride concentrations in the solution provided were unknown. The study predicted sodium fluoride concentrations of 0.21 wt%, 0.08 wt% and 0.25 wt% for solutions having 0.20 wt%. 0.1 wt% and 0.3 wt% of fluoride, respectively.Example 6

[0094] This Example illustrates the improved retention of fluoride on HAp disks using a composition comprising xanthan gum.

[0095] One HAp disk was added to a vial containing Formulation 1 with 0.1% NaF and xanthan gum. Another disk was added to a vial containing a corresponding formulation with 0.1% NaF, but not containing xanthan gum. The absorbance of the solutions to which the HAp disks were added were then measured as shown in FIG. 2. “As-is” in FIG. 2 refers to the absorbance measured for those solutions (no XG, left; containing XG, right). Since this method detects fluoride levels, the absorbance was essentially the same between the solutions because both initial solutions to which the HAp disks were added contain 0.1% NaF.

[0096] The HAp disks were allowed to sit in the above-mentioned solutions for a period of time, removed, quickly rinsed to remove excess solution and placed in water again for a period of time.

[0097] The absorbance of these water solutions was then measured as shown in FIG. 2 under the category of “rinse” (no XG, left; containing XG, right).

[0098] The “no XG” absorbance measurement shows lower absorbance, which indicates that there is more fluoride detected in the final rinse, suggesting less fluoride retained on the HAp disk. Conversely, the solution containing the disk treated with the formulation including fluoride with xanthan gum shows a higher absorbance, with less fluoride in the rinse and suggesting more fluoride is retained on the disk itself.1077927-00- WO-Ol-OCExample 7

[0099] Methods of the disclosure include measuring the atomic percent of fluoride on a hard tissue-mimicking substrate, such as an HAp disk. In this Example, X-Ray Photoelectron Spectroscopy (XPS) was used to determine fluoride uptake on HAp disks treated with either a mouthwash formulation containing xanthan gum or with a corresponding mouthwash that did not contain xanthan gum. The disk treated with the xanthan mouthwash exhibited a significant xanthan gum surface coating, which was not removed from the surface by deionized water rinses. Results of the analysis are presented in Table 4.Table 4: Surface composition of Hap disks

[0100] The disk treated with the xanthan gum mouthwash also had a higher F / Ca ratio (0.27) than the disk treated with xanthan gum-free mouthwash (0.10), suggesting a greater amount of fluoride present on the disk surface. The data thus suggest that the xanthan gum coating facilitates a greater amount of fluoride retention on the HAp disk surface compared to that provided by mouthwash without xanthan gum.Example 8 - Preparation of mouthwash serums containing a zinc salt

[0101] Two additional neat mouthwash serum formulations (Formulations 4 and 5) were prepared for testing, along with Formulation 3 and a positive control. The two mouthwash serums contained a zinc salt (zinc citrate trihydrate), and Formulation 5 contained NaF. The positive control contained 0.02% NaF. The composition of each formulation is provided in Tables 5-7 below. Table 5 - Mouthwash Formulation 4 composition1077927-00- WO-Ol-OC>Table 6 - Mouthwash Formulation 5 composition>Table 7 - Positive Control composition1077927-00- WO-Ol-OC>

[0102] The Enamel Fluoride Uptake (EFU) and Enamel Solubility Reduction (ESR) were measured for Formulations 3, 4, and 5, as well as the positive control. The results are shown in Table 8 below. To measure the EFU. the methodology set forth in Procedure 43 of the FDA monograph was followed. Namely, for enamel powder preparation, whole enamel crowns were crushed and ground into powder. The enamel powder was placed on an ASTM 100-mesh sieve. The 100-mesh sieve was covered and shaken over a 200-mesh sieve. The powdered enamel collected on the 200-mesh was passed under a magnet to remove any metal fillings. Then the powder was placed in a separatory funnel containing bromoform to separate the powdered enamel from the powdered dentin. The powdered enamel was separated from the bromoform via filtration and allowed to air dry at ambient temperature. The dry powder was then washed with acetone to remove any residual bromoform. Eater, the powder was washed with distilled water and dried in an oven at 37oC. The dry powder was then stored until used.

[0103] The enamel treatments were performed using 1:2 dilutions of fluoride rinses. Distilled water was used as a control. The solutions contained 30 mE oral rinse and 60 mL distilled water. The pH of each solution was adjusted to 6.6 using acetic acid and / or sodium hydroxide. A 75-mL portion of each supernatant was used to treat a 200 mg sample of powdered enamel. Each enamel sample being treated was placed in a 37 °C shaking water bath for 60 minutes. At the end of treatment, the powdered enamel samples were collected on 200-mesh sieves. The enamel samples were immediately washed with a minimum of one liter of distilled water. Finally, the enamel samples were dried on their respective sieves in a 37 °C oven overnight.

[0104] For fluoride analysis, a 100-mg portion of each enamel sample was placed into appropriately labeled 25 ml volumetric flask. Then, the volume was adjusted to 25 ml with 0.5 MHC104 and the powder allowed to dissolve. Next, 2.5 mL of the dissolved solution along with 2.5 mL of TISAB (total ionic strength buffer adjusted w / NaOH) was added to a small beaker, yielding a solution with a final pH of 5.2. Finally, the concentration of fluoride was measured using a fluoride ion selective electrode.

[0105] The amount of fluoride absorbed by the enamel is calculated by dividing the product of the electrode reading and the total volume of sample by the product of the enamel weight and the aliquot volume. The units are ppm / g, such that fluoride (ppm / g) = electrode reading (ppm) x 25 mL, and enamel weight (g) x 2.5 mL.

[0106] For ESR etching and analysis, a 50-mg portion of each enamel sample was placed into appropriately labeled flask. Then 20 mL of etching solution (2 M Sodium Acetate Buffer at pH 4.0) was added to each flask at one-minute intervals. Each sample was placed in a 37 °C shaking water bath and allowed to etch for 45 minutes. After etching each sample was filtered through a number 1 Whatman paper. A 5.0 mL portion of each filtrate was delivered into a 100 mL volumetric flask containing 25.0 mL of color-forming solution. Each volumetric flask was filled to the mark with distilled water and allowed to stand at room temperature for 30 minutes. Finally each sample was analyzed for phosphorus content via UV spectroscopy at a wavelength of 460 nm.

[0107] To calculate the ESR, the percent of enamel solubility reduction was computed as the difference between the absorbance readings of the water control and each individual sample, divided by the absorbance of the water control, and multiplied by 100.Table 8 - Enamel Fluoride Uptake (EFU) and Enamel Solubility Reduction (ESR) Results<

[0108] For both the EFU and ESR results, an Analysis of Variance (one way ANOVA p>0.05) indicated that the formulations were not statistically equivalent, and Bonferroni comparisons indicated that the values of Formulation 3 and Formulation 5 were not significantly different..1077927-00- WO-Ol-OC

[0109] The present disclosure has been described with reference to exemplary implementations. Although a limited number of implementations have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these implementations without departing from the principles and spirit of the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

CLAIMSWhat Is Claimed Is:

1. A method for detecting the presence of fluoride deposited on a substrate from an oral care composition, which comprises:contacting a surface of the substrate with the oral care composition to form a treated surface of the substrate;contacting the treated surface of the substrate with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;assessing the color of the treated surface of the substrate; anddeducing from the color of the treated surface of the substrate whether fluoride is deposited on the substrate.

2. The method of claim 1, wherein the substrate is a hard or soft tissue-mimicking substrate.

3. The method of claim 2, wherein the substrate comprises hydroxyapatite.

4. The method of any one of claims 1-3, wherein the oral care composition is a liquid oral care composition.

5. The method of claim 4, wherein contacting the surface of the substrate with the liquid oral care composition comprises immersing at least a portion of the substrate in the oral care composition.

6. The method of claim 5, which comprises immersing at least a portion of the substrate in the oral care composition for 1 minute or longer, 5 minutes or longer, or 10 minutes or longer.

7. The method of any one of claims 1-6, wherein the reagent solution comprises iron (III) chloride.

8. The method of any one of claims 1-6, wherein the reagent solution comprises iron (III) nitrate.1077927-00- WO-Ol-OC9. The method of any one of claims 1-8, wherein contacting the treated surface of the substrate with the reagent solution comprises immersing at least a portion of the substrate in a colorless aqueous solution then adding the reagent to the aqueous solution.

10. The method of any one of claims 1-9, wherein assessing the color of the treated surface of the substrate comprises detecting the presence or absence of a color change of the treated surface of the substrate upon contact with the reagent solution.

11. The method of claim 10, which comprises detecting the absence of a color change of the treated surface of the substrate upon contact with the reagent solution; anddeducing that fluoride is deposited on the substrate.

12. The method of any one of claims 1-11, which further comprises:contacting a surface of a comparative substrate with a comparative oral care composition to form a treated surface of the comparative substrate;contacting the treated surface of the comparative substrate with the reagent solution; assessing the color of the treated surface of the comparative substrate; anddeducing from the colors of the treated surfaces of the substrate and of the comparative substrate whether more or less fluoride is deposited on the substrate than on the comparative substrate.

13. The method of claim 12, which comprises:detecting less of a color change of the treated surface of the substrate than of the treated surface of the comparative substrate; anddeducing that more fluoride is deposited on the substrate than on the comparative substrate.

14. The method of claim 13, which comprises:detecting the absence of a color change of the treated surface of the substrate and a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface1077927-00- WO-Ol-OCof the comparative substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.

15. The method of claim 12, which comprises:detecting less of a color change of the treated surface of the comparative substrate than of the treated surface of the substrate; anddeducing that less fluoride is deposited on the substrate than on the comparative substrate.

16. The method of claim 15, which comprises:detecting the absence of a color change of the treated surface of the comparative substrate and a color change of the treated surface of the substrate of from white to yellow, from white to orange, or from white to red; ordetecting a color change of the treated surface of the comparative substrate of from white to yellow, from white to orange, or from white to red and a more prominent color change of the treated surface of the substrate of from white to a darker yellow, from white to a darker orange, or from white to a darker red.

17. A kit for detecting fluoride deposition on a substrate, which comprises:iron (III) chloride or iron (III) nitrate;potassium thiocyanate; anda hard or soft tissue-mimicking substrate.

18. The kit of claim 17, wherein the substrate comprises hydroxyapatite.

19. A liquid oral care composition, which comprises:a fluoride source;an antibacterial agent;a thickener; andoptionally a pearlescent agent.

20. The oral care composition of claim 19, wherein the fluoride source is sodium fluoride, stannous fluoride, potassium fluoride, sodium fluorosilicate, ammonium fluorosilicate, potassium monofluorophosphate, sodium monofluorophosphate, ammonium monofluorophosphate, indium1077927-00- WO-Ol-OCfluoride, an amine fluoride, ammonium fluoride, titanium fluoride, hexafluorosulfate, or a combination thereof.

21. The oral care composition of any one of claims 19-20, which comprises from about 25 ppm to about 25,000 ppm of fluoride.

22. The oral care composition of any one of claims 19-21, wherein the antibacterial agent is cetylpyridinium chloride.

23. The oral care composition of any one of claims 19-22, wherein the antibacterial agent is present in the oral care composition in an amount ranging from about 0.01 wt% to about 2 wt%, such as from about 0.05 wt% to about 0.1 wt%, based on the total weight of the oral care composition.

24. The oral care composition of any one of claims 19-23, wherein the thickener is xanthan gum.

25. The oral care composition of any one of claims 19-24, wherein the thickener is present in the oral care composition in an amount ranging from about 0.1 wt% to about 1 wt%, such as from about 0.3 wt% to about 0.5 wt%, based on the total weight of the oral care composition.

26. The oral care composition of any one of claims 19-25, which comprises a pearlescent agent, and wherein the pearlescent agent comprises glycol distearate, laureth-4 and cocamidopropyl betaine.

27. The oral care composition of any one of claims 19-26, wherein the pearlescent agent is present in the oral care composition in an amount ranging from about 0.1 wt% to about 5 wt%, such as from about 1 wt% to about 3 wt%, based on the total weight of the oral care composition.

28. The oral care composition of any one of claims 19-27. wherein the oral care composition is in the form of a mouthwash or mouth rinse.

29. A method for detecting the presence of fluoride in a liquid oral care composition, which comprises:1077927-00- WO-Ol-OCcombining a sample of the liquid oral care composition with a reagent solution, wherein the reagent solution comprises:iron (III) chloride or iron (III) nitrate; andpotassium thiocyanate;assessing the color of the combined solution; anddeducing from the color of the combined solution whether the aqueous oral care composition comprises fluoride.

30. The method of claim 29, wherein combining the sample of the liquid oral care composition with the reagent solution comprises first providing the reagent solution then adding the sample of the liquid oral care composition to the reagent solution.

31. The method of any one of claims 29-30, wherein assessing the color of the combined solution comprises detecting the presence or absence of a color change in the reagent solution upon combination with the sample of the liquid oral care composition.

32. The method of claim 31, which comprises detecting a color change of the reagent solution upon combination with the sample of the liquid oral care composition, wherein the color change is of from red to orange, from orange to yellow, or from yellow to colorless; and deducing that the aqueous oral care composition comprises fluoride.

33. The method of claim 29, wherein assessing the color of the combined solution comprises measuring light absorbance of the combined solution.

34. The method of claim 33, which comprises quantifying the concentration of fluoride in the combined solution from the measured light absorbance.

35. The method of claim 34, which comprises quantifying the concentration of fluoride from a calibration equation derived from measured calibration data, wherein the calibration equation expresses the concentration of fluoride as a function of the measured light absorbance.

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