FILM COMPOSITIONS FOR ORAL USE

BACKGROUND

[O001J Using pigments within a polymer film in toothpaste is a technology used in markets outside of the US. In the US, however, only dye is allowed in oral care products. A significant problem of using water soluble dye is that the dye is water soluble and leaches out of a film almost immediately upon addition to a formulation that contains water, causing an unacceptable color bleedirm.

[9002) There is a need for dentifrices, such as toothpastes, comprising films which contain a dye, such that the dye does not appreciably leach out from the polymer film until use.

SUMMARY

[0003) It has been discovered that when a dye is entrapped in a silica sol-gel and incorporated into a polymer film that is in turn incorporated into an orally acceptable carrier vehicle, the dye does not substantially leach from the film into the carrier vehicle until use, i.e., when diluted with saliva and/or subjected to mechanical forces such as brushing. The compositions of the

invention are oral care compositions can be color-changing films, which are attractive and stable in the formulation and provide a color change signal after a sufficient period of use. The oral compositions of the invention are stable upon storage, e.g., the dye does not substantially leach, migrate or leak from the film into the carrie vehicle during storage, but is released upon

introduction into the oral cavity which, in some embodiments, provides a visible signal upon use.

[0004) in one embodiment the compositions comprise films comprising a high concentration of silica sol-gel/dye material, which are stable in formulation, but are adapted io provide a color change after a sufficient period of brush ing. The user would be instructed to continue brushing until the color change was observed, to help ensure that they have brushed for a sufficient period of time.

[0005) In accordance with the present invention there is provided an oral care composition such as a dentifrice comprising:

(i) flakes of a water dissolvable or soluble film (hereinafter sometimes referred to as "film flakes") comprised of (a) a water soluble cellulose ether polymer and polyvinyl acetate in the form of a polymer matrix, and

(b) a silica sol-gel/dye material entrained in the polymer mairix, and, optionally, other actives, and

( s.) an orally acceptable carrier vehicle, wherein the film flakes are pliable and preferably comprise betaine.

[0006] In one embodiment of the invention there is provided an aesthetically decorative dentifrice having distributed throughout film flakes in which a decorative silica sol-gel/dye material is entrained in the film mairix, the dentifrice vehicle being substantially clear so that the aesthetically decorative effect can be viewed by the user.

[0007] In another embodiment other actives such as therapeutic and/or cosmetic agents, in addition to the silica sol-gel/dye material, are entrained in the film polymer matrix and/or the orally acceptable carrier vehicle.

|ttO 81 The entrain ent of silica sol-gel/dye material and, optionally, other therapeutic and cosmetic agents in the film flake matrix suspended in the orally acceptable carrier vehicle isolates these agents from interaction with reactive ingredients present in the orally acceptable carrier vehicle so that the film flake agents are maintained substantially separate from the reactive dentifrice ingredients i the orally acceptable carrier vehicle during manufacture and storage while subsequently being released from the film matrix when th dentifrice containing the film flakes is topically applied to the tooth surface as by tooth brushing. The other ingredients can be, for example, fragrance, flavor, topical anesthetic, or topical antibacterial agent.

{00 91 Some embodiments of the present invention further provide a composition which is subjected to agitatio and moisture during use, e.g., an oral care product which is applied by brushing or scrubbing, for example a toothpaste.

[0010] Further areas of applicability of the present invention wil l become apparent from the detailed description provided hereinafter, it should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of il lustration only and are not intended to limit the scope of the in vention. DETAILED DESCRIPTION

[0Θ.Π j The following description of the preferred erabodiraent(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses,

(0012| Sitka soi-gelA ye material

[0013! The silica sol-gel/dye .material comprises a dye entrapped or encapsulate into a silica sol-gel Such materials can be made by techniques known in the art, for example as disclosed in WO 2005/028604, WO 2004/081222, US 6,074,629, US 6,495,352,and US 2013/00 1637 incorporated herein by reference.

[O014J Silica sol-gels refer to silicon dioxide based materials made through a sol-gel process.

[00151 Sols are formed first, which consist of a colloidal solution of very small (nanometer sized) polysiloxane particles formed through hydrolysis of the silane starting materials. Further polymerization/chemical reaction/hydrolysis converts the sols into gels by chemically linking together the individual colloidal sol particles into monolithic gels.

[0016! The sol-gel process in volves low-temperature hydrolysis of suitable monomelic precursors and is suitable for encapsulation of dyes. The sol is usual ly formed by hydroiysis of an alkoxy silane precursor followed by condensation to yield a polymeric oxo-bridged SiCb network. In the process, molecules of the corresponding alcohol are liberated,

[0017! A. sol can also be formed by the neutralization of a alkali metal salt of a silicate or oraanosiliconate with an acid.

[0018| In one embodiment a silica sol-gel matrix/dye is prepared by forming a silica sol from a solution of a silicon oxide and alkali metal oxide, such as potassium oxide or sodium oxide, in water, adjusting the pH to a pH value less than approximately 7 to stabilize the silica sol, forming a silica sol matrix solution, adding a solution containing a dye to be entrapped or encapsulated to form a silica sol matrix with entrapped dye, aging said silica sol matrix with entrapped dye, and forming a gel material .

[0019| i another embodiment a water-soluble dye to be encapsulated is dissolved in a prepared SiOx sol without using any further additives such as immobilizing or cornplexmg agents. The dyed sol is subjected to a spray-drying process for .ge.il.ing. Any solvent .residues possibly present are removed by secondary drying. Starting mater ials suitable for the production of the spray- dried sol-gels are a!koxysiSane sols which are produced from tmsuhstituted organosilicon compounds by hydrolysis, preferably heterogeneous catalysis. Tetraet oxysilane is a preferred starting material for the production of the alkoxysilane sol. Hydrolysis of the aqueous-organic alkali silicate solutions is effected at weakly acidic pH values, preferably at pH values of 5.0 to 6.5, particularly at pH values of 5.5 to 6.0. Acidification can he effected by careful addition of acids, Hydrolysis can he effected in the form of a heterogeneous c atalysis, preferably with addition of acidic ion exchangers.

i«020i The Film

|0021| The fi l ms of the present invention are formed from film forming polymers in the form of a polymer matrix comprised of a cellulose polymer in which is entrained a silica sol-gel/dye material, and, optionally other agents such as a flavorant, a sweetener and/or a therapeutic agent such as an antibacterial agent or a breath freshening agent. The film matrix can further comprise water, additional film forming agents such as com starch, e.g., Hi-Set C™ from National Starch, or polyvinyl acetate; p!asticizing agents, e.g., propylene glycol; surfactants comprising betaine; and emulsifying agents. The films of the invention are preferable single layer and pliable. By the term "pliable" is meant that the film will not easily tear nor crack during normal

manufacturing and handling.

|0022| Cocamidopropyl beiaim

|0023| Cocamidopropyl betaine (sometimes referred to herein simpl as "betaine") is an organic compound derived from coconut oil and dimethylarnraopropylaraine. It is a zwitterion,

consisting of both a quaternary ammonium cation and a carboxylate. Betaine is available as viscous pale yellow solution that is used as a surfactant. The name reflects that the major part of the molecule, the lauric acid group, is derived from coconut oil, Cocamidopropyl. betaine can. be viewed as the combination of cocamide and glycine betaine. it is however prepared by

combining chloroacetic acid with the amide derived from dimethylammopropylamme and lauric acid.

j0024| It has been surprisingly discovered that when the film of the invention containing the silica sol-gel/dye material also contains betaine as part or all of the surfactant, such film is pliable, whereas if a conventional surfactant, such as Tween SO, is used alone in forming the polymer film, such film is brittle. Even when the amount of plasticizer, such as propylene glycol, is increased, the resulting film is still brittle if the only surfactant used is Tween 80. Therefore, it is preferred that the surfactant used for film formation comprises betaine. {0β25| Preparation of FVm Matrix

{0026J In preparing the film matrix according to the present invention the hydroxyalkyl cellulose, polyvinyl acetate, silica soS-gel/dye material, and optionally, flavor, sweetener and/or therapeutic agents and other film forming ingredients such as surfactant and plasticizer are dissolved in a compatible solvent to form a film forming composition. Compatible solvents include water, alcohols such as ethanol, ethyl acetate, acetone, and mixtures thereof. The film forming composition is cast on a releasable carrier and dried to form a sheet of film matrix materia!. The carrier material must have a surface tension which allows the film solution to spread evenly across the intended carrier width without soaking to form a destructive bond between the film carrier substrates. Examples of suitable carrier materials include glass, stainless steel. Teflon and polyethylene-impregnated paper. Dry ing of the film may be carried out at high temperature using a drying oven, drying terminal, vacuum drier, or any other suitable drying equipment, which does not adversely affect the ingredients of which the film is composed,

{0027} The film thickness ranges in size from about 1 to 10 mils, in one embodiment about 1 to 5 mils, in another embodiment about 2 to 4 mils. The dried film of the present invention is then cut, punched or ground into flakes having a particle size of 10 to 100 mesh or 20 to 60 mesh or 30 to 50 mesh,

[0928J If desired, additional stability can be provided to the shapes formed from the dried film, by applying to the film, before shaping into flakes, a protective barrier overcoat such as a food grade shellac or ethyl cellulose.

j0029| When the film is to be used for decorative effect, the film once formed is punched into various attractive shaped flakes such as hearts, stars, diamonds and circles. Optionally, the film can be ground into flakes using conventional grinding techniques known in the art. The film flakes are incorporated in the orally acceptable carrier vehicle of the present invention at a coiicentration of about 0.05 to 1.0% by weight and in one embodiment about 0.1 to about 0.5% by weight.

ίθ030| ¾¾ Forming Polymers

100311 The film forming polymer comprises a cellulose polymer, in particular cellulose ethers, e.g., selected from alkylcellulose, e.g., methylcellulose hydroxyalkyl cellulose, e.g., selected from hydroxypropyl. methyl, cellulose, hydroxyethylpropyl cellulose, hydroxy butyl methyl cellulose, hydroxy propyl methyl cellulose, carboxymethyl cellulose: and mixtures thereof. A preferred film forming polymer is hydroxypropylmethyl cellulose (HPMC). Preferably the cellulose ether polymer is a low viscosity hydropropylmethyl cellulose. The cellulose ether is incorporated in the film matrix in amounts ranging from about 10 to about 60% by weight and in one embodiment about 15 to about 40% by weight. Other film forming polymers may also be used in addition to the cellulose ether, for example, polyvinyl acetate, starch, e.g., a

pregelatinized starch, and the like. HPMC is available commercially, for example, from the Dow Chemical Company under the trade designation Methocel™, including, for example, Methocel™ E5LV, Methocel™ E50, and Methocel ^1'8 * 1.00. Methocel™ E5 LV is a USP grade, low viscosity H PMC having 28 to 30 (29.1) % rnethoxyl groups and 7 to 12 (9) % hydroxypropyl group substitution. As used herein, hydroxypropyimethyf cellulose E5 refers to

hydroxypropytaieraylce ^' lhilose have a viscosity of about 5 (4 to 6} mPas (cps), and

hydroxypropylmetlry lcel I u!ose E50 refers to hydroxy propyhnethy I cellulose have a viscosity of about 50 (40 to 60) mPas (cps). The viscosity for the hydroxypropylemethyl cellulose is measured in a 2 weight % solution in water at 20° C. with a Ubbelohde tube viscometer.

(00321 it is an advantage of the composition of the invention that the film does not require a polyme that functions as a mucoadhesive polymer, e.g., polymers containing aery late repeating units such as Carhopol.® polymers. The film of the invention also does not require starch, although it can be present in some embodiments.

(0033j The film flakes typically comprises about 0.01 to 5%, mote typically about 0.015 to 5%, more particularly about 0.015 to 3% of the oral composition of the invention.

034| Dm

[0035J Preferred dyes are water soluble dyes. The term "water-soluble" in this particular context generally means that the dye has an aqueous solubility of at least 1.0 g/L at 25. degree. C, most preferably at least 100 g/L at 25°C. (where the solubility is determined in im-buffered distilled water). Triarylmethane dyes are examples of water soluble dyes useful in the present invention, in some embodiments, dyes useful herein are anionic rriphenylmethane dyes, and especially diaminotriphenylmethane dyes containing f om two to four sulphonate groups, such as those corresponding to general formula (1 ):

(1) in which _¾ R ₂ , R.¾ and R* are monovalent moieties which are each independently selected from hydrogen (~H), hydroxyl OH), halo (e.g. -CI) and sulphonate (-SO ) groups., with the proviso that at least two of s to Rj are siilphonate groups.

|0036J An example of a dye useful herein is FD&C Blue #1 , also known as Brilliant Blue FCF (Blue 1) as well as other commercial names, which corresponds to general formula (I), wherein R. ₂ is -U and Rj , and 4 are siilphonate groups. FD&C Blue #1 is a colorant for foods and other sitbstances to mduce a color change. It is denoted by E number E l 33 and has a color index of 42090. it has the appearance of a reddish-blue powder, it is soluble m water, and the solution has a maximum absorption at about 628 nanometers, it is a synthetic dye produced using aromatic hydrocarbons from petroleism. It is usually a disodium salt. The diammonium salt has CAS number [2650-18-2]. Calcium and potassium salts are also known. Other dyes include red dyes such as FD&C Red#33, FD&C Red#40, and the like; yellow dyes such as F &C Yellow#5, FD&C Yellow#6, FD&C Yeilow#15. and the like; green dyes such as FD&C Green#3: as well as other color dyes and mixtures of any two or more dyes.

f0037j In some embodiments the amoimt of silica sol-gel/dye material in the oral coraposition is from 0.01 to 0.3%. more particularly from 0.02 to 0.1%, and more particularly from 0.03 to 0.08% by weight. The silica sol-gel/dye material may be spread throughout die composition or, it may be dispersed in a second phase such as a stripe or other coextmded second phase. Such "dual phase" compositions have the advantage that the phases may be differently colored, presenting a more visually attractive product to the consumer

[00381 Wofer

[0039J Water may also be present in the oral compositions of the invention. Water, employed in the preparation of commercial oral compositions should be deionized and free of organic impurities. Water commonly makes up th balance of the compositions and includes about 0.1% to about 90%, about 10% to about 80% or about 20% to about 70%, or about 30% to about 60% by weight of the oral compositions. This amount of water includes the free water which is added plus that amoimt which is introduced with other materials such as with sorbitol or an

components of the invention. Water can be present in the film flakes, orally acceptable carrier vehicle, or both.

j0040| I!amechmts

f0041 | Within certain embodiments of the oral compositions, it is also desirable to incorporate a humectant to prevent the composition from hardening upon exposure to air. Certain humectants can also impart desirable sweetness or flavor to dentifrice compositions. The humectant, on a pure humectant basis, generally includes about 15% to about 70% in one embodiment, or about 30% to about 65% in another embodiment by weight of the dentifrice composition. Suitable humectants include edible polyhydric alcohols such as glycerine, sorbitol, xylitol, prop lene glycol as well as other polyols and mixtures of these humectants. Mixtures of glycerine and sorbitol may b used in certain embodiments as the humectan component of the toothpaste compositions herein. The humectant can be present in the film flakes, orally acceptable carrier vehicle, or both. {0β42| Pretty. Acceptable Carrier Vehicle

j0043| The oral care compositions of the invention include a vehicle or base into which the film flakes are incorporated. Examples of orally acceptable carrier vehicles include carrier polymers, humectants, water, abrasives, foaming agents, anti-calculus agents, thickener silicas, and the like, or any combination of two or more thereof ^* The term "orally-acceptable" refers to a polymer or ingredient which can be used to apply to the oral cavity in a safe manner during normal use. {0044) Carrier polymers

{0045) Carrier polymers can comprise one or more anionic or nonionic polymers, and also may include additional polymers to adjust the viscosity of the formulation or enhance the solubility of other ingredients.

(0046) Suitable carrie polymers include polyethylene glycols, polysaccharides (e.g., cellulose derivatives, for example carboxymethyl cellulose, or polysaccharide gums, for example xanthan gum or carrageenan gum). Acidic polymers, for example polyacrylate gels, may be provided m the form of their free acids or partially or fully neutralized water soluble alkali metal (e.g..

potassium and sodium) or ammonium salts. Anionic polymers useful herein may enhance the effect of the water insoluble whitening complex, for example in a amount of from about 0.001 to about 5%, more particularly about 0.01 to 5%, more particularl about 0,05 to 4%, more particularly about 0.05 to 3% of the composition. Such agents are known generally for use in dentifrice, although not for this particular application., useful in the present invention are disclosed in U.S. Pat. Nos. 5,188,821 and 5,192,531 ; and include synthetic anionic polymeric polycarboxylates, such as 1:4 to 4:1 copolymers of maleic anhydride or acid with another polymerizable ethylenicaliy unsaturated monomer, preferably methyl vinyl ether/maleic anhydride having a molecular weight (M.W.) of about 30,000 to about 1 ,000,000, most preferably about 300,000 to about 800,000, These copolymers are available for example as Gantrez®. e.g.. A 13 (M.W. 500,000), AN 19 (M.W. 250,000) and preferably S-97

Pharmaceutical Grade (M.W. 700,000) available from ISP Technologies, Inc., Bound Brook, N.J. 08805. Other operative polymers include those such as the 1 : 1 copolymers of maleic anhydride with ethyl acrylate, hydroxyeihyl methacryiate, ~vinyl~2~pyrollidone, or ethylene, the latter being available for example as Monsanto EMA No. 1 103. M.W. 10,000 and BMA Grade 61 , and 1 : 1 copolymers of acrylic acid with methyl or hydroxyeihyl methacryiate, methyl or ethyl acrylate, isobutyl vinyl ether or Suitable generally, are polymerized oletlnically or ethylenicaily unsaturated carboxylic acids containing an activated carbon-to-carbon olefinic double bond and at least one carboxyl group, that is, an acid containing an olefinic double bond which readily functions in polymerization because of its presence in the monomer molecule either in the alpha-beta position with respect to a carboxyl group or as part of a terminal methylene grouping. Illustrative of such acids are acrylic, methacrylic, ethacry!k, alpha-chlotoaerylic, crotonic, beta-acryloxy propionic, sorbic, alpha-chlorsorbk, cinnaraic, beta- styrylacrylie, muconic, itactmic, citraconic. mesaconic, giutaconic, acomtic, aipha-phenylacrylic, 2-benxyl acrylic. 2-cyclohexylacrylic, angelic, umbellic, funiaric, nialeic acids and anhydrides. Other different olefinic monomers copoiymerizable with such carboxylic monomers include vinylacetate, vinyl chloride, dimethyl maleate and the like. Copolymers contain sufficient carboxylic salt groups for water-solubility. A further class of polymeric agents includes a composition containing homopolymers of substituted acrylamides and/or homopo!ymers of unsaturated sulfonic acids and salts thereof, in particular where polymers are based on

unsaturated sulfonic acids selected from acrylamidoalykane sulfonic acids such as 2-acryIamide 2 meth l propane sulfonic acid having a molecular weight of about 1 ,000 to about 2,000,000, described in U.S. Pat. No. 4,842,847, Jim. 27, 1 89 to Zahid, incorporated herein by reference. Another useful class of polymeric agents includes polyaniino acids containing proportions of anionic surface-active amino acids such as aspartic acid, glutamic acid and phosphoserine, (in addition to the basic amino acid polymers), e.g. as disclosed in U.S. Pat. No. 4,866,161 Sikes et at, incorporated herein by reference,

(0047J S ! preparing oral care compositions, it is sometimes necessary to add some thickening material to provide a desirable consistency or to stabilize or enhance the performance of the formulation, in certain embodiments, the thickening agents are carbox vin l polymers,

carrageenan, hydroxyethy! cellulose and water soluble salts of cellulose ethers such as sodium carboxymethyl cellulose and sodium carboxymethyt hydroxyethyl cellulose. Hydroxyalkyl methyl cellulose may also be present in the non-film portion of the oral composition. Natural gums such as karaya, gum arable, and gum tragacanth can also be incorporated. Colloidal magnesium aluminum silicate or finely divided silica can be used as component of the thickening composition to further improve the composition's texture. In certain embodiments, thickening agents in an amount of about 0.05% to 5%, more particularly about 0.5 io 5% by weight of the total composition are used. Orally acceptable carrier polymers for use in the invention are typically water soluble. Suitable orally acceptable carrier polymers for use in the invention will generally dissolve or disperse in water at a temperature of 25°C.

|0048J The amount of orally acceptable carrier vehicle polymer in composiiioos of the invention, whether enhancers, deposition aids, thickeners or the like, or of a combination thereof, suitably ranges from about 0,001 to 10%, more particularly about 01)05 to 5%, more particularly about 1 to 5%. and more particularly about I to 3%.

\W49\ Abrasives

j ^' OOSOj The compositions of the invention, e.g. Composition 1 et seq. may comprise a calcium phosphate abrasive, e.g., tricalcium phosphate (Qt3(P04)2), hydroxyapatite

(Cal0(PO4)6(OH}2), or dicaicium phosphate dihydrate (CaHP04 * 2H20, also sometimes referred to herein as DiCal) or calcium pyrophosphate. The compositions may include one or more additional abrasives, for example silica abrasives such as precipitated silicas having a mean particle size of up to about 20 microns, such as Zeodent 1 15®, marketed by J. M. Huber. Other useful abrasives also include sodium metaphosphate, potassium metaphosphate, aluminum silicate, calcined alumina, bentonite or other siliceous materials, or combinations thereof. The silica abrasive polishing materials useful herein, as well as the other abrasives, generally have an average particle size ranging between about 0, 1 and about 30 microns, about between 5 and about 15 microns. The silica abrasives can be from precipitated silica or silica gels, such as the silica xerogels described in U.S. Pat. No. 3,538,230, to Pader et at. and U.S. Pat. No. 3,862,307, to Digiul!o, both incorporated herein by reference. Particular silica xerogels are marketed under the trade name Sy!oid® by the W. R. Grace & Co. , Davison Chemical Division. The

precipitated silica materials include those marketed by the J. M. Huber Corp. under the trade name Zeodeni©, including the silica carrvina the designation Zeodent 1 1.5 and 1 19. These silica abrasives are described in U.S. Pat. No. 4,340,583, to Wason, incorporated herein by reference, in certain embodiments, abrasive materials useful in the practice of the oral care compositions in accordance with the invention include silica gels and precipitated amorphous silica having an oil absorption value of less than about 100 cc. 1 0 g silica and in the range of about 45 cc/100 g to about 70 cc/100 g silica. Oil absorption values are measured using the A ST A Rub-Out Method 281 , In certain embodiments, the silicas are colloidal particles having an average particle size of about 3 microns to about 12 microns, and about 5 to about 10 microns. Low oil absorption silica abrasives particularly useful in the practice of the invention are marketed under the trade designation Sylodent XWA® by Davison Chemical Division of W.R. Grace & Co., Baltimore.. Md. 2.1203. Sylodent 650 XWA®, a silica hydrogel composed of particles of colloidal silica having water content of 29% by weight averaging about 7 to about 10 microns in diameter, and an oil absorption of less than about 70 cc/IOO g of silica is an example of a low oil absorption silica abrasive useful in the practice of the present invention. The abrasive is present in the oral care compositio of the present inventio at a concentration of about 10 to about 60% by weight, in other embodiment about 20 to about 45% by weight, and in another embodiment about 30 to about 50% by weight.

[00511 Product Form

[00521 Examples of suitable product forms tor compositions of the invention include dentifrices, mouthwashes, chewing gums and lozenges.

[0053] A type of product form of the present invention is a dentifrice. The term "dentifrice" generally denotes formulations which are used to clean the surfaces of the oral cavity. The dentifrice is an oral composition that is not intentionally swallowed for purposes of systemic administration of therapeutic agents, but is applied to the oral cavity, used to treat the oral cavity and then expectorated. Typically the dentifrice is used in conjunction with a cleaning implement such as a toothbrush, usually by applying it to the bristles of the toothbrush and then brushing the accessible surfaces of the oral cavity. Preferably the dentifrice is in the form of a paste or a gel. (or a combination thereof),

[00541 Active Agems

[0055] The effective concentration of the active ingredients for optional use herein will depend on the particular agent and the delivery system used. It is understood that a toothpaste for example will typically be diluted with water upon use, while a .mouth rinse typically will not. be. Thus, an effective concentration of active in a toothpaste will ordinarily be 5-15x higher than required for a mouth rinse. The concentra tion will also depend on the exact salt or polymer selected. For example, where the active agent is provided in salt form, the counterion will affect the weight of the salt, so that if the counterion is heavier, more salt by weight will be required, to provide the same concentration of active ion in the final product. Active agents can include one or more of fluoride ion source, an anti-calculus agent, an amino acid, a whitenin agent. , an antibacterial agent, and the like. |ft056| A.rginine, where present, may be present at levels from, e.g., about 0, 1 to about 20 wt %(expressed as weight of free base), e.g., about 0.1 to about 3 wt % for a mouthrinse, about 1 to about 10 wt % for a consumer toothpaste or about 7 to about 20 wt % for a professional or prescription treatment product. Fluoride where present may be present at levels of e.g. , about 25 to about 25,000 ppm, for example about 25 to about 250 ppm for a mouthrmse, abou 750 to about 2,000 ppm for a consumer toothpaste, or about 2,000 to about 25,000 ppm for a professional or prescription treatment product.

[0057J Antibacterial agents may be included in the oral composition of the present in vention and particularly noncationic halogenated diphenyl ethers agents which are desirable from

considerations of effectiveness and safety such as 2 ',4, 4 ^s triehloro-2 hydroxy-diphenyl ether (Triclosan) and ^'-dihydroxy-S^' dibromophenyl ether. The antibacterial agent, when present in the oral compositio is present in concentrations of about 0.05 to about 2% by weight and preferably 0.1 to about 1% by weight. Levels of antibacterial agents will vary similarly, with levels used in toothpaste being e.g. , about 5 to about 15 times greater than used in mouthrinse. For example, a triclosan mouthrinse may contain, e.g., about 0.03 wt % triclosan while a triclosan toothpaste may contain about 0.3 wt % triclosan.

[0058] Agents used to diminish teeth sensitivity such as potassium chloride, potassium nitrate and potassium citrate may also be included in oral compositions of the present invention at concentrations of about 0.1 to about 10% by weight.

|0059f Whitening agents

[0060] Whitening agents which may be present in the oral composition include peroxides, metal chiorites, perborates, perearbonates, peroxyacids, persulfates, and combinations thereof. Suitable peroxide compounds include hydrogen peroxide, urea peroxide, calcium peroxide, and mixtures thereof. Suitable metal chiorites include calcium chlorite, barium chlorite, magnesium chlorite, lithium chlorite, sodium chlorite, and potassium chlorite.

[0061] Fluoride km Source

[0062] The oral care compositions may further include one or more fluoride ion sources, e.g., soluble fluoride salts. A wide variety of fluoride ion-yielding materials can be employed as sources of soluble fluoride in the present compositions. Examples of suitable fluoride ion- yielding materials are found in U.S. Pat. No. 3,535,421 , to riner et ah; U.S. Pat. No. 4,885,155, to Parran, Jr. et al. and U.S. Pat. No. 3,678,354, to VVidder et a!., incorporated herein by reference. Representative fluoride ion sources include, but are not limited to, stannous fluoride, sodium fluoride, potassium fluoride, sodium jnonoflaoroptiosphate. sodium fluorosilicate, ammonium fluorosilicate, amine fluoride, ammonium fluoride, and combinations thereof. In certain embodiments the fluoride ion source includes stannous fluoride, sodium fluoride, sodium monofluorophosphate as well as mixtures thereof. m certain, embodiments, the oral care

compositio of the invention may also contain a source of fluoride ions or fluorine- r viding i ngredient in amounts sufficient to supply about. 25 ppm to about 25,000 ppm of fluoride ions, generally at least about 500 ppm, e.g., about 500 to about 2000 ppm, e.g.. about 1000 to about 1600 ppm. e.g.. about 1450 ppm. The appropriate level of fluoride will depend on the particular application, A toothpaste for general consumer use would typically have about 1000 to about 1500 ppm, with pediatric toothpaste having somewhat less. A dentifrice or coating for professional application could have as much as about 5,000 or even about 25,000 ppm fluoride. Fluoride ion sources may be added to the compositions of the invention at a level of about 0,01 wt. % to about 10 wt. % in one embodiment or about 0.03 wt. % to about 5 wt. %, and in another embodiment about 0. 1 wt % to about 1 wt. % by weight of the composition in another embodiment. Weights of fluoride salts to provide the appropriate level of fluoride ion will obviously vary based on the weight of the counter ion in the salt.

[0063J Foammg genis

(0064 j The oral care compositions of the invention also may include an agent to increase the amount of foam that is produced when the oral cavity is. brushed. Illustrative examples of agents that increase the amount, of foam include, but are not limited to polyoxyethyiene and certain polymers including, but not limited to, alginate polymers. The polyoxyethyiene may increase the amount of foam and the thickness of the foam generated by the oral care carrier component of the present invention. Polyoxyethyiene is also commonly known as polyethylene glycol ("PEG") o polyethylene oxide. The polyoxyefhylenes suitable for this invention will have a molecular weight of about 200,000 to about 7,000,000. In one embodiment the molecular weight will be about 600,000 to about 2,000,000 and in another embodiment about 800,000 to about 1,000,000. Polyox® is the trade name for the high molecular weight polyoxyethyiene produced by Union Carbide. The polyoxyethyiene may be present in an amount of about 1% to about 90%, In one embodiment about 5% to about 50% and in another embodiment about 1.0% to about 20% by weight of the oral care carrier component of the oral care compositions of the present invention. The dosage of foaming agent in the oral care composition (i.e., a single dose) is about 0.01 to about 0.9 % by weight, about 0.05 to about 0.5% by weight, and in another embodiment about 0.1 to about 0.2 % by weight.

|0G65| Anfi alcu is agents

[0066} The oral composition can include at least one anti-calculus composition, such as one or more of the anti-calculus compositions recited in U.S. Pat. No. 5,292,526 titled "Antibacteria Anti-plaque Anticalculus Oral Composition," which is incorporated herein by reference. In various embodiments, the anti-calculus composition includes one or more polyphosphates. The anti-calculus composition can include at least one wholly or partially neutralized alkali metal or ammonium trtpolyphosphate or he ametaphosphate salt present in the oral composition at an effective anti-calculus amount. The anti-calculus composition can also include at least one water soluble, linear, molecularly dehydrated polyphosphate salt effective in an anticalculus amount. The ant i -calculus composition can also include a mixture of potassium and sodiuiii salts at least one of which is present in an effective anti-calculus amount as a polyphosphate anti-calculus agent. The anti-calculus composition can also contain an effective anticalculus amount of linear molecularly dehydrated polyphosphate salt anti-calcuius agent present in a mixture of sodium and potassium salts. Other useful anticalculus agents include polycarboxyiate polymers and polyvinyl methyl ether/maleic anhydride (PVME MA) copolymers, such as GA.NTREZ.RTM. 0067| Swiaeiants

The compositions useful in the invention may contain anionic and/or noniomic surfactants, for example:

i. water-soluble salts of higher fatty acid monogSyceride monosulfates, such as the sodium salt of the monosulfated monog ^' lyceride of hydrogenated coconut oil fatty acids such as sodium N-methyl -cocoyl taurate, sodium cocomonoglyceride sulfate,

ii. higher alky! sulfates, such as sodium, !auryi sulfate,

iii. higher alkyl-ether sulfates, e.g., of formula 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 f Ce ₃ (CH ) 10CH ₂ (OCH ₂ Ce ₂ ) ₂ OSO Na).

iv. higher alkyl aryl sulfonates such as sodium dodecyi benzene sulfonate (sodium lauryS benzene s ul fon a te ) v. higher alky ! su!foacetates, such as sodium iauryi sulfoacetate (dodecyi sodium snlfoaeefate), higher fatty acid esters of 1,2 dihydroxy propane sulfonate, sulfocolaurate (N-2- etbyl laurate potassium sulfoaeetamide) and sodium iauryi sarcosmate.

|0068| By "higher alkyl" is meant, e.g., C6-30 aikyi. In particular embodiments, the anionic surfactant is selected from sodium Iauryi sulfate and sodium ether iauryi sulfate. The anionic surfactant may be present in an amount which is effective, e.g., > 0.01% by weight of the formulation, but not at a concentration which would be irritating to the oral tissue, e.g., <!0%, and optimal concentrations depend on the particular formulation and the particular surfactant. For example, concentrations used for a mouthwash are typical l y on the order of one tenth that used for a toothpaste. In one embodiment, the anionic surfactant is present in a toothpaste at from about 0.3% to about 4.5% by weight, e.g., about 1.5%.

0069J Nonionic surfactants include nonanionic polyoxyethyiene surfactants such as Poiyoxamer 407, Steareth 30, Polysorbate 20, and PEG-40 castor oil and amphoteric surfactants such as cocamiopropyi betaine (tegobaine) and cocamidopropyl betaine iauryi glucoside condensation products of ethylene oxide with various hydrogen containing compounds that are reactive therewith and have long hydorphobic chains (e.g., aliphatic chains of about 12 to 20 carbon atoms), which condensation products ("ethoxamers") contain hydrophiiic polyoxyehtylene moieties, such as condensation products of poly (ethylene oxide) with fatty acids, fatty alcohols, fatty amides and other fatty moieties, and with propylene oxide and polypropylene oxides (e.g., PIuronic. TM.materiais).

j00?0| The compositions of the invention may optionally contain mixtures of surfactants, e.g. , comprising anionic surfactants and other surfactants that may be anionic, cationic, zwitterionic or nonionic. Generally, surfactants are those which are reasonably stable throughout a wide pH range. Surfactants are described more fully, for example, in U.S. Pat. No. 3,959,458, to Agricola et at; U.S. Pat. No. 3,937,807, to Haefele; and U.S. Pat. No. 4,051 ,234, to Gieske et ai, which are incorporated herein by reference. In certain embodiments, the anionic surfactants useful herein include the water-soluble salts of alkyl sulfates having about 10 to about I S carbon atoms in the alkyl radical and the water-soluble salts of sulfonated monoglycerides of fatty acids having about 10 to about 18 carbon atoms. Sodium iauryi sulfate, sodium lauroyl sarcosmate and sodium coconut monoglyeeride sulfonates are examples of anionic surfactants of this type. In a particulax embodiment, the composition of the invention, e.g.. Composition 1 , et seq., comprises sodium iauryl sulfate.

|007l| The surfactant or mixtures of compatible surfactants can be present in the compositions of the present i nventio in about 0.1% to about 5.0%, in another embodiment about 0,3% to about 3.0% and in another embodiment about 0.5% to about 2.0% by weight of the total composition.

{O072J Flavoring Agents

[0073J The oral care compositions of the invention may also include a flavoring agent.

Flavoring agents which are used in the practice of the present invention include, but are not limited to, essential oils as well as 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 anetbole. Certain embodiments emplo the oils of peppermint and spearmint. The flavoring agent may be incorporated in the oral composition at a concentration of about O. i to about 5% by weight and about 0,5 to about 1.5% by weight. The dosage of flavoring agent in the individual oral care composition dosage (i.e., a single dose) is about 0.001 to 0.05% by weight and in another embodiment about 0.005 to about 0.015 % by weight.

{0O74| Other optional ingredients

{0075J In addition to the above-described components, the embodiments of this invention can. contain a variety of optional dentifrice ingredients some of which are described below. Optional ingredients include, for example, but are not limited to, adhesives, sudsing agents, sweetening agents, and additional coloring agents. These and other optional components are further described in U.S. Pat No. 5,004,597, to Majeti; U.S. Pat. No. 3,959,458 to Agricoia et al. and U.S. Pat. No. 3,937.807. to Haefele. all being incorporated herein by reference.

[0076J As used throughout, ranges are used as shorthand tor describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict i a definition in the present disclosure and that of cited reference, the present disclosure controls. |ft077| In general, the various agents and materials described herein, e.g., fluoride ion source, antibacterial, flavoring agents, whitening agents, and the like, can be present in the film flakes, orally acceptable carrier vehicle, or both.

(007$| Unless otherwise specified, al l percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material. For convenience, components of the composition of invention are expressed in the singular; however it is to be understood that mixtures of components are encompassed by use of the singular expression, for example, "an orally acceptable carrier polymer" may include mixtures of two or more polymers described herein. Some embodiments of the present invention provide an oral care composition (Composition I ) comprising:

{ i) flakes of a water dissolvable or soluble film comprised of

(a) a water soluble cellulose polymer in the form of a polymer matrix, and

(b) a silica sol-gel/dye material entrained in the polymer matrix, and. optionally, other actives, and

(ii) an orally acceptable carrier vehicle,

wherein the film is pliable, for example:

1.1. Composition 1 wherein the cellulose polymer comprises cellulose ethers, e.g., selected from

(i) alkylcelluiose, e.g., raethylcellulose;

(is) hydroxyalkyl cellulose, e.g., selected from hydroxypropyl methyl cellulose, hydroxyethy!propyi cellulose, hydroxybutyl methyl cellulose, hydroxy propyl methyl cellulose, carboxymethyl cellulose and mixtures thereof;

and (iii) mixtures thereof;

1.2. Any of the foregoing compositions wherein the film comprises a starch, e.g. a pregelatinized starch;

1.3. Any of the foregoing compositions wherein the film comprises a plasticizer, e.g, a polyalcohoi, e.g., sorbitol, propylene glycol, glycerol, or low molecular weight polyethylene glycol, e.g., PEG 200; 1.4. Any of the foregoing compositions wherein the film comprises propylene glycol, e.g., in an amount effective to provide plasticity to the film, e.g., about 20-30% by dry weight of the film;

1.5. Any of the foregoing compositions wherei the film comprises betaine, e.g., in an amount effective to provide a pliable film, e.g., about 1-5% by dry weight of the film;

1.6. Composition 1 wherein the cellulose polymer Is hydroxypropylmeihy! cellulose.

1.7. Any of the foregoing compositi ons w herein the film does not contain a polymer that functions as a mucoadhesive polymer, e.g., polymers containing acrySate repeating units.

i , 8. Any of the foregoing composi tions wherein the film does not contai starch,

1.9. Any of the foregoing compositions wherein the dye is an anionic

triphenyhnetbane dye, e.g., diaminotriphenylmethane dyes containing from two to four sulphonaie groups, such as FD&C Blue #1;

1.10, Any of the foregoing compositions wherein the fi lm is substantially dissolved after a period of greater than 30 seconds and less than ISO seconds of brushing, scrubbing or agitation in the oral cavit or on the skin in tlie presence of water;

1.1 1 . Any of the foregoing compositions wherein the average thickness of the film is 1- 10 mil. i e.a. 1.5- 3 mil, e.a. about 1.5 mil , about 2 mil or about 3 mil;

1.12. Any of the foregoing compositions wherein the film comprises, by dry weight of the film, 20-60% hydroxypropylmeihy. cellulose; 10-30% propylene glycol; .1-5% betaine; and 15-30 or 15-55% silica sol-gel/dye material;

L I 3. Any of the foregoing compositions wherein the film additionally comprises

flavors, fragrances, antibacterial agents, anesthetic agents or combinations thereof;

1.14. Any of the foregoing compositions wherein the films flakes have a particle size of 10- 100 mesh or 20-60 mesh or 30-50 mesh;

1. 15. Any of the foregoing compositions wh.re.in the film, is in an orally acceptable carrier vehicle which comprises a synthetic anionic polymeric polycarboxy!ate; 1.16. Any of the foregoing compositions wherein the orally acceptable carrier vehicle is a J :4 to 4:1 copolymers of omleie anhydride or acid with another polynierlzable eihylenicalSy unsaturated monomer;

1.17. Any of the foregoing compositions wherein the film is in an orally acceptable carrier vehicle wherei the orally acceptable carrier vehicle comprises a methyl vinyl ether/raaleic anhydride copolymer having an average molecular weight (M. W.) of about 30,000 to about 1,000,000, e.g. about 300,000 to about 800,000;

1.18. Any of the foregoing compositions wherein, the film is in an orally acceptable carrier vehicle wherein the orally acceptable carrier vehicle comprises about 1 ~ 5%, e.g., about 2% of the weight of the total composition;

i , 19. Any of the foregoing composi tions further comprising an effec tive amount of fluoride, e.g., wherein the fluoride is a salt selected from stannous fluoride, sodium fluoride, potassium fluoride, sodium monofluorophosphate, sodium uorosilicaie, ammonium fluorosilicate, amine fluoride (e.g., N'~

octadecyltrimethylendiamine- ,Ν, '- nis(2-ethanoi)-dihydrofluoride),

ammonium fluoride, titanium fluoride, hexafluorosulfate, and combinations thereof;

1.20. Any of the foregoing compositions comprising L~arginine in free or orally

acceptable salt form;

1.21. An of the foregoing compositions comprising buffering agents, e.g., sodium phosphate buffer (e.g., sodium phosphate monobasic and disodium phosphate)

1.22. Any of the foregoing compositions comprising an additional humectant, e.g., selected from, sorbitol, propylene glycol, polyethylene glycol, xyhtol, and mixtures thereof;

1.23. Any of the foregoing compositions farther comprising an abrasive or particulate;

1.24. The foregoing composition wherein the abrasive or particulate is selected from sodium bicarbonate, calcium phosphate (e.g., dicalcium phosphate difrydrate), calcium sulfate, precipitated calcium carbonate, silica (e.g., hydrated silica), iron oxide, aluminum oxide, periite, plastic particles, e.g.. polyethylene, and

combinati ons thereof; Any of the foregoing compositions comprising an abrasive in an amount of about 15 L % to about 70 wt. % of the total composition weight;

Any of the foregoing compositions comprising one or more surfactants., e.g., selected from anionic, cationie, zwitterionic. and non ionic surfactants, and mixtures thereof, e.g., comprising an anionic surfactant, e.g., a surfactant selected from sodium lauryi sulfate, sodium ether Saury! sulfate, and mixtures thereof, e.g. in an amount of iro.ro about 0.3% to about 4.5% by weight;

Any of the foregoing compositions further comprising a viscosity modifying amount of one or more polymers selected from polyethylene glycols,

polysaccharides (e.g., cellulose derivatives, for example carboxyroethyl cellulose, polysaccharide gums, for example xanthan gum or carrageenan gum), and combinations thereof;

Any of the foregoing compositions comprising one or more antibacterial agents, for example comprising an antibacterial agent selected from halogenated di henyl 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, epigaliocateehin gallate, epigaliocateehin, gallic acid, nis ak extract, sea-buckthorn extract), bisguanide antiseptics (e.g., eliSorhexidine, alexidine or octenidine), quaternary ammonium compounds (e.g., cetylpyridimum chloride (CPC), benzalkonium chloride, tetradecylpyridmium chloride CTPC), N-tetradec l-4-ethylpyridinium chloride (TDEPC)}, phenolic antiseptics, bexetidine, octenidine.. sangyinarine, povidone iodine, delmopinol, salifiuor, metal ions (e.g., zinc salts, for example, zinc citrate, stannous salts, copper salts, iron salts), sang narine, propolis and oxygenating agents (e.g., hydrogen peroxide, buffered sodium perox vborate or peroxycarbonafe), phthalic acid and its salts, monoperthaSic acid and its salts and esters, aseorbyl stearate, oleoyi sarcosine, alky! sulfate, dioctyl sulfosuccinate, salicylanilide, domiphe bromide, delmopinol, octapi.iiol. and other piperidi.no derivatives, nkin

preparations, chlorite salts; and mixtures of any of the foregoing; e.g., comprising triclosan or cetylpyridimum chloride; 1.29. Any of the foregoing compositions comprising a whitening agent, e.g., a selected from the group consisting of peroxides, metal chlorites, perborates, percarbonates, peroxyacids, hypochlorites, and combinations thereof;

1.30. Any of the foregoing compositions further comprising hydrogen peroxide or a hydrogen. eroxide source, e.g., urea peroxide or a peroxide sail; or complex (e.g., such as peroxyphosphate, peroxycarbonate, perborate, petoxysilicate, or persulphate salts; for example calcium peroxyphosphate, sodium perborate, sodium carbonate peroxide, sodium peroxyphosphate, and potassium persulfate);

1.31. Any of the foregoing compositions further comprising a source of calcium and phosphate selected from (i) calcium-glass complexes, e.g., calcium sodium phosphosihcates, and (ii) cakiurn-protein complexes, e.g., casein phosphopeptide- ainorphous calcium phosphate;

1.32. Any of the foregoing compositions further comprising a soluble calcium salt, e.g., selected from calcium sulfate, calcium chloride, calcium nitrate, calcium acetate, calcium lactate, and combinations thereof;

i .33, An of the foregoing compositions farther comprising a physiologically or orally acceptable potassium salt, e.g., potassium nitrate or potassium chloride, in an amount effective to reduce dentinal sensitivity;

1.34. Any of the foregoing compositions in the form of a dentifrice, for example a

toothpaste, e.g., a clear gel or opaque toothpaste;

.1.35. Any of the foregoing compositions in the form of a clear gel or opaque toothpaste and the dye is released upon dissolution of the fi lm thereby changing the color of the toothpaste after brushing for a period of 30 - - 180 seconds, e.g., about 45-60 seconds in a toothpaste for us by a child or about 90-120 seconds in a toothpaste for use by an adult, thereby releasing the dye and providing a color signal to the user of adequate brushi ng;

[0079] The invention further provides a method of cleaning the teeth comprising brushing wi th a toothpaste comprising an orally acceptable dissolvable film of a cellulose polymer and having entrained therein a silica sol-geS/dye material (e.g.. Composition I et $eq.) _> wherein brushing is continued until, the film disintegrates and the dye provides a color signal to the user of adequate brushing, for example, wherei the brushing time before the film matrix dissolves is between 30 and 180 seconds, e.g., about 45-60 seconds for a toothpaste for use by a child and about 90-120 seconds for a toothpaste for use by an adult.

[0080 J In some embodiments, the composition is clear gel toothpaste; wherein the dye is released from the first film after brushing for a period of 30 to 120 seconds. In some

embodiments, the dye is released from the first film after brushing for a period of 60 seconds. In. some embodiments, the dye is released from the first film after brushing for a period of 90 seconds. In some embodiments, the dye is released from the first film after brushing for a period of 120 seconds.

[008! I The invention further provides a method of cleaning the teeth, removing plaque, treating halitosis, or treating gingivitis comprising brushing the teeth with Composition 1, et seq..

(00821 hi some embodiments, the film is substantially dissolved after a period of greater than 30 seconds and less than 180 seconds of brushing, scrubbing or agitation in the presence of water.

[0083] in some embodiments, substantially all of the dye is released from the film at the same point in time.

[00841 In some embodiments the composition is stable, i.e., no visible dye is observed in the carrier vehicle, for a period of 1 month or 2 months, or 3 months, or 6 months, or 1 year or 2 years upon storage at about room temperature.

[008SJ Yet other embodiments provide a method of cleaning the teeth comprising brushing with a toothpaste according to Composition 1 etseq., wherein brushing is continued until the film releases substantially all of the dye; thereby providing a color signal to the user of adequate brushing.

f0086| ° some embodiments, substantially all of the dye is released at one time. As used herein, the term "substantially all" refers to greater than 90% of the total amount of dye contained in the film.

{ ^" 0087} In another embodiment is provided a method for providing storage stability to a dentifrice containing dye comprising entrapping said dye in a silica sol-gel and incorporating said entrapped dye in a film comprised of a cellulose polymer and incorporating said film into an orally acceptable carrier vehicle.

(00881 As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any vaioe within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. in the event of a conflict in a definition in die present disclosure and that of a cited reference, the present disclosure controls.

|0089J Unless otherwise specified, all percentages aod amoimts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight.

EXAMPLE

Example I

|0090j film making Procedure.

{00911 Approximately fifty percent of the required film formula water is weighed out and heated as necessary depending on the polymer type. Polymers (HPMC ₅ MC, etc) are slowly added to the water under mixing conditions and the polymers are allowed to disperse and hydrate for 10~ 15 minutes. Additional water up to the full amount is added until the slurry has the consistency of .honey. Plasticizers and surfactants should then be added while mixing and allowed to mix for 5 minutes. Other particles such as dyes, etc should then be added to the mixture and allowed to mix for 10 additional minutes. The slurry should then be de-aerated. Films can then he cast and dried from the slurry to the desired thickness typically 1-10 mils.

[00921 Films are made from the ingredients in Table land evaluated for pliability. Film pliability is an importan aspect of film making as it dictates the feasibility of manufacture. Films that lack pisabiiity will crack during drying resulting in a material that cannot be handles easily and thus cannot be manufactured. Pliability is eas to assess by taking a piece of film a minimum of 3 inches square and tuuid g and foldms the film. Pliable films will not easilv tear nor crack during this manipulation.

Table L

|0093J An experiment is carried to evaluate the ability of the fi lms to retain dye. Film stability is determined, by measuring the degree of color bleeding using a spectrophotometer which can measure on the L, a, b scale. Films are loaded into a gel toothpaste where there is higher clarity and high water mobility and permitted to age at room temperature for a minimum of 24 hours and up to 3 months. Films can be filtered out of the gel prior to color evaluation. As noted in the Table 2 there is a minimal change in any of the measured color parameters indicating thai the films are stable and exhibit minimal bleeding.

Table 2

L* a* b*

i itial 96.08 -0.23 0.63

3Monih 95.24 -1.38 0.17