The sweetening capability provided by neotame results in an improvement in the taste or aroma properties of personal care products.

Description of the Prior Art Personal care products are considered substances which when taken orally or applied to the surface of the body provide some sort of health or hygiene benefit. In their common forms these types of products are dentifrices (for example, toothpaste, dental creams), dental tablets (for example, chewing gums, lozenges), tooth powders (for example, dental polishing agents, dental impression materials), mouthwashes and oral rinses, lip balms (for example, sticks. lip moisturizers, and salves), and applied body substances (for example, shampoos, cosmetics. masks, creams, lotions, soaps, and moisturizers). The products in the ordinary course of usage are not normally ingested or swallowed but simply applied on the lips, face, body extremities, or in the mouth for a time sufficient to achieve the desired benefit.

Personal care products contain essential ingredients (i. e. active ingredients) which without the aid of a taste-masking agent inherently may result in taste or aroma characteristics deemed undesirable by most consumers. To the consumer it is important that these products, when applied orally have a desirable flavor, while those applied externally have a pleasing aroma.

A pleasing taste or aroma is necessary to help achieve the heath or hygiene benefit of these products since offsetting undesirable taste or aroma qualities will naturally result in a more thorough use and administration of the particular product. Flavoring ingredients are therefore added in order to mask any undesirable off-taste or aromas contributed by either the active or inactive ingredients required for functionality. Flavor systems used in personal care products generally include a variety of different flavoring agents, including oils such as peppermint, spearmint, and sassafras, as well as numerous flavor-modifying compounds recognized as flavoring ingredients in the food industry. A high-intensity sweetener such as saccharin has also been used commercially to improve the flavor of toothpaste, dental impression materials, lip balms, lip sticks, and mouthwash products. The ingredient is generally incorporated into the personal care composition to improve the taste or aroma, either by masking or modifying the undesirable flavor attributes.

Despite the need for improving the taste and aroma of personal care compositions to make these products more acceptable to consumers, substances which provide the improvement cannot be used without first considering the other ingredients which make up the personal care composition. First, the flavoring improvement agent needs to be compatible with both the active and non-active ingredients that make up the particular product. For example, ingredients used in oral care products such as dentrifices include humectants, abrasives, surfactants, and bulk polymers which may not be compatible with certain flavorings or taste- masking agents. Similarly, mouthwashes generally have alcohol contents ranging from 10- 20% which may interfere with the solubility properties of certain flavoring and taste-masking ingredients. Thus, any incompatibility with the other ingredients in the personal care composition will naturally result in a less than desired taste or aroma improvement. Second, the flavoring improvement agent must also be compatible and blend well with other flavors of the composition. Typically personal care products contain multiple flavoring ingredients in order to achieve an acceptable product. Addition of a flavoring improvement agent must first be compatible with the entire flavoring system before providing an additional benefit of improved taste or aroma. In addition, it may not be desirable to completely change the flavor profile of the product, but instead mask certain off-flavors associated with certain ingredients.

For example, the goal of using a flavor improvement agent may be simply to mellow the aseptic flavor of a mouthwash, or mask the bitter taste of a dentrifice containing a bitter- tasting active ingredient.

There are several examples of improving the taste or aroma of personal care products by various flavoring ingredients and flavoring improvement agents. U. S. Patent No. 5,811,080 describes a process for preparation of dentifrice products which reduces the amount of flavor while still achieving the same flavor impact as a dentifrice made from the same flavor. A mouthwash composition is described in U. S. Patent No. 5,817,295 where blends of essential oils such as thymol, eucalyptol, menthol, and peppermint are used to in conjunction with lowered alcohol amounts to produce a pleasing-tasting product. U. S. Patent No. 5,626,837 describes the use of water-soluble flavors extracted from flavor oils using ethanol in various oral compositions. In addition, U. S. Patent 5,711,937 discloses the use of cineole, methyl salicylate, ethyl butyrate, cinnamic aldehyde, and menthol as means to improve the taste of oral compositions.

The high-intensity sweeteners saccharin and acesulfame-K have been used to modify the tastes of toothpastes and mouthwashes but their use has not been without their own inherent disadvantages. Use of saccharin may be considered undesirable since saccharin is associated with bitter and metallic aftertastes, either as an inherent attribute or as a result of saccharin's incompatibility with other flavoring components or other ingredients used.

A disadvantage of using acesulfame-K in these compositions may be due to the incompatibility of acesulfame-K with other ingredients in the formulation, imparting extra bitterness, and cost. Thus, despite the advances of flavor improvement of personal care products, there is still a need in the industry to improve these products and provide flavor improvements which are cost effective.

The N-alkylated aspartame derivative, neotame, is a highly intense non-nutritive sweetening agent useful to impart sweetness of a wide variety of food products. This compound, disclosed in U. S. Patent No. 5,480,668, is approximately 8,000 times as sweet as sucrose and 40 times as sweet as aspartame on a weight basis. Surprisingly, it has been found that neotame is able to mask or diminish undesirable tastes and aromas of personal care products and as a result make such products more pleasing and acceptable. It has also been discovered that neotame is able to improve the taste and aroma of personal care products by modifying flavoring ingredients traditionally used. Due to its high sweetness potency, only small amounts of neotame are needed in personal care compositions. It therefore would be advantageous to utilize these properties of neotame in personal care products. Such use is not described or suggested by the prior art.

SUMMARY OF THE INVENTION This invention relates to compositions containing N- [N- (3, 3-dimethylbutyl)-L-a-aspartyl]-L- phenylalanine 1-methyl ester, or neotame, of the formula: It has been discovered that neotame can be formulated into personal care compositions to provide improved taste and aroma properties, with the usage level of neotame being extremely low. The invention is directed to personal care products comprising neotame in an amount effective to mask or modify undesirable tastes or aromas of various ingredients used in the personal care composition. The invention is also directed to personal care products comprising neotame in an amount effective to modify various flavoring ingredients traditionally used in personal care compositions. The invention is also directed to personal care products comprising a blend of neotame with either another sweetener, flavor improvement agent, or flavor ingredient in a combined amount effective to improve the taste or aroma of the personal care product. The invention also relates to the method of preparing compositions of personal care products containing neotame.

DETAILED DESCRIPTION OF THE INVENTION This invention is related to the improvement of the taste or aroma of personal care products by neotame. If neotame is used exclusively the amount will range from about 1 to about 2000 parts per million (ppm). More preferably, the amounts will range from about 5 to about 500 ppm. If neotame is used as part of a flavoring system comprising other flavoring agents or flavor improvement agents the amount of neotame will range from about 0.01 to about 1000 ppm.

The types of personal care compositions are diverse and represent a variety of different uses and benefits. The personal care compositions of this invention include dentifrices (for example, toothpaste) in which case the composition is typically a blend of a base ingredient,

humectant, gelling or binding agent, and cleaning agent; a dental aid (for example, chewing gums, lozenges), in which case the composition contains an art-recognized gum base, binding agent, and dentally acceptable cleaning agent; tooth powders (for example, polishing agents, dental impression materials) which are generally used in the field of dentistry; lip balms (for example, sticks, lip moisturizers, salves); mouthwashes, in which case the composition is generally aqueous-alcohol based, facial cosmetics, and various body lotions. Dentifrices, mouthwashes, facial cosmetics, and body lotions are preferred embodients of the present invention.

Another aspect of the invention is the longer lasting perception of taste and aroma of the personal care composition containing neotame. For example, it has surprisingly been discovered that neotame is capable of extending the flavor of dental chewing gums, lozenges, and mouthwashes, the taste and aroma of lip balms, and the aroma of facial cosmetics and body lotions. Without being bound to any proposed theory, it is believed that the more thorough compatibility of neotame and flavor ingredients used in oral care products results in a longer lasting perception of the taste and aroma ingredients.

Extending the taste and aroma attributes of many personal care products is desirable and is not taught in the art by use of other high-intensity sweeteners.

Personal care products typically are formulated with a variety of ingredients to achieve a desired functionality but contribute to an undesirable off-taste or off-aroma. The use of neotame in these formulations results in a masking or diminishing of undesirable taste sensations, for example, sensations such as harshness, burning, bitterness, and astringency.

For instance, mouthwashes generally contain alcohol which can impart a burning sensation when used, while toothpastes generally contain ingredients which impart an alkaline flavor.

In many instances flavors such as mints and fruit flavors are used to provide a masking effect.

Neotame, when used at levels as described in this invention, diminishes the alcohol burn in a mouthwash, while at the same time rounds out the mint flavor present, thereby resulting in a product which tastes better and is much more palatable. In toothpaste, neotame has the effect of mellowing out the harshness of the alkaline taste, thereby reducing the irritation caused by the alkaline tasting ingredients.

The neotame used in these types of personal care compositions may take any form. For example, it may be a salt or complex such as described in U. S. Patent Application No.

09/146,963, U. S. Patent Application No. 09/146,964, U. S. Patent Application No.

09/148,134, U. S. Patent Application No. 09/146,965, U. S. Patent Application No.

09/154,568, and U. S. Provisional Patent Application No. 60/126,363, the disclosure of each of which is incorporated by reference herein. Other exemplary forms of neotame that may be

used in this invention include co-crystallized forms and cyclodextrin complexes, such as described in U. S. Patent Application No. 09/154,568 and U. S. Provisional Patent Application No. 60/100,867, the disclosures of each of which are incorporated by reference herein.

Agglomerates and other processed forms of neotame, and various forms of neotame crystallized using different processes may also be used.

Neotame described herein may be blended with one or more other sweeteners to improve the taste or aroma of the personal care compositions. These sweeteners may either be conventional caloric sweeteners, sugar alcohols, high-intensity sweeteners, or combinations thereof. Caloric sweeteners include xylose, ribulose, glucose (dextrose), mannose, galactose, fructose (levulose), sucrose (sugar), maltose, and mixtures thereof.

Other sugar related substances include maltodextrins, starch hydrolysates, hydrogenated hexoses, hydrogenated disaccharides, and mixtures thereof. Sugar alcohols include sorbitol, xylitol, mannitol, lactitol, and mixtures thereof.

Examples of suitable high-intensity sweeteners which can be blended with neotame include (A) water-soluble naturally-occurring intense sweeteners such as dihyroxychalcones, monellin, steviosides, glycyrrhizins, dihydroflavenol, and L- aminodicarboxylic acid aminoalkenoic acid ester amides, such as those disclosed in U. S.

Pat. No. 4,619,834, and mixtures thereof; (B) water-soluble artificial sweeteners including the soluble saccharin salts of 3, 4-dihydro-6-methyl-1, 2,3-oxathiazine-4-one-2,2-dioxide, the potassium salt of 3, 4-dihydro-6-methyl-1, 2,3-oxathiazine-4-one-2,2-dioxide (Acesulfame-K), the free acid form of saccharin, and the like, and mixtures thereof ; (C) dipeptide based sweeteners including aspartame, L-aspartic acid derivatives described in U. S. Pat. No. 3,492,131, L-alpha-aspartyl-N- (2,2,4,4-tetramethyl-3-thietanyl)-D- alaninamide hydrate (alitame), methyl esters of L-aspartyl-L-phenyl-glycerine and L- aspartyl-L-2, 5-dihydrophenyl-glycine, L-aspartyl-2,5-dihydro-L-phenylalanine, L- aspartyl-L- (l-cyclohexene)-alanine, and the like, and mixtures thereof; (D) water-soluble intense sweeteners derived from naturally occurring water-soluble sweeteners, such as chlorinated derivatives of ordinary sugar (sucrose), e. g. chlorodeoxysugar derivatives and mixtures thereof, and (E) protein based intense sweeteners such as thaumaoccous danielli (thaumatin I and II). se of these sweeteners in the personal care composition may actually reduce the level of neotame required for a particular application.

Personal care products such as dentifrices, tooth powders, lip balms, facial cosmetics, and body lotions generally require the use of a base ingredient that provides most of the bulk of the composition. The base ingredient generally provides the desired physical functionality but can also contribute to the overall taste or aroma of the product, and in

some cases contribute to an undesirable off-taste of the product. These ingredients can include glycerol, sorbitol, and other sugar alcohols such as xylitol, mannitol, maltitol, and lactitol. Typically the end-use formulation will be based on the ability of the base ingredient to provide its inherent taste and aroma contribution. Use of these base ingredients in the personal care products industry is well known and the particular formulation considerations in using a particular base ingredient can be utilized by those skilled in the art.

Personal care compositions also generally contain a variety of different colorants and flavorings. There are no limitations as to the types of colorants that can be used in compositions containing neotame and therefore any colorant recognized as a traditional colorant by those skilled in the art can be used. Similarly, there is no limitation as to the types of flavoring ingredients which can be used in an personal care product containing neotame. Traditional flavoring ingredients include the mints such as spearmint and peppermint, menthol, vanillin, cinnamon derivatives, and various fruit flavors, whether employed individually or in admixture. The amounts of colorants and flavorings used are normally a matter of preference subject to type and desired level.

In general, the amount of neotame used will be dependent on the particular application. For specific personal care applications, the desired ranges of neotame may vary due to targeted taste improvement level, pH, alkalinity, and processing conditions. The objective in determining the exact amount of neotame for a particular composition is guided by the flavor and level of taste or aroma improvement desired in view of compositions formulated without neotame.

One embodiment of this invention relates to dentrifices (for example, dental creams and toothpastes) formulated with neotame. Dentrifices can be formulated to include various base materials such as sorbitol, hydrocolloids, and starches. The dentrifice can also be formulated with a variety of different flavoring ingredients, generally spearmint, peppermint, and cinnamon flavored. The dentrifice can be formulated to be a gel or opaque-like consistency. The usage range level of neotame that provides an acceptable improvement in taste or aroma in dentrifices is about 0.1 ppm to about 250 ppm, more preferably between 1 ppm and 150 ppm, and most preferably between 5 ppm and 100 ppm.

Another embodiment of this invention is directed to dental tablets (for example, chewing gums, dental lozenges, and effervescent tablets or capsules) containing neotame. These types of compositions are formulated with a variety of different ingredients. The usage

range level of neotame that provides acceptable sweetness in dental tablets confections is about 0.1 ppm to about 2000 ppm, more preferably between 1 ppm and 1000 ppm, and most preferably between 5 ppm and 100 ppm.

Another embodiment of this invention relates to the use of neotame to provide a taste and aroma improvement of tooth powders (for example, dental polishing agents, dental impression materials). These materials generally are used in the field of dentistry and typically consist of diatomaceous earth as the base ingredient along with various percentages of calcium sulfate, alginate, and tetrasodium pyrophosphate. The usage range level of neotame that provides acceptable sweetness in tooth powder compositions is about 0.1 ppm to about 2000 ppm, more preferably between 1 ppm and 1000 ppm, and most preferably between 5 ppm and 300 ppm.

Yet another embodiment of this invention includes the use of neotame to improve the taste and aroma properties of mouthwash compositions. Mouthwashes are typically alcohol (methanol and ethanol) in water solutions containing a variety of flavoring ingredients such as menthol, cinnamic aldehyde, and oil of clove. The composition typically contains acidulants such as hydrochloric acid, zinc chloride, and boric acid. The usage range level of neotame that provides an acceptable improved mouthwash composition is about 0.1 ppm to about 230 ppm, more preferably between 1 ppm and 130 ppm, and most preferably between 5 ppm and 75 ppm.

Another embodiment of this invention is the use of neotame to provide a taste and aroma improvement of lip balms (for example, sticks, moisturizers, and salves). These types of personal care compositions use a variety of different ingredients and flavoring systems.

Typically the flavoring ingredients include the mints (spearmint and peppermint), menthol derivatives, and artificial colors and flavors are commonly used. The usage range level of neotame that provides a taste and aroma improvement of lip balms is about 0.1 ppm to about 130 ppm, more preferably between 1 ppm and 100 ppm, and most preferably between 5 ppm and 75 ppm.

Still another embodiment of this invention relates to the use of neotame to approve the taste and aroma of applied body substances (for example, facial masks, creams, shampoos, cosmetics, and body lotions). These products generally consist of various colors and perfumes and though not normally ingested, the consumer can by accident administer the facial mask or cream to the mouth and lips. The usage range level of neotame that provides acceptable facial mask or cream is about 0.1 ppm to about 200 ppm, more preferably between 1 ppm and 100 ppm, and most preferably between 5 ppm and 40 ppm.

When blends consisting of other sweeteners or flavoring agents are used in the personal care composition, the amount of neotame required to provide a taste or aroma improvement is between about 0.1 ppm to about 2000 ppm, based on the total amount of the personal care composition. Preferably, neotame is present in an amount between about 1 ppm and about 1000 ppm. More preferably, neotame is present in an amount between about 10 ppm and about 100 ppm of neotame. These ranges are of a general nature and will tend to vary in accordance with the particular personal care formulation, as well as the desired taste or aroma improvement level.

The neotame, neotame/sweetener, neotame/flavor improvement agent, or neotame/flavoring ingredient blend may be incorporated into the personal care composition in a variety of ways. For example, neotame or the said neotame blend may be applied as a coating or glaze, or incorporated in the actual composition as part of the ingredient formulation and processed. The personal care products of this invention may be prepared using ingredients and techniques that are well known to those skilled in the art.

The examples which follow are intended only as an illustration of certain preferred embodiments of the invention and no limitation of the invention is implied. In each example, it is anticipated that the use of neotame in the specified composition yields a product with improved taste and aroma characteristics compared to the identical formulation prepared without neotame.

Example 1 Opaque Toothpaste with Neotame Table 1 provides a prophetic formulation for an opaque toothpaste that can be prepared according to the present invention. Sorbitol, neotame, and titanium dioxide are mixed together in a jacketed tank held at 66 °C (150 °F). The syloid 63 FP and xanthan gum are combined together and then added to mix tank. The syloid 244 FP and water are combined together and added in 5-6 small increments while mixing thoroughly after each addition. The sodium hydroxide is added and mixed followed by the addition of the sodium lauryl sulfate.

Flavoring and coloring are then added. The paste is then removed from the mix tank and packaged in cellophane tubes prior to sensory evaluation.

TABLE 1. Formulation of an opaque toothpaste with neotame.

Ingredient Formula Wt. % Water 41. 366 Sorbitol, 70% solution 38. 061 Syloid 244 FP silica (Davison of W. R. Grace & Co. Baltimore, MD) 10.875 Syloid 63 FP silica 4.350 Sodium lauryl sulfate 1.616 Keltrol xanthan gum (NutraSweet-Kelco) 1.087 Flavor T-1338 (IFF, NYC, NY) 1.087 Titanium dioxide (H. Kohnstamm, NYC, NY) 1.087 Sodium hydroxide, 50% solution 0. 435 Neotame 0.020 FD&C blue #1 color 0.016 TOTAL 100. 000

Example 2 Clear Gel Toothpaste with Neotame Table 2 provides a prophetic formulation for a clear gel toothpaste that can be prepared according to the present invention. The sorbitol, neotame, and syloid 244 FP silica are added to a jacketed mix tank held at 60-65°C (140-149°F). Syloid 63 FP silica is slowly added to the mix tank followed by addition of the water and the mix is then blended together. Sodium hydroxide is then added and mixed for around two minutes followed by addition of a pre-dry blend of xanthan gum and sodium citrate, after which the composition is mixed together for approximately 15 minutes. The sodium lauryl sulfate and flavor are then added, uniformly mixed, and the toothpaste composition packaged in cellophane tubes prior to sensory evaluation.

TABLE 2. Formulation of a clear gel toothpaste with neotame. Ingredient Formula Wt. % DI water 5. 133 Sorbitol, 70% solution 76. 500 Syloid 244 FP silica (Davison of W. R. Grace & Co. Baltimore, MD) l Syloid 63 FP silica (Davison) 4.130 Sodium lauryl sulfate 1. 520 Kelcogel F gellan gum (Nutrasweet-Kelco) 0.200 Flavor T-1338 (IFF, NYC, NY) 1.020 Kowet Titanium Dioxide (H. Kohnstamm, NYC, NY) 1.087 Sodium hydroxide, 50% solution 0. 210 Sodium citrate 0. 100 Neotame 0. 020 TOTAL 100.000

Example 3 Dental Impression Mix With Neotame Table 3 provides a prophetic formulation for a dental impression mix that can be prepared according to the present invention. Celite diatomaceous earth, calcium sulfate, sodium alginate, tetrasodium pyrophosphate, and neotame are dry blended together in a large mortar container and ground thoroughly. Water is then added and the mixture stirred with a spatula for around 1 minute to form the dental impression material having a creamy-paste like consistency. The material can be evaluated for sensory attributes by applying to the mouth.

TABLE 3. Formulation of a dental impression mix with neotame. Ingredient Formula Wt. % Celite diatomaceous earth, (FCC) JohnsManvile Minerals 73. 134 TERRA ALBA calcium sulfate, (F&P grade) FMC Corp Industrial Group 12. 189 Keltone sodium alginate (Nutrasweet-Kelco) i Tetrasodium pyrophosphate, anhydrous powder 2.438 Neotame 0. 050 TOTAL 100.000 Example 4 Mouthwash With Neotame Table 4 provides a prophetic formulation for a mouthwash that can be prepared according to the present invention. A 25% zinc chloride solution in water is prepared and then added to the hydrochloric acid. Separately, a 25% boric acid solution in water is prepared. In a separate container, oil of clove leaf, cinnamic aldehyde, and menthol are added to the alcohol.

The three solutions are then added and mixed together, followed by the addition of neotame and the remaining water. The solution is mixed thoroughly for around 5 minutes and then stored in screw-capped glass containers prior to sensory evaluation.

TABLE 4. Formulation of a mouthwash containing neotame. Ingredient Formula Wt. % Alcohol SD38 11. 15000 Boric Acid 1.00000 Menthol 0.07000 Zinc Chloride 0.10000 Hydrochloric Acid 0.00040 Cinnamic Aldehyde 0.14000 Oil of Clove Leaf 0.06000 Neotame 0. 00800 Water 87. 47160 TOTAL 100.00000

Example 5 Facial Mask With Neotame Table 5 provides a prophetic formulation for a facial mask that can be prepared according to the present invention. Magnesium carbonate, calcium sulfate, sodium alginate, tetrasodium pyrophosphate, and neotame are dry blended together. Water was then added while stirring with a spatula to form the facial mask having a creamy paste-like consistency. The final product can be applied immediately to the face and allowed to set for around four minutes, at which time it forms an elastic masque. After the desired length of time the mask can be removed with a washcloth and warm water. The aroma characteristics of the facial mask can be evaluated during the application process.

TABLE 5. Formulation of a facial mask containing neotame. Ingredient Formula Wt. % Magnesium carbonate 62. 853 TERRA ALBA calcium sulfate, F&P grade 15. 700 Keltone sodium alginate 15. 700 Tetrasodium pyrophosphate 5. 700. Neotame 0. 047 TOTAL 100.000