METHODS FOR COATING DENTAL DEVICES WITH DRY-TO-THE-TOUCH SALIVA SOLUBLE FLAVORS

Abstract

Methods for imparting a dry-to-the-touch, saliva soluble, coating containing high levels of flavors and active ingredients to disposable, one-handed, dental devices comprising imparting tumbling motion to said devices and simultaneously coating said tumbling devices with multiple coatings of the dry-to-the-touch-coatings, wherein said multiple coatings comprise from between about 0.25 and about 6% by weight of said multicoated devices.

Description

PREFERRED EMBODIMENTS OF THE INVENTION

Preferably, the surfactant is included with a film forming polydimethylsiloxane, i.e., MICRODENT® or ULTRAMULSION®. As used herein, the terms “MICRODENT®” and “ULTRAMULSION®” refer emulsions of polydimethylsiloxane at various molecular weights in various poloxamer surfactants as described and claimed in U.S. Pat. Nos. 4,911,927; 4,950,479; 5,032,387; 5,098,711; 5,165,913; 5,538,667; 5,645,841; 5,651,959 and 5,665,374. These mouth conditioners are preferably included in crystal-free contact coatings of various disposable one-handed dental devices of the invention.

In a particularly preferred embodiment of the invention, the dry-to-the-touch, saliva soluble flavor coatings of the invention also contain a film-forming agent. Preferably, at least one film-forming agent is utilized in the preparation of the coating mixture. Representative film-forming agents include hydroxypropyl cellulose, methyl cellulose (i.e., methyl ether of cellulose), ethyl cellulose, hydroxypropyl methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, gelatin, mixtures thereof, and the like. Preferably, a branched chained film-forming agent such as hydroxypropyl cellulose, is utilized. Preferably, the hydroxypropyl cellulose has a Brookfield viscosity of not less than 145 cps for a 10% aqueous solution at 25° C. The coating emulsion can contain more than one film-forming agent and as such, for example, hydroxypropyl cellulose and methyl cellulose may be utilized. In such a combination the branched chained film-forming agent (e.g., hydroxypropyl cellulose) can be used in amounts of about 0.05 to about 1.5 wt. % with about 0.01 to about 0.5 wt. % being preferred, and the straight chained film-forming agent (e.g., methyl cellulose) can be used in amounts of about 0.5 about 1.0 wt. % with about 0.1 to about 0.5 wt. % being preferred.

Another particularly preferred embodiment of the invention utilizes the unique flavor adsorbing and retention properties of various dry-film forming agents and various surfactants, as described above. The modified cellulose film forming agent and the surfactants function as attractants for flavor molecules, to such an extent that they will adsorb and hold a high percentage of flavor molecules even from volatile sources after the film formers and surfactants have been coated onto the devices of the invention. This property of adsorbing and holding flavor molecules provides much of the consumer satisfaction associated with the present invention, as adsorbed flavor molecules are released upon the coatings dissolving in the saliva, thereby releasing the flavorings accessible to olfactory organs in the oral cavity.

This can be accomplished by coating devices of the invention with formulation minus the desired flavors and drying the coated devices by one of the mechanical procedures described above, followed by a final step of introducing volatile flavoring agents from the flavor reservoir. The coated devices can then be packed off either in bulk or consumer packaging material which is a sufficient barrier to flavor molecules to allow the flavors to be volatilized inside the container. This is easily accomplished by placing the desired quantity of volatile flavor oils into a flavor reservoir such as on a piece of adsorbent paper, or into a polymer such as polyvinylacetate (Elvax as supplied by Dupont) which adsorbs/desorbs at a high rate, into the package. Equilibrium is quickly established so that the bulk of the flavor moves from the flavor reservoir into the dry-film forming agents and/or surfactants present in the coated devices.

In another embodiment, to reduce the loss of volatile flavor molecules during the high temperature/high velocity air contact of the coatings during drying with the dragee method, the dental devices are coated to the desired thickness with a dry-film forming composition minus the volatile flavoring agents. As a last step, an alcoholic solution of the flavor oils is sprayed or otherwise introduced onto the moving dental devices in the dragee kettle for distribution across the surfaces. In the same manner that an alcoholic solution of perfume oils can be applied to the skin and dry off leaving almost all the perfume oils adsorbed into the skin, the alcoholic carrier of the flavor oils volatilizes off at very low temperatures which essentially eliminates the loss of volatile flavor oils. The thin film of flavor oils so deposited on the previously laid down device coating is almost instantly adsorbed due to the adsorption properties of the dry-film forming agents and/or surfactants. Surprisingly, any dis-uniformity in flavor oil across the surface of the disposable, coated, one-handed dental device is quickly made uniform by the inexorable principles of equilibrium as the oils move from points of higher concentration in the coating to those of lower concentration until equilibrium is reached.

It is self-evident in the forgoing preferred embodiments that non-volatile flavor components, such as sweeteners, must be added to the initial un-flavored coats as they cannot be transferred easily by equilibrium techniques.

Other substances can be added to the dry-to-the-mouth, saliva soluble flavor coatings of the invention including:

• • (a) A flavoring agent may be present in the emulsion in an amount within the range of from about 0.1 to about 10.0 wt. %, and preferably from about 0.5 to about 3.0 wt. %, of the emulsion. The flavoring agents may comprise essential oils, synthetic flavors, or mixtures thereof including, but not limited to, oils derived from plants and fruits such as citrus oils, fruit essences, peppermint oil, spearmint oil, clove oil, oil of wintergreen, anise and the like. Artificial flavoring components are also contemplated for use in coating emulsions of the present invention. Those skilled in the art will recognize that natural and artificial flavoring agents may be combined in any sensorially acceptable blend. All such flavor sand flavor blends are contemplated by the present invention.
  • (b) The colorant used may include dyes, pigments, lakes and natural colors. The colorant may be blended with melted wax, preferably carnauba wax, which melts at 80°-90° C., then cooled and ground to a find particle size that will pass at least 99% through a #100 mesh sieve (less than 150 microns). Other waxes that may be used include beeswax, candelilla wax, spermaceti wax, and mixtures of the foregoing. Another method of blending is to powder blend the colorant with the wax. In either method, the preferred ratios are 1-30% colorant and 70.99% wax, and more preferably 5-15% colorant and 85-95% wax. It is preferable to use powdered colorants that have a particle size that will pass at least 99.9% through a #325 mesh sieve (small than 45 microns) so that the blended color/wax will still pass at least 99% through a #100 mesh sieve, having a particle size of 150 microns or less.
  • (c) Artificial sweeteners such as the soluble saccharin salts, i.e., sodium or calcium saccharin salts, cyclamate salts, acesulfam-K, and the like, and the free acid form of saccharin may optionally be added to the dry-to-the-touch, saliva soluble flavor coatings of the invention. Dipeptide sweeteners such as L-aspartyl-L-phenylalanine methyl ester and materials described in U.S. Pat. No. 3,492,131, and the like may also be used. These sweeteners may be used in amounts of about 0.005 wt. % to about 0.5 wt. % based on the weight of the total coating emulsion, and preferably about 0.05 wt. % to about 0.25 wt. %. Usually the first coating emulsion can contain about 0.02 wt. % to about 0.06 wt. % and most preferably 0.05 wt. % of artificial sweetener. A second emulsion can usually contain about 0.05 wt. % to about 0.2 wt. %, based on the weight of the coating emulsion, with about 0.08 wt. % to about 0.15 wt. % being preferred of artificial sweetener.
  • (d) Flavoring in the coating emulsion will be present in an amount within the range of from about 0.5 to about 5% and preferably from about 1.25 to about 4% by weight of the emulsion. Such flavoring may comprise oils derived from plants, leaves, flowers, fruit, etc. Representative flavor oils of this type include citrus oils such as lemon oil, orange oil, lime oil, grapefruit oil, fruit essences such as apple essence, pear essence, peach essence, strawberry essence, apricot essence, raspberry essence, cherry essence, plum essence, pineapple essence, as well as the following essential oils: peppermint oil, spearmint oil, mixtures of peppermint oil and spearmint oil, clove oil, bay oil, anise oil, eucalyptus oil, thyme oil, cedar leaf oil, cinnamon oil, oil of nutmeg, oil of sage, oil of bitter almonds, cassia oil, and methylsalicylate (oil of wintergreen). Various synthetic flavors, such as mixed fruit, may also be incorporated in the dry-to-the-touch, saliva soluble flavor coatings of the invention with or without conventional preservatives.

In a particularly preferred embodiment of the invention, the polyalcohol, xylitol in a mixture with mono-, di- and triglycerides of the fatty acids of: palmitic, stearic and oleic acids, is included in the dry-to-the-touch, saliva soluble flavor coatings of the invention. Xylitol can be represented by the structured formula:

Xylitol is commercially available both in solid form and in the form of aqueous concentrated solutions. However, contrary to the saccharose shell, that of xylitol deteriorates rapidly with time. In particular, already after a few hours a xylitol shell cracks and its outer surface initially smooth becomes wrinkled; at the same time even the intimate constitution of the shell, initially sufficiently microcrystalline, changes into a course, rough structure fastidious to the palate and in chewing. A xylitol/dry-to-the-touch, saliva soluble flavor coating offers the peculiar advantage of being refreshing to the mouth (owing to an appreciable negative heat of solution); however, this advantage does not compensate the aforesaid drawbacks.

Those mixtures of glycerides are preferred which exhibit a strong prevalence of a determined glyceride. Mono- and diglycerides suitable for the purposes of this invention may present a melting point ranging from about 40° to about 70° C., keeping in mind that the melting point can be lowered (owing to formation of eutectics) by addition of a triglyceride having a convenient melting point. The preferred fatty substance is cocoa butter which, as is known, melts around 35° C.

The invention will be further understood by those skilled in the art upon reviewing the Examples set forth below.

EXAMPLE 1

Fifteen grams of Klucel LF (hydroxypropylcellulose) is added slowly to 100 grams of water heated to 90 degrees centigrade. A solution of PEG 1450 (300 grams water with 10 grams PEG) was heated to 40 degrees centigrade. Spearmint flavor, 10 grams, was added with stirring along with 3 grams of sodium saccharin added to the PEG solution. The Klucel suspension was cooled to 50 degrees centigrade and the PEG solution added with stirring. The resulting solution is then sprayed in 5 aliquots with 4 minute intervals onto 1,000 plastic flossers contained in a rotating drum fitted with fins and a hot air tube delivering 40 degree air while tumbling at 21 RPM. The flossers were tumbled with hot air until the glistening effect of liquid coating was not evident after each aliquot. The coated flossers were very flavorful and had a coating of 14 mg per flosser.

EXAMPLE 2

An aqueous suspension of hydroxypropylcellulose (100 grams water with 15 grams HPC) is heated to 90 degrees centigrade. A second container is heated with 300 grams water and 12 grams poloxamer 407 with heating to 40 degrees centigrade. Ten grams of flavor, vanillamint, is then added to the surfactant solution along with 4 grams of sodium saccharin. The aqueous HPC solution is cooled to 50 degrees and the surfactant solution is then added with stirring. After cooling to 30 degrees centigrade the combined solutions are sprayed in 4 aliquots with 5 minute drying intervals onto 10,000 round wooden toothpicks on a vibrating screen. Warm air at 40 degrees centigrade is directed up through the screen while the vibrating toothpicks are dried. The toothpicks have a coating of 2.4 mg each and show no marks or lines due to uneven coating.

Claims

1. A method for coating disposable, one-handed dental devices with dry-to-the-touch, saliva soluble coatings containing high levels of flavors and active ingredients, comprising: a. introducing said devices into a moving coating drum that imparts tumbling motion to said dental devices,b. introducing, periodically into said drum, a dry-to-the-touch, saliva soluble, coating mixture containing high levels of flavors and active ingredients,c. coating said moving dental devices with coatings of said dry-to-the-touch, saliva soluble, coating mixtures,d. removing substantially all the moisture between coatings, ande. discharging said coated dental devices from said coating drum, at such time as said dry-to-the-touch coating comprises from between about 0.25 and about 6% by weight of said coated devices.

2. An apparatus useful for coating disposable, one-handed dental devices with multiple dry-to-the-touch saliva soluble coatings that includes: (a) a coating drum arrangement, which preferably rotates around an axis, keeping dental devices introduced into said drum in motion, (b) a means for periodically introducing a dry-to-the-touch, saliva soluble, coating mixture containing high levels of flavors and active ingredients into said drum at a controllable rate, and (c) controllable heat and air flow means for removing moisture from said dry-to-the-touch coated dental devices between coatings as they are tumbled in said coating drum.

3. A method for coating disposable, one-handed dental devices with dry-to-the-touch, saliva soluble, coating mixtures containing high levels of flavors and active ingredients comprising: introducing said devices into a coating vessel that imparts motion to said devices, periodically introducing said dry-to-the-touch, saliva soluble, coating mixtures containing high levels of flavors and active ingredients into said coating vessel, and removing moisture from said vessel between coating applications with the introduction of controllable heat and air flow.

4. A method according to claim 1, wherein said dry-to-the-touch, saliva soluble, coating mixtures containing high levels of flavors and active ingredients contains a surfactant selected from the group consisting of solid and liquid surfactants and mixtures thereof.

5. A method according to claim 1, wherein said emulsion contains a polydimethylsiloxane.

6. A method according to claim 1, wherein said dry-to-the-touch, saliva soluble, coating mixtures contains a film former.

7. Disposable, one-handed dental devices produced by adapting confectionery coating processes, including: a. introducing said devices into a moving coating drum that imparts tumbling motion to said dental devices,b. introducing, periodically into said drum, a dry-to-the-touch, saliva soluble, coating mixture containing high levels of flavors and active ingredients,c. coating said moving dental devices with said coating mixtures,d. removing substantially all the moisture between coatings, ande. discharging said dry-to-the-touch coated dental devices from said coating drum, as such time as said coating comprises from between about 0.25 and about 6% by weight of said coated devices.

8. In confectionery coating technology, the improvement comprising introducing disposable, one-handed dental devices into a rotating confectionery coating drum and periodically introducing dry-to-the-touch, saliva soluble, coating mixtures containing high levels of flavors and active ingredients to coat said devices with multiple coatings of dry-to-the-touch, saliva soluble, uniform coating mixtures containing high levels of flavors and active ingredients.