Title:  Process for controlling release of active agents from a chewing gum coating and product thereof

United States Patent:  6,586,023

Issued:  July 1, 2003

Inventors:  Song; Joo H. (Chicago, IL); Townsend; Donald J. (Moores Hill, IN); Record; David W. (River Forest, IL); Tyrpin; Henry T. (Palos Park, IL); Russell; Michael P. (Evergreen Park, IL); Schnell; Philip G. (Downers Grove, IL); Ream; Ronald L. (Plano, IL); Corriveau; Christine L. (Orland Park, IL)

Assignee:  Wm. Wrigley Jr. Company (Chicago, IL)

Appl. No.:  552290

Filed:  April 19, 2000

Abstract

A method for producing a coated chewing gum with a controlled release of an active agent, as well as the chewing gum so produced, is obtained by physically modifying an active agent's properties by coating and drying. An active agent is coated by encapsulation, partially coated by agglomeration, entrapped by absorption, or treated by multiple steps of encapsulation, agglomeration, and absorption. The coated active agent is then co-dried and particle sized to produce a release-modified active agent. When incorporated into a chewing gum coating, these particles release into the mouth but mask bitter and other off-tastes in the mouth, and are readily ingested.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Caffeine is a natural chemical found in a variety of food products such as coffee, tea, cocoa, chocolate, and various other beverages. Caffeine is known as an effective stimulant to increase energy and reduce drowsiness. Caffeine has a naturally bitter taste. The bitterness, however, actually improves the flavor perception of some beverages such as coffee and carbonated beverages.

When caffeine is added to stick chewing gum at a level of about 0.2% to about 5%, caffeine imparts an intense bitterness to the chewing gum that lasts throughout the chewing period. The higher the level used, the stronger the bitterness. At about 0.2%, which is about 5 mg per 2.7 gram stick, the bitterness is below the threshold limit and is not readily discernible. Taste limits in stick chewing gum are generally about 0.4% (10 mg) to about 4% (100 mg) of caffeine in a stick of gum. The 60-80 mg level of caffeine is about the level of caffeine found in a conventional cup of coffee. The target level of caffeine in stick gum is about 40 mg per stick, with a range of about 25-60 mg, so that a five stick package of gum would contain about 200 mg of caffeine, or the equivalent of caffeine in two strong cups of coffee. However, at this level caffeine bitterness overwhelms the flavor initially and lasts throughout the chewing period.

For coated pellet gum, piece weight is generally about 1.5 grams per piece. However, one coated piece of gum is about equal to 1/2 piece of stick gum. Two pellets are equivalent to a stick of gum, and together weigh about 3 grams. The above-noted target level of 40 mg per stick is equivalent to 20 mg per coated piece, or a range of about 12 to 30 mg caffeine per piece. This is about 0.8% to about 2% caffeine in a piece of coated gum, or a target level of 1.3%.

Caffeine is not a highly water soluble substance and, therefore, has a moderately slow release from stick chewing gum. Caffeine is 2.1% soluble in water at room temperature, 15% soluble in water at 80^oC. and 40% soluble in boiling water. This gives caffeine a moderately slow release as shown below:

Chewing Time          % Caffeine Release
                  0 min                     --
                  5 min                     56
                 10 min                     73
                 20 min                     88
                 40 min                     97
 

Generally, highly water soluble ingredients in stick gum are about 80-90% released after only five minutes of chewing. For caffeine, only about 50% is released, while the other 50% remains in the gum after five minutes of chewing. After 20 minutes almost 90% of caffeine is released.

Even if caffeine is dissolved in hot water and mixed in the stick gum, when the gum is cooled or kept at room temperature, caffeine may return to its normal crystalline state and release at the same rate as shown above.

When unmodified caffeine is added to a coating of a coated gum piece, the coating, which is very water soluble and is very easily dissolved in the mouth, will dissipate in the mouth very quickly. This will give a fast release of caffeine into the mouth, giving a very strong bitter taste. This bitter taste from the caffeine will remain in the mouth even after the caffeine has been ingested. However, when an encapsulated caffeine is employed in the gum coating, upon dissipation of the encapsulated caffeine in the mouth the encapsulating agent masks or shields the caffeine from the taste receptors of the mouth, thus reducing the bitterness experienced by the chewer. After being ingested into the digestive tract, the caffeine will be released from its encapsulating agent and will be absorbed and effective as a stimulant. Accordingly, the employment of encapsulated caffeine in a chewing gum coating allows for the delivery of caffeine to a user in a manner which does not result in the user experiencing significant bitterness, and at a minimum results in the user experiencing significantly less bitterness than would be experienced utilizing unencapsulated caffeine in the coating. Furthermore, the use of encapsulated caffeine in a gum coating allows for significantly higher levels of caffeine to be provided in a given piece of coated gum without the chewer experiencing the bitterness associated with the caffeine than would otherwise be achievable in the absence of caffeine encapsulation. This would allow for delivery of caffeine levels on the order of that found in a cup of coffee to be provided in only two, or possibly even only one, piece of coated gum, without the chewer experiencing the bitterness which would otherwise result in the absence of encapsulating the caffeine. Additionally, the encapsulating agent may be selected to provide a time delay of release of the caffeine, or two or more encapsulating agents may be utilized having different release rates to provide a selectively controlled time release of the caffeine subsequent to ingestion of the caffeine.

Caffeine salt compounds such as caffeine citrate, caffeine sodium benzoate, caffeine sodium salicylate, which may be more water soluble and less bitter than caffeine, may also be encapsulated or entrapped for use in a chewing gum coating in accordance with the present invention.

Other active agents or medicaments that may have a bitter or unpleasant off-taste may be included in the present invention. By the terms "active agent" the present invention refers to a compound that has a desired therapeutic or physiological effect once ingested and/or metabolized. The therapeutic effect may be one which decreases the growth of a xenobiotic or other gut flora or fauna, alters the activity of an enzyme, provides the physical relief from a malady (e.g., diminishes pain, acid reflux or other discomfort), has an effect on the brain chemistry of molecules that determine mood and behavior. Of course these are just examples of what is intended by therapeutic effect. Those of skill in the art will readily recognize that a particular agent has or is associated with a given therapeutic effect.

The active agent may be any agent that is traditionally used as a medicament and lends itself to being administered through the oral cavity. Such active agents may be vitamins, chemotherapeutics; antimycotics; oral contraceptives, nicotine or nicotine replacement agents, minerals, analgesics, antacids, muscle relaxants, antihistamines, decongestants, anesthetics, antitussives, diuretics, anti-inflammatories, antibiotics, antivirals, psychotherapeutic agents, anti-diabetic agents and cardiovascular agents, nutraceuticals and nutritional supplements.

Vitamins and co-enzymes that may be delivered using this invention include but are not limited to water or fat soluble vitamins such as thiamin, riboflavin, nicotinic acid, pyridoxine, pantothenic acid, biotin, flavin, choline, inositol and paraminobenzoic acid, carnitine, vitamin C, vitamin D and its analogs, vitamin A and the carotenoids, retinoic acid, vitamin E and vitamin K.

Examples of chemotherapeutics agents include but are not limited to cisplatin (CDDP), procarbazine, mechlorethamine, cyclophosphamide, camptothecin, ifosfamide, melphalan, chlorambucil, bisulfan, nitrosurea, dactinomycin, daunorubicin, doxorubicin, bleomycin, plicomycin, mitomycin, etoposide (VP16), tamoxifen, taxol, transplatinum, 5-fluorouracil, vincristin, vinblastin and methotrexate or any analog or derivative variant thereof.

Antimicrobial agents that may be used include but are not limited to naficillin, oxacillin, vancomycin, clindamycin, erythromycin, trimethoprim-sulphamethoxazole, rifampin, ciprofloxacin, broad spectrum penicillin, amoxicillin, gentamicin, ceftriazoxone, cefotaxime, chloramphenicol, clavunate, sulbactam, probenecid, doxycycline, spectinomycin, cefixime, penicillin G, minocycline, .beta.-lactamase inhibitors; meziocillin, piperacillin, aztreonam, norfloxacin, trimethoprim, ceftazidime, dapsone.

Antifungal agents that may be delivered include but are not limited to ketoconazole, fluconazole, nystatin, itraconazole, clomitrazole, and amphotericin B. Antiviral agents that may be used include but are not limited to acyclovir, trifluridine, idoxorudine, foscarnet, ganciclovir, zidovudine, dideoxycytosine, dideoxyinosine, stavudine, famciclovir, didanosine, zalcitabine, rifimantadine, and cytokines.

Antacids include cimetidine, ranitidine, nizatidine, famotidine, omeprazole, bismuth antacids, metronidazole antacids, tetracycline antacids, clarthromycin antacids, hydroxides of aluminum, magnesium, sodium bicarbonates, calcium bicarbonate and other carbonates, silicates, and phosphates.

Antihistamines are represented by but are not limited to cimetidine, ranitidine, diphenydramine, prylamine, promethazine, chlorpheniramine, chlorcyclizine, terfenadine, carbinoxamine maleate, clemastine fumarate, diphenhydramine hydrochloride, dimenhydrinate, prilamine maleate, tripelennamine hydrochloride, tripelennamine citrate, chlorpheniramine maleate, brompheniramine maleate, hydroxyzine pamoate, hydroxyzine hydrochloride, cyclizine lactate, cyclizine hydrochloride, meclizine hydrochloride, acrivastine, cetirizine hydrochloride, astemizole, levocabastine hydrochloride, and loratadine.

Decongestants and antitussives include agents such as dextromethorphan, levopropoxyphene napsylate, noscapine, carbetapentane, caramiphen, chlophedianol, pseudoephedrine hydrochloride, diphenhydramine, glaucine, pholcodine, and benzonatate.

Anesthetics include etomidate, ketamine, propofol, and benodiazapines (e.g., chlordiazepoxide, diazepam, clorezepate, halazepam, flurazepam, quazepam, estazolam, triazolam, alprozolm, midazolam, temazepam, oxazepam, lorazepam), benzocaine, dyclonine, bupivacaine, etidocaine, lidocaine, mepivacaine, promoxine, prilocaine, procaine, proparcaine, ropivacaine, tetracaine. Other useful agents may include amobartital, aprobarbital, butabarbital, butalbital mephobarbital, methohexital, pentobarbital, phenobarbital, secobarbital, thiopental, paral, chloral hydrate, ethchlorvynol, clutethimide, methprylon, ethinamate, and meprobamate.

Analgesics, include opioids such as morphine, mepidine, dentanyl, sufentranil, alfentanil, aspirin, acetaminophen, ibuprofen, indomethacine, naproxen, atrin, isocome, midrin, axotal, firinal, phrenilin, ergot and ergot derivatives (wigraine, cafergot, ergostat, ergomar, dihydroergotamine), imitrex.

Diuretics include but are not limited to acetazolamide, dichlorphenamide, methazolamide, furosemide, bumetanide, ethacrynic acid torseimde, azosemide, muzolimine, piretanide, tripamide, bendroflumethiazide, benzthiazide, chlorothiazide, hydrochlorothiazide, hydroflumethiazide, methyclothiazide, polythiazide, trichlormethiazide, indapamide, metolazone, quinethazone, amiloride, triamterene, sprionolactone, canrenone, and potassium canrenoate.

Anti-inflammatories include but are not limited to salicylic acid derivatives (e.g. aspirin) paraminophenol derivative (e.g. acetaminophen) indole and indene acetic acids (indomethacin, sulindac and etodalac) heteroaryl acetic acids (tolmetin diclofenac and ketorolac) aryl propionic acid derivatives (ibuprofen, naproxen, ketoprofen, fenopren, oxaprozine), anthranilic acids (mefenamic acid, meclofenamic acid) enolic acids (piroxicam, tenoxicam, phenylbutazone and oxyphenthatrazone).

Psychotherapeutic agents include thorazine, serentil, mellaril, millazine, tindal, permitil, prolixin, trilafon, stelazine, suprazine, taractan, navan, clozaril, haldol, halperon, loxitane, moban, orap, risperdal, alprazolam, chlordiaepoxide, clonezepam, clorezepate, diazepam, halazepam, lorazepam, oxazepam, prazepam, buspirone, elvavil, anafranil, adapin, sinequan, tofranil, surmontil, asendin, norpramin, pertofrane, ludiomil, pamelor, vivactil, prozac, luvox, paxil, zoloft, effexor, welibutrin, serzone, desyrel, nardil, parnate, eldepryl.

Cardiovascular agents include but are not limited to nitroglycerin, isosorbide dinitrate, sodium nitroprisside, captopril, enalapril, enalaprilat, quinapril, lisinopril, ramipril, losartan, amrinone, lirinone, vesnerinone, hydralazine, nicorandil, prozasin, doxazosin, bunazosin, tamulosin, yohimbine, propanolol, metoprolol, nadolol, atenolol, timolol, esmolol, pindolol, acebutolol, labetalol, phentolamine, carvedilol, bucindolol, verapamil, nifedipine, amlodipine and dobutamine.

It is envisioned that depending on the active agent or medicament, the resultant chewing gum can be used to treat inter alia: coughs, colds, motion sickness; allergies; fevers; pain; inflammation; sore throats; cold sores; migraines; sinus problems; diarrhea; diabetes, gastritis; depression; anxiety, hypertension; angina and other maladies and symptoms. Also these gums may be useful in ameliorating cravings in substance abuse withdrawal. Specific active agents or medicaments include by way of example and limitation: caffeine, aspirin, acetaminophen; ibuprofen; cimetidine, ranitidine, famotidine, dramamine, omeprazole, dyclonine, chlorpheniramine maleate, pseudoephedrine hydrochloride, dextromethorphan, benzocaine, naproxen, and nicotine.

Compositions that may be formulated into a suitable chewing gum formulation are described in, for examples, U.S. Pat. No. 5,858,423; U.S. Pat. No. 5,858,413; U.S. Pat. No. 5,858,412 and U.S. Pat. No. 5,858,383. Additionally, Goodman and Gilman's "The Pharmaceutical Basis of Therapeutics" (Eds. Hardman et al., Publ. McGraw Hill, N.Y.) provides comprehensive guidance of useful drugs and their mechanisms of action. Medicated chewing gums have been particularly effective in the delivery of agents such as nicotine as described in for example, U.S. Pat. No. 5,866,179; and U.S. Pat. No. 5,889,028. U.S. Pat. No. 5,846,557 describes general chewing gum compositions containing cough suppressing agents. These patents are incorporated herein by reference as providing a teaching of the incorporation of medicinal agents into oral chewable formulations. It should be understood that the present chewing gum formulation(s) are not limited to the agents listed herein above, indeed any medicinal or other active agent that lends itself to ingestion may be formulated into the chewing gum formulations of the present invention.

Nutraceuticals and nutritional supplements may also be added to chewing gums as active agents. Among these are herbs and botanicals that include, but are not limited to capsicum, chamomile, cat's claw, echinacea, garlic, ginger, ginko, various ginseng, green tea, golden seal, kava kava, nettle, passion flower, saw palmetto, St. John's wort, and valerian. Also included are mineral supplements such as calcium, copper, iodine, iron, magnesium, manganese, molybdenum, phosphorous, and selenium. Other nutraceuticals that also can be added to chewing gum as active agents are fructo-oligosaccharides, glucosamine, grapeseed extract, guarana, inulin, phytosterols, phytochemicals, isoflavones, lecithin, lycopene, oligofructose, polyphenol and psyllium as well as weight loss agents such as chromium picolinate and phenylpropanolamine.

Preferably, the active agents or medicaments are contained in the chewing gum formulation at levels of approximately 50 micrograms to 500 milligrams. The specific levels will depend on the active ingredient. For example, if chromium picolinate is the active ingredient in an embodiment, it would be present at a level of 50 micrograms per serving (3.0 grams/two pieces of gum); aspirin would be preset at a level up to 325 milligrams per 3.0 gram serving (two pieces). To obtain the higher levels, additional coatings in the gum will be needed. This will increase piece size for a two piece serving size.

If the agent is a stimulant, such as caffeine, to be used to enhance performance then the chewing gum would be chewed, in a preferred embodiment ten minutes or less before the performance. It has been surprisingly found that with an extra five minutes of chewing a caffeine-containing chewing gum a high level of alertness is achieved.

The medicament or active agent can be contained in a variety of different chewing gum compositions. Referring now to the chewing gum, pursuant to the present invention, the chewing gum including the medicament or active agent may be based on a variety of different chewing gums that are known. For example, the chewing gums can be low or high moisture, sugar or sugarless, wax containing or wax free, low calorie (via high base or low calorie bulking agents), and/or may contain dental agents.

Pursuant to the present invention, depending on the active agent or medicament, the dosing regiment will change. For example, it the medicament is an analgesic, the chewing gum would be taken on an as needed basis. Of course, similar to the oral administration of an analgesic, there would be restrictions on the number of pieces of chewing gum chewed, for example, not more often than two pieces every four hours and not more often than four to five times a day.

Physical modifications of the active agent such as caffeine by encapsulation with a highly water soluble substrate will increase its release in stick chewing gum as well as from the gum coating by increasing the solubility or dissolution rate of caffeine. However, preferably the active agent such as caffeine may also be encapsulated or entrapped to give a delayed release from stick chewing gum and from a gum coating. Any standard technique which gives partial or full encapsulation of the active agent can be used. These techniques include, but are not limited to, spray drying, spray chilling, fluid-bed coating and coacervation. These encapsulation techniques may be used individually in a single step process or in any combination in a multiple step process.

Active agents such as caffeine may be encapsulated with sweeteners, more specifically high-intensity sweeteners such as thaumatin, dihydrochalcones, acesulfame K, aspartame, sucralose, alitame, saccharin and cyclamates. These can also have the effect of reducing unpleasant tastes such as bitterness. Additional bitterness inhibitors or taste maskers can also be combined with active agents and sweeteners to give a reduced unpleasant taste such as bitterness with delayed release active agent(s).

The encapsulation techniques described herein are standard coating techniques and generally give varying degrees of coating from partial to full coating, depending on the coating composition used in the process.

Generally, compositions that have high organic solubility, good film-forming properties and low water solubility give better delayed release of active agents such as caffeine, while compositions that have high water solubility give better fast release. Such low water-solubility compositions include acrylic polymers and copolymers, carboxyvinyl polymer, polyamides, polystyrene, polyvinyl acetate, polyvinyl acetate phthalate, polyvinylpyrrolidone and waxes. Although all of these materials are possible for encapsulation of active agents such as caffeine, only food-grade materials should be considered. Two standard food-grade coating materials that are good film formers but not water soluble are shellac and Zein. Others which are more water soluble, but good film formers, are materials like agar, alginates, a wide range of cellulose derivatives like ethyl cellulose, methyl cellulose, sodium hydroxymethyl cellulose, and hydroxypropylmethyl cellulose, dextrin, gelatin, and modified starches. These ingredients, which are generally approved for food use, may give a fast release when used as an encapsulant. Other encapsulants like acacia or maltodextrin can also encapsulate active agent(s) and give a fast release rate in gum.

The amount of coating or encapsulating material on the active agent also may control the length of time for its release from chewing gum. Generally, the higher the level of coating and the lower the amount of active agent, the slower the release during mastication with low water soluble compositions. The release rate is generally not instantaneous, but gradual over an extended period of time for stick gum. When used in a coating, delayed release allows the active agent to be masked in the mouth before being ingested, thus reducing bitterness or other unpleasant tastes. To obtain the delayed release, the encapsulant should be a minimum of about 20% of the coated active. Preferably, the encapsulant should be a minimum of about 30% of the coated active, and most preferably should be a minimum of about 40% of the coated active.

Another method of giving a modified release of active agents such as caffeine and the other agents described herein is agglomeration with an agglomerating agent which partially coats the active agents. This method includes the step of mixing active agents and an agglomerating agent with a small amount of water or solvent. The mixture is prepared in such a way as to have individual wet particles in contact with each other so that a partial coating can be applied. After the water or other solvent is removed, the mixture is ground and used as a powdered active agent.

Materials that can be used as the agglomerating agent are the same as those used in encapsulation mentioned previously. Some of the better agglomerating agents for delayed release are the organic polymers like acrylic polymers and copolymers, polyvinyl acetate, polyvinylpyrrolidone, waxes, shellac and Zein. Other agglomerating agents are not as effective in giving a delayed release as are the polymers, waxes, shellac and Zein, but can be used to give some delayed release. Other agglomerating agents include, but are not limited to, agar, alginates, a wide range of water soluble cellulose derivatives like ethyl cellulose, methyl cellulose, sodium hydroxymethyl cellulose, hydroxypropylmethyl cellulose, dextrin, gelatin, modified starches, and vegetable gums like guar gum, locust bean gum and carrageenan. Even though the agglomerated active agent such as caffeine is only partially coated, when the quantity of coating is increased compared to the quantity of the active agent, the release can also be modified. The level of coating used in the agglomerated product is a minimum of about 5%. Preferably, the coating level is a minimum of about 15% and more preferably about 20%. Depending on the agglomerating agent, a higher or lower amount of agent may be needed to give the desired release of the active agent.

Caffeine or other active agents may be coated in a two-step process or a multiple step process. Caffeine or other active agents may be encapsulated with any of the materials as described previously and then the encapsulated caffeine or other active agents can be agglomerated as previously described to obtain an encapsulated/agglomerated/caffeine or other active agent product that could be used in chewing gum to give a delayed release of the caffeine or other active agent.

In another embodiment of this invention, caffeine or other active agent may be absorbed onto another component which is porous and become entrapped in the matrix of the porous component. Common materials used for absorbing caffeine or other active agent include, but are not limited to, silicas, silicates, pharmasorb clay, sponge-like beads or microbeads, amorphous carbonates and hydroxides, including aluminum and calcium lakes, all of which result in a delayed release of caffeine or other active agent.

Depending on the type of absorbent materials and how it is prepared, the amount of caffeine or other active agent that can be loaded onto the absorbent will vary. Generally materials like polymers or sponge-like beads or microbeads, amorphous sugars and alditols and amorphous carbonates and hydroxides absorb about 10% to about 40% of the weight of the absorbent. Other materials like silicas and pharmasorb clays may be able to absorb about 20% to about 80% of the weight of the absorbent.

The general procedure for absorbing caffeine or other active agent onto the absorbent is as follows. An absorbent like fumed silica powder can be mixed in a powder blender and a solution of caffeine or other active agent can be sprayed onto the powder as mixing continues. The aqueous solution can be about 1 to 2% solids, and higher solid levels to 15-30% may be used if temperatures up to 90^oC. are used. Generally water is the solvent, but other solvents like alcohol could also be used if approved. As the powder mixes, the liquid is sprayed onto the powder. Spraying is stopped before the mix becomes damp. The still free-flowing powder is removed from the mixer and dried to remove the water or other solvent, and is then ground to a specific particle size.

After the caffeine or other active agent is absorbed or fixed onto an absorbent, the fixative/active agent can be coated by encapsulation. Either full or partial encapsulation may be used, depending on the coating composition used in the process. Full encapsulation may be obtained by coating with a polymer as in spray drying, spray chilling, fluid-bed coating, coacervation, or any other standard technique. A partial encapsulation or coating can be obtained by agglomeration of the fixative/active agent mixture using any of the materials discussed above.

Another form of encapsulation is by entrapment of an ingredient by fiber extrusion or fiber spinning into a polymer. Polymers that can be used for extrusion are PVAC, hydroxypropyl cellulose, polyethylene and other types of plastic polymers. A process of encapsulation by fiber extrusion is disclosed in U.S. Pat. No. 4,978,537, which is hereby incorporated by reference. The water insoluble polymer may be preblended with caffeine or other active agents prior to fiber extrusion, or may be added after the polymer is melted. As the extrudate is extruded, it results in small fibers that are cooled and ground. This type of encapsulation/entrapment generally gives a very long, delayed release of an active ingredient.

The four primary methods to obtain a treated caffeine or other active agent are: (1) encapsulation by spray drying, fluid-bed coating, spray chilling and coacervation to give full or partial encapsulation, (2) agglomeration to give partial encapsulation, (3) fixation or absorption which also gives partial encapsulation, and (4) entrapment into an extruded compound. These four methods, combined in any usable manner which physically modifies caffeine or other active agents dissolvability or modifies the release of caffeine or other active agents, are included in this invention.

After the active agent is treated it is used in the coating/panning of a pellet chewing gum. Pellet or ball gum is prepared as conventional chewing gum, but formed into pellets that are pillow shaped or into balls. The pellets/balls can then be sugar coated or panned by conventional panning techniques to make a unique sugar coated pellet gum. Treated active agent(s) can be easily dispersed in a sugar solution prepared for sugar panning. Preferably, treated active agent(s) can be added as a powder blended with other powders often used in some types of conventional panning procedures often called dry charging. The weight of the coating may be about 20% to about 50% of the weight of the finished gum product, but higher levels of coating may be used when high doses of active agents are needed.

Conventional panning procedures generally coat with sucrose, but recent advances in panning have allowed the use of other carbohydrate materials to be used in the place of sucrose. Some of these components include, but are not limited to, dextrose, maltose, palatinose, xylitol, lactitol, maltitol, hydrogenated isomaltulose and other new alditols or a combination thereof. These materials may be blended with panning modifiers including, but not limited to, gum arabic, gum talha, maltodextrins, corn syrup, gelatin, cellulose type materials like carboxymethyl cellulose or hydroxymethyl cellulose, starch and modified starches, vegetable gums like alginates, locust bean gum, guar gum, and gum tragacanth, insoluble carbonates like calcium carbonate or magnesium carbonate and talc. Antitack agents may also be added as panning modifiers which allow for the use of a variety of carbohydrates and sugar alcohols in the development of new panned or coated gum products. Flavors, sweeteners and cooling agents may also be added with the coating and with treated active agents to yield unique product characteristics.

The previously described encapsulated, agglomerated or absorbed active agent may readily be coated onto a chewing gum composition. The remainder of the chewing gum ingredients are non-critical to the present invention. That is, the treated particles of active agent can be coated onto conventional chewing gum formulations in a conventional manner. Treated active agent may be coated onto a sugar chewing gum or a sugarless chewing gum.

In general, a chewing gum composition typically comprises a water-soluble bulk portion, a water-insoluble chewable gum base portion and typically water-insoluble flavoring agents. The water-soluble portion dissipates with a portion of the flavoring agent over a period of time during chewing. The gum base portion is retained in the mouth throughout the chew.

The insoluble gum base generally comprises elastomers, resins, fats and oils, waxes, softeners and inorganic fillers. Elastomers may include polyisobutylene, isobutylene-isoprene copolymer and styrene butadiene rubber, as well as natural latexes such as chicle. Resins include polyvinylacetate and terpene resins. Fats and oils may also be included in the gum base, including tallow, hydrogenated and partially hydrogenated vegetable oils, and cocoa butter. Commonly employed waxes include paraffin, microcrystalline and natural waxes such as beeswax and carnauba. According to the preferred embodiment of the present invention, the insoluble gum base constitutes between about 5% and about 95% by weight of the gum. More preferably the insoluble gum base comprises between about 10% and about 50% by weight of the gum, and most preferably between about 20% and about 45% by weight of the gum. When high levels of gum coatings are needed, gum base may comprise up to 95% of the gum center formula.

The gum base typically also includes a filler component. The filler component may be calcium carbonate, magnesium carbonate, talc, dicalcium phosphate or the like. The filler may constitute between about 5% and about 60% by weight of the gum base. Preferably, the filler comprises about 5% to about 50% by weight of the gum base.

Gum bases typically also contain softeners, including glycerol monostearate and glycerol triacetate. Further, gum bases may also contain optional ingredients such as antioxidants, colors, and emulsifiers. The present invention contemplates employing any commercially acceptable gum base.

The water-soluble portion of the chewing gum may further comprise softeners, sweeteners, flavoring agents and combinations thereof. Softeners are added to the chewing gum in order to optimize the chewability and mouth feel of the gum. Softeners, also known in the art as plasticizers or plasticizing agents, generally constitute between about 0.5% and about 15% by weight of the chewing gum. Softeners contemplated by the present invention include glycerin, lecithin and combinations thereof. Further, aqueous sweetener solutions such as those containing sorbitol, hydrogenated starch hydrolyzates, corn syrup and combinations thereof may be used as softeners and binding agents in gum.

As mentioned above, the treated active agent of the present invention may be used in sugar or sugarless gum formulations. Sugar sweeteners generally include saccharide-containing components commonly known in the chewing gum art which comprise, but are not limited to, sucrose, dextrose, maltose, dextrin, dried invert sugar, fructose, levulose, galactose, corn syrup solids and the like, alone or in any combination. Sugarless sweeteners include components with sweetening characteristics but which are devoid of the commonly known sugars and comprise, but are not limited to, sugar alcohols such as sorbitol, mannitol, xylitol, hydrogenated starch hydrolyzates, maltitol and the like, alone or in any combination.

Depending on the particular active agent release profile, the treated active agent of the present invention can also be used in combination with uncoated high-potency sweeteners or with high-potency sweeteners coated with other materials and by other techniques. Also, untreated active agents could be added to the coating.

A flavoring agent may also be present in the chewing gum in an amount within the range of from about 0.1% to about 10%, preferably from about 0.5% to about 5%, by weight of the gum. 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 gums of the present invention. Those skilled in the art will recognize that natural and artificial flavoring agents may be combined in any sensorally acceptable blend. All such flavors and flavor blends are contemplated by the present invention.

Optional ingredients such as colors, emulsifiers and other pharmaceutical agents may be added to the chewing gum.

In general, chewing gum is manufactured by sequentially adding the various chewing gum ingredients to a commercially available mixer known in the art. After the ingredients have been thoroughly mixed, the gum mass is discharged from the mixer and shaped into the desired form such as extruding into chunks or casting into pellets, which are then coated or panned.

Generally, the ingredients are mixed by first melting the gum base and adding it to the running mixer. The base may also be melted in the mixer itself. Color or emulsifiers may also be added at this time. A softener such as glycerin may also be added at this time, along with syrup and a portion of the bulking agent. Other optional ingredients are added to the batch in a typical fashion, well known to those of ordinary skill in the art.

The entire mixing procedure typically takes from five to fifteen minutes, but longer mixing times may sometimes be required. Those skilled in the art will recognize that many variations of the above described procedure may be followed.

As noted above, the coating may contain ingredients such as flavoring agents, as well as artificial sweeteners and dispersing agents, coloring agents, film formers and binding agents. Flavoring agents contemplated by the present invention include those commonly known in the art such as 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, other mint oils, clove oil, oil of wintergreen, anise and the like. The flavoring agents may be used in an amount such that the coating will contain from about 0.2% to about 3% flavoring agent, and preferably from about 0.7% to about 2.0% flavoring agent.

Artificial sweeteners contemplated for use in the coating include but are not limited to synthetic substances, saccharin, thaumatin, alitame, saccharin salts, aspartame, sucralose and acesulfame-K. The artificial sweetener may be added to the coating syrup in an amount such that the coating will contain from about 0.05% to about 0.5%, and preferably from about 0.10% to about 0.3% artificial sweetener.

Dispersing agents are often added to syrup coatings for the purpose of whitening and tack reduction. Dispersing agents contemplated by the present invention to be employed in the coating syrup include titanium dioxide, talc, or any other antistick compound. Titanium dioxide is a presently preferred dispersing agent of the present invention. The dispersing agent may be added to the coating syrup in amounts such that the coating will contain from about 0.1% to about 1.0%, and preferably from about 0.3% to about 0.6% of the agent.

Coloring agents are preferably added directly to the syrup in the dye or lake form. Coloring agents contemplated by the present invention include food quality dyes. Film formers preferably added to the syrup include methyl cellulose, gelatins, hydroxypropyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and the like and combinations thereof. Binding agents may be added either as an initial coating on the chewing gum center or may be added directly into the syrup. Binding agents contemplated by the present invention include gum arabic, gum talha (another type of acacia), alginate, cellulosics, vegetable gums and the like.

The coating is initially present as a liquid syrup which contains from about 30% to about 80% or 85% of the coating ingredients previously described herein, and from about 15% or 20% to about 70% of a solvent such as water. In general, the coating process is carried out in a rotating pan. Sugar or sugarless gum center tablets to be coated are placed into the rotating pan to form a moving mass.

The material or syrup which will eventually form the coating is applied or distributed over the gum center tablets. Flavoring agents may be added before, during and after applying the syrup to the gum centers. Once the coating has dried to form a hard surface, additional syrup additions can be made to produce a plurality of coatings or multiple layers of hard coating.

In a hard coating panning procedure, syrup is added to the gum center tablets at a temperature range of from about 100^oF. to about 240^oF. Preferably, the syrup temperature is from about 130^oF. to about 200^oF. throughout the process in order to prevent the polyol or sugar in the syrup from crystallizing. The syrup may be mixed with, sprayed upon, poured over, or added to the gum center tablets in any way known to those skilled in the art.

In general, a plurality of layers is obtained by applying single coats, allowing the layers to dry, and then repeating the process. The amount of solids added by each coating step depends chiefly on the concentration of the coating syrup. Any number of coats may be applied to the gum center tablet. Preferably, no more than about 75 coats are applied to the gum center tablets. More preferably, less than about 60 coats are applied and most preferably, about 30 to about 60 coats are applied. In any event, the present invention contemplates applying an amount of syrup sufficient to yield a coated comestible containing about 10% to about 65% coating. Preferably, the final product will contain from about 20% to about 50% coating. Where higher dosage of an active agent is needed, the final product may be higher than 50% coating.

Those skilled in the art will recognize that in order to obtain a plurality of coated layers, a plurality of premeasured aliquots of coating syrup may be applied to the gum center tablets. It is contemplated, however, that the volume of aliquots of syrup applied to the gum center tablets may vary throughout the coating procedure.

Once a coating of syrup is applied to the gum center tablets, the present invention contemplates drying the wet syrup in an inert medium. A preferred drying medium comprises air. Preferably, forced drying air contacts the wet syrup coating in a temperature range of from about 70^o to about 115^oF. More preferably, the drying air is in the temperature range of from about 80^o to about 100^oF. The invention also contemplates that the drying air possess a relative humidity of less than about 15 percent. Preferably, the relative humidity of the drying air is less than about 8 percent.

The drying air may be passed over and admixed with the syrup coated gum centers in any way commonly known in the art. Preferably, the drying air is blown over and around or through the bed of the syrup coated gum centers at a flow rate, for large scale operations, of about 2800 cubic feet per minute. If lower quantities of material are being processed, or if smaller equipment is used, lower flow rates would be used.

For many years, flavors have been added to a sugar coating of pellet gum to enhance the overall flavor of gum. These flavors include spearmint flavor, peppermint flavor, wintergreen flavor, and fruit flavors. These flavors are generally preblended with the coating syrup just prior to applying it to the core or added together to the core in one or more coating applications in a revolving pan containing the cores. Generally, the coating syrup is very hot, about 150^o to 200^oF., and the flavor may volatilize if preblended with the coating syrup too early.

The concentrated coating syrup is applied to the gum cores as a hot liquid, the sugar or polyol allowed to crystallize, and the coating then dried with warm, dry air. This is repeated in about 30 to 80 applications to obtain a hard shell coated product having an increased weight gain of about 50%. A flavor is applied with one, two, three or even four or more of these coating applications. Each time flavor is added, several non-flavored coatings are applied to cover the flavor before the next flavor coat is applied. This reduces volatilization of the flavor during the coating process.

For mint flavors such spearmint, peppermint and wintergreen, some of the flavor components are volatilized, but sufficient flavor remains to give a product having a strong, high impact flavor. Fruit flavors, that may contain esters, are more easily volatilized and may be flammable and/or explosive and therefore, generally these type of fruit flavors are not used in coatings.

In a preferred embodiment of this invention, a treated active agent such as caffeine is preblended with a gum arabic solution to become a paste and then applied to the cores. To reduce stickiness, the preblend may be mixed with a small amount of coating syrup before being applied. Forced air drying is then continued as the gum arabic binds the treated active agent to the cores. Then additional coatings are applied to cover the treated active agent and imbed the treated active agent in the coatings.

Claim 1 of 34 Claims

We claim:

1. A method of producing a coated chewing gum product containing a physically-modified active agent in order to modify the release of the active agent in the mouth of an individual comprising the steps of:

a) mixing a quantity of the active agent, which comprises a compound that has a desired therapeutic or physiological effect, with a modifying agent to produce a physically-modified active agent; and then

b) applying the physically-modified active agent and other coating ingredients to a chewing gum core to form the coated chewing gum product wherein the coating includes a quantity of the physically-modified active agent to provide an active agent level in the coated chewing gum product of from about 50 micrograms to about 500 milligrams.

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