Field of the invention

The present invention relates to a novel chewing gum composition comprising one or more antiseptic agents, to methods of their preparation and to methods of treatment of oral bacterial and fungal infections.

More particularly, the invention relates to chewing gum compositions comprising 2,4- dichlorobenzyl alcohol and/or amyl-m-cresol.

Background of the invention

2,4-Dichlorobenzyl alcohol (DCBA) is active against a wide range of bacteria and fungi and is one of two active ingredients sold commercially in the UK, usually in the form of a lozenge under the brand Strepsils® for the treatment of mild bacterial or fungal infections of the throat and/or oral cavity.

The other major active ingredient in Strepsils® is amyl-m-cresol (AMC).

UK Patent application number 865672 describes various compositions of DCBA in the form of mouth washes, toothpastes, pastilles, lozenges and boiled sweets for medication of the throat, ointments, jellies and lotions and powders for the treatment of the skin. UK '672 also describes that other substances which possess bacteriostatic and/or fungistatic properties may be included in the compositions, such as, hexachlorophene and amyl-m-cresol. UK Patent Application No. GB 2453770 discloses an oral composition in the form of lozenges comprising a cooling agent, e.g. xylitol, sorbitol, mannitol or erythritol, and one or more active agents. International Patent Application No. WO 2005/067906 discloses acidulated compositions for the treatment of infections caused by severe acute respiratory syndrome (SARS). SARS is a respiratory disease in humans which is caused by the SARS coronavirus (SARS-CoV). However, chewing gums are increasingly popular, particularly with younger people. So much so, that in 2006 the world wide chewing gum industry had an estimated value of US $1 billion in sales or 1.3 million metric tonnes of gum. Furthermore, the industry is estimated to have grown by more than 7% in the last three years. In addition, in some countries, such as Japan and the USA, chewing gum is preferred over conventional confectionary, such as lozenges.

Therefore, there is a need for an antiseptic chewing gum composition for the treatment or alleviation of mild bacterial or fungal infections of the throat, oral cavity and/or nasal cavity which would be attractive to the aforementioned groups and thereby, inter alia, improve patient compliance.

Summary of the invention

Thus, according to a first aspect of the present invention we provide a chewing gum composition comprising a therapeutically effective amount of 2,4-dichlorobenzyl alcohol (DCBA). According to a second aspect of the invention we provide a chewing gum composition comprising a therapeutically effective amount of amyl-m-cresol (AMC). According to a further aspect of the invention we provide a chewing gum composition comprising a therapeutically effective amount of 2,4-dichlorobenzyl alcohol (DCBA) and amyl-m-cresol (AMC).

Desirably the chewing gum composition may include a therapeutically effective amount of other antiseptic, antibacterial and analgesic therapeutic agents. Such agents include but shall not be limited to, analgesics, such as flurbiprofen and oxycodone; antiseptics, such as, hexylresorcinol; cetylpyridinium chloride, dequalinium chloride and combined therapies, such as oxyprofen; local anaesthetics, such as, lidocaine, benzocaine and menthol; mucolytic agents, such as, ambroxol hydrochloride; antitussive agents, such as, dextromethorphan hydrobromide; expectorants, such as, guaifenesin; and combinations thereof.

The therapeutically effective amount of the active agent, e.g. DCBA, AMC, etc, will vary depending upon, inter alia, the nature of the active agent(s) present in the composition, the severity of the infection to be treated, etc.

Thus, for example, the amount of DCBA present may be, for example, from 0.5 to 2.0mg per gum piece, or from 0.8 to 1.8mg, or from lmg to 1.5mg, e.g. 1.2 mg. Thus, for example, the amount of AMC present may be, for example, from 0.1 to lmg per gum piece, or from 0.3 to 0.8mg, or from 0.5mg to 0.7mg, e.g. 0.6mg.

When both DCBA and MCA are present in the composition then the DCBA to AMC ratio will be about from 4:1 to 1.1 or from 3:1 to 1:1, e.g. 2:1.

The chewing gum composition will generally include gum base. The composition of gum base may vary, but as will be understood by the person skilled in the art it will generally comprise one or more ingredients capable of providing the viscoelastic properties essential to the "chewability" of the gum. Such gum bases may be selected from the group consisting of; elastomers for providing elasticity, which may comprise a natural latex, such as, couma macrocarpa, loquat, tunu, jelutong, balata, namaquland rubber, almeidana gum, abba rubber and gutta-percha; vegetable gums, such as chicle, spruce gum and mastic gum; synthetic rubbers, such as, copolymers of butadiene and styrene, butyl rubber; synthetic elastomers such as polyisobutylene and polyisoprene, etc.; resins for providing a cohesive body, such as glycerol esters of gums, terpene resins, resins such as cumarone resins, copal gum, kauri gum, dammar gum, sweet bay gum, spruce gum, and balsams, and polyvinyl acetate; waxes as softening agents, such as paraffin wax, beeswax or microcrystalline wax; fats as plasticisers, such as hydrogenated or partially hydrogenated vegetable oils such as soy bean oil, cottonseed oil, corn oil, peanut oil, and palm; animal fats such as tallow and lard; emulsifiers, such as lecithin or glycerol monostearate; fillers, to provide texture, such as, calcium carbonate or talc; and antioxidants to increase shelf-life, such as butylated hydroxytoluene. Other materials which can be used include cocoa butter, paraffin, beeswax, carnauba, petroleum wax, polyethylenes, and polyvinyl polymers. The amount of the gum base present will vary depending upon the chewing gum, the type of sweeteners present, the active ingredient, etc. The gum base should be present in quantities sufficient to make a balanced formula which produces a gum which has sufficient flavour but is also processable to allow for processibility, e.g. into desired shapes, etc. Generally the gum base will be present in amounts ranging from about 8 to about 25% w/w of the chewing gum or from about 12 to about 20% w/w for chewing gum produced in the shape of cubes, pillows, blocks, etc. For chewing gums in the form sticks of gum, gum base may be from about 18 to about 24% w/w.

The formulation may contain additional excipients as required. Typical excipients include, but are not limited to, acidity regulators, opacifiers, colouring agents, stabilising agents, buffering agents, sweeteners, flavourings, preservatives and the like.

Some antiseptic agents, such as DCBA, may have an undesirable taste and therefore a taste masking agent may be included in the chewing gum composition of the invention. Such taste masking may include, but shall not be limited to, compounds such as menthol or peppermint oil. Alternatively or in addition, the chewing gum composition may comprise a sweetener. Optionally the sweetener may be present as a taste masking agent. Such sweeteners may include, but shall not be limited to, sweeteners, such as, aspartame, polyol sweeteners, such as, (crystalline) xylitol, sorbitol (which is also an excellent humectant and texturising agent), mannitol and erythritol. Examples of some commonly available sweeteners include, but shall not be limited to, sucrose, lactose, dextrose, maltose, dextrin, dried inverted sugar, fructose, levulose, galactose, corn syrup and their solids, hydrogenated starch hydrolysates, maltitol, sucralose, aspartame, salts of acesulfame potassium, alitame, saccharin and its salts, cyclamic acid and its salts, glycyrrhizin, dihydrochalcones, thaumatin, monellin, and the like, and optionally mixtures thereof.

The amount of sweetener present in the chewing gum composition may vary depending upon, inter alia, the nature of the sweetener, but generally it will be present in an amount in the range of about from 1 to 5% w/w or about from 1 to 3% w/w. The chewing gum composition of the invention may also include one or more flavouring agents. Such flavouring agents may comprise essential oils, synthetic flavours, or mixtures thereof including, but not limited to, oils derived from plants and fruits such as citrus oils, including lemon, orange, lime, grapefruit, fruit essences, including apple, pear, peach, grape, strawberry, raspberry, cherry, plum, pineapple, apricot, banana, blueberry, tutti frutti, etc; mint, peppermint oil, spearmint oil, clove oil, oil of wintergreen, anise, sassafras, sage, eucalyptus, marjoram, cinnamon, methyl salicylate, and the like. The person skilled in the art will recognise that natural and artificial flavouring agents may be used independently or combined in an acceptable blend. Other flavouring agents which may be mentioned include natural and artificial flavouring agents, such flavouring agents may be synthetic flavour oils, flavouring aromatics and/or oils, oleoresins and extracts derived from plants, leaves, flowers, fruits, etc. and combinations thereof. Non-limiting representative flavour oils include bay oil, anise oil, thyme oil, cedar leaf oil, oil of nutmeg, allspice, oil of sage, mace, oil of bitter almonds, cassia oil, and vanilla, and mixtures thereof. Other flavouring agents include, but are not limited to, acetaldehyde (apple), benzaldehyde (cherry, almond), anisic aldehyde (liquorice, anise), cinnamic aldehyde (cinnamon), citral, i.e., alpha-citral (lemon, lime), neral, i.e., beta-citral (lemon, lime), decanal (orange, lemon), ethyl vanillin (vanilla, cream), heliotrope, i.e., piperonal (vanilla, cream), vanillin (vanilla, cream), alpha-amyl cinnamaldehyde (spicy fruity flavours), butyraldehyde (butter, cheese), valeraldehyde (butter, cheese), citronellal (modifies, many types), decanal (citrus fruits), aldehyde C-8 (citrus fruits), aldehyde C-9 (citrus fruits), aldehyde C-12 (citrus fruits), 2-ethyl butyraldehyde (berry fruits), hexenal, i.e., trans-2 (berry fruits), tolyl aldehyde (cherry, almond), veratraldehyde (vanilla), 2,6-dimethyl-5-heptenal, i.e., melonal (melon), 2,6-dimethyloctanal (green fruit), and 2-dodecenal (citrus, mandarin), cherry, grape, strawberry shortcake, and mixtures thereof. The flavouring agent may be employed in either liquid form or dried form. The amount of flavouring agent employed herein may vary, depending upon, inter alia, the nature of the therapeutically active agent(s), and the flavouring agent(s), the gum base employed, etc. Thus, the flavouring agent may generally be present in an amount from about 0.02% to about 5% w/w, or from about 0.1% to about 2% w/w, or from about 0.8% to about 1.8% w/w of the chewing gum composition.

The chewing gum composition of the invention may also include one or more colouring agents. Colouring agents may include natural food dyes or artificial colourings, such as brilliant blue (E133), indigotine (E132), Fast green (E143), Allura red (E129) Erythrosine (pink)(E127), tartrazine (E102) and sunset yellow (El 10). Waxes, useful as softening agents include natural and synthetic waxes, hydrogenated vegetable oils, petroleum waxes such as polyurethane waxes, polyethylene waxes, paraffin waxes, microcrystalline waxes, fatty waxes, sorbitan monostearate, tallow, propylene glycol, mixtures thereof, etc which may be incorporated into the gum base.

Suitable fillers and/or texturisers may include magnesium carbonate, calcium carbonate, sodium sulphate, ground limestone, silicates, such as magnesium silicate and aluminium silicate, kaolin, clay, aluminium oxide, silicium oxide, talc, titanium oxide, mono-, di- and tri-calcium phosphates, cellulose polymers, and combinations thereof. Suitable fillers and/or texturisers may also include natural organic fibres such as fruit or vegetable fibres, grain, rice, celluloses and combinations thereof. Other useful fillers substances include sorbitol, mannitol, dextrins, maltodextrins, inositol, erythritol, isomalt, lactitol, maltitol, mannitol, xylitol, low- substituted hydroxypropylcellulose, starches or modified starches (e.g. potato starch, maize starch, rice starch, pre-gelatinised starch), polyvinylpyrrolidone, polyvinylpyrrolidone/vinyl acetate copolymer, agar (e.g. sodium alginate), carboxyalkylcellulose, dextrates, gelatine, gummi arabicum, hydroxypropyl cellulose, hydroxypropylmethylcellulose, methylcellulose, microcrystalline cellulose, polyethylene glycol, polyethylene oxide, polysaccharides e.g. dextran, soy polysaccharide, sodium carbonate, and sodium chloride.

A unit of the chewing gum composition of the invention may be coated or uncoated. When the chewing gum composition is coated a suitable coating may be a hard coating, a soft coating, a film coating or a sealing coating or any combination of the aforementioned. When the chewing gum unit is coated, the coating may comprise in from 10 to 40% w/w, or 15-30% w/w or 20 to 30% w/w of the chewing gum unit. The coating may be a hard coating, including a sugar coating or a sugar-free coating, and combinations thereof. The objects of hard coating are to obtain a sweet, crunchy layer, which is appreciated by the consumer, and to protect the composition for various reasons. When the coating is a sugar coating the sugar is desirably a crystallisable sugar, such as sucrose or dextrose. Other coating substances which may be mentioned include polyols, e.g. sorbitol, maltitol, mannitol, xylitol, erythritol, lactitol, isomalt and tagatose, maltose, fructose or levulose, xylose, erythrose, lactose, isomaltulose and D-galactose, respectively. One advantage of using polyols in the coating is that they act simultaneously as a sweetener and as a taste-masking agent for the bitter taste of an active therapeutic agent. Preferably, the chewing gum composition of the invention does not comprise a cooling agent.

The chewing gum composition of the present invention may be an acidulated chewing gum or a non-acidulated chewing gum. A non-acidulated chewing gum is preferred.

Alternatively, the coating may be a soft coating. Such a soft coating may comprise one or more a sugar-less sweetening compound and a starch hydrolysate. Suitable film-coating polymers include edible cellulose derivatives such as cellulose ethers including methylcellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC) and hydroxypropyl methylcellulose (HPMC). Other useful film- coating agents are acrylic polymers and copolymers, e.g. methylacrylate aminoester copolymer or mixtures of cellulose derivatives and acrylic polymers. Film coating polymers which may be mentioned include cellulose acetate phthalate, polyvinyl acetate phthalate, methacrylic acid copolymers, cellulose acetate trimellitate, and HP C.

The coating may generally comprise a plurality of layers.

It will be understood by the person skilled in the art that reference to chewing gums herein shall also include compositions such as bubble gums and the like.

Thus, according to a further aspect of the invention we provide a method of treatment of a patient suffering from an oral or nasal infection which comprises the administration of a therapeutically active amount of 2,4-dichlorobenzyl alcohol (DCBA) in a chewing gum composition.

According to a yet further aspect of the invention we provide a method of treatment of a patient suffering from an oral or nasal infection which comprises the administration of a therapeutically active amount of amyl-m-cresol (AMC) in a chewing gum composition.

According to a yet further aspect of the invention we provide a method of treatment of a patient suffering from an oral or nasal infection which comprises the administration of a therapeutically active amount of 2,4-dichlorobenzyl alcohol (DCBA) and amyl- m-cresol (AMC) in a chewing gum composition.

The method of treatment according to this aspect of the invention may include the administration of a therapeutically effective amount of other antiseptic, antibacterial and analgesic therapeutic agents as hereinbefore defined incorporated into the chewing gum composition.

According to an additional aspect of the invention we provide the use of 2,4- dichlorobenzyl alcohol (DCB A) in the manufacture of a chewing gum composition.

According to a further aspect of the invention we provide the use of amyl-m-cresol (AMC) in the manufacture of a chewing gum composition. According to a yet further aspect of the invention we also provide a method of delivery of a therapeutically active agent wherein the therapeutically active agent comprises 2,4-dichlorobenzyl alcohol (DCBA), the method comprise the incorporation of DCBA in a chewing gum composition. According to a further aspect of the invention we also provide a method of delivery of a therapeutically active agent wherein the therapeutically active agent comprises amyl-m-cresol (AMC), the method comprise the incorporation of AMC in a chewing gum composition. We further provide a method of preparing a chewing gum composition comprising a therapeutically active antiseptic agent as hereinbefore described said method comprising;

a) providing a portion of a therapeutically active antiseptic agent as hereinbefore described;

b) admixing the portion a) with a chewing gum base and optionally other chewing gum ingredients as hereinbefore defined;

c) compressing a) and b) after dosing, to obtain a first compressed chewing gum unit. The method of the invention may comprise the incorporation of one or more therapeutically active antiseptic agents as hereinbefore described and optionally include other antiseptic, antibacterial and analgesic therapeutic agents.

The method as hereinbefore described includes melting the chewing gum base prior to or after the admixture with the therapeutically active antiseptic agent.

According to a further aspect of the invention provides an alternative method of preparing a chewing gum composition comprising 2,4-dichlorobenzyl alcohol (DCBA) and/or amyl-m-cresol (AMC) as active antiseptic agent said method comprising;

a) optionally coating chewing gum pieces with a sugar, e.g. sucrose, solution;

b) optionally applying a wax , e.g. carnauba wax, to the optionally coated chewing gum pieces;

c) applying coatings of 2, 4-dichlorobenzyl alcohol and/or amyl-m-cresol in a solvent, such as ethanol;

d) compressing the coated chewing gum pieces into a chewing gum unit; and

e) optionally applying a sugar, e.g. sucrose, coating to the chewing gum units. It will be understood by the person skilled in the art that a "chewing gum" is distinct from a "gum" since, inter alia, a chewing gum is designed to release its ingredients (active ingredient, flavourings, etc.) upon mastication. In addition, the ingredients of a chewing gum will generally comprise, for example, sugar, a gum base, corn syrup, dextrose (sugar), glycerol, lecithin, a sweetener, such as aspartame, acesulfame, etc., colouring, and an antioxidant, such as BHT (butylated hydroxytoluene). Whereas a gum or a gummy candy will comprise a gelling agent, such as gelatin. Thus, the chewing gum composition of the present invention does not include gelatin. Therefore, the present invention provides a chewing gum composition as hereinbefore described comprising a therapeutically effective amount of 2,4-dichlorobenzyl alcohol (DCBA) with the proviso that gelatin is substantially absent; and methods associated thereto. The present invention further provides a chewing gum composition as hereinbefore described comprising a therapeutically effective amount of amyl-m- cresol (AMC) with the proviso that gelatin is substantially absent. The present invention further provides a chewing gum composition as hereinbefore described comprising a therapeutically effective amount of 2,4-dichlorobenzyl alcohol (DCBA) and a therapeutically effective amount amyl-m-cresol (AMC) with the proviso that gelatin is substantially absent. It is also within the scope of the present invention to provide a liquid filled chewing gum which releases amounts of the antiseptic agents as hereinbefore described into the oral cavity. The liquid filled chewing gum may include a solid phase and a liquid phase, the solid phase comprising a gum base matrix including a network of one or more voids or pockets laced throughout the matrix, and the liquid phase comprising the antiseptic agent composition, retained in the one or more voids or pockets, and surrounded by gum base. Upon chewing, the liquid antiseptic agent composition is released into the oral cavity.

There is also provided a method for forming the liquid filled chewing gum as hereinbefore described.

The invention will now be described by way of example only.

Example 1

DCBA Formulation

Uncoated chicle chewing gum pieces (about lg each) are coated with a sucrose solution (80% w/v) in a coating pan. Powdered hydrogenated castor oil is dusted onto the coated chicle pieces and a coating of 2, 4-dichlorobenzyl alcohol in ethanol is applied. Successive applications of the coating are made until approximately 1.2 mg of 2, 4-dichlorobenzyl alcohol have been deposited on each chicle piece. A finishing coating of a sucrose solution is applied containing desired flavourings and colourings. A polishing coat of wax is optionally added.

Example 2

AMC Formulation

Uncoated chicle chewing gum pieces (about lg each) are coated with a sucrose solution (80% w/v) in a coating pan. Powdered hydrogenated castor oil is dusted onto the coated chicle pieces and a coating of amyl-m-cresol in ethanol is applied. Successive applications of the coating are made until approximately 0.6 mg of amyl- m-cresol has been deposited on each chicle piece. A finishing coating of a sucrose solution is applied containing desired flavourings and colourings, A polishing coat of wax is optionally added.

Example 3

DCBA/AMC Formulation

Uncoated chicle chewing gum pieces (about lg each) are coated with a sucrose solution (80% w/v) in a coating pan. Powdered hydrogenated castor oil is dusted onto the coated chicle pieces and a coating of 2, 4-dichlorobenzyl alcohol and amyl-m- cresol in ethanol is applied. Successive applications of the coating are made until approximately 1.2mg of 2, 4-dichlorobenzyl alcohol and 0.6 mg of amyl-m-cresol have been deposited on each chicle piece. A finishing coating of a sucrose solution is applied containing desired flavourings and colourings. A polishing coat of wax is optionally added. Example 4

DCBA/AMC Formulation

Commercially available uncoated chewing gum pieces (about 3g each) were rolled into small spheres that were coated with a sucrose solution (80% w/v) in a coating pan. Carnauba wax was applied to the coated gum spheres and a coating of 2, 4- dichlorobenzyl alcohol and amyl-m-cresol in ethanol was applied. Successive applications of the coating were made until approximately 1.2mg of 2, 4- dichlorobenzyl alcohol and 0.6 mg of amyl-m-cresol had been deposited per gram of uncoated chewing gum. A finishing coating of a sucrose solution was applied containing desired flavourings and colourings. The a chewing gum composition of the invention is useful for, inter alia, alleviating, mitigating or preventing sore throat symptoms, including, but, not limited to, pain, dryness and/or inflammation. The effectiveness of the chewing gum composition of the invention is demonstrated by means of clinical trials in which patients suffering from sore throats are administered the chewing gum composition of the invention, such as that described in Examples 1, 2, 3 and 4 or a placebo. After having chewed the gum, the patient is asked to assess the effectiveness of the treatment, referring to parameters such as the relief of the pain associated with the sore throat, the ease of, or improvement in, swallowing and/or reduction in the swelling of the throat. The patients are also examined by a clinician.

Example 5

A clinical trial is conducted as follows: 5.1 Subjects

Subjects are eligible to participate if they are otherwise healthy, have at least moderate symptom severity and report symptoms of 48 hours or less duration. Symptoms are sore throat symptoms, namely, pain, dryness and/or inflammation of the throat. The trial is blinded.

5.2 Study Medications

Subjects are randomly assigned to receive coated chewing gum pieces (about lg each) or a placebo chewing gum. The subject chews on gum piece every 2 to 3 hours from about 8 a.m. to 6 p.m. Subjects are instructed to avoid any other cold, flu or sore throat treatments whilst participating in the study. 5.3 Study Procedures

The study is a randomised, placebo-controlled clinical trial which is optionally blinded or double-blinded.

Prior to the first chewing gum piece being administered baseline symptom evaluations are made using a symptom severity scale of 0 to 4, corresponding to absent, mild, moderate, moderately severe, and severe. The symptoms rated are overall throat symptom assessment, sore throat, cough; overall nasal symptom assessment, sneezing, runny nose, nasal obstruction; overall sinus symptom assessment, sinus pain, sinus pressure, sinus congestion; headache, muscle pain, and malaise. These symptom assessments are made by the subjects based on their self-perception of symptom type and location. Height and weight are recorded. Subjects are instructed to record their self-perception of symptoms after chewing each gum. The symptoms and severity scale used in these assessments are the same as those used for the baseline evaluation.

Subjects also record the occurrence of any adverse effect. Each subject reports their symptom assessment after 24 to 48. Study diaries are returned and reviewed.