BACKGROUND OF THE INVENTION The treatment of topical fungal infections has traditionally resulted in variable success. See, e. g., Lauhearanta, Clin. Expert. Dermatol. 17 (supp. 1): 41-43 (1992); Reinel, et al., Clin. Exp. Dermatol. 17 (supp.

1): 44-49 (1992); and Zang, et al., Clin Exp. Dermatol.

17 (supp. 1): 61-70 (1992). This variability is likely due to the fact that fungi in the growing state (e. g., hyphae) are more susceptible to the toxic action of the antifungal drugs than fungi in resting state (e. g., spores and arthrocomidia). This inability to eradicate all the fungi during antifungal treatment often results in poor treatment efficacy, long treatment duration, and a high recurrence rate.

The present invention relates to a method of improving current antifungal treatment by changing the biological status of fungi from a resting (e. g., dormant) state to the growing (e. g., vegetative) state, thereby increasing the efficacy of antifungal treatment.

The conversion of fungi from resting state to growing state is accomplished by topically applying nutrients essential to the growth and reproduction of fungi, either prior to or during the antifungal treatment. The

nutrients in the fungal growth medium induces the fungal spores to grow, thereby making them more susceptible to the toxicity of the antifungal agent.

SUMMARY OF THE INVENTION In one aspect, the invention features a method of treating or preventing a topical fungus infection on a mammal (e. g., a human) comprising the steps of: topically applying to the fungus-infected tissue (e. g., the skin or nails) an amount of a fungal growth medium effective to induce the fungus from the dormant state into the vegetative state; and administering to the mammal a therapeutically effective amount of an antifungal agent.

The antifungal agent may administered prior to or during the administration of the fungal growth medium. Examples of topical fungal infections include, but are not limited to, onychomycosis, tinea capitis, tinea pedis, tinea manuum, and dandruff. In one embodiment, the method is for the prevention of fungal infections (e. g., administering the fungal growth medium and antifungal agent to the site of a wound or other topical area susceptible to fungal infection).

In another aspect, the invention features a composition comprising a therapeutically effective amount of an antifungal agent and an amount of a fungal growth medium capable of inducing fungus from the dormant state into the vegetative state.

In another aspect, the invention features a bandage comprising an amount of a fungal growth medium capable of inducing fungus from the dormant state into the

vegetative state. The bandage may further comprise a therapeutically effective amount of an antifungal agent.

Other features and advantages of the present invention will be apparent from the detailed description of the invention and from the claims DETAILED DESCRIPTION OF THE INVENTION It is believed that one skilled in the art can, based upon the description herein, utilize the present invention to its fullest extent. The following specific embodiments are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Also, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.

The present invention relates to the finding that the presence of large loads of spores and arthrocomidia at the infection site was a good predictor of future therapeutic failure and/or frequent recurrence of the fungal infection. In fact, we found that resting fungal cells were almost completely non-susceptible to the toxic action of current oral and topical antifungal agents. We, however, also found that the application of a fungal growth medium would help transform dormant fungal cells into growing hyphae, and, in this growing state, the fungi were more readily susceptible to antifungal treatment.

What is meant by"fungal growth medium"is a composition that is capable of stimulating the transformation of dormant fungi (e. g., spores and arthrocomidia) in to growing fungi (e. g., hyphae). In one embodiment, the growth medium comprises about 0.1 to about 20% (e. g., between about 1 and 10%), by weight, of a carbon hydrate. Examples of carbon hydrates include, but are not limited to, monosaccharides such as glucose, fructose, mannose, ribose and galactose, disaccharides such as sucrose, maltose and lactose, polysaccharides such as dextrins, dextrans, and starches such as amylose and amylopectin.

In one embodiment, the growth medium comprises about 0.1 to about 20% (e. g., between about 0.1 and 10%), by weight, of a nitrogen-containing compound. Examples of nitrogen-containing compounds include, but are not limited to, amino acids and compounds comprising amino acids such as peptides, polypeptides, proteins, and fragments thereof (e. g., a peptone broth and other partially or fully hydrolyzed proteins of animal and plant origins). Other examples of nitrogen-containing compounds include nitrates, ammonia, and ureas.

In one embodiment, the growth medium comprises between about 0.05 to about 20 % (e. g., between about 0.1 and 5%), by weight, of a salt. Examples of salts include, but are not limited to, sodium chloride, potassium chloride, and lithium chloride.

In one embodiment, the growth medium further comprises a pH adjusting agent (e. g., an acidic, basic, or buffering agent). Examples of acidic agents include, but are not limited to, hydrochloric acid, citric acid,

lactic acid, glycolic acid, salicylic acid, and phosphoric acid. Examples of basic agents include, but are not limited to, sodium hydroxide, potassium hydroxide and ammonium hydroxide. Examples of buffering agents include, but are not limited to, phosphate buffers and citrate buffers. Other such pH adjusters and buffering agents are listed in the International Cosmetic Ingredient Dictionary and Handbook, eds. Wenninger and McEwen p. 1625 and 1653 (7th ed. 1997). In one embodiment, the growth medium has a pH of between about pH 3 and about pH 7 (e. g., a pH 4 and about pH 6 such as a pH of about 5. 6).

In one embodiment, the growth medium comprises a supporting matrix to provide a solid (e. g., gauzes and non-woven pads) or semi-solid (e. g., gelling agents) structure to the growth medium. Examples of gelling agents include, but are not limited to, agar, gelatin, pectins, alginates, gums (e. g., karaya gum, gum arabic, tragacanth gum, carrageenan gum, guar gum, gum ghatti, locust bean gum, tamarind gum and xanthan gum), hydrophilic cellulose polymers (e. g., hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and carboxymethylcellulose), polyacrylamide, polyethylene oxide, polyethylene glycols, polypropylene glycols, polyvinyl alcohols, polyvinylpyrrolidones, starches and their modifications, polyacrylic acid and its homologs, polyacrylates, and copolymers and polymer blends of aforementioned polymers. Other such gelling agents are listed in Hand of Water-soluble Gums and Resins, eds. Crawford and Williams, (1980, McGraw-Hill, Inc.).

Other ingredients that may be added to the fungal growth medium include effective amounts of mold growth inhibitors (e. g., cycloheximide), antibacterial/antibiotics (e. g., penicillin, streptomycin, and choramphenical), boron, metals and metal containing compounds such as zinc, manganese, copper, iron, molybdenum, and magnesium oxide, P205, K20, those ingredients listed in Difco Manual-Dehydrated Culture Media and Reagents for Microbiology, (lots Edition, 1984, Difco Laboratories, Detroit, MI).

Suitable fungal growth mediums are described in Difco Manual-Dehydrated Culture Media and Reagents for Microbiology, (lots Edition, 1984, Difco Laboratories, Detroit, MI). Examples of such fungal growth mediums include, but are not limited to, Sabouraud's agar (glucose (2-4%), peptone (1%), agar (2%), and distilled water (q. s. 100%)) and Kimmig's agar (glucose (1%), peptone (0.5%), sodium chloride (0.5%), culture broth (1%), flake agar (3%), and distilled water (q. s. 100%)).

The fungal growth medium may be topically administered to the infection site as a solution, lotion, cream, shampoo, liposome formulation, spray, lacquer, or gel, or incorporated into a bandage to be affixed to the infection site as described below.

Examples of antifungal drugs include, but are not limited, azoles (e. g., imidazoles) such as miconazole, econazole, ketoconazole, itraconazole, fluconazole, bifoconazole, terconazole, butaconazole, tioconazole, oxiconazole, sulconazole, saperconazole, clotrimazole, voriconazole, clotrimazole, and elubiol, allylamines such as terbinafine, morpholines such as amorolfine and

naftifine, griseofulvin, undecylenic acid, haloprogin, butenafine, tolnaftate, nystatin, cyclohexamide, iodine, ciclopirox, tea tree oil, and pharmaceutically acceptable salts thereof.

The antifungal agent may comprise one or more pharmaceutically acceptable carriers as a pharmaceutical formulation. The carrier must be"acceptable"in the sense of being compatible with the antifungal and not deleterious to the subject to be treated. The antifungal formulation may be administered as an oral (e. g., a pill or capsule), parenteral (e. g., intravenous, intramuscular, or subcutaneous solution), or topical dosage form (e. g., topically administered to the infection site as a solution, lotion, cream, ointment, spray, lacquer, or gel, or incorporated into a bandage to be affixed to the infection site as described below). The antifungal agent may also be added to the topical fungal growth medium. Examples of topical dosage formulations (e. g., antifungal creams for skin and vaginal fungal infections, and shampoos to treat dandruff) are described below. U. S. Patent Nos.

4,775,678 and 5,514,698 describe antifungal cream compositions and manufacturing procedures. This invention can also be used to prepare antifungal diaper rash ointment comprising an antifungal agent (e. g., miconazole nitrate), fungal growth medium, fine zinc oxide particles, and petrolatum.

The dose of the antifungal agent for treating the fungal infections varies depending upon the type of fungal infection, the antifungal used, the manner of administration, and the age and body weight of the

subject to be treated, and ultimately will be decided by the attending physician or veterinarian. Such amount of the antifungal is referred herein as a"therapeutically effective amount."In one embodiment, the antifungal formulation comprises between 0.01 and 10 percent (e. g., 0.5 to about 5 percent), by weight, of the antifungal agent.

In one embodiment, the method further comprises the step of administering at least one keratin-softening agent capable of increasing penetration of the antifungal agent and/or fungal growth medium into fungus-infected keratinous tissues. The keratin-softening agent may be used to treat keratinous tissues (e. g., the nail) prior to or during application of the fungal growth medium and/or the antifungal agent. The keratin-softening agent may also be added to the fungal growth medium formulation and/or the antifungal agent formulation.

Examples of the keratinous tissues include nails, the stratum corneum of the skin, and the overgrowth of the skin's horny outer layer such as callus. Keratin- softening agents in the present invention include, but are not limited to, sulfur containing compounds, urea, salicylic acid, and a mixture thereof. According to the invention, the term"sulfur containing compounds"refers to (a) thio-compounds with one or more sulfhydryl functional groups capable of reacting with disulfide bonds of keratin, (b) thio-containing amino acids and their derivatives, and (c) certain sulfides. Examples of thio-compounds with one or more sulfhydryl functional groups capable of reacting with disulfide bonds of keratin, include but are not limited to, thioglycolic

acid and its salts (e. g., glycolates of calcium, sodium, strontium, potassium, ammonium, lithium, magnesium, and other metal salts), thioethylene glycol, thioglycerol, thioethanol, and thioactic acid, thiosalicylic acid, and their salts. Examples of thio-containing amino acids and their derivatives include, but are not limited to, the L- or D-isomers of cysteine, D-cysteine, N-acetyl-cysteine, homocysteine, cysteine methyl ester, cysteine ethyl ester, and N-carbamoyl cysteine, glutathion, and cysteamine. Examples of sulfides include but are not limited to, calcium, sodium, potassium, lithium and strontium sulfides. U. S. Patent No. 5,696,164 describes the use of thio-containing amino acids and their derivatives to soften the nail for treatment of nail fungal infections.

When the sulfur containing compounds are thio- containing amino acids and their derivatives, the pH of the composition is preferably below pH 7 (e. g., below pH 5). Alternately, if the sulfur containing compounds are thio-compounds and sulfides, the pH of the composition is preferably above pH 6 (e. g., above pH 9). The concentration of a sulfur containing compound may range between about 0.5 % to about 20% (e. g., between about 1% and about 10%), by weight, of the administered composition. When the other keratin-softening agents urea and salicylic acid are used, the concentration of urea to be used ranges from about 1% to about 50% (e. g., from about 5% to about 40%, by weight, of the administered composition, and the concentration of salicylic acid to be used ranges from about 0.1% to

about 40% (e. g., from about 1 % to about 20%), by weight, of the administered composition.

In one embodiment, the fungal growth medium, antifungal agent, and/or keratin-softening agent are incorporated into a bandage device to be affixed to the infection site (e. g., to provide desirable occlusion and protection from the accidental wiping-off of the agents). The bandage devices described in U. S. Patent Nos. 5,696,164,5,181,914, and 5,814,031 may be used for this purpose, and is hereby incorporated by reference.

Such devices are constructed in such a way that during the treatment, only the infection site is in direct contact with the agents. Thus, contact between the agents and the surrounding skin tissues is minimized in order to prevent skin irritation. In another embodiment, the agents of the present invention are incorporated in an adhesive layer, which is coated on a pliable polymeric backing sheet. This device resembles an adhesive tape, only with the treatment composition embedded in the adhesive layer.

In still another embodiment, the agents of the invention are incorporated in a hydrogel device where an aqueous solution or suspension of the agents are immobilized in a hydrogel layer, which is coated on a pliable polymeric backing sheet. During the application, the hydrogel layer is situated over the fungal infection site. The hydrogel device is secured to its position by the adhesion between the hydrogel layer and the infected tissue and/or surrounding skin tissue.

Alternatively, the hydrogel device is secured by an adhesive layer coated on the polymeric backing sheet at

the edges of the hydrogel device in a configuration commonly known in the art as an"island-type bandage".

U. S. Patent Nos. 5,160,328,5,181,914,5,260,066 and 5,620,702 describe the basic composition and construction of such hydrogel devices that may be used according to the present invention.

In one embodiment, a bandage device with an absorbent pad (e. g., a gauze or non-woven pad) on an adhesive-coated backing layer, may also be used as a carrier device according to the present invention. See U. S. Patent Nos. 4,530,353,4,549,653,4,622,089, 5,633,070, and 5,814,031. The aforementioned hydrogel- bandages and absorbent-pad-bandages may be occlusive in order to retain the moisture and to facilitate permeation.

The topically infected tissues to be treated by the present invention may include the nail, skin, and mucosal membranes. Examples of fungal infections include those of the nails (e. g., onychomycosis), the skin (e. g., dermatomycosis), the mucosal membranes (e. g., fungal infections in vaginal and buccal membranes), the ear (e. g., the external auditory meatus-otomycosis), and the cornea (e. g., keratomycosis). Examples of skin fungal infections include teanea capitis, tinea nodosa, tinea axillaris, tinea barbae, tinea pedis, tinea versicolor, and dandruff which is associated with a yeast pityrosporum ovale.

The following is a description of a clinical application of the present invention and four compositions of the present invention. Other methods and compositions of the present invention can be conducted in

an analogous manner by a person of ordinary skill in the art.

Example 1: A total of eight adult patients suffering from dermatophytic onychomycosis of the great toenail participated in the study. Their conditions had previously been unsuccessfully treated for months with fluconazole (Diflucan@, Pfizer, 100 mg/week), itraconazole (Sporanox, Janssen, 400 mg/day, 1 wk./month), or terbinafine (Lamisil@, Novartis, 250 mg/day). In all cases, the disease recurred within six months after terminating the above oral treatment.

Each patient applied a 5% amorolfine nail lacquer (Loceryl@, Roche) once weekly. Every second day of the rest of the week, each patient applied a piece of Sabourand's agar (Mycoline bioMerieux, Marcy L'Etoile, France) to the affected nail. The agar was held in place for 24 hr with an adhesive (Hansamed, Beiesdorf, Hamburg, Germany). The treatment was continued for one month, followed by a month or no treatment, and in some cases followed with another month of the same treatment.

Mycological cultures were performed 2,4, and 6 months after treatment. Three of the patients (38%) were mycologically cured after the first month of treatment, four of the patients (50%) needed the second one-month treatment to be so cured, and only one patient (12%) failed to be so cured.

Example 2: Miconazole Nitrate/Fungal Growth Medium Cream A topical antifungal cream containing the antifungal miconazole nitrate and a fungal growth medium comprising glucose and peptone is manufactured by blending the following ingredients together: INGREDIENT WEIGHT % MiconazoleNitrate 2.0 Glucose 2.0 Peptone 1.0 BenzoicAcid 0.2 ButylatedHydroxyanisole0.1 MineralOil(Heavy)3.0 PEGLICOL-5-Oleate 3. 0 PEGOXOL-7-Stearate 20.0 PurifiedWater 68.7

Example 3: Econazole Nitrate/Funval Growth Medium Cream A topical antifungal cream containing the antifungal econazole nitrate and a fungal growth medium comprising glucose and peptone is manufactured by blending the following ingredients together: INGREDIENT WEIGHT% EconazoleNitrate 2.0 Glucose 2.0 Peptone 1.0 BenzoicAcid 0.2 ButylatedHydroxyanisole 0.1 MineralOil 3.0 PEGLICOL-5-Oleate 3. 0 PEGOXOL-7-Stearate 20.0 PurifiedWater 69.7

Example 4: Ketoconazole/Funoal Growth Medium Shampoo An anti-dandruff shampoo containing the antifungal ketoconazole and a fungal growth medium comprising glucose and peptone is manufactured by blending the following ingredients together: INGREDIENT WEIGHT Ketoconazole 1.0 Glucose 2.0 Peptone 1.0 SodiumLaurethSulfate 30.0 SodiumCocoylSarcosinate 10.0 CoconutMonoethanolamide 4.0 EthyleneGlycolDistearate 1.25 AcrylicAcidCopolymer 0.6 (Carbomer1342fromBFGoodrich) CosmeticFragrance 0.5 Acrylatmide-DMDAACCopolymer 1.0 TetrasodiumEDTA 0.5 1- (3Chloroallyl)-3,5,7-triaza-1-azonia-0.05 adamantanechloride(Quaternium-15) Cosmeticcolorant 0.001 Butylated Hydroxytoluene 0.1 SodiumChloride 0.25 PurifiedWater 47. 5 SodiumHydroxideadjusttopH7 0.25

Example 5: Antifungal Drug/Funeral Growth Medium Cream A topical antifungal cream containing an antifungal agent and a fungal growth medium comprising glucose and peptone is manufactured by blending the following ingredients together: INGREDIENT WEIGHT% AntifungalDrug 0.1-10.0 CarbonHydrate 0.1-10.0 Nitrogen-containingcompound 0.1-10.0 CetylAlcool 1.0-7.0 StearylAlcool 5.0-15.0 IsopropylMyristate 1.0-5.0 PropyleneGlycol 10.0-25.0 Polysorbate60or80 1.0-5.0 ButylatedHydroxyanisole 0.01-0.50 SodiumorPotassiumHydroxideSufficienttoadjust pHbetween3-7 PurifiedWater q.s.100

It is understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims.

Other aspects, advantages, and modifications are within the claims.

What is claimed is: