1. Field of the Invention
This invention relates to a topical solutions and method useful for treating fungal infections of human fingernails and toenails, and for alleviating other symptoms often associated with such fungal infections.
2. Description of Related Art
Fungal infections in, under and around human fingernails and toenails can be painful, unattractive and difficult to treat. Such fungal infections, otherwise referred to as onychomycosis, ringworm of nails or tinea unguium, can cause thickening, roughness and splitting of nails. Known fungal organisms include Epidermophyton floccusum, Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton megninii, Trichophyton schoenleinii, Trichophyton tonsurans and Candida albicans. Although numerous systemic and topical medicaments have been disclosed previously for use in treating onychomycosis, most are ineffective, cause side effects, or are prohibitively expensive.
U.S. Pat. No. 5,916,545 discloses an antifungal composition comprising water, alcohol, a gel-forming agent and an effective amount of tioconazole, with compositions comprising from about 50 to 90 weight percent alcohol, 1 to 10 percent water, 15 to 30 percent tioconazole, 0.5 to 5 percent gel-forming agent, and a plasticizer being preferred.
U.S. Pat. No. 5,696,105 discloses a topical composition for treatment of onchomycosis comprising a therapeutically effective amount of mometasone furoate in a hydro-alcoholic base comprising 15 to 50 weight percent propylene glycol, 20 to 40 percent isopropyl alcohol, 20 to 60 percent water, 0.1 to 3 percent thickening agent and sufficient buffer to adjust the pH to between 3.0 and 6.0, and most preferably between 4.0 and 5.0.
U.S. Pat. No. 5,972,317 discloses a method for treated diseased nails with a nail-permeable topical composition comprising a medicament component in combination with a proteolytic enzyme.
U.S. Pat. No. 5,486,537 discloses an antifungal composition comprising a solution of cinnamic aldehyde, up to about 20 weight percent griseofulvin and at least 5 volume percent of an alcohol selected from ethanol and isopropanol for topical application to skin and keratinous tissue.
U.S. Pat. No. 4,919,920 discloses a topical composition for hardening nails, the composition comprising a cosmetically acceptable aqueous vehicle including an effective amount of fluoride ion and having a pH of about 3.5 to 8. The fluoride ion is from a fluoride compound selected from water-soluble fluoride salts and complex fluoride salts, including aluminum fluoride, sodium fluoride, potassium fluoride, stannous fluoride, stannous monofluorophosphate, etc.
U.S. Pat. Nos. 5,395,241, 5,057,309 and 3,346,578 disclose the use of stannous fluoride in oral hygiene preparations.
Compositions useful for treating fungal infections of fingernails and toenails are desirably aqueous, fast-drying and non-greasy. Such compositions are preferably easy to apply topically, will penetrate around and under a nail, and into surrounding and underlying skin, and will desirably control or eradicate the offending fungal organisms without damaging skin or other healthy tissue.
The invention disclosed herein is an antifungal composition preferably comprising water, a wetting agent such as an alcohol, a water-soluble fluoride ion donor compound providing a concentration of fluoride ions sufficient to effectively treat a fungal infection in, on or adjacent to a human fingernail or toenail. The pH of the subject compositions preferably ranges from about 2.8 to about 3.5. The antifungal composition of the invention can desirably penetrate skin and will desirably adjust the pH on, through and under the skin to a level that is lethal to the fungal organisms without damaging the nail, skin or other surrounding tissue. A method for treating infections proximal to human nails is also disclosed that comprises periodically applying to and around an infected nail one or more drops of the subject composition for so long as the infection lasts.