Stabilized efinaconazole formulations

A method of treating onychomycosis comprising administering a therapeutically effective amount of an efinaconazole composition to the nails of a patient in need of such treatment,

• wherein the efinaconazole composition comprises about 8% to about 12% efinaconazole by weight, water, C12-15 alkyl lactate, diisopropyl adipate, cyclomethicone, ethanol, butylated hydroxytoluene (BHT), a salt of ethylenediaminetetraacetic acid (EDTA), and citric acid,
• wherein the amount of BHT is in the range of about 0.01% (w/w) to about 2% (w/w),
• wherein the amount of the salt of EDTA is in the range of about 0.0001% (w/w) to about 1.5% (w/w),
• wherein the amount of citric acid is in the range of about 0.05% (w/w) to about 0.25% (w/w),
• wherein the composition is formulated as a solution, and
• wherein the amounts of BHT and the salt of EDTA are sufficient to ensure the composition is (i) colorless upon initial formulation and (ii) colorless or pale yellow after storage for three weeks at a temperature of about 40° C.