The aim of this study is to establish the efficacy, clinical benefits, and safety of treatment with TDT 067 for clinically diagnosed distal subungual onychomycosis of the toenails caused by dermatophytes confirmed by positive mycology.

Inclusion Criteria:

1. Patients must be between 18 and 75 years of age inclusive, of any race, and of either sex.

   Female patients must be either surgically sterile, postmenopausal (no menses for the previous 12 months), or must be practicing an effective method of birth control as determined by the Investigator.

2. Patients must have at least 1 great toenail (target toenail) with clinically diagnosed distal subungual onychomycosis involving between 25% and 65%, inclusive, of the nail and confirmed by KOH visualization and fungal culture positive for dermatophytes. (Patients with culture positive for dermatophytes alone or dermatophytes and non dermatophytes are eligible to participate.) If both great toenails meet inclusion criteria, the one with the greater involvement will be designated the target nail.

3. Patients must be able to understand the requirements of the study, abide by the restrictions, and return for all of the required examinations.

4. Patients must be willing to sign a statement of informed consent.

5. Patients must have a target great toenail with the capability to grow as determined by history of nail cutting.

6. Patients must be willing to refrain from using any nail polish products and other nail cosmetic products on any of the toenails and must be willing to refrain from professional pedicures for the duration of this study.

Exclusion Criteria:

1. Patients who have been treated with an investigational drug within 1 month prior to study start.
2. Patients who are pregnant or planning to become pregnant or who are lactating.
3. Patients with hypersensitivity to terbinafine or to any other ingredients of the formulation.
4. Patients who are unable to spray their toenails and the surrounding tissues on the affected foot without assistance.
5. Patients with symptomatic tinea pedis requiring treatment.
6. Patients using oral terbinafine within 6 months prior to the start of study; patients who have received other oral antifungals within 3 months.
7. Patients using topical antifungal treatments for onychomycosis within 1 month prior to the start of study; patients using topical antifungal treatments for the feet within 1 month prior to the start of the study.
8. Patients with any nail dystrophy that will interfere with the assessment of a clear nail. Patients who have toenail abnormalities or dystrophies that could prevent the restoration of a normal appearing nail in spite of a mycological cure for dermatophytes, including patients with psoriasis, lichen planus, malignancy or pigmentation disorders involving the nail unit, chemical damage, or onychodystrophy due to trauma or other structural deformities.
9. Patients with superficial white or proximal subungual onychomycosis.
10. Patients with a toenail infection involving a non dermatophyte alone.
11. Patients with involvement of the matrix (lunula) or the proximal 2 mm of nail as measured from the proximal nail fold.
12. Patients who have a nail plate with thickness greater than 2 mm or total thickness of the nail plus subungual debris measuring greater than 3 mm.
13. Patients with yellow streaks or dermatophytoma of the target toenail.
14. Patients with a history of peripheral arterial disease or diabetes mellitus.
15. Patients with any condition that in the opinion of the Investigator renders the patient unsuitable for participation in this study.
16. Patients with alanine aminotransferase (ALT) or aspartate (AST) levels greater than 2 times the upper limit of normal without clinical reason, unless, in the opinion of the Investigator, participation in this study would not place the patient at undue risk.