The purpose of the study is to determine the safety and efficacy of 2.5%, 5.0%, and 7.5% AN2690 Solutions compared to the vehicle alone in the treatment of distal, subungual onychomycosis of the great target toenail.

The intent is for all subjects to complete a 180 day treatment period consisting of 90 consecutive days of once daily treatment with their assigned study treatment followed by an additional 90 days of three times weekly dosing, even if the treated toenail(s) is evaluated as a "complete responder" prior to the end of treatment 180 day treatment period.

At the end of the 180-Day treatment period, subjects who remain in the study will be classified as complete responders, partial responders, or non-responders. All complete or partial responders will continue to be followed for an additional 180 days until the last evaluation for inclusion in the final analysis.

Periodic efficacy and local tolerance evaluations of the test medication will be performed of the target great toenail and all other treated toenails. KOH wet mounts and fungal cultures from the treatment-targeted great toenail will be performed on the same schedule.

Subjects will also be queried for adverse events and evaluated for application site reactions. Clinical laboratory assessment for safety will be made at Screening, periodically throughout the study, and upon premature discontinuation from the study.

Inclusion Criteria:

1. Witnessed, signed informed consent approved by Institutional Review Board/Ethics Committee.
2. Male or female subjects of any race at least 18 years of age but not older than 65 years of age.
3. Subjects with a diagnosis of onychomycosis of at least one great toenail and with a positive KOH wet mount and a positive fungal culture for a dermatophyte.
4. Onychomycosis involving 20-60% of the affected great toenail as determined at baseline (Day 1) by visual inspection after the nail has been trimmed.
5. The combined thickness of the distal nail plate and the associated hyperkeratotic nail bed < 3 mm.
6. Affected great toenail to be treated is capable of re-growth as documented by history or recent observation of at least 2 mm of growth.
7. Normal or not clinically significant screening safety labs.

Exclusion Criteria:

1. Females of childbearing potential not using a highly effective method of birth control (e.g. implants, injectables, combined oral contraceptives, some intrauterine contraceptive devices) during the study.

2. Diabetes mellitus requiring treatment other than diet and exercise.

3. Subjects with chronic moccasin type of T. pedis.

4. Subjects with a history of having failed any previous topical antifungal therapy for their onychomycosis.

5. Subjects unwilling to refrain from the use of nail cosmetics such as clear and/or colored nail lacquers from the screening visit until the end of the study.

6. Subjects that have not undergone the specified washout period(s) for the following topical preparations or subjects who require the concurrent use of any of the following topical medications:

   1. Topical antifungal applied to the feet (does not include antifungals for treatment of T. pedis during the study): 4 weeks
   2. Anti-inflammatories, corticosteroids, topical immunomodulators: 2 weeks

7. Subjects that have not undergone the specified washout period(s) for the following systemic medications or subjects who require the concurrent use of any of the following systemic medications:

   1. Corticosteroids (including intramuscular injections): 2 weeks
   2. Antifungals for treatment of onychomycosis or any systemic antifungal with known activity against dermatophyte: 24 weeks
   3. Systemic immunomodulators: 4 weeks

8. Treatment of any type for cancer within the last 6 months.

9. History of any significant internal disease.

10. Subjects with a medical history of current or past psoriasis of the skin and/or nails.

11. Concurrent lichen planus.

12. Subjects who are known to be allergic to any of the test product(s) or any components in the test product(s) or history of hypersensitivity or allergic reactions to any of the study preparations as described in the Investigator's Brochure.

13. Nail or anatomic abnormalities of the toe, e.g., genetic nail disorders, primentary disorders, onychogryphosis, trauma to the nail(s) to be treated.

14. AIDS or AIDS related complex.

15. History of street drug or alcohol abuse.

16. Any subject not able to meet the study attendance requirements.

17. Subjects who have participated in any other trial of an investigational drug or device within 60 days prior to enrollment or participation in a research study concurrent with this study