The first group of 30 protocol-qualified subjects will be assigned to Treatment Group 1 and given 5% AN2690 Solution. Provided that there is adequate evidence of clinical safety after two weeks of dosing with 5% AN2690 Solution, a second group of 30 protocol-qualified subjects will be assigned to Treatment Group 2 and given 7.5% AN2690 Solution. A third group of 30 subjects will be enrolled and assigned the highest safe concentration of AN2690 evaluated in this study.