Healthy, adult volunteers of either sex will be patched on his/her back with AN2690 Solution 2.5%, AN2690 Solution 5%, AN2690 Solution 7.5%, AN2690 Solution Vehicle and Sodium Laurel Sulfate 0.5% over the course of 21 consecutive days. After 24 hours, the patches are to be removed and the site evaluated using a five-point scale for irritation.