Pharmacokinetics of Transdermal Metronidazole

Half of enrolled subjects will undergo this intervention. Baseline measurements of transepidermal water loss, electrical resistance, and color will be made at 3 sites on the upper arm. Color will only be measured at baseline. Micropatch application will occur at 2 sites, followed by application of metronidazole gel and then covered with an occlusive covering. One site will be covered with an occlusive covering only (no micropatch or gel). At 48 hours occlusive coverings and gel are removed and electrical resistance measurements are repeated. Fresh gel and occlusive patches are reapplied. At 96 hours the patches are removed and electrical resistance measurements repeated. Blood samples are taken daily for 5 days. Measurements from the 3rd site allow each subject to serve as their own control in data analysis. After a minimum 7 days washout period, all of these procedures will be repeated again except that there will be no micropatch application at any of the 3 sites.

Half of enrolled subjects will undergo this intervention. Baseline measurements of transepidermal water loss, electrical resistance, and color will be made at 3 sites on the upper arm. Color will only be measured at baseline. Micropatch application will occur at 2 sites, followed by application of metronidazole cream and then covered with an occlusive covering. One site will be covered with an occlusive covering only (no micropatch or cream). At 48 hours occlusive coverings and cream are removed and electrical resistance measurements are repeated. Fresh cream and occlusive patches are reapplied. At 96 hours the patches are removed and electrical resistance measurements repeated. Blood samples are taken daily for 5 days. Measurements from the 3rd site allow each subject to serve as their own control in data analysis. After a minimum 7 days washout period, all of these procedures will be repeated again except that there will be no micropatch application at any of the 3 sites.

Baseline measurements of transepidermal water loss will be made at 3 sites on the upper arm. In the study periods that have micropatch application, the measurements will be repeated after micropatch application and removal (before any metronidazole product is applied).

Baseline measurements of electrical resistance will be made at 3 sites on the upper arm. In the study periods that have micropatch application, the measurements will be repeated after micropatch application and removal (before any metronidazole product is applied). In all study periods the measurements will also be repeated at 48 hours and 96 hours, when metronidazole product and occlusive coverings are removed from the skin.

Baseline measurements of skin color will be made at 3 sites on the upper arm.

All subjects will undergo this intervention. Baseline measurements of transepidermal water loss, electrical resistance, and color will be made at 3 sites on the upper arm (color only measured at baseline). Two sites will have micropatch application + metronidazole product with occlusive covering. One site will have micropatch application + occlusive covering, no metronidazole product. Micropatch application will only occur on day 1 (a micropatch is a patch of 50 microneedles). Transepidermal water loss and electrical resistance are repeated after micropatch application and removal. At 48 hours occlusive coverings and metronidazole are removed; electrical resistance measurements are repeated. Metronidazole product and fresh occlusive patches are reapplied. At 96 hours patches are removed and electrical resistance measurements repeated. Blood samples are taken daily for 5 days. Measurements from the 3rd site allow each subject to serve as their own control in data analysis.