including biocompatible gels and adhesive backing. The device
utilizes a 6-volt power source, has a mask delivery area of 331.29 cm2, and a mask area power output of 1.8 μAm per cm2. The ground area power output is 14.14 μAm per cm2.
Penetration of Vitamin C
Before conducting the current study, an experiment was performed
to measure the depth that vitamin C penetrates into the skin when delivered via an iontophoresis patch identical in materials and construction to the FFIM. Three investigators
(D.O.D., J.C.S., and M.C.) studied iontophoresis of vitamin C in 4 subjects (2 male, 2 female; mean age, 21.75 ± 2.63 years) recruited by classroom volunteer. Each subject had < 5 mm of adipose tissue in the treatment area and was free of any injury,
swelling, or infection for at least 3 months before the study. Under sterile conditions, an intramuscular microdialysis
probe was inserted at the musculotendinous junction of the gastrocnemius muscle at a depth of 0.2 cm with a 27-gauge needle used as a guide cannula. The entrance and exit sites of the skin were separated by at least 2.5 cm. The guide cannula was inserted horizontally in the dermis, and the microdialysis probe was fed through the guide cannula. The cannula was removed, and the probe left in place. Doppler ultrasound was used to verify the depth of the microdialysis probe.
After placement, the probe was perfused with 0.9% saline at a rate of 0.6 mL/hr with a Harvard infusion pump and the perfusate was collected in an Eppendorf container taped to the lateral portion of the leg. A 60-minute flush and recovery period was performed to allow local skin blood flow to return to baseline. Following the recovery period, the Eppendorf container was removed and replaced
with a new one. A small amount of vitamin C solution was applied to the skin on the treatment site directly over the microdialysis
probe. The battery-powered iontophoresis patch was placed with the negative pad directly over the microdialysis probe. Once the pad comes in contact with the skin, the current begins to flow. The treatment duration was 30 minutes, during which the 0.9% saline continued to flow through the probe at a rate of 0.3 mL/hr, pushing any vitamin C that penetrated the skin into the Ep-