pendorf container. At the conclusion of the treatment, the patch was removed and any adhesive from the electrodes left on the dermis was cleaned. The intramuscular microdialysis probe was removed, and portal sites within the tissue were treated with triple antibiotic ointment and covered with a sterile bandage.
A 20-μL sample was taken from each perfusate and analyzed using high-performance liquid chromatography (HPLC). A 2% diluted sample of the vitamin C solution in HPLC revealed 1 peak at 2 minutes, which was used as the standard to identify the vitamin C in the perfusate samples (D.O. Draper et al, written communication, 2008). The quantity of vitamin C was measured as an area under the curve in mAU*s, the ultraviolet (UV) detectorâ€™s electronic absorption units. The HPLC results for subjects 1 through 4 were as follows: 41.71, 30.99, 49.23, and 29.02 mAU*s. These results demonstrate that the vitamin C solution delivered via iontophoresis penetrated the skin to a depth of 0.2 cm.
As shown in Table 1, 34 of the 35 patients were women. The mean patient age was 47.6 years. The majority of patients (32 of 35) had Fitzpatrick skin types III, IV, and V. After FFIM vitamin C treatment, patient follow-up varied from 1 to 54 months, with a mean follow-up duration of 26 months. Patients tolerated the treatment well. The only adverse event reported was a minor acne breakout following one of the early treatments, which may or may not have been related to the FFIM vitamin C treatment.
The mean improvement in melasma pigmentation from baseline was 73%. Greater than 25% improvement was observed in 32 of 35 patients, and greater than 50% improvement noted in 22 of 35 patients (Figure 2). Mean improvements in skin texture and wrinkles were 62% and 39%, respectively. As shown in Table 2, MASI scores also demonstrated substantial improvement from baseline for all patients (mean improvement, 15.7). Before and after treatment photos of 3 patients are shown in Figures 3 and 4.
Vitamin C used in combination with a full-face iontophoretic mask produced rapid improvement in appearance of melasma and PIH within 1 to 2 months in all skin types studied. With a daily skin care maintenance regimen of mandelic/malic acid, UVA/UVB sunblock and sun-avoidance behavior, the improvements were sustained up to 54 months. The combination treatment appears to be both safe and effective in maintaining long-term improvement in the appearance of melasma and PIH.
Wrinkles, skin tone, and texture were incidentally observed to improve during the study. This is not surprising, considering the long-term use of highly concentrated vitamin C and α-hydroxy acid products. Generalized facial lightening was also observed anecdotally in many of the patients in the study; however, data were not collected on this parameter.
Vitamin C therapy delivered via FFIM for 1 to 2 months was well tolerated in this study with only one minor acne breakout possibly related to the treatment. Other long-term therapies for melasma and PIH that have been effective are associated with adverse effects. Long-term therapy with a triple combination product (hydroquinone, tretinoin, and fluocinonide) appears to be effective. However, there is a measureable risk of skin atrophy and telangiectasia.5,21 Other hydroquinone products also have adverse effects when used long-term, including irritation, exogenous ochronosis, PIH, and instability leading to decreased efficacy.6,7
The long-chain mandelic and malic acids skin care regimen is well tolerated long-term. (M.B.T., unpublished data, 2002-2008). The 6 % mandelic/6% malic acid product is well tolerated in sensitive and darker skin types (Fitzpatrick types V and VI) without causing PIH. In addition, patients are often able to upgrade