2005 Volume 4 Issue 3 Pages 299-308
Two clinical studies using different types of iontophoresis equipment was performed to confirm the effects of vitamin C derivatives on pigmented macules such as solar lentigines and ephelides by a controlled half face study.
In the first study, iontophoresis with 5% sodium L-ascorbyl-2-phosphate was performed on one side of the face using an in-hospital iontophoresis equipment by a dermatologist weekly for three months. During this study, the other side of the face, as control side, was not given any treatment. In the second study, the patient applied the agent daily for four months using home iontophoresis equipments on one side of the face, with simple topical application of the agent on the other control side.
The skin findings and image analyses showed improvement on the iontophoresis sides in 31 out of 32 cases in the first study and 37 out of 37 cases in the second one. The treated side revealed significantly higher degree of improvement than the control side in both studies.
Skin color tone analysis using a spectrophotometer showed that the increase of L* and decrease of b* were obtained in the iontophoresis side which indicates that basal facial skin tone became more clear and lighter. Moreover, the texture of the cheek became more fine as the replica analysis showed the higher density of sulcus cutis and crista cutis.
These findings indicate that iontophoresis enhances the lightening effect of vitamin C derivatives on pigmented macules as well as improves skin color tone and texture.
