Abstract
It is well known that tranexamic acid (TA) and sodium L-ascorbyl phosphate (APS) are used as medicines for pigment spots. Since their pharmacological mechanisms are different, the concomitant use of these medicines was expected to be more effective. Because anodal and cathodal iontophoresis were effective for TA and APS, respectively, the sequential effect of iontophoresis was investigated. When the anodal iontophoresis for TA was performed after the cathodal iontophoresis for APS, the APS concentration in epidermis decreased remarkably. When the sequence of iontophoresis was reversed, no remarkable change of TA or APS was found. The results suggested that the sequence of applied electric field can affect the permeation rate of medicine into the skin.
