The present invention relates to an iontophoretic preparation for treating breast cancer and/or mastitis characterized in that it contains a non-steroidal antiinflammatory analgetic agent of the kind such as hereinbefore described and/or an anticancer agent of the kind such as hereinbefore described as an active ingredient in an amount of from 0.01 to 20 mass % and has a donor comprising an electrode and a pad containing the active ingredient to be applied on a nipple part and a receptor to be applied on the breast part for topical administration of the active ingredient from the nipple to a mammary gland by application of electric potential at 3 V.
