The present invention is to provide means to treatbreast cancer and/or mastitis by topically administeringa non-steroidal antiinflammatory analgetic agent and/oran anticancer agent and allowing them efficiently toarrive into the mammary gland. The present inventionprovides an iontophoretic preparation for treating breastcancer and/or mastitis which contains a non-steroidalantiinflammatory analgetic agent and/or an anticanceragent as an active ingredient and has a donor to beapplied on a nipple part for topical administration ofthe active ingredient from the nipple part to the mammarygland by application of electric potential.
