PROBLEM TO BE SOLVED: To provide: a novel base that, after application to a skin surface, can rapidly form a coating film and moreover has mitigated skin irritation and occurrence of odors and an external preparation for skin.SOLUTION: A base is used in an external preparation for skin that administers an active ingredient transdermally, and is characterized in that: it contains at least an acrylic-based synthetic polymer and a volatile oil it is liquid or in the form of an ointment prior to application to the skin surface and after application, the volatile oil is evaporated and then forms a hydrophobic coating film in which the volatile oil is in the range of 0-60 wt% with respect to 100 pts. by weight of the acrylic-based synthetic polymer.COPYRIGHT: (C)2014,JPO&INPIT【課題】本発明は、皮膚表面への塗布後、速やかに被膜を形成することができ、しかも臭気の発生や皮膚刺激性を緩和した新規な基剤、及び皮膚外用剤を提供することを目的とする。【解決手段】有効成分を経皮吸収的に投与する皮膚外用剤に用いられる基剤であって、アクリル系合成ポリマーと揮発性油剤とを少なくとも含有し、皮膚表面への塗布前には、液状又は軟膏状であり、塗布後には、前記揮発性油剤が蒸散して、前記アクリル系合成ポリマー100重量部に対して前記揮発性油剤が0~60重量%範囲内の、疎水性の被膜となることを特徴とする基剤。【選択図】なし
