To provide external preparations for skin with excellent feeling of use in which a compound effective for prevention or improvement of skin aging is stably and uniformly solubilized.SOLUTION: Disclosed herein is an external preparation for skin in which a compound represented by Formula (1) or isomer and/or pharmaceutically acceptable salt thereof is dissolved in C2-C9 alcohol, where Ris a C1-C4 straight/branched alkyl group substituted with a carboxyl group or a C1-C4 straight/branched alkyl group substituted with a carboxylic acid ester group having a C1-C4 alkyl group； Rand Rare independently a C1-C4 straight/branched alkyl group.SELECTED DRAWING: None【課題】皮膚の老化の予防あるいは改善に有効な化合物を、安定かつ均一に可溶化し、使用感触に優れた皮膚外用剤の提供。【解決手段】式（１）に表される化合物その異性体及び／又はそれらの薬理学的に許容される塩を、Ｃ２～９のアルコールに溶解させた皮膚外用剤。[Ｒ１はカルボキシル基で置換のＣ１～４の直鎖／分岐のアルキル基又はＣ１～４のアルキル鎖を有するカルボン酸エステル基で置換のＣ１～４の直鎖／分岐のアルキル基；Ｒ２及びＲ３は夫々独立にＣ１～４の直鎖／分岐のアルキル基]【選択図】なし
