Provided is a core-shell structure which exhibits excellent fast-acting properties in terms of percutaneous absorption of an active ingredient. A core-shell structure which is provided with a core part that contains an active ingredient and a shell part that contains a surfactant having an HLB value of 4-14. The core part is a solid； and the surfactant has a saturated hydrocarbon group having 7-15 carbon atoms or an unsaturated hydrocarbon group having 7-17 carbon atoms.本發明提供一種於有效成分之經皮吸收時速效性優異之核殼構造體。 本發明之核殼構造體具備：核部，其含有有效成分；及殼部，其含有HLB值為4～14之界面活性劑；且上述核部為固體，上述界面活性劑具有碳數為7～15之飽和烴基、或碳數為7～17之不飽和烴基。
