PROBLEM TO BE SOLVED: To provide a percutaneous absorbable formulation that is a formulation comprising a core-shell structure having both percutaneous absorption properties and durability.SOLUTION: The invention provides a formulation comprising a core-shell structure in which the core part comprises a drug and the shell part comprises a surfactant, wherein (A) 1-99% in scattering intensity of the core-shell structure with a mean particle diameter of less than 100 nm is comprised, and (B) 1-99% in scattering intensity of the core-shell structure with a mean particle diameter of 100 nm or more is comprised, and the mean particle diameter and the scattering intensity are obtained by measuring by dynamic light scattering method using the filtrate filtered through a 1.0 μm filter after the dispersion of the formulation into a liquid.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】コアシェル構造体を含有する製剤であって、経皮吸収性と持続性の両方を兼ね備えた経皮吸収性製剤を提供する。【解決手段】コア部が薬物を、かつシェル部が界面活性剤をそれぞれ含有するコアシェル構造体を含有する製剤であって、(A)平均粒子径が100nm未満のコアシェル構造体を、散乱強度で1~99%、及び(B)平均粒子径が100nm以上のコアシェル構造体を、散乱強度で1~99%含み、前記平均粒子径及び前記散乱強度が、当該製剤を、液体中に分散させた上で、1.0μmのフィルターにて濾過した濾過液を用いて動的光散乱法により測定して得られるものであることを特徴とする、製剤。【選択図】なし
