| abstract |
PROBLEM TO BE SOLVED: To provide an external composition for skin in which a drug having an ester group or amide group in the molecule is present stably over time. A drug having an ester group and / or an amide group in the molecule; An alkylene oxide derivative represented by the following general formula (I): An external composition for skin, comprising water. (Chemical formula 1) R 1 O - [(AO) m (EO) n] -R 2 (I) (In the formula, AO is an oxyalkylene group having 3 to 4 carbon atoms, EO is an oxyethylene group, m and n are the average added moles of AO and EO, respectively, 1 ≦ m ≦ 70, 1 ≦ n ≦ 70. The ratio of EO to the total of AO and EO is 20 to 80% by mass, AO and EO may be added in a block shape or randomly, R 1 and R 2 are (It is the C1-C4 hydrocarbon group or hydrogen atom which may be the same or different, and the ratio of the number of hydrogen atoms with respect to the number of hydrocarbon groups is 0.15 or less.) |