PROBLEM TO BE SOLVED: To provide an external agent for skin-whitening, such as a skin-whitening cosmetic, which is high in the skin infiltration of a skin-whitening ingredient, can make many skin-whitening ingredients to quickly pass through horny layers, and can exhibit a high whitening effect.SOLUTION: The external agent comprising at least one alkylene oxide derivative represented by formula (I), Z-{O(AO)l(EO)m-(BO)nH}a, and a water-soluble skin-whitening ingredient. Therein, Z is the hydroxyl group-removed residue of a compound having 3 to 9 hydroxyl groups AO is a 3 to 4C oxyalkylene group EO is an oxyethylene group BO is a 4C oxyalkylene group (a) is 3 to 9 (l), (m) and (n) are the average addition molar numbers of AO, EO and BO, respectively, wherein 1&lel&le50, 1&lem&le50 and 0.5&len&le5 (AO/EO) weight ratio is 1/5 to 5/1 AO and EO may be added in a random-like or block-like form.COPYRIGHT: (C)2010,JPO&INPIT【課題】美白成分の皮膚浸透性が高く、多くの美白成分が角質層を迅速に通過でき、高い美白効果を発揮することのできる美白化粧料等の美白用外用剤を提供すること【解決手段】下記式(I):(式中、Zは3~9個の水酸基を有する化合物の水酸基を除いた残基を表し;AOは炭素数3~4のオキシアルキレン基を表し;EOはオキシエチレン基を表し;BOは炭素数4のオキシアルキレン基を表し;aは3~9を表し;l、m及びnは、それぞれ、AO、EO及びBOの平均付加モル数であって、1≦l≦50、1≦m≦50及び0.5≦n≦5であり;AOとEOとの重量比(AO/EO)は1/5~5/1であり;AO及びEOはランダム状又はブロック状に付加していてもよい)で表される、少なくとも1つのアルキレンオキシド誘導体を水溶性美白成分と組み合わせて使用する。【選択図】なし
