A method for improving dermal retentivity of a compound, which compound is effective for prevention or improvement of skin aging, is provided. The oil-gel-form external preparation for skin containing: 1) a compound represented by the following General Formula (1), an isomer thereof, and/or a pharmaceutically acceptable salt thereof； and 2) a partially cross-linked methyl polysiloxane； of the present invention allows easy penetration of the effective component of 1) from the preparation into the skin while enhancing the percutaneous absorbability and improving the intradermal retentivity. [In the formula, R 1 represents a C 1 -C 4 linear or branched alkyl group substituted by a carboxyl group(s), or a C 1 -C 4 linear or branched alkyl group substituted by a carboxylic acid ester group(s) having a C 1 -C 4 alkyl chain, and R 2 and R 3 each independently represent a C 1 -C 4 linear or branched alkyl group.]
