Provided is a method for blending a compound effective in preventing or improving skin aging with a composition in a chemically stable manner. Also provided is a method for increasing the uniform dispersibility of the compound in the composition. A compound represented by the following general formula (1), an isomer thereof, and/or a pharmacologically acceptable salt thereof is dispersed in an oiling agent having 0 to 2 hydroxy groups to prepare an oil-based composition, thereby suppressing the decomposition of the compound. Moreover, the composition further contains a powder, a solid fat and/or a semi-solid fat, thereby suppressing the sedimentation of the compound in the composition over time.[In formula (1), R1 represents a linear or branched C1-4 alkyl group substituted with a carboxyl group or a linear or branched C1-4 alkyl group substituted with a carboxylic acid ester group having a C1-4 alkyl chain, and R2 and R3 each independently represent a linear or branched C1-4 alkyl group.]
