The object of the invention is to provide a method for manufacturing a transdermal absorption preparation containing imidafenacin. The method of the invention is characterized in that the drug contained in the transdermal absorption preparation will not crystallize and can sufficiently penetrate the skin.The transdermal absorption preparation containing imidafenacin of the invention further contains isostearic acid and fatty acid ester as anti-crystallization agents.本發明之目的在於製造一種皮膚吸收型製劑，其係在含有咪達那新(imidafenacin)的經皮吸收型製劑中，不僅使藥物不析出結晶，又能具有充分的皮膚穿透性。本發明是在含有咪達那新的經皮吸收型製劑中，含有：發揮作為抗結晶劑的機能的異硬脂酸及脂肪酸酯。
