Disclosed is a transdermally absorbable preparation in which the crystallization of a medicinal agent can be prevented even when the medicinal agent has poor solubility in a base material and is contained in the base material at a high concentration, and which exhibits excellent long-term stability and transdermal absorbability of the medicinal agent. By adding a complex of an organic acid and an organic acid salt and a medicinal agent to a base material, it becomes possible to produce a transdermally absorbable preparation in which the crystallization of the medicinal agent can be prevented and which has excellent preparation properties and transdermal absorbability. Also disclosed is use of a complex of an organic and an organic acid salt for preventing the crystallization of a medicinal agent in a transdermally absorbable preparation.
