Disclosed is an eye drop which can achieve high intraocular migration of a medicinal agent contained therein without the need of any carrier such as a liposome. Also disclosed is a method for producing the eye drop. The eye drop is characterized by comprising particles composed of a hydrophobic or liposoluble prodrug that can become hydrophilic or water-soluble upon hydrolysis, wherein the particles have a particle size of not smaller than 10 nm and smaller than 1 µm.