[Problem] There is a demand for a process for producing a pharmaceutical preparation that is obtained by encapsulating a uniform, poorly water-soluble drug in a block copolymer, that dissolves immediately with the addition of water, and that does not contain residues of organic solvents. [Solution] Provided is a process for producing a drug—block-copolymer composite, the process being characterized by spraying and drying a mixed solution prepared by: mixing, in at least one type of non-aqueous solvent, a poorly water-soluble drug and a block copolymer formed by binding a hydrophilic segment and a hydrophobic segment； and warming the mixture as necessary.
