A method for producing a crystal of the poorly water-soluble pharmaceutical compound, comprising mixing a good solvent solution of the poorly water-soluble pharmaceutical compound with nanobubble water or an aqueous solution of nanobubbles to precipitate the crystal of the poorly water-soluble pharmaceutical compound . Crystals of poorly water-soluble pharmaceutical compounds obtained by this method have fine and more uniform particle size distribution, and are excellent in absorbability and sustainability.難水溶性医薬化合物の良溶媒溶液とナノバブル水またはナノバブル水溶液とを混合することにより、該難水溶性医薬化合物の結晶を析出させることを特徴とする、該難水溶性医薬化合物の結晶の製造方法。当該方法により得られる難水溶性医薬化合物の結晶は、微粒かつより均一な粒径分布を有し、吸収性・持続性に優れる。
