Novel co-crystal and eutectic crystal of kojic acid and a co-former that are excellent in physical properties are provided. In one aspect, novel co-crystals of kojic acid and a co-former that is maltol or ethyl maltol are provided. In another aspect, novel crystal of a eutectic mixture of kojic acid and a co-former that is selected from the group consisting of, maltol, ethyl maltol, methyl paraben and propyl gallate are provided. Methods for producing the novel co-crystal or eutectic crystal are also described. The novel co-crystals and eutectic crystals may be included in a pharmaceutical composition, a health food product or a medical food product for the treatment and/or prophylaxis of a neuropsychiatric disorder.在此揭示由麴酸與一共形物組成之具有優異物性的新穎共晶和共熔結晶。一方面，提供一種由麴酸與一共形物(麥芽酚或是乙基麥芽酚)組成之新穎共晶。另一方面，提供一種由麴酸與一共形物(選自由麥芽酚、乙基麥芽酚、對羥基苯甲酸甲酯或沒食子酸丙酯組成的群組中)組成之共熔物的新穎結晶。亦提供前述新穎共晶或共熔結晶的製造方法。所揭示的新穎共晶和共熔結晶可被納入於藥學組合物、保健食品或是醫藥性食品中，以治療和或預防神經精神疾病。
