PROBLEM TO BE SOLVED: To provide novel crystalline forms of a benzoic acid derivative for treatment, prevention or management of diseases ameliorated by modulation of premature translation termination or nonsense-mediated mRNA decay, and a preparation method thereof.SOLUTION: The present invention relates to novel Form A and Form B crystalline forms of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]-benzoic acid. Form A is mainly produced by crystallization from an alcohol or ether, DMF and water etc., and Form B is produced by crystallization from water and a solvent having a carbonyl or ether structure, such as acetic acid, acetone and dioxane.【課題】早期翻訳終止又はナンセンス介在性mRNA崩壊の調節により改善される疾患の治療、予防又は管理の為の安息香酸誘導体の新規の結晶形及びその調整方法の提供。【解決手段】下記式で表される3-[5-(2-フルオロフェニル)-[1,2,4]オキサジアゾール-3-イル]-安息香酸（I）の新規なＡ型及びＢ型結晶形。Ａ型は、主として、アルコール類、エーテル類とＤＭＦと水等より結晶化し、Ｂ型は酢酸、アセトン、ジオキサン等のカルボニルやエーテル構造を有する溶媒と水で結晶化して製造される。【選択図】なし
