Novel crystals of 5-(1Z, 2E) -2-methyl-3-phenyl-2-propenylidene -4-oxo-2-thioxo-3-thiazolidineacetic acid, a method for producing the same and a drug containing the crystal as an active ingredient

摘要

Kind Code: A1 The present invention provides a novel and uniform crystal of 5-[(1Z, 2E) -2-methyl-3-phenyl-2-propenylidene] -4-oxo-2-thioxo-3-thiazolidineacetic acid having excellent photostability. Provided are a production method and a drug containing the crystal as an active ingredient. SOLUTION: 5-[(1Z, 2E) -2-methyl-3-phenyl-2-propenylidene]-having at least one of the physicochemical data represented by the following A, B and C: Form A crystal of 4-oxo-2-thioxo-3-thiazolidineacetic acid, a method for producing the same, and a drug containing the same as an active ingredient: A: having a powder X-ray diffraction spectrum shown in FIG. 1 (selection diagram); B: Infrared absorption spectrum (IR) measured using the reflection method is shown in FIG. 2; C: Differential scanning calorimetry (DSC) result is shown in FIG. [Selection diagram] Fig. 1