1961 年 81 巻 7 号 p. 956-959
Calcium pyruvate isoniazone comes in three kinds of crystal form, spindle-shaped, prismatic, and granular, and these three kinds of crystals were found to differ in their solubility in water and in viscosity-temperature curves of their saturated aqueous solution. These curves cross at 27° and 71°. Spindle-shaped crystals are stable below 27°, prismatic crystals in the temperature range of 27-71°, and granular crystals are stable at temperatures above 71°. Crystals in the temperature range of metastable state change into the crystal form stable at that temperature. X-Ray diffraction patterns of these three kinds of crystal differ and the difference in crystal form of calcium pyruvate isoniazone is thought to be due to the difference in crystal structure.