| abstract |
To provide a novel crystal of 5-aminolevulinic acid phosphate having a high thermal stability, a high melting point, and an excellent moisture absorption resistance as well as a process for producing the same. A crystal of 5-aminolevulinic acid phosphate, which shows characteristic peaks at 7.9°±0.2°, 15.8°±0.2°, 18.9°±0.2°, 20.7°±0.2°, 21.1°±0.2°, 21.4°±0.2°, 22.9°±0.2°, 33.1°±0.2°, and 34.8±0.2° as diffraction angles 2θ in a powder X-ray diffraction, and a process for producing the same. |