Patent ID: 7169799

Claim:
A production method for a crystal of (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl]sulfinyl]benzimidazole·n′H 2 O (wherein n′ is about 0 to about 0.1) or a salt thereof, which comprises obtaining the crystal by crystallization from an organic solvent solution or suspension in which (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl]sulfinyl]benzimidazole·nH 2 O (wherein n is about 0.1 to about 1.0) or a salt thereof has been dissolved or suspended; wherein the crystal of (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridyl]methyl]sulfinyl]benzimidazole·n′H 2 O (wherein n′ is about 0 to about 0.1) shows characteristic peaks at interplanar spacings(d) of 11.68, 6.77, 5.84, 5.73, 4.43, 4.09, 3.94, 3.89, 3.69, 3.41 and 3.11 Angstroms in powder X-ray diffraction.