Patent ID: 7045633

Claim:
A process for preparing a compound, which is a hydrate of 5-[4-[2-(N-methyl-N-(2-pyridyl)amino)ethoxy]benzyl]-thiazolidine-2,4-dione, maleic acid salt, said process comprising crystallizing a maleic acid salt of 5-[4-[2-(N-methyl-N-(2-pyridyl)amino)ethoxy]benzyl]thiazolidine-2,4-dione from an aqueous alkanolic solvent selected from the group consisting of aqueous denatured ethanol, aqueous isopropanol and mixtures thereof, wherein said compound contains water in the range of from 0.2 to 1.1 % w/w and said compound provides at least one of: (i) an infra red spectrum containing peaks at 764 and 579 cm −1 ; and (ii) an X-ray powder diffraction pattern substantially in accordance with FIG. II.