The present invention provides a process for the preparation of 2-(4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid ethyl ester. The present invention also provides a process for the preparation of 2-(3-formyl-4-hydroxyphenyl)-4-methylthiazole-5-carboxylic acid ethyl ester. The present invention further provides novel crystalline Forms of febuxostat, processes for their preparation and pharmaceutical compositions comprising them. The present invention further provides febuxostat crystalline particles having a mean particle size of less than about 25 µm, the methods for the manufacture of said crystalline particles, and pharmaceutical compositions comprising said crystalline particles.Linvention concerne un procédé de préparation déthylester dacide 2-(4-hydroxyphényl)-4-méthylthiazole-5-carboxylique. Linvention concerne également un procédé de préparation déthylester dacide 2-(3-formyl-4-hydroxyphényl)-4-méthylthiazole-5-carboxylique. Linvention concerne en outre de nouvelles formes cristallines de fébuxostat, leurs procédés de préparation et des compositions pharmaceutiques les contenant. De surcroît, linvention concerne des particles cristallines de fébuxostat dont la taille particulaire moyenne est inférieure à 25 µm environ, les procédés de fabrication de telles particules, et des compositions pharmaceutiques les contenant.
