Manufacture of High-Purity Meloxicam via Its Novel Potassium Salt Monohydrate

An improved procedure for the manufacture of 4-hydroxy-2-methyl-N-(5-methyl-1,3-thiazol-2-yl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide (meloxicam) is described. The key intermediate of this protocol is the new potassium salt monohydrate of meloxicam, which makes possible the efficient removal of impurities, resulting in an environmentally friendly manufacturing process of the high-purity (>99.90%) drug substance.