Abstracto

Identification and characterization of potential impurities of tizanidine hydrochloride

Ghanta Mahesh Reddy, Singamsetty Radha Krishna, Mandava Venkata Naga Brahmeshwar Rao, Vuzzini Satish, Vurimidi Himabindu

During the analysis of laboratory batches of Tizanidine HCl, six impurities were detected by a simple isocratic reverse-phase high performance liquid chromatography (HPLC) whose area percentage ranged from0.10 to 0.30%. A thorough study has been undertaken to isolate and characterize these impurities, LCMSwas performed to identify themass number of the impurities. The structures of the impurities characterized as: N-(4,5-dihydro-1Himidazol- 2-yl)-2,1,3-benzothiadiazole-4-amine hydrochloride [impA],N-(5- chloro-2,1,3-benzothiadiazol-4-yl)thiourea (imp B), dimer of TizanidineHCl (imp C), S-methyl-N-(5-chloro-2,1,3-benzothiadiazol-4-yl)-isothiouronium iodide (impD), 4-amino-5-chloro-2,1,3-benzothiadiazole (imp E), and N,Nbis( 5-chloro-2,1,3-benzothiadiazol-4-yl)-N-(4,5-dihydro-1H-imidazol-2- yl)guanidine (imp F).