DETERMINATION OF SULFAMATE AND SULFATE AS DEGRADATION PRODUCTS IN AN ANTIEPILEPTIC DRUG USING ION CHROMATOGRAPHY AND INDIRECT UV DETECTION

Topiramate (bis-0-(1-methylethylidene)-fructopyranose sulfamate) is a potent antiepileptic drug currently in phase III clinical trials. Sulf amate and sulfate have been found to be two stoichiometrically formed degradation products in topiramate. An ion chromatographic method with indirect UV detection has been developed to assay sulfamate and/or su lfate in topiramate drug substance and formulated products. When used in combination with an HPLC assay method, this method is stability-ind icating and can be used as a regulatory method.