STABILITY-INDICATING METHODS FOR THE SPECTROPHOTOMETRIC DETERMINATIONOF NORFLOXACIN

Two spectrophotometric procedures for the selective determination of n orfloxacin (NF) in the presence of its decarboxylated degradant are de scribed. The first depends upon measurement of the pH-induced absorban ce difference (Delta A) of the drug solution between 0.1 N HCl and 0.1 N NaOH at 280 nm. The second involves chelation of the intact drug wi th iron(II) in acetate buffer solution (pH 5.7 +/- 0.1) to form a yell ow-coloured chelate which absorbs at 358 nm. The two procedures are ap plied successfully for the determination of the intact drug both in pu re form and in tablet form. The two methods retain their accuracy in t he presence of up to 62% and 76% degradants, respectively. (C) 1998 El sevier Science B.V. All rights reserved.