Extractive Spectrophotometric Determinations of Amiodarone and Ondansetron in Pharmaceutical Formulations

T. Siva Rao, P. S. N. H. Rama Chandra Rao, A. V. S. S. Prasad and C. S. P. Sastry*

Department of Organic Chemistry, Foods, Drugs and Water Andhra University, Visakhapatnam- 530 003, (India)

Four simple sensitive and reproducible visible spectrophotometric methods (A-D) for the determination of Amiodarone (as hydrochloride, AD) or Ondansetron (as hydrochloride, OST) in bulk samples and pharmaceutical formulations are described. Methods A, B and C are based on the formation of ion-association complexes between AD or OST and tropaeolin oo (TPoo, lmax 420nm), tropaeolin ooo (TPooo, lmax 480nm) or wool fast blue BL (WFB, lmax 580nm). Method D is based on the formation of a molecular complex between AD or OST and cobalt thiocyanate (CTC, lmax 620nm). Regression analysis of Beer's law plots showed good concentration ranges (2.5-15, 0.6-6.0), (3.0-30, 0.5-7.5), (0.75-7.5, 0.3-4.5) and (25-300, 20-240) μg.ml-1 for (AD, OST) in methods A,B,C and D respectively. Relative standard deviations were typically

Spectrophotometric method; amiodarone (AD); ondansetron (OST); tropaeolin oo; tropaelin ooo; cobalt thiocyanate