Abstrato

Development of a new potentiometric modified carbon paste electrode for losartan potassium determination in pharmaceutical formulations

Ikram Jebali, Jamel Eddine Belgaied

In this paper, the development of an extremely inexpensive potentiometric modified carbon paste electrode for losartan potassium is described. Commercially available graphite pencil was ground to fine powder and used to prepare the carbon paste electrode. The electrode is based on the ion-pair complex of losartan potassiumwith 1,10-phenanthroline-iron (II) as modifier and dissolved in 2-nitrophenylpentyl ether (2–NPPE) as pasting liquid. The proposed electrode showed a near-Nernstian slope of –58.3 ± 0.7 mV/ decade over the concentration range of 1.0 × 10-4 to 1.0 × 10-2 M with the limit of detection 5.0 × 10–5 M over the pH range 6.5 – 9.0. The electrode exhibits good selectivity for losartan anions over many inorganic anions, sugars and amino acids. The electrode was applied for the determination of losartan potassium in its different pharmaceutical dosage forms. The results obtained were satisfactorywith excellent percentage recovery comparable withHPLCmethod.