The voltammetric behavior of nizatidine and its determination in biological fluids

The voltammetric behavior of nizatidine (a newly introduced antiulcer drug) was studied using direct current (DCt, alternating current and differentia l pulse polarography (DPP). Well-defined cathodic waves were obtained over the whole pH range in Britton-Robinson buffers, in addition to 0.1 and 1 M HCl media. The main reduction wave was characterized as being irreversible and diffusion-controlled although adsorption phenomena played a limited rol e in the electrode process. The current-concentration relationship was foun d to be rectilinear over the range 1 x 10(-5) - 6 x 10(-4) and 2 x 10(-6) - 2 x 10(-4) M using DC, and DPP modes respectively, with a minimum detectab ility (SIN = 2) of 2 x 10(-7) M using the latter technique. The number of e lectrons involved in the reduction process was established, and the mechani sm of electrode reaction was verified. The proposed method was successfully applied to determination of nizatidine in spiked human plasma and urine an d the percentage recoveries were 96.12 +/- 0.40 and 97.12 +/- 0.17, respect ively. (C) 1999 Elsevier Science B.V. All rights reserved.