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 differential 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 role in the electrode process. The current-concentration relationship was found 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 detectability (SIN = 2) of 2 x 10(-7) M using the latter technique. The number of electrons involved in the reduction process was established, and the mechanism of electrode reaction was verified. The proposed method was successfully applied to determination of nizatidine in spiked human plasma and urine and the percentage recoveries were 96.12 +/- 0.40 and 97.12 +/- 0.17, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.