Differential Pulse Adsorptive Stripping Voltammetric Determination of Nifedipine and Nimodipine in Pharmaceutical Formulations, Urine, and Serum Samples by Using a Clay‐Modified Carbon‐Paste Electrode

Abstract

A simple, rapid, and selective differential pulse adsorptive stripping voltammetric (DPAdSV) method has been developed for the determination of nifedipine and nimodipine based on reduction of an aromatic nitro group in the drugs at a bare carbon‐paste electrode (CPE) and a clay‐modified carbon‐paste electrode (CMCPE). Compared with a bare CPE, CMCPE gave the highest sensitivity in the present developed method. The analytical parameters that affect the electrode reaction process have been studied in terms of pH of the supporting electrolyte, accumulation time, accumulation potential, and composition of a modifier on the adsorptive stripping response by using differential pulse voltammetry. When CMCPE was used, the peak current vs. concentration relationship was found to be linear over the range 4.6 × 10⁻¹⁰–2 × 10⁻⁷ M and 5.4 × 10⁻¹⁰–4 × 10⁻⁷ M, with a limit of detection (LOD) 3.9 × 10⁻¹⁰ and 4.8 × 10⁻¹⁰ M, and correlation coefficient of 0.9996 and 0.9998 for nifedipine and nimodipine, respectively. The method was applied successfully for the direct determination of nifedipine and nimodipine in tablet dosage forms, urine, and serum samples.

Keywords:

• Nifedipine
• Nimodipine
• Pharmaceutical formulations
• Urine
• Serum samples
• Differential pulse adsorptive stripping voltammetry
• Clay‐modified carbon‐paste electrode

Acknowledgments

The authors gratefully acknowlede financial support from the University Grants Commission, New Delhi.