Determination of verapamil by adsorptive stripping voltammetry in urine and pharmaceutical formulations

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 30; no. 4; pp. 921 - 929
• Main Authors: Kasim, Ensaf Aboul, Ghandour, M.A, El-Haty, M.T, Ahmed, Mahasen M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 07.11.2002; Elsevier Science
• Subjects: Adsorption; Analysis; Biological and medical sciences; Chemistry, Pharmaceutical; Electrochemistry - methods; General pharmacology; Humans; Medical sciences; Pharmacology. Drug treatments; Urine; Verapamil; Verapamil - analysis; Verapamil - chemistry; Verapamil - pharmacokinetics; Verapamil - urine; Verapamil ampoule; Voltammogram; Urine; Verapamil; Verapamil ampoule; Adsorption; Voltammogram; Biological fluid; Injectable form; Analysis method; Parenteral form; Calcium antagonist; Aralkylamine; Dosage form; Antihypertensive agent; Voltammetry; Quantitative analysis
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/S0731-7085(02)00322-9

A sensitive reduction peak of verapamil is obtained by adsorptive stripping voltammetry in 0.01 M phosphate (pH 7.4) at an accumulation time of 30 s. The peak potential is −1.81 V (vs. Ag/AgCl). The peak current is directly proportional to the concentration of verapamil (1×10 −8–1×10 −6 M), with a 3 σ detection limit of 5×10 −10 M (0.246 ng/ml). The R.S.D. at the 1×10 −7 M level is 1.8%. The interference of some metal ions, and some amino acids, and the application of the method to analysis of urine, and pharmaceutical formulations are described. The method is simple (no extraction), rapid (30 s accumulation time), sensitive (the detection limit of verapamil is 0.491 ng/ml), reproducible(within day R.S.D. of 1.28–1.8%), and suitable for routine analysis of verapamil, urine, and pharmaceutical formulation.