title: Voltammetric determination of nilvadipine in dosage forms and spiked human urine.
abstract: The voltammetric behaviour of nilvadipine was studied adopting direct-current, differential-pulse and alternating current polarography. Nilvadipine-being nitroderivative-exhibited well-defined cathodic waves over the whole pH range in Britton-Robinson buffers. At pH 5, the diffusion-current constant, (Id) was 4.78. The current-concentration plots are rectilinear over the range 1.5-20 and 0.2-10 microg/ml using the direct current and differential pulse-polarographic techniques with minimum detectability of 0.05 microg/ml (1.3 x 10(-7) M) using the latter technique. The proposed method was applied to commercial capsules containing the drug. The percentage recoveries were in agreement with those obtained by a reference method. Furthermore, the method was applied to spiked human urine, the percentage recovery was 95.54+/-2.137.
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. ffbelal@ksu.edu.sa
authors.forename: F
authors.initials: F
authors.lastname: Belal
authors.forename: H
authors.initials: H
authors.lastname: Abdine
authors.forename: N
authors.initials: N
authors.lastname: Zoman
mesh_terms: D000959:Antihypertensive Agents / Q000737:chemistry / Q000652:urine*; D004304:Dosage Forms; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000652:urine*; D011048:Polarography; D012680:Sensitivity and Specificity
chemical_list: D000959:Antihypertensive Agents; D004304:Dosage Forms; C035100:nilvadipine; D009543:Nifedipine