title: Voltammetric behavior of zaleplon and its differential pulse polarographic determination in capsules.
abstract: In this work both the electrochemical behavior and the analysis of the hypnotic pyrazolopyrimidine derivative zaleplon were studied. Zaleplon in ethanol-0.1M Britton Robinson buffer solution (30-70) showed 2 irreversible, well-defined cathodic responses in the pH range of 2-12 using differential pulse polarography (DPP), tast polarography, and cyclic voltammetry. From chronocoulometric studies, it was possible to conclude that one electron was transferred in each reduction peak or wave. For analytical purposes, the DPP technique working at pH 4.5 for peak I was selected, which exhibited adequate repeatability, reproducibility, and selectivity. The recovery was 99.97 +/- 1.52%, and the detection and quantitation limits were 5.13 x 10(-7)M and 1.11 x 10(-6)M, respectively. The DPP method was applied successfully to the individual assay of capsules in order to verify the content uniformity of zaleplon. Treatment of the sample is not required because the excipients do not interfere, the method is not time consuming, and it is less expensive than column liquid chromatography.
authors.affiliation: University of Chile, Chemical and Pharmaceutical Sciences Faculty, Bioelectrochemistry Laboratory, PO Box 233, Santiago 1, Chile.
authors.forename: Gipsy
authors.initials: G
authors.lastname: Larenas
authors.forename: Soledad
authors.initials: S
authors.lastname: Bollo
authors.forename: Marcelo
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Igor
authors.initials: I
authors.lastname: Lemus
authors.forename: Luis J
authors.initials: LJ
authors.lastname: Nuñez-Vergara
authors.forename: Juan A
authors.initials: JA
authors.lastname: Squella
authors.forename: Alejandro
authors.initials: A
authors.lastname: Alvarez-Lueje
mesh_terms: D000081:Acetamides / Q000032:analysis*; D000927:Anticonvulsants / Q000032:analysis*; D002138:Calibration; D002214:Capsules; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid; D004304:Dosage Forms; D004305:Dose-Response Relationship, Drug; D004345:Drug Industry; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D011048:Polarography / Q000379:methods*; D011743:Pyrimidines / Q000032:analysis*; D015203:Reproducibility of Results; D013696:Temperature
chemical_list: D000081:Acetamides; D000927:Anticonvulsants; D002214:Capsules; D004304:Dosage Forms; D011743:Pyrimidines; C085665:zaleplon