title: Rapid and sensitive high performance liquid chromatographic determination of zonisamide in human serum application to a pharmacokinetic study.
abstract: An accurate and very rapid method for determination of zonisamide an antiepileptic drug, in human serum is described. The analytical procedure involves liquid-liquid extraction of the analyte and an internal standard (vanillin) from human serum by ethyl acetate as extracting solvent. Chromatographic separation was achieved using a monolithic C18 analytical column and a mixture of 0.05 M phosphate buffer containing triethylamine (1 ml/l; pH 2.7) and methanol (83:17 v/v) was used as the mobile phase. The detection wavelength was set at 240 nm. The calibration curve was linear over a concentration range of 0.015-6.4 μg/ml of zonisamide in human serum. The total run time of analysis was 3.5 min and the lower limits of detection and quantification were 0.005 and 0.015 μg/ml, respectively. The method validation was carried out in terms of specificity, sensitivity, linearity, precision, accuracy and stability. The validated method was applied in a randomised crossover bioequivalence study of two different zonisamide preparations in 24 healthy volunteers, and the assay was sensitive enough to measure drug levels up to 8 days following a single dose administration of zonisamide.
authors.affiliation: Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: M B
authors.initials: MB
authors.lastname: Majnooni
authors.forename: B
authors.initials: B
authors.lastname: Mohammadi
authors.forename: R
authors.initials: R
authors.lastname: Jalili
authors.forename: G H
authors.initials: GH
authors.lastname: Bahrami
keywords: Bioequivalence study; chromatography; high performance liquid chromatography; zonisamide