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.

New Methods Used in Pharmacokinetics and Therapeutic Monitoring of the First and Newer Generations of Antiepileptic Drugs (AEDs)

“…The current reference range for ZNS in plasma is 10-40 mg/L [10,29]. Several techniques have been developed to quantify ZNS in human matrices including HPLC or UHPLC methods with UV detection at various wavelengths in the 235-312 nm range [51,167,168] and with MS/MS detection [68,76,78]. The techniques used to prepare the sample before analysis include the precipitation of protein (PP) with acetonitrile, trichloroacetic acid or methanol [51,68,78,109,167], LLE with ethyl acetate [168], surfactant-assisted liquid-liquid dispersion microextraction (SA-DLLME) [51], MEPS [167] or reaction with NBD-Cl chemosensor [169].…”

UHPLC: The Greening Face of Liquid Chromatography

“…As those areas of research require a large amount of API determination, a widespread use of UHPLC methods may help to solve the problem of excessive time and solvent consumption while maintaining adequate resolution and sensivity. The UHPLC methods can be used in analysis of API in the biological matrixes involving identification of metabolites and bioequivalence studies in biological fluids [ 53 – 58 ]. Ultimately, the determination of API at the lowest possible concentration levels may be achieved by the coupling of UHPLC with the mass spectrum detector [ 59 ].…”