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Microemulsion electrokinetic chromatography applied for separation of levetiracetam from other antiepileptic drugs in polypharmacy
Author(s) -
Ivanova Mariela,
Piunti Alessandra,
Marziali Ettore,
Komarova Natalja,
Raggi Maria Augusta,
Kenndler Ernst
Publication year - 2003
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200390143
Subject(s) - chemistry , microemulsion , chromatography , micellar electrokinetic chromatography , sodium dodecyl sulfate , aqueous solution , levetiracetam , aqueous two phase system , pulmonary surfactant , capillary electrophoresis , organic chemistry , biochemistry , neuroscience , epilepsy , biology
Microemulsion electrokinetic chromatography was applied for the separation of levetiracetam from other antiepileptic drugs (primidone, phenobarbital, phenytoin, lamotrigine and carbamazepine) that are potentially coadministered in therapy of patients. The influence of the composition of the microemulsion system (with sodium dodecyl sulfate as charged surfactant) was investigated, modifying the kind of cosurfactant (lower alcohols from C3 to C5), the pH (and salinity) of the aqueous background electrolyte, and the ratio of aqueous phase to organic constituents forming the microdroplets of the oil‐in‐water emulsion. Separation selectivity was depending on all these parameters, resulting even in changes of the migration sequence of the analytes. Only moderate correlation was observed for the microemulsion system compared with a micellar system, both consisting of the aqueous borate buffer (pH 9.2) and SDS as micelle former (linear correlation coefficient for analyte mobilities is 0.974). The sample solvent plays an important role on the shape of the resulting chromatograms: methanol at concentrations higher than 35% impairs peak shape and separation efficiency. The microemulsion method (with 93.76% aqueous borate buffer (pH 9.2, 10 m M ), 0.48% n ‐octane, 1.80% SDS, 3.96% 1‐butanol, all w/w) is suitable for the determination of levetiracetam in human plasma (combined with a sample pretreatment based on solid‐phase extraction).