Separation and characterization of modified pregabalins in terms of cyclodextrin complexation, using capillary electrophoresis and nuclear magnetic resonance

Szabolcs Béni, Tamás Sohajda, Gábor Neumajer, Róbert Iványi, Lajos Szente, Béla Noszál

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

The (S)-(+)-isomer of 3-isobutyl-GABA (pregabalin), the blockbuster drug in the treatment of neuropathic pain has been separated from its R isomer by cyclodextrin modified capillary zone electrophoresis (CZE) using uncoated fused-silica capillary. Derivatization of the single isomer and the racemate with tosyl- and dansyl-chloride was carried out to introduce strong UV chromophores of different size. CE-pH titrations were performed to determine the dissociation constants for both derivatives. 30 cyclodextrin (CD) derivatives as chiral agents were used at four different pH values to study the enantioseparation of the differently protonated guest molecules. The separation was optimized as a function of CD concentration, buffer type and concentration, pH and applied voltage. For the tosylated derivate the best resolution (Rs = 2.76) was found with 6-monodeoxy-6-mono-(3-hydroxy)-propylamino-beta-cyclodextrin hydrochloride (PA-β-CD) at pH 6.8, while with the same selector at pH 7.2 enantioseparation with an Rs value of 4.32 could be achieved for the dansylated pregabalin. At pH 2.5 for the dansylated derivative trimethylated alpha- and beta-CD systems resulted the most significant separation (Rs = 7.38 and Rs = 7.74, respectively). Experiments with dual CD systems were carried out as well. The stoichiometry of the complexes was determined using the Job plot method and resulted in a 1:1 complex in both cases. The structures of the inclusion complexes were elucidated using 2D ROESY NMR experiments.

Original languageEnglish
Pages (from-to)842-852
Number of pages11
JournalJournal of Pharmaceutical and Biomedical Analysis
Volume51
Issue number4
DOIs
Publication statusPublished - Mar 11 2010

Keywords

  • Capillary electrophoresis
  • Enantioseparation
  • Lyrica
  • NMR
  • Synthesis

ASJC Scopus subject areas

  • Analytical Chemistry
  • Pharmaceutical Science
  • Drug Discovery
  • Spectroscopy
  • Clinical Biochemistry

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