Analysis of enantiomers of sibutramine and its metabolites in rat plasma by liquid chromatography-mass spectrometry using a chiral stationary-phase column.
Sibutramine, a monoamine reuptake inhibitor, is used as a racemate, for the treatment of obesity. It is converted in vivo mainly to two desmethyl active metabolites, mono-desmethylsibutramine (MDS) and di-desmethylsibutramine (DDS). In the present study, we introduced a rapid and simple chromatographic method for separating the R(+)- and S(-)-isomers of sibutramine, MDS, and DDS, respectively. The stereoisomers of the three compounds were extracted from rat plasma using diethyl ether and n-hexane under alkaline conditions. After evaporating the organic layer, the residue was reconstituted in the mobile phase (10 mM ammonium acetate buffer adjusted to pH 4.03 with acetic acid:acetonitrile, 94:6, v/v). The enantiomers in the extract were separated on a Chiral-AGP stationary-phase column and were quantified in a tandem mass spectrometry. The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This method was used to measure the concentrations of the enantiomers of sibutramine, MDS, and DDS in plasma after a single oral dose of 10 mg/kg racemic sibutramine in rats.
Bae
Kyoungjin
K
College of Pharmacy, Catholic University of Daegu, Hayang-eup, Kyoungbuk 712-702, South Korea.
Noh
Kyeumhan
K
Jang
Kiyoung
K
Kim
Sohee
S
Yong
Chul Soon
CS
Choi
Han-Gon
HG
Kang
Jong Seong
JS
Chen
Jianbo
J
Ma
Eunsook
E
Lee
Manhyung
M
Shin
Beom Soo
BS
Kwon
Kwang-Il
KI
Kang
Wonku
W
D000818:Animals; D000928:Antidepressive Agents / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D003503:Cyclobutanes / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism
D000928:Antidepressive Agents; D003503:Cyclobutanes; C058254:sibutramine