title: Determination of the active metabolites of sibutramine in rat serum using column-switching HPLC.
abstract: A simple and direct analysis using column-switching HPLC method was developed and validated for the quantification of active metabolites of sibutramine, N-mono-desmethyl metabolite (metabolite 1, M1) and N-di-desmethyl metabolite (metabolite 2, M2) in the serum of rats administered sibutramine HCl (5.0 mg/kg, p.o.). Rat serum was directly injected onto the precolumn without sample prepreparation step following dilution with mobile phase A, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (8.3:4.5:87.2 by volume). After the endogenous serum components were eluted to waste, the system was switched and the analytes were eluted to the trap column. Active metabolites M1 and M2 were then back-flushed to the analytical column for separation with mobile phase B, i. e., methanol-ACN-20 mM ammonium phosphate buffer (pH 6.0 with phosphoric acid) (35.8:19.2:45 by volume) and detected at 223 nm. The calibration curves of active metabolites M1 and M2 were linear in the range of 0.1-1.0 microg/mL and 0.15-1.8 microg/mL. This method was fully validated and shown to be specific, accurate (10.4-10.7% error), and precise (1.97-8.79% CV). This simple and rapid analytical method using column-switching appears to be useful for the pharmacokinetic study of active metabolites (M1 and M2) of sibutramine.
authors.affiliation: Department of Pharmacology, National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Um
authors.forename: Kyu-Bong
authors.initials: KB
authors.lastname: Kim
authors.forename: Seon Hwa
authors.initials: SH
authors.lastname: Kim
authors.forename: Young Cheol
authors.initials: YC
authors.lastname: Ju
authors.forename: Hye Sang
authors.initials: HS
authors.lastname: Lee
authors.forename: Hye young
authors.initials: Hy
authors.lastname: Oh
authors.forename: Ki Hwan
authors.initials: KH
authors.lastname: Choi
authors.forename: Myeon Woo
authors.initials: MW
authors.lastname: Chung
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D003503:Cyclobutanes / Q000008:administration & dosage / Q000097:blood*; D008297:Male; D015394:Molecular Structure; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism
chemical_list: D003503:Cyclobutanes; C058254:sibutramine