Evaluation of high-performance liquid chromatography and mass spectrometry method for pharmacokinetic study of local anesthetic ropivacaine in plasma

Kohei Sawaki, Migiwa Okubo, Takashi Shimomiya, Eri Tukagoshi, Takayuki Sakai, Takaki Yamazaki, Masahiro Kenmochi, Mariko Miyao, Yuzuru Kaneko, Tatsuya Ichinohe, Mitsuru Kawaguchi
2009 Biomedical research  
We studied the viability of high-performance liquid chromatography and mass spectrometry (LC/ MS) as a selective and sensitive analytical method for measuring blood concentrations of the local anesthetic ropivacaine. Ropivacaine was effectively separated using a reverse-phase column and monitored at 275 m/z ion. The LC/MS method allowed measurement of concentrations of ropivacaine of lower than 75 ng/mL. The standard curve was linear and in the range of < 1.5 μg/mL. Recovery of ropivacaine in
more » ... of ropivacaine in plasma samples was over 90% after precipitation of plasma protein with trichloroacetic acid. The method was tested on the pharmacokinetics of plasma ropivacaine after single intravenous or subcutaneous administration in rabbits. The pharmacokinetic parameters showed a one-compartment model and a mean elimination half-life of 0.54 ± 0.05 h and 2.83 ± 0.51 h after administration at doses of 0.4 mg/kg, i.v. and 5 mg/kg, s.c., respectively. These values were in approximate agreement with previously obtained results in dogs. The results of the present study demonstrated that the LC/MS method was highly selective and sensitive for the measurement of ropivacaine, indicating that it offers a useful tool for monitoring the therapeutic effects and determining the pharmacokinetic parameters of this drug in blood.
doi:10.2220/biomedres.30.319 pmid:20051639 fatcat:d2snygzlknbkbalzkatf5pzs5i