Evaluation of high-performance liquid chromatography and mass spectrometry method for pharmacokinetic study of local anesthetic ropivacaine in plasma.
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 microg/mL. Recovery 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.
Sawaki
Kohei
K
Department of Pharmacology, Tokyo Dental College, Chiba, Japan. sawaki@tdc.ac.jp
Okubo
Migiwa
M
Shimomiya
Takashi
T
Tukagoshi
Eri
E
Sakai
Takayuki
T
Yamazaki
Takaki
T
Kenmochi
Masahiro
M
Miyao
Mariko
M
Kaneko
Yuzuru
Y
Ichinohe
Tatsuya
T
Kawaguchi
Mitsuru
M
D000577:Amides / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D000779:Anesthetics, Local / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004285:Dogs; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D011817:Rabbits; D000077212:Ropivacaine
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine