Simultaneous determination of raltegravir and raltegravir glucuronide in human plasma by liquid chromatography-tandem mass spectrometric method.
Raltegravir is a highly efficacious inhibitor of HIV integrase. Large pharmacokinetic variability has been reported in clinical trials and this could be due to glucuronidation of raltegravir, the only reported metabolism pathway. In order to precisely evaluate and monitor the raltegravir and raltegravir glucuronide simultaneously, a novel, sensitive and robust liquid chromatography-tandem mass spectrometric method was developed and validated for simultaneous determination of raltegravir and raltegravir glucuronide in human plasma. A simple protein precipitation with acetonitrile was utilized for plasma sample preparation prior to analysis. Baseline chromatographic separation was achieved on a ZORBAX Eclipse XDB-C8 using gradient elution mode. The run time was 9 min at a constant flow rate of 0.4 ml/min. The mass spectrometer was operated under a positive electrospray ionization condition. Excellent linearity (r(2) ≥ 0.9997) was achieved for raltegravir and raltegravir glucuronide in the range of 2-2000 nmol/l. The average recovery of raltegravir and raltegravir glucuronide was 105.8% and 102.2%, respectively. The precision (coefficient of variation) was 1.6-6.6% for raltegravir and 2.1-6.9 for raltegravir glucuronide, respectively. The accuracy was 98.6-106.1% for raltegravir and 96.3-100.3% for raltegravir glucuronide. The plasma samples were tested to be stable after nine freeze-thaw cycles and exposure to room temperature for 24 h. This well-validated assay was applied for the quantification of raltegravir and raltegravir glucuronide in plasma samples within 24 h after a single oral dose of 400 mg raltegravir in six healthy subjects.
Cancer Science Institute of Singapore, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore. csiwl@nus.edu.sg
Ling-Zhi
LZ
Wang
Lawrence Soon-U
LS
Lee
Win-Lwin
WL
Thuya
Gaik Hong
GH
Soon
Li-Ren
LR
Kong
Pei-Ling
PL
Nye
Edmund Jon Deoon
EJ
Lee
Charles
C
Flexner
Boon-Cher
BC
Goh
D019540:Area Under Curve; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D020719:Glucuronides / Q000097:blood*; D006801:Humans; D011760:Pyrrolidinones / Q000097:blood* / Q000493:pharmacokinetics; D000068898:Raltegravir Potassium; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
D020719:Glucuronides; D011760:Pyrrolidinones; D000068898:Raltegravir Potassium