HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ELECTROSPRAY TANDEM MASS-SPECTROMETRY FOR THE MEASUREMENT OF 1-(3,4-DICHLOROBENZYL)-5-OCTYLBIGUANIDEIN HUMAN SERUM
S. Kudo et al., HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ELECTROSPRAY TANDEM MASS-SPECTROMETRY FOR THE MEASUREMENT OF 1-(3,4-DICHLOROBENZYL)-5-OCTYLBIGUANIDEIN HUMAN SERUM, Therapeutic drug monitoring, 20(6), 1998, pp. 697-705
1-(3,4-dichlorobenzyl)-5-octylbiguanide (OPB-2045) is a new biguanide
antimicrobial agent currently in clinical use as a topical bactericida
l antiseptic. A method combining high-performance liquid chromatograph
y (HPLC) with electrospray ionization (triple and quadruple stage) tan
dem mass spectrometry (ESI-MS/MS) was developed to quantify OPB-2045 i
n human serum. Solid phase extraction was performed on 0.2 ml of sampl
e to ensure a high level of sensitivity before HPLC-ESI-MS/MS analysis
. The limit of quantitation for the method was set at 0.05 ng/ml. Intr
a-assay and interassay precision were less than 13.7%, with a deviatio
n from the expected value of no greater than 10.5% at a concentration
range of 0.05 ng/ml to 5 ng/ml. Decomposition of OPB-2045 in human ser
um did not occur after storage for 15 months at -20 degrees C, even af
ter three repetitions of freezing and thawing. Application of this met
hod was demonstrated in a pharmacokinetic study of OPB-2045 in healthy
patient subjects after a single topical application of 5 g/L preparat
ion of its liquid formulation.