Specific gas chromatographic analysis of diethylcarbamazine in human plasma using solid-phase extraction.
Diethylcarbamazine (DEC, 1-diethylcarbamyl-4-methylpiperazine) is an antiparasitic piperazine derivative used in the treatment of lymphatic filariasis. DEC-N-oxide is a major metabolite in humans which has antifilarial activity. Gas chromatographic analysis of DEC in plasma can be complicated by the presence of the metabolite, since the thermally unstable DEC-N-oxide is converted to a material which coelutes with DEC under the conditions of the analysis. We now report a method to separate DEC-N-oxide from DEC in plasma using solid-phase extraction with subsequent gas chromatographic analysis using a nitrogen specific detector. 1-Diethylcarbamyl-4-ethylpiperazine (E-DEC) was the internal standard. The standard curve of DEC is linear in the range of 10 to 200 ng/ml. The limit of detection is 4 ng/ml. Reproducibility at 10, 100 and 200 ng/ml concentration points of the standard curve gives coefficients of variation of 6.1%, 7.8% and 1.6%, respectively. Recovery following solid-phase extraction is 99.3% for DEC and 94.8% for the internal standard. This sensitive and specific analytical method is suitable for pharmacokinetic studies of DEC.
Lee
S
S
The University of Iowa, College of Pharmacy, Iowa City 52242, USA.
Casteel
D A
DA
Fleckenstein
L
L
D002152:Calorimetry, Differential Scanning; D002849:Chromatography, Gas / Q000379:methods*; D004049:Diethylcarbamazine / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D004355:Drug Stability; D005369:Filaricides / Q000097:blood*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013816:Thermodynamics
D005369:Filaricides; D004049:Diethylcarbamazine