High-performance liquid chromatographic determination of alfuzosin in biological fluids with fluorimetric detection and large-volume injection.
A high-performance liquid chromatographic method has been developed for the determination of alfuzosin, a new antagonist of alpha 1 post-synaptic adrenergic receptors, in blood, plasma or urine. With fluorimetric detection and the large volume injection technique, the limit of detection in plasma is 0.5-1 ng ml-1, which is sensitive enough for pharmacokinetic studies in man. The calibration graph is linear between 1 and 200 ng ml-1 in blood plasma, with coefficients of variation of 6.2 and 1%, respectively. In urine, the linearity range is 0.05-10 micrograms ml-1; at the lowest concentration, the coefficient of variation is about 10%. A constant plasma/blood concentration ratio (1.25 +/- 0.05) allows the measurement of drug in either fluid. In blood or plasma, alfuzosin is stable at 37 degrees C for 24 h and at -20 degrees C for 6 months. As expected for reversed-phase chromatography, the retention times of alfuzosin and a few of its analogues decrease inversely with the concentration of acetonitrile in the mobile phase. However, as this concentration reaches about 75%, the retention times increase sharply. This U-shaped curve may be explained by interactions of the amino groups with silanol groups of the stationary phase.
Guinebault
P
P
Broquaire
M
M
Colafranceschi
C
C
Thénot
J P
JP
D000317:Adrenergic alpha-Antagonists / Q000032:analysis* / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D011799:Quinazolines / Q000032:analysis* / Q000097:blood / Q000652:urine; D013050:Spectrometry, Fluorescence
D000317:Adrenergic alpha-Antagonists; D007202:Indicators and Reagents; D011799:Quinazolines; C047638:alfuzosin