Determination of 7-piperidino-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2-one (DN-9693) in human plasma and urine by high-performance liquid chromatography with electrochemical detection: application to studies on disposition of DN-9693 in healthy human volunteers.

A procedure for the determination of a newly developed antiadhesive agent, 7-piperidino-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2-on e (DN-9693; 1), in human plasma and urine at low nanogram levels by high-performance liquid chromatography with electrochemical detection is described. Plasma and urine samples were made alkaline with 1 M KOH solution and extracted with chloroform. After removing organic solvent, the extracts reconstituted in methanol were applied to a reversed-phase octadesyl-packed column and eluted with a methanol: phosphate buffer (pH 8.0) mobile phase. The applied potentials were set at 0.80 and 0.95 V versus a silver-silver chloride reference electrode for the analyses of plasma and urine specimens, respectively. The method provides a recovery of greater than 90% and a within-day precision of less than 5%. The minimum quantifiable levels for 1 in plasma and urine using 1 mL of sample are 1 and 4 ng/mL, respectively. The method has been successfully used for the determination of 1 in plasma and urine samples from healthy human volunteers after intravenous infusion of the drug.