[Solid phase clean-up and determination of vesnarinone in plasma by high performance liquid chromatography]

Vesnarinone, a new positive inotropic agent, was synthesized by Tominaga et al of the Otsuka Pharmaceutical Co. Ltd. Institute in 1982. Determination of Vesnarinone plasma level in dogs by reversed-phase HPLC was developed and presented in this paper. A plasma sample preparation was carried out by solid phase cleaned-up through neutral aluminum column (10 x 1 cm I.D.) eluting with methanol. The chromatography consisted of a slim-pack CLC ODS column (150 x 6.0 mm I.D.) with methanol: 1 mmol/L HAc (55:45) as the mobile phase at a flow rate of 0.8 ml/min. Spectrophotometric detection was at 271 nm, and column temperature was at 25 degrees C. Using 3,4-dihydro-6-(4-(4-methoxybenzoyl)-1-piperazinyl)-2 (1H) quinolinone as an internal standard. The cleaned-up procedure is simple, rapid and satisfactory. The detection limit of vesnarinone was 0.5 ng/ml (R/N, 3:1). The calibration curve was liner (r = 0.99998) in the concentration range of 5-500 ng/10 microliters. Within-day and day-to-day precisions (CV%) were 1.56 and 1.98. The recoveries obtained from cleaned-up and spiked plasma samples were up to 86.52 +/- 2.77% and 96.26 +/- 5.46%, respectively.