STUDIES ON PHARMACOKINETICS AND TISSUE CONCENTRATION OF OLAQUINDOX IN COMMON CARPS

The concentration of olaquindox in the plasma and tissues of common carps was determined by high performance liquid chromatography(HPLC). Using a C18 column, the mobile phase consisted of methanol/tridistilled water (15:85). The UV detection wavelength was 372 nm. Samples were deproteined with trichloro acetic acid. The precipitated mixture was shaken and then centrifuged, the filtrate was evaporated to dryness. Within the range of 0.2-25.6 μg/mL, Olaquindox had a good linearity. The detectability was 0.04 μg/g and the average recovery of olaquindox was 85.93%-100.2%. The within day and day to day precision expressed by RSD was less than 10% at three drug levels. Pharmacokinetics parameters and residues of olaquindox were investigated in common Carps, after orally administered at a dose of 30mg/kg fish, The C T curve was in accordance with one-compartment open model with the first order absorption. The pharmacokinetic parameters of olaquindox in carps are as follows: the elimination half life(T1/2k) is 5.876h, the distribution half life(T1/2ka) is 1.466h, the peak time (Tp) is 3.913h, the peak concentration (Cmax) is 30.25ug/mL and the area under the curve(AUC) is 406.92 mg/L·h. By means of the determination of contents of olaquindox in tissus, its remnant in carp musles after oral administration with a single dose and several doses and the olaquindox excreted in the prototype. The rhythms were found in the metabolism of olaquindox in muscles, liver and kindey after oral delivery in single dose and in muscles after oral delivery in several doses. The drug excreted in the prototype accounted for 6.9% of the total amount of the drug administered. The optimum drug feeding programe and drug administration ceasing period were suggested.