| This study developed a method to detect doramectin in dog plasma and tissues using high performance liquid chromatorgraphic with fluorescence detector method. Pharmacokinectics and residue of doramectin in dogs were investigated in this paper. 1, Pharmacokinetics studies of doramectin in dog.Blood sample was collected from forelimb vein of dog at different intervals after following single subcutaneous administration at a dose of 0.3mg/kg. The concentration of doramectin was detected with high performance liquid chromatorgraphic with fluorescence detector.The resuLts were evaluated according to the external standard method and the concentration-time data were calcuLated with 3P97.The limit of detection of doramectin in plasma was 0.5ng/mL under this experiment condition.Lineary was expressed by correlation between chromatographic peak areas and concentration of standards at a wide concentration range of 0.1～100ng/mL, the standard calibration curve was linear in this range and the linear equation of doramectin was A = 5846.2C+14041 (r = 0.9997) .Three concentradtion levels (50ng/mL, 10ng/mL, 0.5ng/mL) of doramectin were analysed,the intra-day coefficient of variance was respectively 1.91%, 1.52%, 2.56%, and the inter-day coefficient of variance was respectively 2.81%, 3.28%, 2.78%,the average recovery was respectively 95.86 ±2.20%. 94.20 ±3.13%, 92.96 ± 2.85%.The procession of doramectin after single subcutaneous administration was fit the one-compartment open model with first-order absorption which was selected based on favorable Akaike Information Criterion(AIC).The main pharmacokinetic parameters of doramectin in dog were as follows: t1/2ka0.58 ± 0.13d, t1/2ke4.78 ± 0.31d, CL/F(s)1.63 ± 0.19mL/g/d, V/F(c)10.96 ± 1.28L/Kg, Tmax2.00 ± 0.29d, Cmax20.29 ± 2.04ng/mL, AUC187.43 ± 24.99ng.d/mL. 2, Studies on residues of doramectin in dogs tissues.Residues studies of doramectin in dog following single subcutaneous administration at a dose of 0.3mg/kg were conducted in this paper.Tissue samples(muscle,liver,kidney,spleen and fat ) were collecter at every different intervals,after being homogenized and extracted,the samples were determined at the... |
