Study On Pharmacokinetics And Pharmacodynamics Of Cefquinome In Ducks Infected By Riemerella Anatipestifer

Cefquinome is a fourth-generation cephalosporin with good antimicrobial activity against a broad spectrum of bacterial species, and is regarded as being highly stable toβ-lactamases. Cefquinome is known for its use as an antibacterial drug in cattle and pigs, but none for the avian diseases. In this article,primary study on the PK/PD of Cefquinome sulphate lyophilized powder was performed to provide theoretical foundation for its clinical application for the infectious serositis of ducks.1 Determination of Cefquinome sulphate in Cefquinome sulphate lyophilized powder by HPLCA HPLC method was established for the determination of Cefquinome sulphate in Cefquinome sulphate lyophilized powder. The assay was performed on Kromasil C₁₈ column (150 mm×4.6 mm,5μm) with the buffer solution of sodium perchlorate-H₃PO₄-triethylamine (pH3.6)-acetonitrile (V: V=90: 10) as mobile phase. And the detection wavelength was set at 270 nm.The flow rate was 0.8mL/min. The results indicated that the Cefquinome sulphate within the range from 0.05-25μg/mL was linearly correlated, r=0.9996, the average recovery was 100.34% (n=9), and the RSD was 1.34%. This method is simple and credible. Therefore, the method can be used for the quality control of the Cefquinome sulphate lyophilized powder.2 Study on the antibacterial activity of cefquinome sulphate against Riemerella AnatipestiferTo study the antibacterial activity of cefquinome sulphate against RA, an antimicrobial susceptibility testing was done by Microdilution method. The results were assessed according to the National Commmittee for Clinical Laboratory Standard (CLSI/NCCLS), and compared with selected antimicrobial agents. The results showed that Cefquinome had good activity against RA. The MIC of the cefquinome against RA was 0.0625μg/mL, which was better than Ceftiofur,Enrofloxacin and Ampicillin. As the fourth- cephalosporins, cefquinome had good activity against G" bacteria. It provided a new method to treat the ducks infected by RA.3 Study on Pharmacodynamics of Cefquinome Sulphate in Ducks Infected Artificially by Riemerella AnatipestiferPharmacodynamics of Cefquinome sulphate lyophilized powder in ducks infected artificially by Riemerella Anatipestifer (RA) were studied in this paper. 140 ducks in 10-day-old were divided into 7 groups randomly. Ducks in 6 groups were infected by RA and then cured with Cefquinome sulphate lyophilized powder (high-dose, medium-dose, low-dose), Ceftiofur and Doxycycine Hyclate. Positive group and control group were also set up. The results showed that the effective rates of the high-dose group(4mg/kg·bw) and medium-dose group(2mg/kg·bw) were both 95.0%. The relative weight increase rates were 91.3% and 89.2% respectively. The parameters were higher than the other groups significantly (P<0.05/0.01).The Cefquinome sulphate lyophilized powder(high-dose, medium-dose could effectively alleviate the symptom, prevent the discreasing weight and reduce the mortality rate of the infectious serositis of ducks.4 Study on Pharmacokinetics of Cefquinome sulphate in DucksPharmacokinetics of Cefquinome sulphate lyophilized powder and Cefquinome sulphate powder were studied in healthy ducks. The plasma concentration of Cefquinome sulphate lyophilized powder and Cefquinome sulphate powder in 20 healthy ducks intramuscular administered in a dose of 2mg/kg·bw was detected by HPLC, respectively. The results showed that the pharmacokinetic characteristics of the two preparations in ducks were both best described by an open two-compartment model with first order absorption rate. The main pharmacokinetic parameters were as follows, respectively:T_1/2α were 2.63±0.72h and 2.79±0.86h,T_1/2β were 5.76±1.23h and 6.57±1.11h,C_max were 3.54±0.81μg/ml and 3.53±1.01μg/ml,T_max were 2.06±0.89h and 2.10±0.46h, CL(s) were 0.10±0.03 mg/mL/h and 0.12±0.02mg/mL/h,AUC were 22.11±5.02 (μg/mL)·h and 23.24±4.34 (μg/mL)·h.The pharmacokinetic characteristics of Cefquinome sulphate lyophilized powder and Cefquinome sulphate powder were not significantly different(P>0.05). The The relative bioavailability of Cefquinome sulphate lyophilized powder was 95.10%. The mean plasma concentration of Cefquinome sulphate lyophilized powder 24h can remain 0.11μg/mL after 24h. It is reanonable to treat the infectious serositis of ducks in the dose of 2mg/kg·bw daily for 3-5 consecutive days.