Two Kinds Of Florfenicol Powder In Pharmacokinetics Studies In Chickens

Florfenicol (FFC), a derivative of chloramphenicol binding irreversibly to the 50S ribosomal subunit preventing protein synthesis, is a broad-spectrum antibiotic widely used in veterinary or aquacultural farms owing to the sensitivity to both Gram-positive and Gram-negative bacteria and the lower toxicity. Recently, FFC is commonly employed in livestock and aquaculture for treating bacterial diseases especially associated with poultry pathogens such as E.coli, Pasteurella and Salmonella, et al. Therefore, in the present study, the pharmacokinetic characteristics of two kinds of FFC,10% and 19.91% content powders, were evaluated and compared in chickens.twenty broilers weighting1.5-2.0 kg were chosen, and randomly divided into two groups, each group of ten chickens (5 male and 5 female). The first group were administrated with 10% Florfenicol powder, and the other group with 19.9% Florfenicol powder at dose of 15 mg/kg b.w. via oral administration, respectively. The blood samples were collected from the vine under the wing according to the stipulated time points. Plasma were obtained through centrifugation at 3000 r/min. FFC were extracted from plasma with ethyl acetate, and then determined with the high performance liquid chromatography (HPLC) method. The mobile phase was acetonitrile: water=30:70 (V/V). Winnonlin5.2 pharmacokinetic analysis software was used to analyze blood drug concentration-time data and calculate pharmacokinetic parameters respectively.After administrated single dose of 10% Florfenicol powder, the main pharmacokinetics parameters were as follows:T1/aβ,7.513 h, Tmax,1.900 h, Cmax,5.106μg/mL, AUC,25.749 μg/mL/hr, MRT,5.695 h. While for 19.91% Florfenicol powder, the values were 0.600 h,5.789 μg/mL,16.474μg/mL/hr,4.357 h respectively. Therefore, compared to 10% florfenicol powder, the elimination rate of 19.91% florfenicol powders were slower. But the Cmax and peak time of 19.91%florfenicol were significantly higher and earlier. The relative bioavailability was 102.816%. The results showed that the absorbtion degree of 19.91% Florfenicol powder through oral administration was the same to the reference substance of 10% Florfenicol. This study will provide the experimental evidence for guiding the rational use of drugs in clinical.