AUTHOR=Liu Shijie , Guo Yanxin , Qu Honglei , Dong Yanjie , Zhao Shancang , Fu Tianze , Kang Ruifen , Cheng Jie , Huang Shimeng , Zhao Lihong , Ma Qiugang 

TITLE=Pharmacokinetics of florfenicol and its metabolite florfenicol amine in the plasma, urine, and feces of fattening male donkeys following single oral administration

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2024

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1314029

DOI=10.3389/fvets.2023.1314029

ISSN=2297-1769

ABSTRACT=<p>Florfenicol (FF) is a commonly used antibacterial agent in animals. We investigated the pharmacokinetics of FF and its metabolite florfenicol amine (FFA) in donkeys. Donkeys were administered FF (30 mg/kg bodyweight, p.o.). Pharmacokinetic parameters were calculated using a non-compartmental model. The FF (FFA) pharmacokinetics parameters were characterized by along elimination half-life (<italic>t</italic><sub>1/2 kz</sub>) of 5.92 h (15.95 h), plasma peak concentration (<italic>C</italic><sub>max</sub>) of 0.13 μg/mL (0.08 μg/mL), and the time taken to reach <italic>C</italic><sub>max</sub> (<italic>T</italic><sub>max</sub>) of 0.68 h (0.72 h). The area under plasma concentration-time curve and mean residence time of FF (FFA) in plasma were 1.31 μg·mL<sup>−1</sup>·h (0.47 μg·mL<sup>−1</sup>·h) and 10.37 h (18.40 h), respectively. The <italic>t</italic><sub>1/2 kz</sub> of FF and FFA in urine was 21.93 and 40.26 h, and the maximum excretion rate was 10.56 and 4.03 μg/h reached at 25.60 and 32.20 h, respectively. The respective values in feces were 0.02 and 0.01 μg·h<sup>−1</sup> reached at 33.40 h. The amount of FF and FFA recovered in feces was 0.52 and 0.22 μg, respectively. In conclusion, FF (FFA) is rapidly absorbed and slowly eliminated after a single oral administration to donkeys. Compared to FF, FFA was more slowly eliminated. FF (FFA) is mostly excreted through urine.</p>