AUTHOR=Ahmad Salah Uddin , Sun Jichao , Cheng Fusheng , Li Bing , Arbab Safia , Zhou Xuzheng , Zhang Jiyu 

TITLE=Comparative Study on Pharmacokinetics of Four Long-Acting Injectable Formulations of Enrofloxacin in Pigs

JOURNAL=Frontiers in Veterinary Science

VOLUME=7

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2020.604628

DOI=10.3389/fvets.2020.604628

ISSN=2297-1769

ABSTRACT=<p>A comparative study on pharmacokinetics of four long-acting enrofloxacin injectable formulations was investigated in 36 healthy pigs after intramuscular injection according to the recommended single dose @ 2.5 mg/kg body weight. The drug concentrations in the plasma were computed using high-performance liquid chromatography (HPLC) with fluorescence detection. WinNonLin5.2.1 software was used to analyze the experimental data and compared it under one-way ANOVA using SPSS software with a 95% confidence interval (CI). The main pharmacokinetic parameters, that is, the maximum plasma concentrations (C<sub>max</sub>), the time to maximum concentration (T<sub>max</sub>), area under the time curve concentration (AUC<sub>all</sub>) and Terminal half-life (T<sub>1/2</sub>) were 733.84 ± 129.87, 917.00 ± 240.13, 694.84 ± 163.49, 621.98 ± 227.25 ng/ml, 2.19 ± 0.0.66, 1.50 ± 0.37, 2.89 ± 0.24, 0.34 ± 0.13 h, 7754.43 ± 2887.16, 8084.11 ± 1543.98, 7369.42 ± 2334.99, 4194.10 ± 1186.62 ng h/ml, 10.48 ± 2.72, 10.37 ± 2.38, 10.20 ± 2.81, and 10.61 ± 0.86 h for 10% enrofloxacin (Alkali), 20% enrofloxacin (Acidic), Yangkang and control drug Nuokang® respectively. There were significant differences among C<sub>max</sub>, T<sub>max</sub>, and AUC<sub>all</sub> of three formulations compare with that of the reference formulation. No significant differences were observed among the T<sub>1/2</sub> for tested formulations compare with the reference formulation. The pharmacokinetic parameters showed that the tested formulations were somewhat better compared to the reference one. The calculated PK/PD indices were effective for bacteria such as <italic>Actinobacillus pleuropneumoniae</italic> and <italic>Pasteurella multocida</italic> with values higher than the cut-off points (C<sub>max</sub>/MIC<sub>90</sub>≥10–12 and AUC/MIC<sub>90</sub> ≥ 125). However, they were not effective against bacteria like <italic>Haemophilus parasuis, Streptococcus suis, E. coli</italic>, and <italic>Bordetella bronchiseptica</italic> where lower values were obtained.</p>