The present study aimed to assess the pharmacokinetic features of enrofloxacin (ENR) and its major metabolite, ciprofloxacin (CIP) in green sea turtles (Chelonia mydas) after single intravenous (i.v.) and intramuscular (i.m.) administration at two dosages of 5 and 7.5 mg/kg body weight (b.w.). The study used 10 animals randomly divided into equal groups. Blood samples were collected at assigned times up to 168 hr. The concentrations of ENR and CIP in turtle plasma were quantified by a validated high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The concentration of ENR in the experimental turtles with respect to time was pharmacokinetically analyzed using a noncompartment model. The concentrations of ENR in the plasma were quantified up to 144 hr after i.v. and i.m. administrations at dosages of 5 and 7.5 mg/kg b.w., whereas CIP was quantified up to 96 and 144 hr, respectively. The elimination half-life values of ENR were 38.7 and 50.4 hr at dose rates of 5 and 7.5 mg/kg b.w. after i.v. administration, whereas CIP was 33.6 and 22.6 hr, respectively. The maximum concentration (C_max) values of ENR were 2.07 and 2.59 μg/ml at dose rates of 5 and 7.5 mg/kg b.w., respectively. The value of area under the curve from 0 to 24 hr (AUC_0–24)/minimum inhibitory concentration (MIC) ratio of ENR was >125 for bacteria with MIC of 0.12 and 0.13 μg/ml after the administration of 5 mg/kg by i.m. and i.v. administration, respectively. Based on the pharmacokinetic data, susceptibility break-point and pharmacokinetic (PK)/pharmacodynamic (PD) indices, i.m. single administration of ENR at a dosage of 5 mg/kg b.w. might be clinically appropriate for treatment of susceptible bacteria in green sea turtles (Chelonia mydas).

中文翻译：

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绿海龟（Chelonia mydas）中的恩诺沙星及其主要代谢物环丙沙星：一项探索性药代动力学研究

本研究旨在评估恩诺沙星 (ENR) 及其主要代谢物环丙沙星 (CIP) 在绿海龟 ( Chelonia mydas ) 中的药代动力学特征。) 以 5 和 7.5 mg/kg 体重 (bw) 两种剂量单次静脉内 (iv) 和肌肉内 (im) 给药后。该研究使用 10 只动物随机分成相等的组。在指定时间收集血样，最多 168 小时。通过配备荧光检测器（HPLC-FLD）的经过验证的高效液相色谱法对龟血浆中的 ENR 和 CIP 浓度进行量化。使用非隔室模型对实验龟中 ENR 浓度随时间的变化进行药代动力学分析。在 iv 和 im 给药 5 和 7.5 mg/kg bw 后，血浆中 ENR 的浓度最多可量化至 144 小时，而 CIP 的量化时间分别为 96 小时和 144 小时。在剂量率为 5 和 7.5 mg/kg bw 时，ENR 的消除半衰期值为 38.7 和 50.4 小时 iv 给药后，而 CIP 分别为 33.6 和 22.6 小时。最大浓度（在 5 和 7.5 mg/kg bw 的剂量率下，ENR 的C _max值分别为 2.07 和 2.59 μg/ml。对于MIC分别为0.12和0.13 μg/ml的细菌，在施用5 mg/kg后，曲线下面积值（AUC _0-24）/ENR的最低抑菌浓度（MIC）比值>125分别通过 im 和 iv 给药。根据药代动力学数据、药敏折点和药代动力学 (PK)/药效学 (PD) 指数，单次给予 5 mg/kg bw 的 ENR 在临床上可能适用于治疗绿海龟的易感细菌。Chelonia mydas）。