Serum concentrations of enrofloxacin (EF) after intravenous (i.v.) or oral administration of single doses (2.5 and 10 mg/kg b.w., respectively) were investigated in seabream (Sparus aurata L.) kept in seawater at 25–27 jC. The tissue disposition of the drug was studied after oral administration. At prefixed time points, from 1 h to 5 days after administration, blood and edible tissues (muscle plus adherent skin) from 10 individuals in each group were collected and stored at 20 jC. Each serum and tissue sample was essayed for EF by HPLC after liquid–liquid extraction. Serum was also checked for the presence of the metabolite ciprofloxacin (CF). The quantification limits for EF were 0.010 Ag/ml in serum and 0.015 Ag/g in tissues. Following intravenous administration, considerably high serum concentrations of EF (range 2.605–3.810 Ag/ml) were detected during the first 4 h. The concentrations decreased subsequently, indicating a first rapid distribution, followed by a slow phase of elimination. At the last time point of the experiment (120 h), there were still detectable amounts of EF in serum samples (range 0.040–0.087 Ag/ml). Enrofloxacin levels of 0.335–1.138 Ag/ml were reached in serum within 1 h after in feed administration. The maximum values were measured at 8 h (1.709–2.846 Ag/ml), then slowly declined and were measurable (0.048–0.149 Ag/ml) for up to 120 h. Compared to serum, lower concentrations of EF were determined in muscle plus skin: 0.156– 0.398 Ag/g after 1 h, 0.102–2.002 Ag/g at 8 h and 0.015–0.031 Ag/g at the last sample point. No CF was found in serum.
The disposition of enrofloxacin in seabream (Sparus aurata S) after single intravenous injection or from medicated feed administration
DELLA ROCCA, Giorgia
;DI SALVO, Alessandra;MALVISI, Jose';
2004
Abstract
Serum concentrations of enrofloxacin (EF) after intravenous (i.v.) or oral administration of single doses (2.5 and 10 mg/kg b.w., respectively) were investigated in seabream (Sparus aurata L.) kept in seawater at 25–27 jC. The tissue disposition of the drug was studied after oral administration. At prefixed time points, from 1 h to 5 days after administration, blood and edible tissues (muscle plus adherent skin) from 10 individuals in each group were collected and stored at 20 jC. Each serum and tissue sample was essayed for EF by HPLC after liquid–liquid extraction. Serum was also checked for the presence of the metabolite ciprofloxacin (CF). The quantification limits for EF were 0.010 Ag/ml in serum and 0.015 Ag/g in tissues. Following intravenous administration, considerably high serum concentrations of EF (range 2.605–3.810 Ag/ml) were detected during the first 4 h. The concentrations decreased subsequently, indicating a first rapid distribution, followed by a slow phase of elimination. At the last time point of the experiment (120 h), there were still detectable amounts of EF in serum samples (range 0.040–0.087 Ag/ml). Enrofloxacin levels of 0.335–1.138 Ag/ml were reached in serum within 1 h after in feed administration. The maximum values were measured at 8 h (1.709–2.846 Ag/ml), then slowly declined and were measurable (0.048–0.149 Ag/ml) for up to 120 h. Compared to serum, lower concentrations of EF were determined in muscle plus skin: 0.156– 0.398 Ag/g after 1 h, 0.102–2.002 Ag/g at 8 h and 0.015–0.031 Ag/g at the last sample point. No CF was found in serum.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
