Pharmacokinetics and bioavailability of cefuroxime in Nile tilapia (Oreochromis niloticus)

Cefuroxime is a broad-spectrum antibiotic extensively utilized in humans and animals. Although it has been reported as beneficial against certain fish infections, pharmacokinetic studies are lacking. The purpose of this study was to evaluate the pharmacokinetics of cefuroxime following intravascular (IV, n = 72), intraperitoneal (IP, n = 72), intramuscular (IM, n = 72), and oral (n = 72) administration of 20 mg/kg in Nile tilapia (Oreochromis niloticus) maintained at 29 ± 1.5 °C. Two hundred and eighty-eight fish were equally distributed among four treatment groups: IV, IP, IM, and oral. Blood samples were obtained from 6 fish per group at 12 distinct time intervals over a duration of 96 h. Cefuroxime plasma concentrations were quantified with high-performance liquid chromatography and subsequently evaluated through non-compartmental analysis. Following IV injection, the t_1/2ʎz was 8.04 h, the V_dss was 1.03 L/kg, and the Cl_T was 0.14 L/h/kg. The C_max of cefuroxime was 53.38±4.28 µg/mL at 0.25 h for IP injection, 28.70±3.41 µg/mL at 0.5 h for IM injection, and 6.77±0.81 µg/mL at 1 h for oral administration. Bioavailability was 80.26% (IP), 69.05% (IM), and 24.35% (oral). This study found that a dosing interval of 24 h for IP and IM injection or 8 h for oral administration is efficient for treating bacteria with a MIC value of ≤ 1 µg/mL. The findings of this study indicate that IP and IM injections of cefuroxime are applicable in tilapia. However, since oral administration is important in aquaculture, studies are needed to develop new formulations with better absorption, to demonstrate therapeutic efficacy in infected fish, and to determine the tissues residue depletion.