Residue Depletion of Gentamicin in Swine Tissues after Intramuscular Administration

A sensitive and robust high-performance liquid chromatographic method with fluorescence detection (HPLC-FLD)was developed for the determination of gentamicin (GEN) residues in swine tissues. The limit of quantification (LOQ) of the method was 50 ng/g for muscle and 100 ng/g for liver and kidney. Mean recoveries at all fortification levels ranged from 82.34 to 93.20% with coefficient of variation (CV) below 5.39%. Residue depletion study of GEN in swine was performed after intramuscular injections twice daily at a dose of 4 mg/kg of bw with 12 h intervals for 5 consecutive days. The concentrations of GEN were determined in injection site, muscle, liver, and kidney by the HPLC-FLD method. The highest GEN concentration was measured in kidney, indicating that kidney was the primary target tissue for GEN residue. GEN concentrations in all examined tissues were below the maximum residue limit (MRL) recommended by the European Union (EU) at 50 days post-treatment.