This study was conducted to reset the withdrawal time (WT) for amoxicillin (AMX) in pigs as a part of positive list system (PLS) program introduction. Forty-two healthy pigs were orally administered with AMX at doses of 10 mg/kg body weight (BW) (AMX-1, n=20) and 20 mg/kg BW (AMX-2, n=20), twice daily for 5 days, respectively. After the treatment, tissue samples were collected from four pigs at 1, 3, 5, 7 and 14 days post-administration, respectively. Based on a previously established analysis method, residual AMX concentrations in pig tissues were determined using LC-MS/MS. In both AMX-1 and AMX-2 groups, AMX levels in all tissues except fat was below the limit of quantification (LOQ) at one day after the final administration. According to the European Medicines Agency’s guideline on determination of withdrawal periods, the withdrawal periods for AMX-1 and AMX-2 in fat tissue were established as 0 and 2 days, respectively. In conclusion, the estimated WT of AMX in edible tissues of pigs is shorter than the current WT recommendation of 5 days for AMX.

• Yeung Bae Jin(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Woo H. Kim(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Kwang Il Park(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Suk Kim(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Jin-Kyung Kim(Department of Dental Hygiene, Daegu Health College, Daegu 41453, Korea) Corresponding author
• Hu-Jang Lee(Department of Dental Hygiene, Daegu Health College, Daegu 41453, Korea) Corresponding author