Marbofloxacin (2nd edition) (Veterinary Medicinal Products)

Abstract Food Safety Commission of Japan (FSCJ) updated the risk assessment of marbofloxacin (MBFX) (CAS No. 115550-35-1), an antibacterial fluoroquinolone. For the application of cattle injection (Forcyl) containing MBFX as an active ingredient, the pharmacokinetics and residue studies on cattle were newly submitted and reviewed for the current version (2nd edition). Adverse effects were detected in the general findings, hematology/blood biochemistry, articular cartilage, and also other observations in subacute toxicity studies in rats and dogs. The lowest no-observed-adverse-effect level (NOAEL) was judged to be 4 mg/kg bw per day. The lowest NOAEL obtained from all the studies was 4 mg/kg bw per day. The ADI was thus specified as 0.004 mg/kg bw per day in considering the lack of chronic and carcinogenic tests. Meanwhile, a microbiological ADI was calculated as 0.0072 mg/kg bw per day by the VICH. The lower value (0.004 mg/kg bw per day) was taken for the ADI of MBFX. FSCJ concluded that an ADI of MBFX should be 0.004 mg/kg bw per day.