Single dose administration (trial 1): Serum and tissue concentrations of amoxicillin (AMX) were investigated in seabream (Sparus aurata L.) kept in seawater at 22 jC and 32xof salinity. Amoxicillin was given intravenously (i.v.) at 40 mg/kg b.w. or orally (p.o.) at 80 mg/ kg b.w. The serum concentrations were examined by using both radioimmunoassay-microbial receptor technology (Charm II test for h-lactams) and microbiological assay (spores of Bacillus stearothermophilus ATCC 10149); the tissue levels were determined by Charm II test. A slow clearance of AMX from serum was observed after i.v. administration, the concentrations at 72 h ranging from 0.94 to 0.66 Ag/ml. Despite using the trihydrate form of amoxicillin, the apparent oral bioavailability was only 0.33%. Low levels were determined in muscle, skin and liver. Multiple dose administration (trial 2): A depletion kinetic study was conducted at water temperature of 22–26 jC after in feed administration (10 days) of AMX at the dose of 80 mg/kg b.w./day. AMX was only occasionally detected at very low concentrations in muscle, liver, skin, and vertebrae both during and after treatment cessation. Different formulations (conventional, micronized and microencapsulated AMX) were assayed in seabream at 24–26 jC after a 5-day period on medicated diet at the dose of 80 mg/kg b.w./day (trial 3) to verify if the nonconventional forms could improve the tissue distribution of AMX after in-feed administration. The results achieved in muscle and adherent skin were below the LOQ at each scheduled sampling time regardless of the formulation administered.
Seabream (Sparus aurata S.): disposition of amoxicillin after single intravenous or oral administration and multiple dose depletion studies
DELLA ROCCA, Giorgia;DI SALVO, Alessandra;MALVISI, Jose'
2004
Abstract
Single dose administration (trial 1): Serum and tissue concentrations of amoxicillin (AMX) were investigated in seabream (Sparus aurata L.) kept in seawater at 22 jC and 32xof salinity. Amoxicillin was given intravenously (i.v.) at 40 mg/kg b.w. or orally (p.o.) at 80 mg/ kg b.w. The serum concentrations were examined by using both radioimmunoassay-microbial receptor technology (Charm II test for h-lactams) and microbiological assay (spores of Bacillus stearothermophilus ATCC 10149); the tissue levels were determined by Charm II test. A slow clearance of AMX from serum was observed after i.v. administration, the concentrations at 72 h ranging from 0.94 to 0.66 Ag/ml. Despite using the trihydrate form of amoxicillin, the apparent oral bioavailability was only 0.33%. Low levels were determined in muscle, skin and liver. Multiple dose administration (trial 2): A depletion kinetic study was conducted at water temperature of 22–26 jC after in feed administration (10 days) of AMX at the dose of 80 mg/kg b.w./day. AMX was only occasionally detected at very low concentrations in muscle, liver, skin, and vertebrae both during and after treatment cessation. Different formulations (conventional, micronized and microencapsulated AMX) were assayed in seabream at 24–26 jC after a 5-day period on medicated diet at the dose of 80 mg/kg b.w./day (trial 3) to verify if the nonconventional forms could improve the tissue distribution of AMX after in-feed administration. The results achieved in muscle and adherent skin were below the LOQ at each scheduled sampling time regardless of the formulation administered.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
