Abstract
Biosynthesized 14C-KW-1070, a new aminoglycoside antibiotics, was administered intramuscularly in rats (20mg/kg), and absorption, distribution and excretion have heen studied.
14C-KW-1070 was rapidly absorbed from the administmtion site to show the highest plasma level of 30μg/ml at 15 min., and was eliminated with a biologlcal half life of 30 minutes.
The drug was highly distributed in cartilageous tissues and was mostly eliminated in 4hours.The mdioactivitywas localized at the kidney cortex for longperiod with a biological half life of approximately 5.4 days, 14C-KW-1070 was exclusively excreted into urine and biliary excretion was very sman.
No metabolite nor degradation product was found in the ruine collected for 6 hours.
Transfer of KW-1070 into the perilymph in guinea pigs has been also investigated. 14C-KW-1070 showed the higbest level (22.0μg/ml) in the perilymph of guinea pigs at 4 hours after administration (100mg/kg, im) and wase liminated with a biological half life of 6.8 hours, which was much longer than plasma elimination half life of 50 minutes, estimated simultaneously.
