In vivo pharmacokinetics of pyribenzoxim in rats.
Pyribenzoxim, benzophenone O-[2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoyl]oxime, is a new post-emergence herbicide providing broad-spectrum weed control in rice fields. [14C]Pyribenzoxim was used to study the pharmacokinetics of the compound after oral administration of a dose of 1000 mg kg-1 to male Sprague-Dawley rats. The material balance ranged from 97.3 to 99.7% of the administered dose and urinary and fecal recovery accounted for 97.1%, with the majority of radioactivity recovered in feces (88.6%) by 168 h after treatment. Elimination as volatile products or as carbon dioxide was negligible. The following values were obtained for the compound in the blood: AUC0-168 h, 28,400 micrograms equiv hg-1; Tmax, 12 h; Cmax, 372 micrograms equiv g-1; half-life, 53 h. Radioactivity in tissue decreased from 96.1% of applied radiocarbon at 6 h to 0.4% at 168 h and the highest concentration of radioactivity among the tissues was observed in liver while the lowest residues were found in brain. The elimination half-lives of radioactivity from tissues was in the range of 7 to 77 h and Tmax values of 12, 24 and 12 h were observed for blood, liver and kidney, respectively. Except for that in the digestive tract, the tissue-to-blood ratio (TBR) was highest in the liver.
Liu
K H
KH
School of Agricultural Biotechnology, Seoul National University, Seodundong 103, Suwon, Kyungi 441-744, Korea.
Moon
J K
JK
Sung
H J
HJ
Kang
S H
SH
Koo
S J
SJ
Lee
H S
HS
Kim
J H
JH
D000284:Administration, Oral; D000465:Algorithms; D000818:Animals; D019540:Area Under Curve; D001577:Benzophenones / Q000097:blood / Q000737:chemistry / Q000494:pharmacology*; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D005243:Feces / Q000737:chemistry; D006540:Herbicides / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D015394:Molecular Structure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013057:Spectrum Analysis; D014018:Tissue Distribution
D001577:Benzophenones; D002250:Carbon Radioisotopes; D006540:Herbicides; C454324:benzophenone O-(2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoyl)oxime; D002245:Carbon Dioxide