Pesticide residues in food — 2007: Toxicological ... - ipcs inchem

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Metabolite RH141,452 (3,5-dichloro-4-hydroxymethyl benzoic acid)
The absorption, distribution, metabolism and elimination of [ 14 C]RH-141,452 (lot No.
955.0005, specific activity, 75.38 mCi/g (2.79 GBq/g) were studied in male rats. Four male rats
were each given a single oral dose of [ 14 C]RH-141,452 in pH-adjusted water at a nominal dose of
1000 mg/kg bw. The rats were sacrificed 78 h after dosing and the total recovery of radiolabelled
residues was determined.
Most of the radioactivity was eliminated in the urine (approximately 98% in urine and cage
rinse), with only a small amount being excreted from faeces (< 2%). Approximately 0.01% of the
administered dose of radioactivity was found in the expired air. The excretion of the 14 C was rapid,
with more than 97% being excreted within 24 h. Studies of metabolism showed that most of the
RH-141,452 was eliminated unchanged in the urine, accounting for > 94% of the administered
dose. Three minor conjugates, M-2, M-3 (glucuronide conjugates), and M-4 (glycine conjugate)
Figure 2. Summary of the metabolic pathway of zoxamide in the rat
From Swenson et al. (1998)
ZOXAMIDE 487–522 JMPR 2007