Absorption, distribution, metabolism and excretion of N,N-d\eX\\y\-mtoluamide (DEET) in the rat

ABSTRACT: This study was conducted to evaluate the pharmacokinetic parameters of absorption, distribution, metabolism, and excretion (ADME) of the personal insect repellent N,N-diethyl-m-toluamide (DEET) after oral or dermal administration of (14CJDEET in the rat. In both cases, the only tissues with 14C residues consistently higher than that of plasma were the liver, kidney, and fat. HPLC analysis of urine from rats in the ADME phase of the study showed that DEET was metabolized completely in all treatment groups, with little or no parent compound excreted in the urine. Two major urinary metabolites were identified by mass spectroscopy. In both metabolites, the aromatic methyl substituent in the DEET molecule was oxidized to a carboxylic acid moiety. One of the metabolites also had undergone N-dealkylation of an ethyl substituent on the amide moiety