Elimination- and biodistribution studies of [14C]dodecylbenzene sulfonate in rats, following low dosing in the daily diet and a single i.p. administration.

14C-labelled sodium dodecylbenzene sulfonate (DBS) was administered daily in the diet at a concentration of 1.4 mg/kg to male rats for 5 weeks. From the total uptake (1.213 +/- 0.08 mg/animal) of DBS, 81.8% was excreted during the dosing period; 52.4% in feces and 29.4% in urine. Low levels of [14C]DBS-derived residues were detected in all tissues analyzed on day 35 of the experiment. Following 1 week on normal diet only 7.8% of the nominally stored amount of 14C was found in the excreta. Single i.p. application of 0.385 mg [14C]DBS/rat (2.26 +/- 0.15 mg/kg body wt.) resulted in a total elimination of 94.5% within 10 days. 84.7% of the dose was eliminated in the first 24 h. All fecal and renal [14C]DBS-derived activity consisted of highly polar metabolites.