THE FATE OF 2,4,6-TRI-(3',5'-DI-TERT.-BUTYL-4'-HYDROXYBENZYL)MESITYLENE (IONOX 330) IN THE DOG AND RAT.

1. Unchanged Ionox 330 is quantitatively eliminated in the faeces of dogs, rats and man after oral administration, and (14)C is absent from the urine and expired gases of rats intubated with [(14)C]Ionox 330. Dogs and rats do not show a sex difference in this pattern of elimination. 2. Quantitative elimination of [(14)C]Ionox 330 and the absence of (14)C in the carcass and viscera of rats 72hr. after dosage show that this substance does not accumulate in the body. 3. No metabolites are formed in consequence of the ingestion of Ionox 330. 4. Rats eliminate three-quarters or more of a dose (285.7mg./kg. body wt.) of Ionox 330 in 24hr. and the remainder during 24-48hr., and dogs eliminate the whole dose (90mg./kg. body wt.) within 48hr. and a variable proportion within 24hr. These rates of elimination are consistent with the passage of unabsorbed material through the alimentary canal. 5. After removal of the alimentary canal, radioactivity is absent from the carcass and remaining viscera of rats 8, 16 and 24hr. after ingestion of [(14)C]Ionox 330, and this strongly suggests the absence of alimentary absorption. 6. The absence of (14)C in the 24hr. bile of animals with biliary fistulae establishes that [(14)C]Ionox 330 is not absorbed from the gastro-intestinal tract.