The metabolism of the local anaesthetic fomocaine (1-morpholino-3-[p-phenoxymethylphenyl]propane) in the rat and dog after oral application.

1. The metabolism of fomocaine following its oral administration to male and female Wistar rats and male beagle dogs has been qualitatively investigated. 2. The drug is metabolized in both species by aromatic hydroxylation, N-oxidation, splitting of the ether link and, in the dog, by removal of the morpholine group. 3. The rat and dog excrete some unchanged fomocaine in the urine together with p-hydroxyfomocaine (free and conjugated), fomocaine-N-oxide, p-hydroxyfomocaine-N-oxide and p-(gamma-morpholinopropyl)benzoic acid. In addition, the dog excretes morpholine in the urine.