The metabolites of procaterol HCl in urine and faeces of dog and man.

1. The metabolites of procaterol HCl in dog urine and faeces and in human urine were qualitatively analysed by an improved g.l.c.-mass spectrometric method. 2. Trimethylsilylated derivatives of procaterol metabolites were identified by mass fragmentography as procaterol glucuronide, 5-(2-amino-1-hydroxybutyl)-8-hydroxycarbostyril (desisopropylprocaterol), 5-formyl-8-hydroxycarbostyril, 8-hydroxycarbostyril and unchanged procaterol. 3. The metabolic pattern of procaterol HCl was species-independent in rats, dogs and man.