Direct assay of conjugates of penbutolol and its metabolites in urine
Lehr, K.H.; Damm, P.; Hajdù, P.
Arzneimittel-Forschung 37(12): 1373-1375
1987
ISSN/ISBN: 0004-4172 PMID: 3449064 Document Number: 303057
The metabolites of 1-tert.-butylamino-3-(2-cyclopentylphenoxy)propan-2-ol (penbutolol, Betapressin), penbutolol 2-glucuronide, 4'-OH-penbutolol 2-glucuronide, 4'-OH-penbutolol 4-sulfate and 1"-dehydropenbutolol 2-glucuronide were determined in urine by high-performance liquid chromatography (HPLC). The compounds were determined after direct injection, that is to say without prior cleavage of the conjugates to the corresponding aglycones. In the case of the glucuronides, the urine was injected into the HPLC system without further sample preparation. The sulfate was determined after ion-pair extraction. Fluorimetric detection was employed. Depending on the compound, the detection limits lay between 0.07 and 0.3 micrograms/ml. This method was used to determine the cumulative urinary excretion of a subject.