Determination of the monocyclic beta-lactam antibiotic carumonam in plasma and urine by ion-pair and ion-suppression reversed-phase high-performance liquid chromatography.
A sensitive and selective high-performance liquid chromatography method has been developed for the determination of the new monocyclic beta-lactam antibiotic carumonam in plasma and urine. The method for plasma involves protein precipitation with acetonitrile and removal of lipids with dichloromethane; urine is diluted with buffer. Separation and quantification are achieved using a mobile phase based on either ion-suppression or ion-pair chromatography on a reversed-phase column with UV detection. The limit of determination is 0.5 micrograms/ml plasma, using a 0.5-ml specimen, and 25 micrograms/ml urine, using a 50-microliter specimen. The inter-assay reproducibility is generally better than 4% when an internal standard is used. Since beta-lactam antibiotics may degrade on storage, close attention must be paid to the stability of these drugs in biological fluids; novel measures to prevent degradation on storage are described. The assay has been successfully applied to the analysis of several thousand samples from pharmacokinetic studies, including a study involving patients with impaired renal function.
Biological Pharmaceutical Research Department, F. Hoffman-La Roche & Co. Ltd., Basle, Switzerland.
H J
HJ
Egger
G
G
Fischer
D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000097:blood / Q000652:urine; D001398:Aztreonam / Q000031:analogs & derivatives*; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D004356:Drug Storage; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D014462:Ultrafiltration; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; C044145:carumonam; D001398:Aztreonam