Determination of trimethoprim and its oxidative metabolites in cell culture media and microsomal incubation mixtures by high-performance liquid chromatography.
A high-performance liquid chromatographic method is presented for the determination of trimethoprim (TMP), 3'-hydroxy-TMP, 4'-hydroxy-TMP, alpha-hydroxy-TMP and two TMP N-oxides. The last two metabolites appear to decompose on liquid extraction. TMP and its oxidative metabolites are separated using a C18 radial-compression column and quantified by UV detection at 230 nm. Calibration curves are linear from 0.5 to at least 50 microM. The limit of detection is 0.05-0.15 micrograms/ml. In in vitro rat liver metabolism studies. 3'- and 4'-hydroxylation of TMP appear to be important metabolic pathways whereas TMP N-oxides are minor metabolites.
van 't Klooster
G A
GA
Department of Veterinary Basic Sciences, University of Utrecht, Netherlands.
Kolker
H J
HJ
Woutersen-van Nijnanten
F M
FM
Noordhoek
J
J
van Miert
A S
AS
D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D008099:Liver / Q000166:cytology / Q000648:ultrastructure; D008297:Male; D008862:Microsomes, Liver / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D014295:Trimethoprim / Q000032:analysis* / Q000378:metabolism
D003470:Culture Media; D014295:Trimethoprim