High-performance liquid chromatographic determination of loracarbef, a potential metabolite, cefaclor and cephalexin in human plasma, serum and urine.
A high-performance liquid chromatographic (HPLC) method is reported for the determination of a new carbacephem antibiotic, loracarbef, a hydroxylated analogue, and two cephalosporins, cefaclor and cephalexin, in plasma, serum, and urine. The antibiotics are extracted from plasma by means of C18 solid-phase cartridges. Urine samples are diluted with water and directly injected on the HPLC system. The HPLC system utilizes a Supelcosil LC-18-DB (250 mm x 4.6 mm I.D.) reversed-phase column and ultraviolet detection at 265 nm. The limit of quantitation is 0.5 micrograms/ml for each compound. Excellent correlation of plasma concentrations is shown between results determined by HPLC and those obtained by microbiological agar-well diffusion assays. Stability studies of loracarbef in human plasma show the antibiotic to be stable for at least 24 h at room temperature and for at least twelve months at -20 degrees C.
Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285.
P M
PM
Kovach
R J
RJ
Lantz
G
G
Brier
D002433:Cefaclor / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002506:Cephalexin / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002511:Cephalosporins / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D015394:Molecular Structure; D013056:Spectrophotometry, Ultraviolet
D002511:Cephalosporins; C054920:loracarbef; D002433:Cefaclor; D002506:Cephalexin