High-performance liquid chromatographic analyses of sulbenicillin and carbenicillin in human urine

A high-performance liquid chromatographic method has been developed for the determination of sulbenicillin (SBPC) and carbenicillin (CBPC) excreted in human urine. The method uses reversed-phase ion-pair chromatography with a bonded hydrophobic stationary phase and methanol-tetra-n-butylammonium bromide solution as the mobile phase. Urine is filtered through a micropore membrane and the filtrate introduced directly into a liquid chromatograph. An in vivo experiment was conducted by administering intravenously 1 g of SBPC or CBPC to volunteers and analysing their urine. One-compartment model analysis of the time-course data revealed that 73.1% of the amount of SBPC dosed was excreted in the urine with a rate constant of 0.579 h-1, and 91.5% of CBPC with a rate constant of 0.845 h-1.