DETERMINATION OF PLASMA NOVOBIOCIN LEVELS BY A REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY

A simple and specific reversed-phase high-performance liquid chromatog raphic (HPLC) assay for the determination of novobiocin levels in huma n plasma has been developed. The sample preparation was performed by d eproteinization with methanol. Prednisone was used as an internal stan dard. Both novobiocin and prednisone were separated on a C-8 column wi th a gradient elution of acidic water (pH 3.0)-methanol. The recovery of novobiocin from plasma was nearly complete. The linear range was 5- 1000 muM in 0.5 ml of plasma with a minimum limit of determination of 2.25 fmol of novobiocin at 254 nm. The method has been implemented and validated in an ongoing clinical trial.