DETERMINATION OF CEFPODOXIME LEVELS AND CEFPODOXIME STABILITY IN HUMAN URINE BY DIRECT INJECTION HPLC WITH COLUMN-SWITCHING

A semi-automated method providing on-line sample extraction and quantitative analysis for cefpodoxime in human urine, injected directly into the HPLC, is reported. Samples were filtered by the analyst, injected into the HPLC system with an autosampler and loaded onto a 3 cm RP-18 precolumn with a mobile phase consisting of 10% methanol in 0.2% phosphoric acid and then automatically eluted onto a RP-18 analytical column using a mobile phase containing 7% acetonitrile in pH 5.2 sodium acetate buffer. The mean between-day precision of the standards was +/- 4.2%. Spiked urine control recovery averaged 96 +/- 6% for controls ranging from 1.0 to 20.0-mu-g/mL. The limit of quantitation for the method was 0.11-mu-g/mL.