AIM: To develop a
high performance liquid chromatography (HPLC) method to deter- mine the concentration of etoposide (Vp-16)
in human plasma. METHODS: The HP 1100 HPLC system was used, including a quaternary pump, a manual injector, a variable wavelength detector and a LC2D ChemStation. The analytical column was a HP Hypersil ODS column (125 mm × 4 mm, 5μm) with a HP Licrosphere guard column. The isocritic mobile phase was the methanol and the water with the rate of 48 ∶52 (v/v). The detective UV wavelength was 220 nm. The plasma samples, added teniposide as internal standard, were deposited down the protein with methanol. The supernatant was evaporated hy N2 at 40℃. The remains was dissolved with 100μl of 50% methanol solution; 20μl was injected to the sam- pler. RESULTS: The
chromatography was good and not interfered by the components of the plasma. The linear equatlon was Y = 0. 992 1X + 0. 048 24 (r = 1.000). The linear range was 0.1 - 10. 0μg/ml. The RSD of intra-day < 10 %, and the RSD of inter-day < 10%. The patients samples were determined with this method after intra-arterial injection of Vp-16 300 mg, 5 fluorouracil 1 g and cisplatin 80 mg. The metabolits and other drugs did not interfere the chromatography of Vp-16. CONCLUSION: This is an accu- rate, sensitive and convenient method to determine the etoposide concentration in plasma.