Determination of Doxofylline in Human Serum by HPLC

OBJECTIVE To establish an HPLC method for determination of doxofylline in human serum. METHODS Ethyl ether was used as the exacted solvent, with carbamazepine as the internal standard. The column was Waters-C₁₈ (3.9 mm×150 mm, 5 μm). The mobile phase was methanol-water(35∶65) and the flow rate was 0.6 mL·min^?1. The detection wavelength was 273 nm. The column temperature was kept at 30 ℃. RESULTS It showed a good linear range of 0.7-28 μg·mL^?1 for doxofylline, the linear regression equation was Y=0.354 9X+0.003 9(r=0.999 7). The methodological recovery was 100.4%, the intra-day RSD and the inter-day RSD were 1.10%-3.87% and 2.11%-4.86%(n=5). CONCLUSION The method is proved to be rapid, simple, accurate and safe. It is suitable for determination of concentration of doxofylline in clinic.