Non-extraction HPLC method for simultaneous measurement of dyphylline and doxofylline in serum
Tagliaro, F.; Dorizzi, R.; Frigerio, A.; Marigo, M.
Clinical Chemistry 36(1): 113-115
1990
ISSN/ISBN: 0009-9147 PMID: 2297899 Document Number: 349034
A direct injection HPLC method for the simultaneous measurement of dyphylline and doxofylline in serum is reported. Chromatography is carried out with a "Pinkerton" internal surface reversed-phase column and phosphate buffer (0.1 mol/L, pH 6.8) as mobile phase. Absorbance at 275 nm is monitored. Only 10 microL of serum is required to detect less than 1 mg of each drug per liter in biological samples. The standard curve for the method is linear over the range 6-100 mg/L, and precision is acceptable for both drugs, with CVs of 2% and 1.5% for respective concentrations of 6.2 and 25 mg/L. None of the 76 drugs tested for interference affected the measurement of either drug. Four samples can be injected per hour. This method provides a fast, accurate way to monitor two interesting therapeutic agents used in chronic obstructive airway diseases.