Simultaneous determination of theophylline and dyphylline by micellar electrokinetic chromatography and application in drug formulations.
A simple micellar electrokinetic chromatography is described for well resolution of theophylline, dyphylline and caffeine. The separation was performed at 25 degrees C using a background electrolyte consisting of 10mM borate buffer at pH 9 and 40 mM sodium dodecyl sulfate (SDS) as running buffer. Under this condition, good separation with high efficiency and short analyses time required is achieved. Several parameters affecting the separation of the drugs were studied, including the pH and concentrations of the borate buffer and sodium dodecyl sulfate. Using caffeine as an internal standard (I.S.), the linear range of the method for the determination of theophylline and dyphylline was over 0.03-1 micromol ml(-1); the detection limit (signal-to-noise ratio 3; injection 0.3 psi, 3s) was 0.01 and 0.02 micromol ml(-1), respectively.
Huang
Wei-Shan
WS
Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Lin
Shun-Jin
SJ
Wu
Hsin Lung
HL
Chen
Su-Hwei
SH
D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D004400:Dyphylline / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D012015:Reference Standards; D015203:Reproducibility of Results; D013806:Theophylline / Q000032:analysis*
D004400:Dyphylline; D013806:Theophylline