LAUSR

A highly sensitive and accurate liquid chromatography/mass/mass spectrometry (LC/MS/MS) system was developed to determine the plasma concentration of procaterol in human subjects. The chromatographic system used for this study included a Lichrospher(superscript ®) Silica column with a mobile phase of 10mM ammonium acetate aqueous solution/acetonitrile (30/70, v/v) and 1.0mL/min flow-rate. Procaterol and betaxolol, the latter used as the internal standard, were detected using mass spectrometry at ionization mode (ESI+), a source block temperature of 90℃ and desolvation temperature of 500℃. The detection mass was 290.99＞273.64 for procaterol and 308.33＞116.31 for betaxolol. The calibration curve over a concentration range of 0.005~1.0ng/mL showed good linearity, with a correlation coefficient of 0.9998. The results of within-run and between-run precision tests for the method have coefficient variation values of no more than 10.2%. The average recovery rates of procaterol in human plasma samples over a wide range of concentrations exceeded 86%. The concentration detection and quantitation limits of the proposed LC/MS/MS method were determined to be 0.001 and 0.005ng/mL, respectively. The pharmacokinetic parameters from volunteers were similar to that previously reported in the literature in a study on patients administered with the same procaterol HCl dose. All results indicate that the LC/MS/MS method proposed in this study is a sensitive, selective, precise, and accurate method to determine concentrations of procaterol in human plasma and hence to evaluate the pharmacokinetic characteristics of human subjects.