Chen_2001_Yao.Xue.Xue.Bao_36_762

AIM To develop a sensitive, specific and accurate method for quantifying bambuterol in human plasma and to study pharmacokinetics of bambuterol in male healthy Chinese. METHODS: Plasma samples were prepared based on a simple liquid-liquid extraction. The extracted samples were analyzed on liquid chromatography using a Zorbax SB C18 column interfaced with a triple quadrupole tandem mass spectrometer and detected by use of selected reaction monitoring mode. RESULTS: The linear calibration curves were obtained in the concentration range of 0.05-4.0 ng.mL-1. The limit of quantification was 0.05 ng.mL-1. The intra- and inter-run precision was measured to be below 7%. The inter-run accuracy was less than 8% for the analyte. After an oral administration of 10 mg bambuterol hydrochloride to 18 healthy Chinese volunteers the main pharmacokinetic parameters of bambuterol were as follows: Tmax was (2.3 +/- 1.3) h; Cmax was (3.95 +/- 2.20) ng.mL-1; T1/2 was (11.4 +/- 6.1) h and AUC0-t was (26.85 +/- 11.77) ng.h.mL-1. CONCLUSION: The method is shown to be accurate, robust and convenient, and suitable for pharmacokinetic studies of bambuterol. It was found that there was marked inter-individual difference in the pharmacokinetics of bambuterol in Chinese volunteers after a single oral dose, which may be attributed to the difference of activity of cholinesterase, an enzyme catalyzing bambuterol metabolism.