[Determination of bromhexine in plasma by gas chromatography-electron capture detection and pharmacokinetic studies].

This paper reports a gas chromatography-electron capture detection(GC-ECD) method for the study of pharmacokinetics of bromhexine in healthy human body. A2 m x 3 mm i.d. silanized glass column packed with 5% SE-30 was used. The carrier gas was nitrogen. The internal standard was 5-chloro-2-amino-diphenyl ketone. After NaH2PO4-Na2HPO4 buffer (pH 6.0) being added, the plasma was extracted with n-hexane-dichloromethane (9:1, V/V). A good linearity was obtained from 1.0 microgram/L to 50.0 micrograms/L of bromhexine in human plasma, r = 0.9994. The detection limit of bromhexine in plasma was 0.5 microgram/L. The average recovery was 97.5%. The pharmacokinetics of bromhexine was determined by this method after a single oral dose of 8 mg bromhexine capsule given to each of 8 volunteers. The results showed that the plasma concentration-time courses conformed to one compartment model. The established GC-ECD method is a good method for the determination of bromhexine in human plasma. The method is rapid, simple, precise and sensitive.