Quantification of prochlorperazine maleate in human plasma by liquid chromatography-mass spectrometry: Application to a bioequivalence study.

A sensitive and specific method using a one-step liquid-liquid extraction with dichloromethane followed by liquid chromatographic-electrospray ionization-mass spectrometric was developed and validated to determine prochlorperazine maleate in human plasma using amitriptyline hydrochloride as an internal standard. The samples were separated using a Thermo Hypersil-Hypurity C18 reversed-phase column (150mmx2.1mm i.d., 5mum). A mobile phase containing 10mM ammonium acetate (pH 3.6)-methanol-acetonitrile (27:68:5, v/v/v) was used isocratically eluting at a flow rate of 0.22ml/min. The average extraction recovery of prochlorperazine and internal standard were 81.8+/-2.2% and 79.5+/-3.7%, respectively. Prochlorperazine maleate and internal standard were measured by electrospray ion source in positive selective ion monitoring mode. The method demonstrated that good linearity ranged from 0.20 to 6.40ng/ml with r(2)=0.9989. The limit of quantification for prochlorperazine maleate in the plasma was 0.20ng/ml. The established method has been successfully applied to a bioequivalence study of two prochlorperazine maleate formulations in 18 healthy male Chinese volunteers.