A rapid and most sensitive liquid chromatography/tandem mass spectrometry method for simultaneous determination of alverine and its major metabolite, para hydroxy alverine, in human plasma: application to a pharmacokinetic and bioequivalence study.

A rapid and highly sensitive method for the determination of alverine (ALV) and its metabolite, para hydroxy alverine (PHA), in human plasma using LC-MS/MS in positive ion electrospray ionization (ESI) in multiple reactions monitoring (MRM) mode was developed and validated. The procedure involves a simple solid phase extraction (SPE). Chromatographic separation was carried out on a Hypersil GOLD C(18) column (50 mm x 4.6 mm, 5 microm) with an isocratic mobile phase and a total run time of 1.5 min. The standard calibration curves showed excellent linearity within the range of 0.060-10.051 ng/mL for ALV and 0.059-10.017 ng/mL for PHA (r > or = 0.990). This method was successfully applied to a pharmacokinetic study after oral administration of alverine citrate 120 mg capsule in Indian healthy male volunteers.