Rapid and sensitive liquid chromatography-tandem mass spectrometry method for the quantitation of levodropropizine in human plasma

A rapid and sensitive LC-MS-MS method for quantifying levodropropizine in human plasma after oral administration of a single-dose (60 mg/day) was developed and validated. The sample preparation used liquid-liquid extraction with a mixture of dichloromethane-diethyl ether (2:3, v/v) in a basic environment. The retention time of levodropropizne and zolmitriptan (used as internal standard) was 1.6 and 1.4 min, respectively. The assay was linear over the range 0.25-500 ng/mL with a LOQ of 0.25 ng/mL. The intra- and inter-day precision were <8.1% and <11.5%, respectively, and the accuracy was in the range 87.6-112%. The levodropropizine concentration profile in human plasma was determined.