A rapid and sensitive liquid chromatography/positive ion tandem mass spectrometry method for the determination of cimetropium in human plasma by liquid–liquid extraction

Abstract

We have developed and validated a simple detection system with high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) for determining cimetropium levels in human plasma using scopolamine butyl bromide as an internal standard (I.S.). The acquisition was performed in the multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 357.9 > 103.1 for cimetropium and m/z 359.9 > 103.1 for butyl-scopolamine. The method involves a simple single-step liquid-liquid extraction with dichloromethane. The analyte was chromatographed on an YMC C18 reversed-phase chromatographic column by isocratic elution with 10 mM ammonium formate buffer-methanol (19:81, v/v; adjusted to pH 4.0 with formic acid). The results were linear over the studied range (0.2-100 ng ml(-1)), with r2 = 1.0000, and the total analysis time for each run was 2 min. Intra- and interassay precisions were 0.70-8.54% and 1.08-4.85%, respectively, and intra- and interassay accuracies were 97.56-108.23% and 97.48-103.91%, respectively. The lower limit of quantification (LLOQ) was 0.2 ng ml(-1). At this concentration, mean intra- and interassay precisions were 8.54% and 4.85%, respectively, and mean intra- and interassay accuracies were 97.56% and 98.91%, respectively. The mean recovery ranged from 62.71 +/- 4.06 to 64.23 +/- 2.32%. Cimetropium was found to be stable in plasma samples under typical storage and processing conditions. The devised assay was successfully applied to a pharmacokinetic study of cimetropium bromide administered as a single oral dose (150 mg) to healthy volunteers.

Quantitative analysis of a quaternary ammonium drug: ipratropium bromide by LC/ESI‐MSn in horse plasma and urine

“…Amongst data available in literature, a long‐term stability study was conducted by Lee et al . () on cimetropium, showing an optimal stability of this QAD after storage during 1 month at −70 °C. Our previous work on QADs (unpublished data) together with the present study did not reveal any instability of IBr in urine and plasma.…”

“…An adequate limit of detection was obtained recently by applying sample dilution (John et al ., ). Liquid–liquid extraction of QADs in plasma or serum has been reported (Lee et al ., ; Wang et al ., ). SPE extraction on Oasis HLB cartridges was also selected by Hotha et al .…”

“…The two methods were set up on three‐dimensional ion trap mass spectrometers, with preliminary solid‐phase extraction (SPE) on either Isolute CBA cartridges or Nexus Sorbent. There are no reports on the sole analysis of ipratropium cation (ICat) in plasma, but LC‐MS/MS has been applied for target analysis of other QADs, such as cimetropium (Lee et al ., ) for trospium (Hotha et al ., ), or for a comprehensive screening in plasma (John et al ., ) or blood, in which ICat was included (Ariffin and Anderson, ). In these methods, sample preparation consisted of either protein precipitation followed by liquid–liquid extraction, or SPE on Oasis HLB or BondElut LRC‐CBA cartridges.…”