Sensitive quantitation of reboxetine enantiomers in rat plasma and brain, using an optimised reverse phase chiral LC–MS/MS method

Assessment of brain‐to‐blood drug distribution using liquid chromatography

“…Suitable extraction solvents, such as ethyl acetate (Baldessarini et al, 1993;Castel-Branco et al, 2003;Greig et al, 1988;Md et al, 2014;Milane et al, 2009;Minocha et al, 2012;Oberoi et al, 2013;Perin et al, 2017;Wang et al, 2011;Xia et al, 2004), ethers like diisopropyl ether (Yang et al, 2015;Zhang et al, 2007bZhang et al, , 2007c, diethyl ether (Jiang et al, 2008;Shimokawa et al, 2005) and methyl tert-butyl ether (Li et al, 2013;Turnpenny & Fraier, 2009), chlorinated solvents like chloroform (Nakashima et al, 2002;Nakashima et al, 2003;Somani & Khalique, 1985) and methylene dichloride (Aravagiri et al, 1998;Aravagiri et al, 1999), hexane (Tsuneizumi et al, 1992) and isopropyl alcohol (Yasir et al, 2017) and solvent combinations such as diisopropyl ether-methyl chloride (Zhang et al, 2008), ethyl acetate-diisopropyl ether (El Zahar et al, 2018, heptane-isoamyl alcohol (Shibanoki et al, 1984) and benzene-isoamyl alcohol (Lister et al, 1983), have all been successfully applied to various analytes. The method often involves a pH adjustment to improve transfer of analytes into the organic phase.…”

“…for the quantitation of reboxetine enantiomers in rat plasma and brain (Turnpenny & Fraier, 2009). For certain analytes, such as cotinine, the separation was carried out using hydrophilic interaction liquid chromatography (HILIC).…”

“…Figure used with permission from (Colovic & Caccia, 2003) to quadrupole mass spectrometers with an ESI ion source, collisioninduced dissociation and multiple reaction monitoring mode have been widely adopted. These lead to exceptional sensitivity, specificity and dynamic range, which are necessary for the effective detection of these drugs in both matrices and the accurate determination of the brain-to-blood ratio (Al-Ghananeem et al, 2010;Ayoub et al, 2018;Chang et al, 2015;El Zahar et al, 2018;Guo et al, 2007;Li et al, 2012;Li et al, 2013;Liang et al, 2012;Ligneau et al, 2007;Md et al, 2014;Minocha et al, 2012;Nirogi et al, 2013;Oberoi et al, 2013;Ohmori et al, 2000;Roma nski et al, 2014;Su et al, 2015;Turnpenny & Fraier, 2009;Wang et al, 2011;Xia et al, 2004;Yang et al, 2015;Zhang et al, 2007bZhang et al, , 2007cZhang et al, , 2008Zheng et al, 2015;Zhou & Gallo, 2010). Fluorescence detection has been performed for the detection of appropriate molecules as in the case of donepezil and moxifloxacin (Nakashima et al, 2006;Respaud et al, 2012).…”

“…Most drugs showed good stability in stored plasma and brain samples so that there was no concentrationdependent degradation observed. Hence they could be stored for a prolonged period of time before final analysis (Ayoub et al, 2018;El Zahar et al, 2018;Li et al, 2012;Li et al, 2013;Md et al, 2014;Minocha et al, 2012;Nirogi et al, 2013;Ohmori et al, 2000;Perin et al, 2017;Roma nski et al, 2014;Singh et al, 2011;Turnpenny & Fraier, 2009;Wang et al, 2008;Wang et al, 2011;Yang et al, 2015;Zheng et al, 2015). Some drugs such as ziprasidone, chlorpromazine and haloperidol were stable after three freeze-thaw cycles and in the autosampler for at least 24 h, but in the case of bench-top stability, spiked samples were stable for only 2 h (Yasir et al, 2017;Zhang et al, 2007bZhang et al, , 2008.…”

Stereo‐specific LC and LC‐MS bioassays of antidepressants and psychotics

“…It was also shown that women have an approximately 30% higher S , S / R , R ratio compared with men. Turnpenny and Fraier () developed an LLE method coupled with LC‐MS for stereo‐selective determination of RBX in rat plasma and brain homogenate. LC conditions utilized a chiral AGP column with 12.5 m M ammonium carbonate buffer adjusted with formic acid (pH 6.7).…”