A novel, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-?-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05-10.0 µg/L with 100 ?L of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalised paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesised by ultrasound-assisted suspension polymerisation, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-?-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015 µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480 h after oral administration of 20 mg (two 10 mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies.
Authors: Qiu HW, Xia L, Gong LM, Ruan LM, Zhao YG. ;Full Source: Drug Test Analysis. 2015 Jun;7(6):535-43. doi: 10.1002/dta.1706. Epub 2014 Sep 10. ;