title: High-performance liquid chromatographic determination of memantine in human urine following solid-phase extraction and precolumn derivatization.
abstract: A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol-water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25-75 h seems adequate for sampling and monitoring memantine in urine.
authors.forename: Karim
authors.initials: K
authors.lastname: Michail
authors.forename: Hoda
authors.initials: H
authors.lastname: Daabees
authors.forename: Youssef
authors.initials: Y
authors.lastname: Beltagy
authors.forename: Magdy Abd
authors.initials: MA
authors.lastname: Elkhalek
authors.forename: Mona
authors.initials: M
authors.lastname: Khamis
mesh_terms: D000328:Adult; D000547:Amantadine / Q000032:analysis / Q000652:urine; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D005615:Freezing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008559:Memantine / Q000032:analysis / Q000652:urine*; D011786:Quality Control; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D016482:Urinalysis / Q000379:methods
chemical_list: D000547:Amantadine; D008559:Memantine