title: Determination of memantine in plasma and vitreous humour by HPLC with precolumn derivatization and fluorescence detection.
abstract: A new HPLC procedure with precolumn derivatization and rimantadine as the internal standard for determining memantine, a candidate agent for the treatment of glaucoma in plasma and vitreous humour, has been developed and validated. Precolumn derivatization was performed with 9-fluorenylmethyl-chloroformate-chloride  (FMOC-Cl) as the derivatization reagent and followed by a liquid-liquid extraction with n-hexane. Optimal conditions for derivatization were an FMOC-Cl concentration of 1.5 mM, a reaction time of 20 min, the temperature at 30°C, the borate buffer pH 8.5, and a borate buffer-acetonitrile  ratio of 1:1. The derivatives were analyzed by isocratic HPLC with the fluorescence detector λex 260 nm λem 315 nm on a Novapack C(18) reversed-phase column with a mobile phase of acetonitrile-water (73:27, v/v), 40°C, and a flow rate of 1.2 mL/min. The linear  range was 10-1000 ng/mL with a quantification limit of ∼ 10 ng/mL for both types of samples. This analytical method may be suitable for using in ocular availability studies.
authors.affiliation: Department of Analytical Chemistry, School of Veterinary Science, University of Zaragoza, Spain.
authors.forename: Belen
authors.initials: B
authors.lastname: Puente
authors.forename: Esther
authors.initials: E
authors.lastname: Hernandez
authors.forename: Susana
authors.initials: S
authors.lastname: Perez
authors.forename: Luis
authors.initials: L
authors.lastname: Pablo
authors.forename: Esther
authors.initials: E
authors.lastname: Prieto
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Garcia
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Bregante
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D005449:Fluorenes / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D008559:Memantine / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D011817:Rabbits; D015203:Reproducibility of Results; D012299:Rimantadine / Q000032:analysis / Q000097:blood; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: C411453:2,7-di-tert-butyl-9-fluorenylmethoxycarbonyl chloride; D005449:Fluorenes; D006586:Hexanes; D012299:Rimantadine; C026385:n-hexane; D008559:Memantine