A validated, sensitive HPLC‐MS/MS method for quantification of cis‐para‐methyl‐4‐methylaminorex (cis‐4, 4'‐DMAR) in rat and human plasma: application to pharmacokinetic studies in rats. Issue 6 (21st September 2016)

• Record Type: Journal Article
• Authors: Lucchetti, Jacopo; Marzo, Claudio M.; Di Clemente, Angelo; Cervo, Luigi; Gobbi, Marco
• Is Part Of: Drug testing and analysis. Volume 9:Issue 6(2017)
• Page Start: 870
• Page End: 879
• Publication Date: 2016-09-21
• Subjects: new psychoactive substances -- para‐methyl‐4‐methylaminorex -- HPLC‐MS/MS -- plasma -- pharmacokinetics; Drugs -- Analysis -- Periodicals; Drug testing -- Periodicals; Chemistry, Forensic -- Periodicals; 615.1901
• DOI: 10.1002/dta.2052
• Languages: English
• ISSNs: 1942-7603

Abstract

Abstract : 4, 4′‐DMAR is an analogue of the known psychostimulants 4‐methylaminorex and aminorex. In the light of reports of deaths associated with its abuse, and the easy access from Internet vendors, the EU Council recently decided on control measures across member states. Here we describe a validated method for measuring plasma levels of cis ‐4, 4′‐DMAR, crucial for preclinical studies and analysis in human plasma. Chromatographic separation was done by gradient elution on a Kinetex C18 column with 0.1% formic acid in water and 0.1% formic acid in acetonitrile at 0.2 mL/min. Detection was by positive electrospray ionization (ESI+) in multiple reaction monitoring mode monitoring the quantifier transitions m / z 191.4 → m / z 148.3 for cis ‐4, 4'‐DMAR and m / z 259.3 → m / z 194.2 for carbamazepine (internal standard). Protein precipitation with 1% of formic acid in acetonitrile was used in cis ‐4, 4'‐DMAR extraction from plasma; recovery was high (>93%) with a negligible matrix effect. This method provides an accurate, precise, and sensitive method for cis ‐4, 4'‐DMAR quantification in human and rat plasma, following European Medicine Agency guidelines for bioanalytical method validation. Pharmacokinetic studies were conducted in rats. After an intravenous dose of 1 mg/kg, plasma levels declined rapidly (≥80% in 4 h), followed by a slow elimination phase (t1/2 of 5.14 ± 0.65 h). Absorption was rapid after intraperitoneal injection (tmax = 15 min) with a rapid decline thereafter; Cmax and AUC0‐240min showed dose‐proportionality over the dose range 1–10 mg/kg. This method was successfully applied to investigate pharmacokinetic properties in rats and could be used to quantify cis ‐4, 4'‐DMAR levels in human plasma. Copyright © 2016 John Wiley & Sons, Ltd. Abstract : We developed and validated a reproducible HPLC‐MS/MS method for measuring the concentrations of the "new psychoactive drug", para‐methyl‐4‐methylaminorex (4, 4'‐DMAR), in rat and human plasma. This drug is subject to control measures across the EU Member States due to reports of deaths associated with its abuse, and the easy access from Internet vendors. The method meets the acceptance criteria of EMA guidelines and it was applied to investigate the pharmacokinetic profile after intravenous and intraperitoneal administration in rats.