Quantification of Temozolomide in Nonhuman Primate Fluids by Isocratic Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry to Study Brain Tissue Penetration Following Intranasal or Intravenous Delivery.

Cynthia McCully,Louis Rodgers,Cody Peer,Katherine Warren,William Figg,Lukas Ronner

doi:10.3390/chromatography3010004

Cynthia McCully, Louis Rodgers + Show 4 more

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https://doi.org/10.3390/chromatography3010004

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Journal: Separations	Publication Date: Feb 4, 2016
Citations: 28	License type: CC BY 4.0

Affiliation: National Cancer Institute

Abstract

A sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometric method was developed for the quantification of temozolomide (TMZ) in nonhuman primate (NHP) plasma, cerebrospinal fluid (CSF), and brain extracellular fluid (ECF) following microdialysis. Ethyl acetate was used to extract the plasma and CSF samples, using theophylline as the internal standard (IS). ECF samples were diluted with acetonitrile prior to analysis. TMZ was separated on a Waters UPLC® BEH C18 column with an isocratic mobile phase of ammonium acetate (10 mM)-0.1% formic acid/acetonitrile (30:70, v/v) in a positive-ion multi pie reaction monitoring mode (m/z 195.5 →137.6 for TMZ; m/z 181.5→124.2 for IS). The retention time of TMZ and theophylline was 0.45 min with a total run time of 2.5 min. The method was validated over the range from 5-2000 ng/mL in NHP plasma, CSF, and ECF with respect to linearity, accuracy, precision, selectivity, and stability. This method was successfully applied toward the measurement of pharmacokinetic samples following various routes of drug administration.

Highlights

Temozolomide (TMZ) is a prodrug that is metabolized to an alkylating agent.Upon exposure to physiological pH, TMZ is spontaneously hydrolyzed to the intermediate5-(3-methyl-triazen-1-yl) imidazole-4-carboxamide (MTIC)
This paper describes an ultra HPLC-MS/MS method designed for the quantitative measurement
This paper describes an ultra HPLC-MS/MS method designed for the quantitative measurement of TMZ in nonhuman primate plasma, cerebrospinal fluid (CSF), and extracellular fluid (ECF) taken directly from designated areas in the brain of TMZ in nonhuman primate plasma, CSF, and ECF taken directly from designated areas in the brain inserted with MD probes

Summary

Introduction

Temozolomide (TMZ) is a prodrug that is metabolized to an alkylating agent.Upon exposure to physiological pH, TMZ is spontaneously hydrolyzed to the intermediate5-(3-methyl-triazen-1-yl) imidazole-4-carboxamide (MTIC). Temozolomide (TMZ) is a prodrug that is metabolized to an alkylating agent. Upon exposure to physiological pH, TMZ is spontaneously hydrolyzed to the intermediate. MTIC further fragments to 5-amino4-imidazolecarboxamide and the extremely reactive methyldiazonium cation, which methylates DNA at several nucleophilic sites. N7 -guanine, N3 -adenine, and O6 -guanine [1]. The formation of O6 -methylguanine accounts for a minority of DNA adducts formed, it is cytotoxic and is correlated with TMZ-mediated cytotoxicity, resulting in mispairing during replication and subsequent strand breakage and tumor cell death. TMZ is FDA approved as a first-line treatment for patients with newly diagnosed glioblastoma multiforme alongside radiotherapy and as a second-line treatment for refractory anaplastic astrocytoma [2]

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