Hydrolytic pathway of 5-fluorouracil in aqueous solutions for clinical use

Autor: Myriam Malet-Martino, Joëlle Azéma, Stéphane Massou, Robert Martino, Rémi Legay
Přispěvatelé: Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB), Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées
Rok vydání: 2014
Předmět:
Zdroj: Journal of Pharmaceutical and Biomedical Analysis
Journal of Pharmaceutical and Biomedical Analysis, Elsevier, 2014, 98, pp.446-462. ⟨10.1016/j.jpba.2014.06.015⟩
ISSN: 1873-264X
0731-7085
DOI: 10.1016/j.jpba.2014.06.015⟩
Popis: The purpose of the study was to investigate the degradation pathway of 5-fluorouracil (FU) in the situation of commercial formulations for clinical use, namely FU dissolved in sodium hydroxide (NaOH) solutions or Tris buffer at pH 8.5-9. Combination of data from (19)F, (1)H and (13)C NMR and in some cases MS led to the identification of 8 and 13 FU degradation products in NaOH and Tris solutions respectively. In FU NaOH solutions, the first stage of FU degradation is a stereoselective hydration of the C5-C6 double bond leading to 5,6-dihydro-5-fluoro-6-hydroxyuracil, the cis stereoisomer being predominant relative to the trans. The second stage involves either a defluorination step with formation of fluoride ion and 5-hydroxyuracil or the cleavage of the N3-C4 bond giving the two diastereoisomeric 2-fluoro-3-hydroxy-3-ureidopropanoic acids. The subsequent N1-C6 bond breakdown of these compounds releases urea and 2-fluoro-3-oxopropanoic acid (FOPA) which in turn losses easily carbon dioxide leading to the formation of fluoroacetaldehyde (Facet). The degradation pathway in FU-Tris solutions is identical, except that Tris reacts with the aldehydes FOPA and Facet to form oxazolidine adducts stable at pH 8.5 but in equilibrium with the aldehyde forms at physiological pH, whereas the high reactivity of free aldehydes leads to numerous unidentified degradation compounds all in very low amounts. The FOPA diastereoisomeric adducts react with Facet to form four diastereoisomeric fused bicyclic five-membered ring compounds. Facet and FOPA are highly cardiotoxic. In Tris formulations, they are trapped as stable oxazolidine adducts which release the free aldehydes at physiological pH thus explaining the higher cardiotoxicity of FU in Tris solutions compared to that of FU in NaOH solutions.
Databáze: OpenAIRE