title: Isotopic finger-printing of active pharmaceutical ingredients by 13C NMR and polarization transfer techniques as a tool to fight against counterfeiting.
abstract: The robustness of adiabatic polarization transfer methods has been evaluated for determining the carbon isotopic finger-printing of active pharmaceutical ingredients. The short time stabilities of the adiabatic DEPT and INEPT sequences are very close to that observed with the one pulse sequence, but the DEPT long time stability is not sufficient for isotopic measurements at natural abundance or low enrichment. Using the INEPT sequence for (13)C isotopic measurements induces a dramatic reduction in the experimental time without deterioration in short time or long time stability. It appears, therefore, to be a method of choice for obtaining the isotopic finger-print of different ibuprofen samples in a minimum time. The results obtained on 13 commercial ibuprofen samples from different origins show that this strategy can be used effectively to determine (13)C distribution within a given molecule and to compare accurately differences in the isotopic distribution between different samples of the given molecule. The present methodology is proposed as a suitable tool to fight against counterfeiting.
authors.affiliation: Université de Nantes, CNRS, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM), UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3, France.
authors.forename: Ugo
authors.initials: U
authors.lastname: Bussy
authors.forename: Christophe
authors.initials: C
authors.lastname: Thibaudeau
authors.forename: Freddy
authors.initials: F
authors.lastname: Thomas
authors.forename: Jean-Roger
authors.initials: JR
authors.lastname: Desmurs
authors.forename: Eric
authors.initials: E
authors.lastname: Jamin
authors.forename: Gérald S
authors.initials: GS
authors.lastname: Remaud
authors.forename: Virginie
authors.initials: V
authors.lastname: Silvestre
authors.forename: Serge
authors.initials: S
authors.lastname: Akoka
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry; D058110:Counterfeit Drugs / Q000032:analysis*; D004348:Drug Labeling; D004355:Drug Stability; D007052:Ibuprofen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D058110:Counterfeit Drugs; D007052:Ibuprofen