Etude thermoanalytique et spectrale de l'interaction lorazepam/PEG 6000

Résumé The solubility and rate of dissolution of a poorly-soluble active principle are of importance when substances are destined for oral administration. Physical blends in wich drug and carrier are able to form particular compositions, such as a eutectic, may exibit an increased rate of dissolution. In this work the interactions lorazepam and PEG 6000, were examined, the particular thermal behaviour of lorazepam being taken into account. An eutectic was obtained and its composition was studied by means of differential scanning calorimetry, thermomicroscopy, infrared spectroscopy and X-ray methods.

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Zusammenfassung Bei der oralen Darreichung von Substanzen ist die L?slichkeit und Aufl?sungsgeschwindigkeit schlechtl?slicher aktiver Komponenten von gro?er Bedeutung. Physikalische Gemische, in denen Wirkstoffe und Tr?gersubstanzen besondere Zusammensetzungen wie zum Beispiel Eutektika zu bilden in der Lage sind, k?nnen eine erh?hte Aufl?sungsgeschwindigkeit zeigen. Vorliegend wird die Wechselwirkung zwischen Lorazepam und PEG 6000 untersucht, wobei das besondere thermische Verhalten von Lorazepam berücksichtigt wurde. Es wurde ein Eutektikum erhalten und dessen Zusammensetzung mittels DSC, Thermomikroskopie, Infrarotspektroskopie und R?ntgenmethoden untersucht.

     

Etude du changement de phase solide-liquide en relation avec la stabilite thermique des formes polymorphes et pseudopolymorphes du lorazepam et identification spectrale

Thermal decomposition of lorazepam begins by lose of a water mole between two groups NH-OH and occurs at different temperatures depending on the formes of polymorphs. Melting temperature of a form can be determined only if it is below that of decomposition.The thermoanalytical and spectral study of lorazepam commercial drugs (a) and (b) recrystallisation product at 20°C in benzine (c), in carbon tetrachlorid (d), in acetonitrile (e) were carried out.Thermal behaviour, RX diffraction, IR spectroscopy allow us to identify polymorph (a, b, c) and two solvates (d and e). The solvates stoechiometry (d and e) has been determined by thermogravimetry (3-2) d, (2-1) e, and confirmed by magnetic nuclear resonance for (e).

Nous exprimons nos vifs remerciements à Madame Eliane Toreilles, Directeur de recherche au CNRS (Laboratoire de Chimie Organiques UA 458 CNRS, Ecole Nationale Supérieure de Chimie de Montpellier) pour sa collaboration personnelle en spectroscopie.     

Phosphonium Diaza-Diylids and Aza-Yldiid as New and Efficient Reagents For Primary and Secondary Amines Synthesis

Abstract

Metallated aminophosphonium ylids, diaza-diylids and azayldiid, are investigated as reagents for primary and secondary amines synthesis.