Physicochemical Study of Ribavirin Complexes with α-, β- and γ-Cyclodextrins

Autor: Nicolas Grancher, Véronique Venard, Chantal Finance, A. Le Faou, F. Kedzierewicz, Alain Marsura
Rok vydání: 2005
Předmět:
Zdroj: Journal of Inclusion Phenomena. 51:149-157
ISSN: 1573-1111
0923-0750
DOI: 10.1007/s10847-005-0170-8
Popis: The aim of this work was to characterise interactions between ribavirin (RBV) and native cyclodextrins (CDs). The extent of complexation in solution has been evaluated by high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Thermogravimetry (TG), differential scanning calorimetry (DSC) and infrared spectroscopy (FT-IR) were used to characterise the solid state of all the binary systems. Complexation of RBV with α-, β-, and γ-CDs was proved by FT-IR, HPLC and thermal analysis. The 1:1 stoichiometry for the complexes was obtained by HPLC. The stability constants for RBV with α-, β- and γ-CD were determined to be 1493, 2606, and 1179 M−1, respectively. Consequently β-CD was the most suitable of the three complexing agents since it showed the highest stability constant. RBV appears not included inside the cavity of the CD because H-3 and H-5 protons were not shifted in the presence of the molecule as proved by NMR. The 2D ROESY spectra did not show any dipolar proton interaction of the RBV with the CDs. Thus the complexation does not seem to be a host–guest inclusion complex but an external intermolecular complex. FT-IR spectral changes due to the RBV carboxamide group vibrations with the CDs confirm this association.
Databáze: OpenAIRE
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