title: Dynamics and interactions of ibuprofen in cyclodextrin nanosponges by solid-state NMR spectroscopy.
abstract: Two different formulations of cyclodextrin nanosponges (CDNS), obtained by polycondensation of β-cyclodextrin with ethylenediaminetetraacetic acid dianhydride (EDTAn), were treated with aqueous solutions of ibuprofen sodium salt (IbuNa) affording hydrogels that, after lyophilisation, gave two solid CDNS-drug formulations.1H fast MAS NMR and13C CP-MAS NMR spectra showed that IbuNa was converted in situ into its acidic and dimeric form (IbuH) after freeze-drying.13C CP-MAS NMR spectra also indicated that the structure of the nanosponge did not undergo changes upon drug loading compared to the unloaded system. However, the13C NMR spectra collected under variable contact time cross-polarization (VCT-CP) conditions showed that the polymeric scaffold CDNS changed significantly its dynamic regime on passing from the empty CDNS to the drug-loaded CDNS, thus showing that the drug encapsulation can be seen as the formation of a real supramolecular aggregate rather than a conglomerate of two solid components. Finally, the structural features obtained from the different solid-state NMR approaches reported matched the information from powder X-ray diffraction profiles.
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32 - 20133 Milano, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Ferro
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32 - 20133 Milano, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Castiglione
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32 - 20133 Milano, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Pastori
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32 - 20133 Milano, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Punta
authors.affiliation: Università degli Studi e-Campus, Via Isimbardi 10, 22060 Novedrate, Como, Italy.
authors.forename: Lucio
authors.initials: L
authors.lastname: Melone
authors.affiliation: CNR-ICRM, Via L. Mancinelli 7, 20131 Milano, Italy.
authors.forename: Walter
authors.initials: W
authors.lastname: Panzeri
authors.affiliation: Elettra - Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, 34149 Trieste, Italy; Department of Physics, University of Trento, via Sommarive 14, 38123 Povo, Trento, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Rossi
authors.affiliation: Department of Chemistry, University of Torino, Via Pietro Giuria 7, 10125 Torino, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Trotta
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32 - 20133 Milano, Italy; CNR-ICRM, Via L. Mancinelli 7, 20131 Milano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mele
keywords: cross-polarization; cyclodextrin; ibuprofen; nanosponges; solid-state NMR