10.1021/jp412566p.s001
Tomaž Čendak
Tomaž
Čendak
Emanuela Žunkovič
Emanuela
Žunkovič
Tina Ukmar Godec
Tina Ukmar
Godec
Matjaž Mazaj
Matjaž
Mazaj
Nataša Zabukovec Logar
Nataša Zabukovec
Logar
Gregor Mali
Gregor
Mali
Indomethacin
Embedded into MIL-101 Frameworks: A Solid-State
NMR Study
American Chemical Society
2014
MIL
trimeric units
NMR experiments
tetrahydrofuran molecules
1 H homonuclear correlation
indomethacin drug
indomethacin molecules
iron centers
linker indomethacin
1.1 g
1 g
delivery systems
framework metal centers
hydrogen bonds
drug molecules
NMR measurements
terephthalic acid
2014-03-27 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Indomethacin_Embedded_into_MIL_101_Frameworks_A_Solid_State_NMR_Study/2311357
Interactions of drug molecules embedded
within the pores of drug-delivery
matrices significantly influence the drug-release rate and profile.
In this Article, we used solid-state NMR experiments to inspect the
interactions of indomethacin drug and tetrahydrofuran solvent molecules
within mesoporous MIL-101 metal–organic framework materials.
MIL-101 matrices were prepared using two types of linkers, terephthalic
acid for MIL-101(Cr) and MIL-101(Fe), and amino-terephthalic acid
for MIL-101(Al)-NH<sub>2</sub> and MIL-101(Fe)-NH<sub>2</sub>. Loading
MIL-101 matrices with indomethacin proved to be very efficient; the
obtained delivery systems accommodated from 0.9 to 1.1 g of indomethacin
per 1 g of MIL-101 material. NMR measurements showed that regardless
of the type of the framework metal centers or the type of the organic
linker indomethacin did not attach to the metal–organic framework.
Interactions between indomethacin molecules themselves were also not
detected. On the contrary, the smaller tetrahydrofuran solvent molecules
did attach to the framework metallic trimeric units with hydrogen
bonds. The bonds and the geometry of the porous system prevented the
tetrahydrofuran molecules to be expelled from the MIL-101 matrix during
drying. Information on interactions and proximities among neighboring
nuclei was obtained by <sup>1</sup>H homonuclear correlation and <sup>1</sup>H–<sup>13</sup>C heteronuclear correlation NMR measurements.
Distance-dependent influence of paramagnetic chromium and iron centers
was also exploited.