English abstract
This work explored the interaction of three different imidazoline drugs, naphazoline nitrate
(Naph), oxymetazoline hydrochloride (OXY) and xylometazoline hydrochloride (XYL) with
two different synthesized cucurbit[n]urils CB[n], cucurbit[7]uril (CB[7]) and cucuribit[8]uril
(CB[8]). Three binary inclusion complexes were investigated in solution and in the solid-state,
by lyophilization and by formation of physical mixtures in most of the cases 1:1 complex was
obtained, for each drug. 1HNMR, electrospray ionization mass spectrometry (ESI-MS), and
matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry
were used to study the complexes prepared in aqueous media. The lyophilized solid complexes
were characterized by Fourier transform-infrared spectroscopy (FT-IR), powder X-ray
diffractometry (PXRD), thermogravimetric analysis (TGA), and differential scanning
calorimetry (DSC). ESI-MS, FT-IR and PXRD experimental results established in this work
reveal that Naph, OXY and XYL molecules form stable inclusion complexes with the two
hosts. The TGA and DSC confirmed the enhancement of the thermal stability of each drug and
the production of a thermally stable solid complex. The 1HNMR has shown that the guests'
protons faced shifting in ppm and broadening of peaks upon formation of inclusion complexes
with the selected CB[n]. The aromatic protons of the guest exhibited the highest changes in the
chemical shifts and shape of the NMR peaks, suggesting their inclusion into the cavity of the
CB[n]. The diffusion coefficients (D), developed from the diffusion-controlled NMR
Spectroscopy (DOSY) measurements, for the complexation of the selected imidazoline drugs
with CB[7] and CB[8], were decreased in presence of hosts compared to the free guests
indicating formation of guest-host adduct. The results presented in this thesis show that the
selected drugs are assumed to form stable inclusion complexes with CB[7] and CB[8] through
non-covalent interactions such as van der Walls interactions, hydrogen bonding, and ion-dipole
interactions resulting in enhanced chemical stability of these pharmaceutical compounds. This
study generates initial data for potential drug delivery systems for these three selected
imidazoline drugs compounds by CB[n]
