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]