Physicochemical characterization of sanguinarine-hydroxypropyl-β-cyclodextrin binary and ternary systems

Complexation of sanguinarine with hydroxy-propyl-beta-cyclodextrin (HP beta CD) in the presence and absence of hydrophilic polymer-polyvinylpyrrolidone K30 was studied. Respective binary and ternary systems were prepared using two techniques, physical mixture and lyophilization, and characterized by FT-infrared spectrometry, differential scanning calorimetry and X-ray diffractometry. The Fourier Transform Infrared spectra of the lyophilized binary and ternary systems showed significant shifts in the regions of 1240-1300 cm(-1), 1450-1525 cm(-1) and 1600-1650 cm(-1), where absorptions of -C-O-C- asymmetrical stretching of sanguinarine rings A and F and nu(C=C) ring vibrations of sanguinarine benzo[c]phenanthridine system can be observed respectively. Moreover, in the case of ternary products nu(C=O) amide band absorption of polyvinylpyrrolidone (1600-1750 cm(-1)) shifted to the lower wavenumbers in both the physical mixture and the lyophilized product. These changes in the spectra of the studied systems proved the involvement of the respective molecular groups in complexation process. Differential scanning calorimetry and X-ray diffractometry indicated different states of drug amorphization and entrapment in HP beta CD in the presence and without polyvinylpyrrolidone. The obtained results let us conclude that obtained binary and ternary systems represent sanguinarine-HP beta CD molecular complexes, with different rate of inclusion in the presence and without polyvinylpyrrolidone.