Structure and stability of fluoroquinolone-(2-hydroxypropyl)-β-cyclodextrin complexes as perspective antituberculosis drugs

The formation of host–guest complexes of fluoroquinolones (FQs), such as levofloxacin, ofloxacin, and moxifloxacin with (2-hydroxypropyl)-β-cyclodextrin (HP–β–CD) was studied by spectroscopic methods. The stoichiometry and dissociation constants of the inclusion complexes were determined. The formation of complexes of FQs with HP–β–CD was confirmed by the solubility studies, the UV and FTIR spectra and the equilibrium dialysis. The use of the complex of levofloxacin with HP–β–CD leads to the prolonged release of the former observed in the dialysis experiments. The formation of inclusion complexes makes it possible to increase the solubility of FQs by two to five times. The research may provide a basis for the development of new FQ-containing drugs involving HP–β–CD as a nanocarrier system.