Physicochemical Properties of the Inclusion Complex of Moxifloxacin with Hydroxypropyl-β-Cyclodextrin Synthesized by RESS

A new method for the synthesis of guest–host inclusion complex of moxifloxacin (MF) with 2-hydroxypropyl-β-cyclodextrin (HPCD) by supercritical fluid technology in the rapid expansion of supercritical solutions (RESS) mode was suggested for developing new drug formulations with improved bioaccessibility. The MF–HPCD complex was synthesized by this method as particles of 2–4 μm, which is the optimum size for creating the oral and inhalation MF drug forms. According to the scanning electron microscopy data, the morphology of MF–HPCD particles (irregular polyhedra) obtained by RESS processing differs from that of the starting components and from that of unbound MF and HPCD obtained by lyophilization from aqueous solution. According to X-ray diffraction data, the crystallinity of MF decreased from 95% to 20–30% after the formation of the HPCD complex. The IR spectroscopic and equilibrium dialysis data showed that RESS provides higher efficiency of drug inclusion in the complex with HPCD compared with that of conventional methods such as lyophilization or mixing of solid components.