Study on the synthesis and drug-loading optimization of beta-cyclodextrin polymer microspheres containing ornidazole

Drug polymer carriers usually have good sustained release character. In this study, epichlorohydrin was used as cross-linking agent for synthesizing the beta-cyclodextrin polymer microspheres (β-CDPM) by adopting the method of inverse emulsion polymerization. The scanning electron microscope, infrared spectra, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric, 1H NMR and solid state nuclear magnetic resonance were utilized to characterize the structure, surface morphology, thermal stability and crystallinity of the obtained β-CDPM. In vitro release experiment of ornidazole-β-CDPM under preferred experimental condition was studied and the cumulative release curves at different pH values were obtained. The drug loading rate of β-CDPM is 8.86% under preferred process. The release time of the synthesized microspheres was 9 h, which showed good sustained-release behavior. Antibacterial test result indicated that β-CDPM did not affect the antibacterial activity of ornidazole.