Adsorption Properties of Mesoporous Silica Gel with β-Cyclodextrin as a Pore-Forming Agent Relative to Moxifloxacin

Abstract

A method for the synthesis of mesoporous silica gel using β-cyclodextrin as a pore-forming agent is developed. The physical properties and structure of the obtained adsorbent are studied by Fourier-transform IR spectroscopy and the low-temperature adsorption–desorption of nitrogen (BET) method. The material has an average specific surface area of 435 ± 5 m²/g and an average pore size of 5 ± 0.5 nm. This value of the pore size indicates the formation of complex structures from columnar associates of β-cyclodextrin in the synthesis of the material. The adsorption capacity of the obtained material is 0.2 ± 0.05 mg of 2-hydroxypropyl-β-cyclodextrin per milligram of the adsorbent. The dissociation constant of the complexes of moxifloxacin with β-cyclodextrin inside the pores of silica gel is of the order of 5 × 10^–3 M. The resulting system of SiO₂-β-CD is promising for application in the biomedical chemistry as a carrier of biologically active molecules, particularly as an antibacterial preparation of moxifloxacin.