Molecular imprinting functionalized silica xerogel for selective recognition of levorotatory ofloxacin

In the present work, molecular imprinting silica xerogel (MISX) with selective recognition function aiming to regulate drug therapy was synthesized using biomimetic method with poly(ethyleneimine)s (PEIs) as the polymer template and levorotatory ofloxacin (LOFL) as recognition template. Ultraviolet spectroscopy wavelength scanning was used to test the removal process of LOFL, and characteristics of selective loading ofloxacin (OFL) into MISX were investigated using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Molecular recognition functionality of MISX was intensively studied, including OFL loading and release. The results suggested that MISX possessed ability to recognize and selectively adsorb LOFL into MISX in OFL aqueous solution. Amorphous phase of adsorbed molecules contributed to molecular recognition because amorphous state increased the stability of LOFL that were selectively adsorbed into MISX, which induced stronger hydrogen bonding formed between LOFL and MISX so as to improve LOFL recognition ability. In vitro release revealed that OFL-MISX tablet initially released LOFL and later gradually OFL into dissolution medium. Thus conversion of drug release with different pharmacological activity had special value in delivering systems.