Synthesis and investigation of a self-assembled hydrogel based on hydroxyethyl cellulose and its in vitro ibuprofen drug release characteristics

Abstract

Self-assembled cellulose-based hydrogels are a new type of supramolecular architecture with potential in biomedical applications. By our preparation, hydrophobic lauryl side-chains were grafted onto hydroxyethyl cellulose (HEC-C12) and ibuprofen molecules were encapsulated and solubilized by poly(β-cyclodextrin) (β-CDP/IBU). The content of active residual cavities in β-CDP with inclusion abilities in β-CDP/IBU was determined to be 31.3 wt% by the phenolphthalein probe method, then the residual cavities were used to spontaneously form a self-assembled hydrogel (gel-(β)CDP-HEC/IBU) in water with the hydrophobic C12 side-chains on HEC-C12. The critical concentrations of HEC-C12 and β-CDP/IBU in the self-assembled hydrogel were fixed at 30 mg mL-1 and 35 mg mL-1 respectively, as shown by the dynamic viscosity results. The synthesized macromolecules and hydrogels were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Gel Permeation Chromatography (GPC) and powder X-ray diffractometry (PXRD). A swelling study and the in vitro drug release characteristics of IBU in gel-(β)CDP-HEC/IBU were investigated. The results showed that the loaded content of IBU in gel-(β)CDP-HEC/IBU was 5 wt%, and that IBU encapsulated in gel-(β)CDP-HEC/IBU presented sustained release characteristics over 1440 min. In addition, the Korsmeyer-Peppas kinetic model gave a better correlation for the release of IBU, and the release procedure was a non-Fickian diffusion process.