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

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-C-12) and ibuprofen molecules were encapsulated and solubilized by poly(beta-cyclodextrin) (beta-CDP/IBU). The content of active residual cavities in beta-CDP with inclusion abilities in beta-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-(beta)CDP-HEC/IBU) in water with the hydrophobic C-12 side-chains on HEC-C-12. The critical concentrations of HEC-C-12 and beta-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 (H-1 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-(beta)CDP-HEC/IBU were investigated. The results showed that the loaded content of IBU in gel-(beta)CDP-HEC/IBU was 5 wt%, and that IBU encapsulated in gel-(beta)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.