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.