Diffusion models of gentamicin released in poly(vinyl alcohol)/chitosan hydrogel

This study presents comparison of our recently formulated two compartmental model with General fractional derivative (GFD) and Korsmeyer–Peppas, Makoid–Banakar and Kopcha diffusion models. We have used our GFD model to study the release of gentamicin in poly (vinyl alcohol)/chitosan/gentamicin (PVA/CHI/Gent) hydrogel aimed for wound dressing in medical treatment of deep chronical wounds. The PVA/CHI/Gent hydrogel was prepared by physical cross linking of poly(vinyl alcohol)/chitosan dispersion using freezing-thawing method, and then was swollen for 48 h in gentamicin soluteion, at 37ºC. Different physicochemical (FTIR, SEM), mechanical and biological (cytotoxicity, antibacterial activity) properties have been determined. The concentration of released gentamicin was determined using a high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS). The ratio between concentration of released gentamicin and initial concentration of gentamicin in the hydrogel was monitored for the prolonged time period in order to obtain gentamicin release profile. It was proven that our novel diffusion GFD model better fitted to experimental data then other models, and enabled the determination of diffusion coefficient precisely for the entire time period.