Reinforced poly(ethylene oxide) blend hydrogel films containing mafenide acetate were prepared by using two freezing-thawing
cycles and the
irradiation crosslinking technique, and their properties and the drug release were assessed. The results showed that the tensile strength of the
reinforced PEO blend hydrogel films increased significantly (p <0.01), the gel fraction and the elongation at break of the films increased slightly as compared with those formed by the irradiation without the freezing-thawing treatment, indicating that the mechanical properties of the PEO blend hydrogel films can be improved by the freezing-thawing cycles. The reinforced films possessed an ideal flexibility, crosslinking density and elasticity as wound dressings. Swelling studies showed that the equilibrium water content of the hydrogel films expressed in the degree of swelling decreased significantly (p <0.01), suggesting that a significant structural rearrangement of the films occurred during the freezing process. The structural densification resulted in the increase of the mechanical strength of the hydrogel films. The hydrogels formed by the irradiation at doses of 40 kGy were comparatively strollger. Release studies were run on the reinforced hydrogels with mafenide acetate which was incorporated before the freezing-thawing treatment. Release was followed over seven days. The drug transport was controlled by a regular diffusion model.