Drug-Release Performance of Acrylic Hydrogel Membranes Synthesized Using a Novel Cross-linker

Hydrogel soft contact lenses have been introduced as alternatives to eye drops for ophthalmic drug delivery, because of their controllable drug loading and release behavior. In this study, acrylic hydrogel membranes were prepared by copolymerization of the novel cross-linker, ethylaluminium diacrylate (EADA), with methyl methacrylate (M1VIA), 2-hydroxyethyl methacrylate (HEMA), and N-vinylpyrrolidone (NVP) in a polypropylene mold. The swelling behavior and mechanical properties of hydrogels containing the newly designed cross-linker were then investigated. Drug release performance was evaluated using a hydrophilic drug, timolol maleate, and a cyclodextrin inclusion complex of the hydrophobic drug, a-tocopherol. For comparison, hydrogels were also prepared using a conventional cross-linker, ethylene glycol dimethacrylate (EGDMA). As the results, tensile strength of the hydrogel membranes using EADA (0.168 MPa) was significantly improved compared to that of the hydrogels made with EGDMA (0.136 MPa). The hydrogel membrane cross-linked with 0.1 mol% EADA showed 66% alpha-tocopherol release after 30 h while the hydrogel membrane cross linked with 0.1 mol% EGDMA showed 42% alpha-tocopherol release. After 2 days of incubation, human fibroblasts on the hydrogel membrane containing EADA showed significantly greater viability than those on EGDMA-containing hydrogel.