Photopolymerization of alicyclic methacrylate hydrogels for controlled release

Alicyclic hydroxy methacrylate monomer, o-hydroxycyclohexyl methacrylate (HCMA), was synthesized and characterized by Fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (H-1-NMR). Photopolymerization kinetics of HCMA was investigated via real-time infrared spectroscopy (RT-IR). Polymeric network hydrogels based on hydroxyethyl methacrylate (HEMA) and HCMA were prepared by using the photopolymerization technique. Mechanical strength, swelling characteristic, and controlled release behavior of hydrogels with various feed compositions were studied. Poly(HEMA-co-HCMA) hydrogel had higher storage modulus than that of poly(HEMA) hydrogel as investigated by dynamic mechanical analysis (DMA). Acid orange 8 was used as a model drug for the investigation of drug release behavior of copolymeric hydrogels. Results indicated that increase in HCMA ratio in hydrogel composition could reduce the swelling rate and prolong the release time. Scanning electron microscopy (SEM) was also utilized to study the surface morphology of hydrogels, and the results indicated that HCMA content influenced pore diameter on the hydrogel surface. Copyright (C) 2008 John Wiley & Sons, Ltd.