Synthesis and Characterization of Sodium Alginate-g-2-Hydroxyethyl Methacrylate Interpenetrating Beads for Controlled Release of Acebutolol Hydrochloride

Sodium alginate-g-2-hydroxyethyl methacrylate (HEMA) synthesis by free-radical polymerization using K2S2O8 as initiator has been carried out by varying 2-hydroxyethyl methacrylate concentration. Poly(HEMA)-grafted-sodium alginate beads were produced by a solvent evaporation technique using three different concentrations of glutaraldehyde as the cross-linking agent. The graft co-polymer beads were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and X-ray diffraction. Scanning electron microscopy confirmed the spherical nature and surface morphology of particles with a mean particle size of 100 mu m. The diffusional exponent (n) values of synthesized beads were found to be in the range 0.1973-0.4764, indicating a Fickian diffusion mechanism with chain relaxation controlled diffusion. Release data have been analyzed using an empirical equation to understand the nature of transport of drug containing solution through the polymeric matrices. The controlled release characteristic of the matrices for acebutolol hydrochloride was investigated in pH 7.4 media. Drug was released in a controlled manner up to 12 h. (C) Koninklijke Brill NV, Leiden, 2011