Glucose oxidase release from calcium alginate gel capsules

Diffusion of glucose oxidase within calcium alginate gel capsules has been assayed and the experimental data fitted to a simple semi-empirical power e quation, which is used to analyse the solute release from polymeric devices . It was found that an increase in the concentration of sodium alginate and calcium chloride gives rise to a reduction in the enzyme leakage. This was verified when glucose oxidase (GOD) diffusion percentages were compared in capsules with thicknesses of the same order of magnitude but obtained unde r different experimental conditions. So, the use of sodium alginate and cal cium chloride solutions of concentrations 0.5% w/v and 2.6% w/v, respective ly, lead to a diffusion percentage of 25 +/- 2. This percentage was reduced to 8 +/- 3 when sodium alginate and calcium chloride concentrations were f ixed at 1% w/v and 4% w/v, respectively, even though the thicknesses of the capsules were of the same order of magnitude. (C) 2000 Elsevier Science In c. All rights reserved.