Seigo Ueda

Factors affecting microencapsulability in simple gelatin coacervation method.

Microencapsulation by way of simple coacervation by gelatin was examined. Five kinds of core material and six kinds of coacervation-inducing agent (CIA) were chosen and the encapsulability of each combination was studied. Some core materials are easily encapsulated, others are difficult to encapsulate, and some show a dependency of encapsulability on the CIA. Electrophoresis and gelatin adsorption studies revealed that encapsulation by way of simple coacervation by gelatin is caused by the affinity between core and coacervate resulting from gelatin adsorption on the core surface. These studies further revealed that cores onto which a large amount of gelatin has been adsorbed before coacervation can be encapsulated.

Core treatment for improving microencapsulability in simple gelatin coacervation method.

In microencapsulation by way of simple coacervation by gelatin, some core materials are encapsulated easily, whilst others are difficult to encapsulate or show an encapsulability dependent on the coacervation-inducing agent. The treatment of core materials to improve encapsulability was studied. It was found that core particle encapsulability can be improved by recrystallization from aqueous solution of an ionic polymer. Electrophoresis, microscopical observation and pH dependency of encapsulability of recrystallized cores revealed that the electrostatic attractive force between gelatin molecules in solution and a polymer attached to the core particle cause gelatin adsorption on the core surface to result in a great improvement in encapsulability.