Principals of Controlled Release Formulations

Akelah, Functionalized Polymeric Materials in Agriculture and the Food Industry, 133 

Con trolled-release delivery system Fig. 3.1 (a) Traditional delivery system, (b) controUed-release deUveiy system 

ControUed-release polymeric systems can be divided into two broad categories based on the concept of combining biologicaUy active substances with polymeric materials to achieve a desired release profile. These systems are either a physical combination in which the polymer acts as a rate-controUing device or a chemical combination in which the polymer acts as carrier for the agent. The choice of the 

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