POLYMER MONOLITHIC SYSTEMS FOR CONTROLLED-RELEASE OF AGROCHEMICALS

Controlled release technology used for agricultural chemicals is now the subject of intensive research. Controlled release (CR) polymer matrix systems offer a number of potential advantages over the conventional means of application. The principal advantage of the CR systems is that they allow much less active agent to be used for the desired period of activity. The design criteria of CR monolithic systems involving the selection of polymer type and other basic components of the formulation are discussed. The monolithic system functions on the principle of diffusion dissolution or membrane-moderated diffusional release mechanism. The release characteristics of the system can be altered by changing the composition, morphology or by use of additives to meet the specific product requirements. A wide variety of monolithic delivery systems for CR of agrochemicals, their performance and type of application are reviewed. Evaluation of these systems in the laboratory and agriculture fields for their efficacy are areas of future research and development.