Controlled release of thiram from neem-alginate-clay based delivery systems to manage environmental and health hazards

The release of pesticides from the controlled release formulations is the best strategy to reduce the agro-environmental pollution. The present study deals with the synthesis of pesticide delivery devices based on neem leaf powder (NLP) and kaolin and bentonite. The beads of different compositions were prepared by varying the amount of clays. These beads were characterized by FTIR, SEMs. EDAX, TGA and swelling study. Formulation characteristics like entrapment efficiency, bead size, percentage equilibrium swelling of the beads and diffusion mechanism for the release of thiram have been evaluated. The incorporation of clays in beads has controlled the release of thiram from the formulations. The release occurred through non-Fickian diffusion mechanism. (C) 2009 Elsevier B.V. All rights reserved.