The controlled and sustained release of a fungicide from starch and alginate beads

Abstract

This paper describes the synthesis of starch and alginate beads as controlled release formulations. Different formulations of the fungicide, thiram, were prepared by using BaCl₂ and AlCl₃ as crosslinkers. The beads thus formed were characterized by FTIR and swelling studies. Formulation characteristics like entrapment efficiency, bead size, percentage equilibrium swelling have been evaluated. The release studies of the fungicide from the beads were carried out in vitro and in soil columns. The beads prepared with AlCl₃ have shown more swelling as well as the fungicide release in comparison to beads prepared with BaCl₂. From the soil column studies it was observed that the release of pesticide from the beads occurred in very controlled and sustained manner.

Keywords:

• Agro-environmental pollution
• alginate-starch beads
• controlled release devices
• fungicide/pesticides
• release dynamics

Acknowledgments

One of the authors (Atul Gupta) wish to thanks the Council of Scientific and Industrial Research, New Delhi–India for providing the financial assistance for this work (Grant No. 9/237(0115)/2007-EMR-I).