Water dispersible granule (WDG)
Water dispersible granules (WDGs) are a solid, non-dusty granular formulation which disperses or dissolves quickly when added to water in the spray tank to give a fine particle suspension.
They provide a system for delivering solid active ingredients to a target organism. They allow for the production of highly-concentrated formulations which are wettable and easily disintegrated on contact with water. WDGs are an attractive alternative to wettable powder (WP) formulations due to their reduction in dust production.
- Non-dusty so reduces inhalation hazard
- High loading of active ingredient is possible (up to 90%)
- No crystal growth or sedimentation
- Package disposal easier to deal with than for liquid formulations
- Granule disintegration suspensibility upon dilution
- Low melting point active ingredients can be problematic
- High processing cost
- Difficult to include bio enhancing adjuvants in the recipe
The Formulator's Toolbox (Full Version)
Recommended products for WDG
Before producing the final granules, a paste must be made. Wetting agents help incorporate the liquid components into this paste. They also reduce drying costs after the granules have been made as less water can be used. On dilution in water prior to application, wetting agents help disintegration and prevent nozzle blockage.
Once the granule has been diluted in water, ready for spraying (with the aid of the wetting agent), a dispersant is required to maintain the particles in suspension and prevent them from agglomerating.