Formulation Technique of Granules Resurfacing after Submerged Application

Abstract

This formulation study is conducted for unique granules with a pesticide delivery system to use the active ingredient efficiently in the paddy field. When the granules are scattered, they sink down on the bottom soil at first. Then the granules resurface and diffuse the active ingredient on the water surface. As the solid materials of the granules dissolve completely into the water, finally the concentrated active ingredient is left there. This resurfacing behavior of particle is caused by the binding agent transformed to a hydrosol with water and to hold air existing in the particle as well as by reduction of the particle weight due to dissolution of the solid material in water. In case of insecticide cycloprothrin granules of this type, about 75% of cycloprothrin was distributed on water surface and in water 2 hours after application, while in case of a ordinary granule formulation only about 20% of the active ingredient was distributed there. This type of granules containing insecticidal active ingredients showed for higher efficacy than the ordinary granules against several kinds of injurious paddy insects. Cycloprothrin 2% granules (Cyclosal 2UG^®) was completed by this granular formulation technique as a result of selection of raw materials, establishment of manufacturing process, product quality investigation, and others.