Summary of common pesticide dosage forms and registration precautions

The vast majority of raw drugs can not be used directly without processing. Under normal circumstances, the active ingredient content in the original drug is very high, after processing into a preparation, not only can dilute the concentration of the active ingredient, so that the pesticide is evenly distributed in the field, but also so that the pesticide can be better attached to the crop or control object during the application process, and give full play to the drug effect.


The pesticide preparation is further processed according to the characteristics and uses of the original drug, and the dosage form of the pesticide is different, the use method is different, the duration of the effect is different, the rapid effect is different, and the safety is different. When registering pesticides, the name of the pesticide preparation generally declared includes three parts, namely, the active ingredient content, the name of the active ingredient of the pesticide and the dosage form, such as 40% chlorothalonil suspension agent and 50% carbendazim wettable powder.


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Common dosage forms on the market
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(1) Cream (EC)



The emulsion is mainly composed of pesticide agents, solvents and emulsifiers, and some emulsifiers are also added to a small amount of co-solvents and stabilizers. Pesticide cream requires a clear and transparent appearance, no particles, no flocculent, stored under normal conditions without stratification, no precipitation, and maintain the original emulsifying properties and efficacy. After the cream is added to the water, it should have good dispersion, and the emulsion is a light blue transparent or translucent solution, and has enough stability, that is, it does not precipitate or precipitate oil in a certain period of time.



(2) Powder (DP)



Powder is a mixture of pesticide and filler processing, some powder is also added to the stabilizer. There are many kinds of fillers, commonly used are clay, kaolin, talc, diatomite and so on. Powder is mainly used for sprinkling powder, mixing toxic soil, etc., can not add water spray.



(3) Wettable powder (WP)



Wettable powder is a mixture of pesticide, filler and wetting agent. Wettable powder should have good wettability and high suspension rate. Wettable powder with poor suspension rate not only has poor efficacy, but also easily causes crop damage. Wettable powders are usually diluted with water and used as sprays.


(4) Granules (GR)



Granule is a mixture of pesticide agent, carrier and auxiliary agent. The carrier can attach and dilute the original drug, and is the basis of the formation of particles (granules). Therefore, the carrier requires no decomposition of pesticides, with appropriate hardness, density, adsorption and water disintegration rate and other properties. The materials commonly used as carriers are white carbon black, diatomite, clay, zviolet rock powder, stone cinder, clay, red brick, sawdust, etc. Common additives are binder (coating agent), adsorbent, wetting agent, dyeing agent and so on. The granule has the advantages of convenient use, safe operation, wide application range and prolonged efficacy.



(5) Solubilizable (SL)



The solution is mainly composed of pesticide and water, and some also add a small amount of preservatives, wetting agents, dyeing agents and so on. The preparation is based on water as the solvent, the pesticide has a high solubility in water, and some pesticide agents exist in the form of salt in water. The solution is easy to process and low cost, but some pesticides are unstable in water and easy to decompose and fail in long-term storage.


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(6) Suspension Agent (SC)



A suspension agent is a fluid, liquid form. It is made from the mixture of pesticide and dispersant additives, and the diameter of the drug is less than 5 microns. Suspensions are usually sprayed with water.



(7) Oil (EP)



Oil agent is the oil solution formulation of pesticide. Some need to add auxiliary solvents or chemical stabilizers during processing. Spray directly without dilution when using.



(8) Ultra Low Volume Liquid (UL)



Ultra-low volume liquid agent is an oily agent, processed by mixing pesticides and solvents, and some also add a small amount of co-solvent, stabilizer and so on. This preparation is designed for use by ultra-low volume sprayers, or aircraft ultra-low volume sprayers, which are sprayed directly without dilution. Due to the fine spray particles, high concentration, and large amount of adhesion per unit area, the pesticide processing of the preparation must be efficient and low toxic, requiring low solvent volatility, high density, high flash point, and crop safety.



(9) Soluble Powder (SP)



Soluble powder is composed of water-soluble pesticide and a small amount of water-soluble fillers mixed and crushed, and some also add a small amount of surfactant. When using, dissolve with water and use spray.



(10) Smoke Agent (FU)



Smoke agent is a powder made of pesticide, fuel (such as wood dust), accelerant (such as oxidizing agent, such as potassium nitrate), and anticombustion agent (such as clay). Its fineness is passed through the 80 gauge screen, in bags or cans, with ignition wire. After the smoke agent is ignited, it can be burned, but there is no flame. The active ingredients of the pesticide are vaporized by heat, cooled in the air and condensed into solid particles, which are deposited on the plants to achieve the purpose of preventing and controlling diseases or pests. Smoke particles in the air can also enter insects through the respiratory system to produce toxic effects. Tobacco agent is mainly used for the prevention and control of forest, warehouse, greenhouse, health and other diseases and pests.



(11) Water Emulsion (EW)



The water emulsion is an oil-in-water opaque thick emulsion liquid pesticide formulation. Water emulsion is made from water-insoluble liquid pesticide crude oil, emulsifier, dispersant, stabilizer, antifreeze and water by homogenization process, without oil as a solvent or only a small amount.



(12) Water Dispersion Granules (WG)



Water dispersible granule is a granular pesticide formulation which can disintegrate quickly and disperse to form suspension after entering water. This dosage form has the advantages of suspension, dispersion and stability of wettable powder and high concentration suspension agent, and overcomes the disadvantages of both. Compared with wettable powder, it has the advantages of good fluidity, easy to pour out from the container, and no dust flying. Compared with high concentration suspension agent, it can overcome the shortcomings of deposition caking during storage, freezing at low temperature and high freight.


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Note the information related to the dosage form when registering
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(1) When registering pesticide preparations, the quality specifications and physical and chemical property test items of different dosage forms are different, and the test items to be carried out need to be determined according to the type of dosage forms.



(2) On the pesticide label, the pesticide product dosage form is indicated by the dosage form name, not by the dosage form code. The name of the dosage form is below the pesticide name, and the font height shall not be less than 1/2 of the pesticide name.



(3) The composition of the product and the dosage form should be consistent. For example, the effective ingredients with better water solubility will not be registered as water dispersion granules, suspension agents and other dosage forms. Preparations that are liquid at room temperature will not be processed into suspension agents. Microbial pesticides are not processed into solvable agents, soluble granules or soluble powders.



(4) The use method and dosage form of the product should also be consistent. For example, the application methods of granules are generally scattered, trench application, etc., and can not be used by spray after dissolution.



(5) For the research and development of new types of dosage forms, improving the efficacy of pesticides and reducing costs are also the efforts of some manufacturers. If the dosage form of some products is not within the range of existing pesticide dosage forms, information such as product composition and production process can be provided to identify the dosage form.