FORM 2
THE PATENTS ACT, 1970
(39 of 1970) AND
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
"IMPROVED STORAGE STABLE COMPOSITIONS OF MUTUALLY INCOMPATIBLE INSECTICIDES"
We } UNITED PHOSPHORUS LIMITED,
Uniphos House,
11th Road, C. D Marg, Khar (West),
Mumbai - 400 052,
State of Maharashtra
INDIAN.
The following specification particularly describes the invention and the manner in which it is to be performed:-
The present application constitutes a patent of addition in respect of Indian patent application No. 1001/MUM/2007 entitled "Improved storage stable compositions of mutually incompatible insecticides" filed on 29 May 2007.
Field of invention
The present invention relates to a pesticidal composition comprising a tetrahydro 1, 3, 5-thiadiazin-4-one derivative and a phosphoramidothioate derivative along with a hydrophobic siliceous barrier that restrain the active ingredients from degradative interaction. The invention also relates to a process for preparing the composition to a method of minimizing degradative interaction between pesticidal active ingredients.
Background
Tetrahydro 1, 3, 5-thiadiazin-4-one derivatives are widely used as insecticidal and acaricidal agents. Buprofezin is a well known tetrahydro 1, 3, 5-thiadiazin-4-one derivative effective as a molting inhibitor against insects. Buprofezin is environmentally benign as compared to other insecticides and has prolonged activity and minimal side- effects. The effectiveness of buprofezin is, however, limited by the fact that it displays maximum activity only during certain stages of insect growth. For example, it is most effective only when the insect is in the molting stage. Further, buprofezin is effective only on certain kinds of insects. To increase the effectiveness of insect control and to widen the spectrum of activity, it is desirable to combine buprofezin with other insecticidal active ingredients.
However, on account of its sensitivity to its immediate chemical environment, formulating buprofezin with other insecticidal active ingredients has been conventionally found to be quite challenging. Stability issues arise primarily due to the interaction of buprofezin with other active ingredient(s) or decomposition products thereof.
Therefore, there is a need to impart stability to compositions containing buprofezin (and, in general, to compositions containing tetrahydro 1, 3, 5-thiadiazin-4-one derivatives); constituting additional insecticidal active ingredient(s) that can effectively broaden the spectrum of insecticidal activity.
Detailed Description
Accordingly, the invention provides, a stable pesticidal Composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient.
In one embodiment, the invention provides a stable pesticidal composition comprising a iirst pesticidaf active ingredient and a second pesticidaf active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is tetrahydro l,3,5-thiadiazin-4-one derivative.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the second active ingredient is a phosphoramidothioate derivative.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the hydrophobic siliceous barrier has a moisture content of not greater than 0.5 %.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is buprofezin.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the second active ingredient is acephate.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the barrier comprises a material commercially available with the tradename Aerosil and code number R972.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is enclosed in the barrier.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is coated with the barrier.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is bound to the barrier through a binder.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is bound to the barrier through a binder selected from the group consisting of lactose, kaolin, talc, attapulgite.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the barrier is present in at least 0.5 % by weight of the composition.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the binder is selected from the group consisting of lactose, kaolin, talc, attapulgite and the binder is present in the range 0.1 to 10 % by weight of the composition.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is bound to the barrier through a binder selected from the group consisting of lactose, kaolin, talc, attapulgite wherein the binder is lactose.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is dispersed substantially uniformly throughout the matrix of the second active ingredient.
In another embodiment, the invention provides a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the composition is in the form of a wettable powder.
In another embodiment, the invention provides a process for preparing a stable pesticidal composition comprising a first active ingredient which is a tetrahydro 1, 3, 5- thiadiazin-4-one derivative and a second active ingredient which is a phosphoramidothioate derivative the process comprising treating the first active ingredient with an hydrophobic siliceous agent such that the degradative interaction between the first active ingredient and the second active ingredient is minimized
In another embodiment, the invention provides a process for preparing a stable pesticidal composition comprising a first active ingredient which is a tetrahydro 1,3,5- thiadiazin-4-one derivative and a second active ingredient which is a phosphoramidothioate derivative the process comprising treating the first active ingredient with an hydrophobic siliceous agent such that the degradative interaction between the first active ingredient and the second active ingredient is minimized wherein the hydrophobic siliceous agent comprises a material commercially available with the tradename Aerosil and code number R972. Other examples could be R812 and R974 and/or Aeroxide Ti02 PF2 and Ti02 P25.
In another embodiment, the invention provides a process for preparing a stable pesticidal composition comprising a first active ingredient which is a tetrahydro 1,3,5- thiadiazin-4-one derivative and a second active ingredient which is a phosphoramidothioate derivative the process comprising treating the first active ingredient with an hydrophobic siliceous agent such that the degradative interaction between the first active ingredient and the second active ingredient is minimized wherein the treatment is carried out in the presence of a binder
In another embodiment, the invention provides a process for preparing a stable pesticidal composition comprising a first active ingredient which is a tetrahydro 1,3,5- thiadiazin-4-one derivative and a second active ingredient which is a phosphoramidothioate derivative the process comprising treating the first active ingredient with an hydrophobic siliceous agent such that the degradative interaction between the first active ingredient and the second active ingredient is minimized wherein the treatment is carried out in the presence of a binder selected from the group consisting of lactose, kaolin, talc and attapulgite.
In another embodiment, the invention provides a method for minimizing degradative interaction between a first pesticidal active ingredient and a second pesticidal active ingredient, the method comprising treating the first active ingredient with a hydrophobic siliceous agent.
In another embodiment, the invention provides a method for minimizing degradative interaction between a first pesticidal active ingredient and a second pesticidal active ingredient, the method comprising treating the first active ingredient with a hydrophobic siliceous agent wherein the hydrophobic siliceous agent has a moisture content of not greater than 0.5 %.
In another embodiment, the invention provides a method for minimizing degradative interaction between a first pesticidal active ingredient and a second pesticidal active ingredient, the method comprising treating the first active ingredient with a hydrophobic siliceous agent wherein the first active ingredient is a tetrahydro 1, 3, 5-thiadiazin-4-one derivative and the second active ingredient is a phosphoramidothioate derivative
In a further embodiment, the invention provides a method for minimizing degradative interaction between a first pesticidal active ingredient and a second pesticidal active ingredient, the method comprising treating the first active ingredient with a hydrophobic siliceous agent wherein the first active ingredient is buprofezin and the second active ingredient is acephate.
In a still further embodiment, the invention provides a method of controlling pests, the method comprising applying the composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof wherein the first active ingredient is a tetrahydro 1,3,5- thiadiazin-4-one derivative.
The present invention provides a pesticidal composition in which the active ingredients are restrained from degradation. The degradation of the active ingredients is restrained by providing a hydrophobic siliceous barrier on treatment of at least one of the active ingredients with a hydrophobic siliceous agent. The siliceous agent could be any siliceous material capable of providing a hydrophobic barrier that could restrain degradative interaction between the active ingredients. Typically, the hydrophilic siliceous agent has a moisture content of not greater than 0.5 %. Typical examples of siliceous materials that could be adapted to restrain the degradative interaction include, but not limited to R812 and R974 and/or Aeroxide Ti02 PF2 and Ti02 P25.
Advantageously the hydrophobic siliceous agent is a silicieous material commercially available under the trade name of Aerosil and bearing the code number R 972.
The composition of the present invention comprises a first active ingredient and a second active ingredient. Advantageously, the first active ingredient is a 1, 3, 5- thiadiazini-4-one derivative while the second active ingredient is a phosphoramidothioate derivative. More advantageously, the first active ingredient is buprofezin and the second active ingredient is Acephate. Typically, the active ingredients are so chosen to have low moisture content and, therefore, are taken from their fresh batches.
The hydrophobic siliceous barrier in the composition of the present invention is capable of restraining the active ingredient from degradation. The barrier could be disposed anywhere between the first active ingredient and the second active ingredient. Typically, either the first active ingredient or the second active ingredient or both the active ingredients are provided with the barrier, by treatment with a hydrophobic siliceous agent. Advantageously, the active ingredient that is present in lesser quantities is provided with the barrier. The active ingredient could be enclosed in the barrier, coated with the barrier or bound to the barrier. Advantageously, the active ingredient is bound to the barrier by way of a binding agent. More advantageously, the binding agent is selected from the group consisting of sugars (lactose, fructose etc) and having glucoside rings or polymers like PVA, PVP, polvactylates etc Still more advantageously, the binding agent is lactose. The binding agent could typically be present in the range of at least 0.1 to 10% by weight of the composition.
In the composition of the present invention, the active ingredient provided with the barrier is usually dispersed in the matrix of the other active ingredient. Typically, a first active ingredient provided with the barrier is substantially uniformly dispersed throughout the matrix of a second active ingredient. The ratio of the first active ingredient to the second active ingredient is in the range of from about 1:1 to about 1:15. Preferably, the ratio of the first active ingredient to the second active ingredient is in the range of from about 1:1 to about 1:10. More preferably, the ratio of the first active ingredient to the second active ingredient is in the range of from about 1:1 to about 1:5.
Furthermore, in the composition of the present invention, the hydrophobic siliceous barrier could be present in at least 0.5% by weight of the composition. Advantageously, the barrier could be present in around 0.5 to 10 % by weight of the composition. More advantageously, the barrier could be present in around 1 to 5 % by weight of the composition.
Apart from the active ingredients, the composition of the present invention could contain other customary ingredients, used in agrochemical formulations, such as wetting agents, dispersing agents and fillers used in agrochemical formulations. Suitable wetting agents that could be employed in the composition of the present invention include, but not limited to Salts of alkyl sulphate, alpha olefin sulfonate, dialkyl sulfosuccinate, Taurates, dialkylnaphthalene sulfonate, alkylnaphthalene sulphonate, sulfated fatty alcohols, alkyl ethoxylates, alkylsuphonated ethoxylates,.. Advantageously a wetting agent commercially known by the trade name Supragil WP is used as the wetting agent. Suitable dispersing agents that could be used in the composition of the present invention is include, but not limited to, Lignosulfonates, poly carboxylates, naphthalene sulfoante formaldehyde condensate, styrene acrylic copolymer, EO/PO condensates. Advantageously a dispersing agent commercially known by the trade name Morwet D 425 is used as the wetting agent. Suitable fillers that could be employed in the composition of the present invention include, but not limited to precipitated silica, kaolin, talc, bentonite, attapulgite, china clay, lactose. Advantageously, a filler having a moisture content of less than 0.2% is used to formulate the composition of the present invention. More advantageously, a filler commercially known by the trade name M-fil 100 is used in the composition of the present invention.
The composition of the present invention could be formulated into various physical forms suitable for pest control. The composition of the present invention could be formulated into various physical forms including, but not limited to, suspension concentrate, emulsifiabie concentrate, wettable powder, microemulsions, micoemulsion concentrates emulsions, granules, coated granules, water dispersible granules, solutions and soluble powders. Advantageously, the composition of the present invention could be formulated into a wettable powder.
The invention also provides a process for preparing a stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient. The process of the invention involves treatment of al least one of the active ingredients with a hydrophobic siliceous agent to form a barrier capable of restraining degradative interaction between the active ingredients. The treated active ingredient is then mixed with other active ingredient(s) and customary ingredients of the formulation.
The invention also provides a method for minimization of degradative interaction between active ingredient(s) by providing at least one active ingredient by a hydrophobic siliceous barrier. Typically, the hydrophobic siliceous barrier is formed by treatment of the active ingredient with a hydrophobic siliceous agent. Advantageously, a hydrophobic siliceous agent having a moisture content less than 0.5 percentage by its weight is used.
The composition of the present invention is suitable for control of broad spectrum of pests The various pests that could be controlled by the composition of the present invention include, but are not limited to sucking insects for e.g. aphids, jassids, whiteflies, thrips, BPH etc and chewing, biting and borer insects. The composition of the present invention could be applied to crops for e.g. rice, cotton, pulses etc and soil in the infected or uninfected state. Various commonly known methods of applications such as spraying, soaking, broadcasting, could be used for delivering the pesticidal compositions of the present invention.
The invention is further illustrated by way of the following non limiting example.
Examcle 1
Ingredient(s) % w/w
Acephate 50.0
Buprofezin 20.0
Diisopropyl naphthalene sulfonate sodium salt 2.0
Sodium salt of naphthalene sulphonate formaldehyde condensate 6.0
Aerosil R972 1.5
Lactose 2.0
M-fil 100 18.5
Total 100

In the examples and results that follow, the various measurements were made following FAO specification and CIPAC test methods, PH measurements were carried out for a 1% suspension following MT 75.3 method. Wet sieve analysis was carried out in a 200BSS sieve following MT 185 method. Suspensibility was determined using MT 184 method. Wettability was measured following MT 53.3 and persistent foam analysis was carried out by MT 47.2 method. Degradation studies of the compositions were carried out by 14 day AHS (Accelerated Heat Stability) test at 54°C. Percentage degradation was calculated using the following formula:
Amount of active under ambient conditions - Amount of Active under AHS
% degradation = X I00
Amount of active ingredient under ambient conditions
AHS (Accelerated heat stability) was determined by subjecting the composition to a temperature of 54 ± 2°C for 14 days.
Example 1: Treatment of the active ingredient with hydrophobic siliceous agent
Step 1: Buprofezin + Hydrophobic Silica + Lactose
Step 2: Mix and grind in Jet Mill
Example 2: Preparation of stable pesticidal composition
Step 1: Buprofezin + Hydrophobic Silica + Lactose
Step 2: Mix and grind in Jet Mill
Step 3: Add surfactant + filler + Mix and grind in Jet Mill
Step 4: De-lumped Acephate Tech + Filler + Physical mix
Step 5: Physical Mix of step 3 and step 4 material
A comparative study of the degradation of of two active ingredients: buprofezin and acephate, in composition containing untreated buprofezin and compositions wherein buprofezin is treated with different barrier materials is displayed in table 1
Table 1: Comparative study of degradation of two active ingredients: buprofezin and acephate, in composition containing untreated buprofezin and compositions wherein buprofezin is treated with different barrier materials.
Experiment No Barrier material for treatment of buprofezin Percentage degradation of active ingredient after 14 day AHS
Buprofezin Acephate
1 Nil 11.00 U.72
2 Butylated hydroxyl toluene 15.24 12.03
3 Epoxidised soyabean oil 26.21 20.14

3 Polyvinyl alcohol 25.54 19.65
4 Polyvinyl pyrrolidone 26.24 16.50
5 Sodium lignosulfonate 9.97 6.68
6 Hydrophobic siliceous agent (Aerosil R972) 3.9 5.0

From table 1 it is clear that % degradation of both the active ingredients, namely, buprofezin and acephate has been found to be significantly less (3.9% for buprofezin and 5.0% for Acephate)when a hydrophobic siliceous agent (Aerosil R972) was used as the barrier material as compare to composition where no barrier material has been used. Furtehr, the percentage degradation of the active ingredients observed by employing other barrier materials other than siliceous agent are considerably higher, making them unsuitable for compositions requiring long shelf life.
Table 2 displays the values of various parameters such as PH, suspensibility and wettability observed for the composition of the present invention as compared to the compositions where the active ingredients are used without any treatment with a hydrophobic siliceous agent.
Table 2: Comparative study of physical parameters* of the active ingredient having siliceous barrier the present invention and the composition having no siliceous barrier.
Parameter Value
For compositions having For compositions
no hydrophobic siliceous provided with
barrier hydrophobic siliceous barrier
pH (1% suspension) 5.40 5.43
Wet sieve (200BSS) 0.1 0.1
Suspensibility (%) 95.90 94.73
Wettability (sec) 97 115

Persistent foam (after 60 sec) 10 10 ml |

From table 2 it is evident that the physical parameters of the compositions where the active ingredient(s) is provided with a hydrophobic barrier are not altered significantly as compared to the compositions where the active ingredient is employed without treatment with a hydrophobic siliceous agent. Therefore, the compositions of the present invention display improved stability without significantly affecting the physical characteristics desired for the compositions.
The stable pesticidal compositions of the presents invention enables broad spectrum of pest control by allowing the active ingredients to stabilize in the presence of a hydrophobic siliceous barrier. The composition of the present invention allows degradatively interacting active ingredients to coexist for a prolonged period of time, thus improving the shelf life. Restraining the active ingredients from degradation also allow savings in cost and improves operational efficiency.
The above description is illustrative only and is not limiting. The present invention is defined by the claims that follow and their full range of equivalents.
We Claim:
1. A stable pesticidal composition comprising a first pesticidal active ingredient and a second pesticidal active ingredient wherein the first active ingredient is provided with a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient or a decomposition product thereof.
2. The composition as claimed in claim 1 wherein the first active ingredient is a tetrahydro 1, 3, 5-thiadiazin-4-one derivative.
3. The composition as claimed in any one of the claims 1 or 2 wherein the second active ingredient is a phosphoramidothioate derivative.
4. The composition as claimed in any one of the claims 1 to 3 wherein the hydrophobic siliceous barrier has a moisture content of not greater than 0.5 %.
5. The composition as claimed in any one of the claims 1 to 4 wherein the first active ingredient.
6. The composition as claimed in any one of the claims 1 to 5 wherein the second active ingredient is Acephate.
7. The composition as claimed in any one of the claims 1 to 6 wherein the barrier comprises a material commercially available with the tradename Aerosil and code number R972.
8. The composition as claimed in any one of the claims 1 to 7 wherein the first active ingredient is enclosed in the barrier.
9. The composition as claimed in any one of the claims 1 to 8 wherein the first active ingredient is coated with the barrier.
10. The composition as claimed in any one of the claims 1 to 9 wherein the first active ingredient is bound to the barrier through a binder.
11. The composition as claimed in claim 10 wherein the binder is selected from the group consisting of lactose, kaolin, talc, attapulgite.
12. The composition as claimed in any one of the claims 1 to 11 wherein the barrier is present in at least 0.5 % by weight of the composition.
13. The composition as claimed in any one of the claims 10 to 12 wherein the binder is present in at least 0.1 - 1.0% by weight of the composition.
14. The composition as claimed in any one of the claims 10 to 13 wherein the binder is lactose.
15. The composition as claimed in any one of the claims 1 to 14 wherein the first active ingredient is dispersed substantially uniformly throughout the matrix of the second active ingredient.
16. The composition as claimed in any one of the claims 1 to 15 wherein the composition is in the form of a wettable powder.
17. A process for preparing a stable pesticidal composition comprising a first active ingredient which is a tetrahydro 1, 3, 5-thiadiazin-4-one derivative and a second active ingredient which is a phosphoramidothioate derivative the process comprising treating the first active ingredient with an hydrophobic siliceous agent to form a hydrophobic siliceous barrier such that the degradative interaction between the first active ingredient and the second active ingredient is minimized.
18. The process as claimed in claim 17 wherein the hydrophobic siliceous agent comprises a material commercially available with the tradename Aerosil and code number R972.
19. The process as claimed in claim 17 or 18 wherein the first active ingredient is treated with the hydrophilic siliceous agent.
20. The process as claimed in any one of the claims 18 to 19 wherein the treatment is carried out in the presence of a binder.
21. The process as claimed in claim 20 wherein the binder is selected from the group consisting of lactose, kaolin, talc and attapulgite.
22. A method for minimizing degradative interaction between a first pesticidal active ingredient and a second pesticidal active ingredient, the method comprising treating the first active ingredient with a hydrophobic siliceous agent to form a hydrophobic siliceous barrier capable of restraining the first active ingredient from degradative interaction with the second active ingredient.
23. The method as claimed in claim 22 wherein the hydrophilic siliceous agent has a moisture content of not greater than 0.5 %.
24. The method as claimed in claim 22 or 23 wherein the first active ingredient is a tetrahydro l,3,5-thiadiazin-4-one derivative and the second active ingredient is a phosphoramidothioate derivative.
25. The method as claimed in any one of the claims 23 to 24 wherein the first active ingredient is buprofezin and the second active ingredient is acephate.
26. A method of controlling pests, the method comprising applying the composition as claimed in any one of the claims 1 to 16.