Claims:WE CLAIM
1. A stable acaricidal composition comprising:
a. an active component containing a combination of propargite in an amount in the range of 40% to 60% by weight of the total composition, and Hexythiazox in an amount in the range of 1% to 6% by weight of the total composition; and
b. a stabilizer containing a combination of epoxidized soyabean oil in an amount in the range of 1% to 5% by weight of the total composition, and ?-butyrolactone in an amount in the range of 1% to 5% by weight of the total composition.
2. The composition as claimed in claim 1, wherein the ratio of propargite to Hexythiazox is in the range of 15: 1 to 25: 1.
3. The composition as claimed in claim 1, wherein the ratio of propargite to Hexythiazox is in the range of 20:1 to 25: 1.
4. The composition as claimed in claim 1, wherein the ratio of epoxidized soyabean oil to ?-butyrolactone is 1: 1.
5. The composition as claimed in claim 1, wherein the composition comprises an excipient in an amount in the range of 40% to 50% by weight of the total composition and the excipient is selected from the group consisting of a surfactant and a solvent.
6. The composition as claimed in claim 5, wherein the surfactant is at least one compound selected from the group consisting of calcium salt of linear alkyl benzene sulphonic acid, lauryl alcohol ethoxylate and castor oil ethoxylate or a blend thereof.
7. The composition as claimed in claim 5, wherein the solvent is a heavy aromatic solvent.
8. The composition as claimed in claim 1, wherein the composition comprises:
a. an active component containing a combination of propargite in an amount in the range of 41% to 50% by weight of the total composition, and Hexythiazox in an amount in the range of 1% to 3% by weight of the total composition; and
b. a stabilizer containing a combination of epoxidized soyabean oil in an amount in the range of 1% to 2% by weight of the total composition, and ?-butyrolactone in an amount in the range of 1% to 2% by weight of the total composition.
9. The composition as claimed in claim 8, wherein the composition comprises an excipient containing a surfactant in an amount in the range of 5% to 8% by weight of the total composition, and a heavy aromatic solvent in an amount in the range of 35% to 45% by weight of the total composition.
10. The composition as claimed in claim 1, wherein the composition is in the form of an emulsifiable concentrate (EC).
, Description:FIELD
The present disclosure relates to a stable acaricidal composition.
DEFINITIONS
As used in the present disclosure, the following term is generally intended to have the meaning as set forth below, except to the extent that the context in which it is used indicates otherwise.
Acaricidal Activity in the context of the present disclosure relates to a property of material / composition that kill members of the arachnid subclass Acari, which includes ticks and mites.
Epoxidized Soyabean oil in the context of the present disclosure relates to a mixture of organic compounds obtained by the epoxidation of soybean oil.
Heavy aromatic solvent in the context of the present disclosure relates to a complex combination of hydrocarbons obtained from distillation of aromatic streams. It consists predominantly of aromatic hydrocarbons having carbon numbers in the range of C9 to C16 and boiling points in the range of approximately 165 °C to 290 °C.
Emulsifiable concentrate in the context of the present disclosure relates to a blend of active ingredient, organic solvent, and surfactants.
BACKGROUND
Agricultural mites harm cotton, vegetables, apples, citrus, tea, flowers and other crops. Currently, different acaricidal compositions are used for the prevention and control of the mites. Acaricidal compositions comprising propargite as an active component are conventionally known.
Propargite also known as 2-(4-tert-butylphenoxy)cyclohexyl prop-2-yne-1-sulfonate, is a low toxicity broad-spectrum acaricide. However, the acaricidal compositions comprising propargite appear to lose potency with time. The activity of propargite decreases upon storage, especially at elevated temperatures. At elevated temperatures, propargite decomposes to bis-[2-[4-(1,1-dimethylethyl)phenoxy]cyclohexyl]sulfite. The formation of bis-[2-[4-(1,1-dimethylethyl)phenoxy]cyclohexyl]sulfite accelerates further degradation of propargite.

Conventionally different stabilizers such as triphenyl phosphite, epichlorohydrin are used to control the degradation of the propargite. However, the conventional stabilizers are not effective.
Therefore, there is felt a need to provide an acaricidal composition that mitigates the drawbacks mentioned hereinabove.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a stable acaricidal composition.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a stable acaricidal composition containing an active component containing a combination of propargite in an amount in the range of 40% to 60% by weight of the total composition, and Hexythiazox in an amount in the range of 1% to 6% by weight of the total composition; a stabilizer containing a combination of epoxidized soyabean oil in an amount in the range of 1% to 5% by weight, and ?-butyrolactone in an amount in the range of 1% to 5% by weight. The composition further comprises an excipient in an amount in the range of 40% to 50% by weight of the total composition. The ratio of propargite to Hexythiazox present in the acaricidal composition is in the range of 15: 1 to 25: 1. Preferably, the ratio of propargite to Hexythiazox present in the acaricidal composition is in the range of 20: 1 to 25: 1.
DETAILED DESCRIPTION
Various acaricidal compositions comprising propargite have been explored to control mites. However, the conventional compositions are associated with drawback such as low storage stability.
In an aspect, the present disclosure provides a stable acaricidal composition with improved stability.
The stable acaricidal composition comprises an active component containing a combination of propargite in an amount in the range of 40% to 60% by weight of the total composition, and Hexythiazox in an amount in the range of 1% to 6% by weight of the total composition; a stabilizer containing a combination of epoxidized soyabean oil, and ?-butyrolactone in an amount in the range of 1% to 5% by weight. In accordance with the present disclosure, the stable acaricidal composition further comprises an excipient in an amount in the range of 40% to 50% by weight of the total composition.
In accordance with the exemplary embodiment of the present disclosure, the composition is in the form of an emulsifiable concentrate (EC).
In accordance with the embodiments of the present disclosure, the ratio of propargite to Hexythiazox present in the acaricidal composition is in the range of 15: 1 to 25: 1. Preferably, the ratio of propargite to Hexythiazox present in the acaricidal composition is in the range of 20: 1 to 25:1.
In accordance with the present disclosure, a combination of propargite, and Hexythiazox is used as an active component. The synergistic effect of the combination of propargite, and Hexythiazox increases the control effect of the pest resistance. The combination of propargite and Hexythiazox is effective against eggs, larvae, nymphs, as well as adult animals.
In accordance with the present disclosure, a combination of epoxidized soyabean oil and ?-butyrolactone is used as the stabilizer.
In accordance with the embodiments of the present disclosure, the excipient is at least one compound selected from the group consisting of a surfactant and a solvent.
In accordance with the exemplary embodiment of the present disclosure, the surfactant is at least one selected from calcium salt of linear alkyl benzene sulphonic acid, lauryl alcohol ethoxylate and castor oil ethoxylate. Preferably, the surfactant is a blend of calcium salt of linear alkyl benzene sulphonic acid, lauryl alcohol ethoxylate and castor oil ethoxylate.
In accordance with the exemplary embodiment of the present disclosure, the solvent is heavy aromatic solvent.
In accordance with the embodiments of the present disclosure, the acaricidal composition comprises an active component containing a combination of propargite in an amount in the range of 41% to 50% by weight of the total composition, and Hexythiazox in an amount in the range of 1% to 3% by weight of the total composition; the stabilizer containing a combination of epoxidized soyabean oil in an amount in the range of 1% to 2% by weight of the total composition, and ?-butyrolactone in an amount in the range of 1% to 2% by weight of the total composition. The composition also comprises an excipient containing a surfactant in an amount in the range of 5% to 8% by weight of the total composition, and a heavy aromatic solvent in an amount in the range of 35% to 45% by weight of the total composition.
The present disclosure further provides a process for the preparation of a stable acaricidal composition.
Initially, a reactor is charged with a fluid medium and Hexythiazox and stirred over magnetic stirrer for 10 minutes to 30 minutes until homogeneous solution is formed. Propargite is then added to the homogeneous solution, followed by addition of a surfactant comprising a blend of calcium salt of linear alkyl benzene sulphonic acid, lauryl alcohol ethoxylate and castor oil ethoxylate. Further, a stabilizer containing a combination of epoxidized soyabean oil and ?-butyrolactone is added and the resultant mixture is stirred for 20 minutes to 50 minutes until homogeneous to obtain the desired acaricidal composition.
The present disclosure teaches using a combination of epoxidized soyabean oil, and ?-butyrolactone in pre-determined amount as a stabilizer. The synergistic effect of the combination substantially avoids formation of bis-[2-[4-(1,1-dimethylethyl)phenoxy]cyclohexyl]sulfite and further controls the degradation of propargite in acaricidal composition.
The present disclosure is further described in light of the following laboratory scale experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. These laboratory scale experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial/commercial scale.
EXPERIMENTAL DETAILS
Experiment 1: Preparation of a stable acaricidal composition in accordance with the present disclosure
A 250 mL sized glass beaker was charged with a heavy aromatic solvent (solvesso 150, trade name) (80 g), followed by addition of Hexythiazox (4.4 g) and stirred over magnetic stirrer for 15 minutes to obtain a homogeneous solution. To the homogeneous solution was added, propargite (96.6 g), a surfactant comprising a blend of calcium salt of linear alkyl benzene sulphonic acid, lauryl alcohol ethoxylate and castor oil ethoxylate (15 g). Further, a stabilizer comprising epoxidized soyabean oil (2 g) and ?-butyrolactone (2 g) was added. The resultant mixture was stirred for 30 minutes until homogeneous to obtain the acaricidal composition of the present disclosure.
Experiment 2: Comparative example
The similar experimental procedure as disclosed in experiment 1 was followed except, a stabilizer comprising 1 g of epoxidized soyabean oil and 1 g of ?-butyrolactone.
Experiment 3: Comparative example
The similar experimental procedure as disclosed in experiment 1 was followed except, a stabilizer. The stabilizer containing epoxidized soyabean oil and ?-butyrolactone was not added.
Experiment 4: Comparative example
The similar experimental procedure as disclosed in experiment 1 was followed except, only epoxidized soyabean oil (1 g) as a stabilizer.
Experiment 5: Comparative example
The similar experimental procedure as disclosed in experiment 1 was followed except, only ?-butyrolactone (1 g) as a stabilizer.
Experiment 6: Comparative example
The similar experimental procedure as disclosed in experiment 1 was followed except, only ?-butyrolactone (2 g) as a stabilizer.
Example 2: Storage Stability study
Samples formulated as per Experiments 1 to 6 were kept for stability study in the oven at 54 °C and after interval of 7 days, one sample from each of the experiments (1 to 6) was removed from the oven and analyzed for propargite and Hexythiazox content. This study was continued for a period of 63 days.
The results for stability study, degradation data, Appearance data, and Emulsion stability data were tabulated in Table 1 to 4 respectively given below:
Table-1: Stability study
Experiment
No. Active Component Initial content of the active component Heat Study at 54oC
No of days
7th 14th 21st 28th 35th 42nd 49th 56th 63rd
1 Propargite 43.36 43.31 43.28 43.26 43.22 43.16 43.11 42.98 42.94 42.89
Hexythiazox 2.14 2.13 2.13 2.12 2.11 2.11 2.10 2.10 2.10 2.10
2
Propargite 43.35 43.32 43.28 43.25 43.21 43.18 43.15 43.11 43.03 24.04
Hexythiazox 2.14 2.13 2.13 2.12 2.12 2.11 2.11 2.10 2.10 2.08
3 Propargite 43.44 43.37 43.24 21.76 - - - - - -
Hexythiazox 2.13 2.11 2.09 1.92 - - - - - -
4 Propargite 43.45 43.40 43.31 21.84 - - - - - -
Hexythiazox 2.15 2.13 2.10 1.94 - - - - - -
5 Propargite 43.41 43.29 21.35 - - - - - - -
Hexythiazox 2.12 2.11 1.89 - - - - - - -
6 Propargite 43.39 43.34 21.37 - - - - - - -
Hexythiazox 2.15 2.13 1.91 - - - - - - -

Table-2: Degradation data

Experiment
No. Propargite Content
% Degradation Hexythiazox Content
% Degradation
No. of Days
Ambient AHS Study Ambient AHS
Study
1 43.36 42.89 1.08% 2.14 2.10 1.87% 63
2 43.35 24.04 44.54% 2.14 2.08 2.80% 63
3 43.44 21.76 49.90% 2.13 1.92 9.86% 21
4 43.45 21.84 49.74% 2.15 1.94 9.77% 21
5 43.41 21.35 50.82% 2.12 1.89 10.85% 14
6 43.39 21.37 50.75% 2.15 1.91 11.16% 14
Table-3: Appearance data
Sr.
No. Experiment No.
1 2 3 4 5 6
1. 1st Day of Formulation Clear, Yellow homogeneous solution Clear, Yellow homogeneous
solution Clear, Yellow homogeneous
solution Clear, Yellow homogeneous
solution Clear, Yellow homogeneous
Solution Clear, Yellow homogeneous
Solution
2. Cold Test
(0oC for 7 days) Clear solution, no crystal Clear solution, no crystal Clear solution, no crystal Clear solution, no crystal Clear solution, no crystal Clear solution, no crystal
3. AHS Study
(54oC) Clear, Yellow homogeneous
Solution
(63rd day) Brown colour hazy solution
(63rd day) Brown colour hazy solution
(21st day) Brown colour hazy solution
(21st day) Brown colour hazy solution
(14th day) Brown colour hazy solution
(14th day)

It is evident from Table 3, that Experiment No. 1, remains clear yellow homogeneous solution up to 63rd day as the combination of stabilizer (epoxidized soyabean oil & ?-Butyrolactone) in pre-determined amount prevents the degradation of Propargite. The Experiment 3 and 4 turns brown hazy solution after 21st day and Experiment 5 and Experiment 6 turns brown hazy solution on 14th day itself.
Table-4: Emulsion stability data
Experiments Water
Hardness (ppm) Hours Volume (ml) creaming/oil with elapsed time
Day of formulation After 63rd day of AHS study at 54oC
1.
342 0 hr. Homogeneous thick, white emulsion Homogeneous thick, white emulsion
1 hr. Nil cream / oil Nil cream / oil
After 24 hr. Nil cream /oil Nil cream /oil

2.
342 0 hr. Homogeneous thick, white emulsion Homogeneous thick, white emulsion
1 hr. Nil cream / oil Nil cream / oil
After 24 hr. Nil cream / oil 0.1 ml oil at bottom

3.
342 0 hr. Homogeneous thick, white emulsion Homogeneous thick, white emulsion
1 hr. Nil cream / oil 0.3 ml oil at bottom
After 24 hr. 0.1 oil at bottom 0.4 ml oil at bottom

4.

342 0 hr. Homogeneous thick, white emulsion Homogeneous thick, white emulsion
1 hr. Nil cream / oil < 0.2 ml oil at bottom
After 24 hr. 0.1 oil at bottom 0.4 ml oil at bottom

5. 342 0 hr. Homogeneous thick, white emulsion Poor emulsion
1 hr. Nil cream / oil 0.2 ml oil at bottom
After 24 hr. 0.1 oil at bottom 0.8 ml oil at bottom

6.
342 0 hr. Homogeneous thick, white emulsion Poor emulsion
1 hr. Nil cream / oil 0.2 ml oil at bottom
After 24 hr. < 0.5 ml oil at bottom 0.8 ml oil at bottom

It is evident from Table 4, that Experiment No. 1, exhibited good stability even at 63rd day of AHS study as compared to Experiments 2 to 6.
From Table 1 to 4, it is evident that the composition prepared in experiment 1 as per the present disclosure exhibits improved stability over longer period of time. The composition is stable even after 63 days and the degradation in the propargite content and the hexythiozox content is very low, i.e. 1.08% and 1.87% respectively.
However, the compositions prepared in experiments 2 to 6 are not stable. Substantial degradation in the propargite content can be seen after only 21 days in case of compositions 3 and 4, and 14 days in case of compositions 5 and 6. Further, the composition prepared in experiment 2 comprises lower amounts of epoxidized soyabean oil, and ?-butyrolactone, which leads to degradation of propargite after 56 days.
Therefore, the acaricidal composition comprising the combination of epoxidized soyabean oil, and ?-butyrolactone in predetermined amount is stable.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a stable acaricidal composition.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.