DESC:FIELD OF THE INVENTION
The present invention relates to an incorporated insecticidal composition in a
polymer matrix and a method of incorporating the same into a substrate.
More particularly, the present invention relates to an insecticidal composition
incorporated in the polymer matrix useful for making Insecticidal treated Nets (ITN) or
long lasting insecticidal net (LLIN).
BACKGROUND OF THE INVENTION
A vector is an organism capable of transmitting infectious agents between humans or from
animals to humans. Vector-borne diseases are caused by parasites, viruses, and bacteria spread by
vectors. Vector control, which is highly effective in preventing infection and reducing disease
transmission, is an essential component of malaria control and elimination strategies. Conventional
vector control methods include insecticidal sprays, mosquito coils to repel mosquito, mosquito
ovitraps etc.
However, all insect species that are major human disease vectors have developed
insecticide resistance. Furthermore, insecticidal sprays and coils often cause throat irritation and
difficulty breathing in people with respiratory problems.
Due to the limitations of traditional insecticide-based strategies, particularly the development
of insecticide resistance, significant efforts have been made to develop alternative eco-friendly
methods such as long-lasting insecticidal nets (LLINs).
LLINs are mosquito nets that have the insecticide incorporated into the fiber and are
generally more effective than conventional insecticide treated nets (ITNs) because they have an
even and quality controlled insecticide application. Furthermore, because it can be used for 3-5
years, LLIN is more cost-effective than distributing conventional bed nets and treating them with
insecticide once or twice a year. These are an essential malaria prevention tool that is widely used.
Long Lasting Insecticidal nets (LLINs) provide better and more effective protection by repelling
and killing mosquitoes.
2
Joachim et al in US20210355139Al discloses insecticidal methods, uses and applications
of pyrimidinium compounds, their stereoisomers, salts, tautomers and N-oxides, and/or
compositions containing such compounds for controlling invertebrate pests. Said invention also
relates to mixtures of these compounds with other active ingredients, which synergistically enhances
the effect of pesticidal composition.
Chongqing et al in CN106676661A pertains to a protection net, more specifically to a
long-lasting insect and bird preventing fiber protection net and its method of manufacturing. The
long-lasting insect and bird repellent fiber protection net comprises of the following components
in weight order: 60-80 parts polypropylene, 2-10 parts melamine-formaldehyde resin, 10-20
parts a modified monomer, 1-5 parts of an antioxidant, 1-3 parts permethrin, and 2-5 parts
deltamethrin.
Mikkel Vestergaard et al in US2019037846Al discloses an insecticidal polymer matrix
containing piperonyl butoxide (PBO) and deltamethrin (DM), wherein the ratio of PBO to DM
content by weight is greater than 3.
Matthieu Zellweger et al in WO2011124227 Al discloses a method of providing longterm
stability to alkali- sensitive biocides in polypropylene products by incorporating biocides
such as deltamethrin with acid into a polymer matrix comprising polypropylene. An article
comprising a thermoplastic polypropylene polymer matrix having a biocide and an acid dispersed
throughout the polymer matrix. The article is a multifilament yarn from which can be used for
preparing mosquito nets.
Despite plethora of literature and known numerous pesticide compounds and their
compositions belonging to various chemical classes have been developed and utilized, excessive
use of these have resulted in the insecticide resistance with due course of time. Therefore, there is
a growing need for new, cost-effective, safe and reliable methods of controlling vectors like insects
and mosquitoes that alleviates the above mentioned drawbacks in the purview of cited prior art.
3
OBJECT OF THE INVENTION
The main object of the present invention is to provide an insecticidal composition that is a
combination of an active substance and a synergist and is incorporated in a substrate.
Another object of the present invention is to provide a method of incorporation said insecticidal
composition on a substrate that is a long lasting insecticidal net (LLIN).
Still another object of the present invention is to provide an insecticidal composition incorporated
in a substrate that is effective on mosquitoes and disease carrying vectors.
SUMMARY OF THE INVENTION
The present invention relates to an incorporated insecticidal composition in polymer
matrix comprising of a pyrethroid insecticide, a pyrrole chemical entity and/or optionally an
organic synergist effective for controlling insects/pests and disease carrying vectors. During it
efficacy testing, it is found very effective against susceptible and synthetic pyrethroid resistant
strains of malaria causing vectors.
Said insecticidal composition in polymer matrix is useful for making insect/pests
Protective nets or insecticide treated nets (ITNs) or long lasting insecticidal net (LLIN).
The present invention also relates to a method of incorporating the insecticidal
composition in polymer matrix comprising the stepsa.
Mixing the pyrethroid insecticide, a pyrrole entity and an organic synergist each
individually or in combination in the polymer matrix in the melt stage in twin screw
compounding extruder
b. Recovering the master batch granules incorporated with insecticide composition
c. Testing the master batch for incorporated insecticide content, wherein the concentration
of pyrethroid insecticide is in range of 5% to 20% w/w, the concentration of pyrrole
insecticide as Chlorfenapyr is in the range of 5% to 20%w/w and the concentration of
organic synergist as Piperonyl butoxide is in the range of 0% to 10%w/w.
The method of incorporating insecticide in the step a. further comprising mixing insecticide
optionally with adjuvant selected from antioxidants, UV Stabilizers/absorbers, processing aids,
coloring agents, release agents, lubricants, surfactants, antistatic agents and viscosity modifiers or
4
adjuvant can be incorporated within polymer matrix separately without combining with
insecticide/s.
The above objects and advantages of the present invention will become apparent from the
hereinafter set forth detailed description and working examples of the invention described herein
below.
DESCRIPTION OF THE INVENTION
The present invention will now be described hereinafter with reference to the
accompanying data in which a preferred embodiment of the invention is shown. This invention
may, however, be embodied in many different forms and should not be construed as being limited
to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will
be thorough, and will fully convey the scope of the invention to those skilled in the art.
The present invention now will be described hereinafter with reference to the detailed
description, in which some, but not all embodiments of the invention are indicated. Indeed, the
invention may be embodied in many different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like elements throughout. The present
invention is described fully herein with non-limiting embodiments and exemplary experimentation.
The embodiments of the present invention provides an incorporated insecticidal
composition in polymer matrix comprising of a pyrethroid insecticide, a pyrrole chemical entity
and/or optionally an organic synergist effective for controlling insects/pests and disease carrying
vectors.
Said incorporated insecticidal composition in polymer matrix may be useful for making
insect/pests protective nets or insecticide treated nets (ITNs) or long lasting insecticidal net
(LLIN).
The incorporated insecticidal composition in polymer matrix wherein, polymer matrix
used is selected from polyethylene or polypropylene.
The incorporated insecticidal composition in polymer matrix wherein, pyrethroid
insecticide is selected from Bifenthrin, ?-Cylohalthrin, a- Cypermethrin or Deltamethrin and said
pyrrole chemical entity is Chlorfenapyr and said organic synergist is Piperonyl butoxide.
The pyrethroid is an organic compound that is derived from naturally occurring
5
pyrethrins compounds and is neurotoxin to insects. Pyrethroids target the central nervous system
of insects by way of interaction with voltage gated sodium channels in neurons of insects thereby
resulting in depolarization, followed by hyper excitation and death of the insects. The pyrrole is
an organic chemical compound that acts as an active ingredient in pest control products. Pyrrole
affects the energy system of an insect by disrupting the functioning of mitochondria of cells and
due to the lack of production of energy, the insects are unable to perform various other functions of
the cells thereby leading to the death of the insects. The organic synergist is a chemical that makes
an insecticide effective in killing pests. The synergists slow down or inhibit the process of
breakdown of pesticide chemical by the insects thereby enabling the insecticide to perform the
process of killing of the insects.
The pyrethroid compound is selected from pyrethroids include Bifenthrin, beta Cyfluthrin,
Cyfluthrin, Cypermethrin, deltamethrin, Esfenvalerate, lambda-cyhalothrin, gamma cyhalothrin,
imiprothrin, prallethrin, resmethrin, tefluthrin, tetramethrin, and tralomethrin. The pyrrole
e n t i t y is selected as Chlorfenapyr. The synergist is selected as Piperonyl butoxide (PBO).
In another embodiment of the present invention, it provide a method of incorporating the
insecticidal composition in polymer matrix comprising the stepsa.
Mixing the pyrethroid insecticide, a pyrrole entity and an organic synergist each
individually or in combination in the polymer matrix in the melt stage in twin screw
compounding extruder
b. Recovering the master batch granules incorporated with insecticide composition
c. Testing the master batch for incorporated insecticide content, wherein the concentration
of pyrethroid insecticide is in range of 5% to 20% w/w, the concentration of pyrrole insecticide
as Chlorfenapyr is in the range of 5% to 20%w/w and the concentration of organic synergist as
Piperonyl butoxide is in the range of 0% to 10%w/w.
In a particular embodiment for method of incorporating the insecticidal composition in
polymer matrix, wherein the step a. method is comprising mixing the pyrethroid insecticide, a
pyrrole entity and an organic synergist each individually providing individual master batch
granules.
The further embodiment according to the invention for method of incorporating the
insecticidal composition in polymer matrix , wherein the step a. comprising mixing insecticide
optionally with adjuvant selected from antioxidants, UV Stabilizers/absorbers, processing aids,
6
coloring agents, release agents, lubricants, surfactants, antistatic agents and viscosity modifiers or
adjuvant can be incorporated within polymer matrix separately without combining with
insecticide/s.
The further embodiment according to the invention for method of incorporating the
insecticidal composition in polymer matrix , wherein, step b of recovering master batch granules
comprising cutting and flash cooling at temperature ranging between 10-17ºC.
In yet further embodiment according to the invention for method of incorporating the insecticidal
composition in polymer matrix , wherein the insecticide treated nets (ITNs) or long lasting
insecticidal net (LLIN) is produced out by warp knitting from monofilament yarn extruded out of
this polymer matrix.
In yet further another embodiment according to the invention for method of incorporating
the insecticidal composition in polymer matrix, wherein the insecticide incorporated
monofilament yarn has thickness ranging between 75 to 250 denier.
In more preferred embodiment of the present invention, the incorporated the insecticidal
composition in polymer matrix, the monofilament yarn has thickness ranging between 90 to 200
Denier. For more clarity, Denier is a unit of measure for the linear mass density of fibers. It is the
mass in grams per 9,000 meters of the fiber. (The denier is based on a natural reference: a single
strand of silk is approximately one denier; a 9,000-metre strand of silk weighs about one gram).
Testing the extruded Incorporated monofilament yarn (fabric) incorporated with
pyrethroid insecticide and a pyrrole insecticide resulted in concentration of pyrethroid insecticide
is in range of 0.01% to 5% w/w, the concentration of pyrrole insecticide as Chlorfenapyr is in the
range of 0.01% to 8%w/w and the concentration of organic synergist as Piperonyl butoxide is in
the range of 0% to 2%w/w.
In one of the specific embodiment according to the present invention, entire process of
making novel insecticidal treated nets (ITN) using incorporated insecticidal composition
technology in polyethylene is summarized here below, though it should not construed for its
limiting the scope.
The ITN polymeric monofilament fiber material as polyethylene was produced using a
Twin-screw- co-rotating close-meshing extruder. The Extruder temperatures were maintained
upto 200 ±5°C maximum in all steps with extruder speed was about 150 ± 10 rpm.
In the first step, it comprised producing a mixture of 10-20% by weight of technical-grade
7
Bifenthrin with 5-10 % by weight of technical Pipronyl butoxide (Mixture-1) and another mixture
of 10-15% by weight of technical-grade Chlorfenapyr with 5-10% by weight of technical-grade
Piperonyl butoxide (Mixture-2). Thereafter, 20-25% of Mixture-1 and 20-25% of Mixture-2 were
each individually combined with 75-80% by weight of Linear Low Density Polyethylene (Grade
-20 MFI).
Alternatively, it may also comprised making a mixture of 5- 10% by weight of technicalgrade
Bifenthrin, 5- 10% by weight of technical-grade Chlorfenapyr and 80-90 % by weight of
Linear Low Density Polyethylene (Grade -20 MFI) without involving use of synergist as
Piperonyl butoxide.
As synergist- Piperonyl butoxide is in liquid state, inventor of the present application
found it preferable to add in two different blends of making the separate master batches. This was
observed to safeguard the consistency of uniform quality of master batches, though other suitable
ways and means may be utilized to achieve the incorporated composition in polymer matrix.
The polyethylene (LLDPE) used contains the customary adjuvant (or additives) selected
from antioxidants, UV Stabilizers/absorbers, processing aids, coloring agents, release agents,
lubricants, surfactants, antistatic agents and viscosity modifiers.
The above composition materials were introduced in solid and liquid forms into the feed
Zone of the twin-screw compounding extruder to produce concentrated master batch of active
ingredients. This master batch produced shall be used for the further stages.
This master batch was diluted in a second step to a High Density Polyethylene (HDPE)
material containing 0.7% by weight of technical-grade Bifenthrin, 0.8% by weight of technicalgrade
Chlorfenapyr, 0.6% by weight of technical-grade Piperonyl butoxide and 0.4% by weight
of the additive, which may be selected from Stearic acid or polyethylene waxes or oleic acid or
silicone based compounds or fluoro-compounds elastomers.
The above produced master batch, 10% by weight is taken and about 90 % by weight of
HDPE were mixed in a suitable or tumble mixer and this mixture was subjected to extrusion using
a close-meshing single-screw monofilament extruder under the above-mentioned conditions.
The polyethylene was supplied to the extruder in pellet form in the feed zone and the
additive was dosed as per the desired quantity into the polymer melt the form of concentrated
master batch.
The polymeric material of the present invention was used to produce insecticide
incorporated monofilament yarn having linear density ranging between 75 - 250 denier, wherein,
8
the polymeric material was melted in a single-screw extruder with temperature controlled to
200±5°C and extruded through a suitable monofilament die.
The further embodiment according to the invention for method of incorporating the
insecticidal composition in polymer matrix, wherein the incorporation of insecticidal composition
is achieved before extrusion process in the direct master batch mixing or molten state of the
polymer matrix using side feeder.
The method of incorporation of the insecticidal composition on a substrate, that is LLIN,
involves the extrusion process that is performed at high temperatures. The high temperature may
disintegrate the active substances of said insecticidal composition, hence, a combination of
polymers and processing aids is employed along with a thermoplastic polymer, preferably high
density polyethylene. The unique of making incorporated formulation according to present
invention is meticulously designed as combination employed in said method maintains the high
level of the temperature to a certain limit so that the active substances are retained intact from any
disintegration during the master batch and subsequently filament extrusion process.
ITN products (fabric or yarn) derived from novel incorporated insecticidal composition in
polyethylene polymer matrix was subjected to their bioefficacy testing for controlling disease
carrying vectors as well as safety evaluations.
The products appear to be promising in their activities and intended role of controlling disease
carrying vectors with mosquitoes or similar insects.
1. ITN products derived from novel incorporated insecticidal composition in polyethylene
polymer matrix are observed to be enough potent and exceeding the WHO threshold
criteria for ITNs specifically Blood Feeding Inhibition (BFI) of = 90% and insects
Mortality of = 80%.
2. ITN products derived from novel incorporated insecticidal composition in polyethylene
polymer matrix were found significantly superior compared from existing WHO
Prequalified Marketed Product, which is apparently an insecticidal coated but not a
polymeric matrix incorporated product.
Further, said novel incorporated products has better expectations, since highly toxic/hazardous
active insecticide/pesticides unlike WHO Prequalified Marketed polyester coated Product, are not
9
excepted to be present on the surface of fabric (knitted fibers) but present in polymer matrix inside,
which not only provides the improved shelf life but also ensure the long term safety from exposure
to the user human beings at fields and homes.
In a separate study was also performed independently for understanding the regeneration
time after washing following WHO criteria for the ITN products derived from novel incorporated
insecticidal composition in polyethylene polymer matrix. Customary tests like Cone Assay and
Tunnel tests were performed as per WHO protocol (WHO Threshold criteria of 95% Knock Down
in 60 min i.e. KD60 and or 80% 72 hour Mortality for Cone Assay). The result outcomes for these
novel ITN products derived from novel incorporated insecticidal composition in polyethylene
polymer matrix according to the present invention surprised the finding that all products obtained
exceeds the WHO Threshold criteria of for regeneration time.
Certain specific aspects and embodiments of the present application will be explained in more
detail with reference to the following examples, which are provided by way of illustration only and
should not be construed as limiting the scope of the invention in any manner.
Example 1 –ITN Formulation with Bifenthrin, Chlorfenapyr and Piperonyl butoxide
incorporated in polyethylene (A)
The polymeric material as polyethylene was produced using a Twin-screw- co-rotating
close-meshing extruder.
The Extruder temperatures were maintained to 200°C maximum in all steps with extruder speed
was about 150 rpm.
In the first step, it comprised producing a mixture of 15% by weight of technical-grade
Bifenthrin with 7.5% by weight of technical Piperonyl butoxide (Mixture-1) and another mixture
of 15% by weight of technical-grade Chlorfenapyr with 7.5% by weight of technical-grade
Piperonyl butoxide (Mixture-2).
Thereafter, 22.5% of Mixture-1 and 22.5% of Mixture-2 were each individually combined
with 77.5% by weight of Linear Low Density Polyethylene (Grade -20 MFI).
The polyethylene (LLDPE) used contains the customary adjuvant (or additives) selected from
antioxidants, UV Stabilizers/absorbers, processing aids, coloring agents, release agents,
lubricants, surfactants, antistatic agents and viscosity modifiers.
The above composition materials were introduced in solid and liquid forms into the feed Zone of
10
the twin-screw compounding extruder to produce two concentrated Masterbatches of active
ingredients with synergist.
Master batch Analysis (By GC):
a) Master batch-1(Mixture-1): Bifenthrin 15.10% w/w + Piperonyl butoxide (PBO) = 7.50%w/w
b) Master batch-2 (Mixture-2): Chlorfenapyr 15.35% w/w + Piperonyl butoxide (PBO) =
7.78%w/w
These concentrated masterbatches were diluted in a second step to a High Density Polyethylene
(HDPE) material containing 0.7% by weight of technical-grade Bifenthrin, 0.8% by weight of
technical-grade Chlorfenapyr, 0.7% by weight of technical-grade Piperonyl butoxide and 0.4%
by weight of the additive (Stearic acid).
To this end, 5% by weight of master batch-1, 5% by weight of master batch-2 above and 89.6%
by weight of HDPE were mixed in a tumble mixer and this mixture was extruded using a closemeshing
single-screw monofilament extruder under the above-mentioned conditions. The
polyethylene was supplied to the extruder in pellet form in the feed zone and the additive was
dosed as per the desired quantity into the polymer melt the form of concentrated master batch.
Entire extrusion took place under the below mentioned conditions.
The polymeric material of the present invention was used to produce insecticide incorporated
monofilament yarn having linear density ranging between 75 - 250 denier, wherein, the polymeric
material was melted in a single-screw extruder with temperature controlled to 200±5°C and
extruded through a suitable monofilament die.
ITN (fabric/yarn) Analysis (By GC): Bifenthrin 0.733% w/w; Chlorfenapyr = 0.857 %w/w and
Piperonyl butoxide (PBO) = 0.716 %w/w; Linear Density= 133 Denier; Fabric weight = 35.7
g/m2 ; Bursting Strength fabric = 426.4kPa
Example 2: ITN Formulation with Bifenthrin and Chlorfenapyr (without Piperonyl
butoxide) incorporated in polyethylene (B)
The ITN incorporated formulation without using Piperonyl butoxide (PBO) in the
polyethylene polymeric material was produced using a Twin-screw-co-rotating close-meshing
extruder.
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The Extruder temperatures were maintained to 200±5°C maximum in all steps with extruder speed
was about 150 rpm.
In the first step, it comprised producing a mixture of 7% by weight of technical-grade Bifenthrin,
and 8% by weight of technical-grade Chlorfenapyr and 85% by weight of Linear Low Density
Polyethylene (Grade -20 MFI).
The polyethylene (LLDPE) of Grade -20 MFI used contained the customary adjuvant selected
from antioxidants, UV Stabilizers/absorbers, processing aids, coloring agents, release agents,
lubricants, surfactants, antistatic agents and viscosity modifiers.
The above composition materials were introduced in solid forms into the feed zone of the twinscrew
compounding extruder to produce concentrated master batch of active ingredients.
Master batch Analysis (By GC): Bifenthrin 7.15% w/w ; Chlorfenapyr = 8.17% w/w
This mixture was diluted in a second step to a High Density Polyethylene (HDPE) material
containing 0.7% by weight of technical-grade Bifenthrin, 0.8% by weight of technical-grade
Chlorfenapyr and 0.4% by weight of the Stearic acid as lubricant additive.
To this end, 10% by weight of above master batch and 90% by weight of HDPE were mixed in a
tumble mixer and this mixture was extruded using a close-meshing single-screw monofilament
extruder under the above-mentioned conditions.
The polyethylene was supplied to the extruder in pellet form in the feed zone and the additive was
dosed as per the desired quantity in the form of master batch into the polymer melt and Extrusion
took place under the below mentioned conditions.
The polymeric material of the present invention was used to produce insecticide incorporated
monofilament yarn having linear density ranging between 75 - 200 denier, wherein, the polymeric
material was melted in a single-screw extruder with temperature controlled to 200±5°C and
extruded through a suitable monofilament die.
ITN (fabric/yarn) Analysis (By HPLC): Bifenthrin 0.737% w/w; Chlorfenapyr = 0.867
%w/w; Linear Density= 130.5 Denier; Fabric weight = 36 g/m2; Bursting Strength fabric = 424kPa
Example 3 –ITN Formulation with Alpha Cypermethrin, Chlorfenapyr and Piperonyl
butoxide incorporated in polyethylene (C)
The ITN incorporated formulation using Alpha Cypermethrin, Chlorfenapyr and Piperonyl
butoxide (PBO) in the polyethylene polymeric material was produced using a Twin-screw-corotating
close-meshing extruder. The Extruder temperatures were maintained to 200±5°C
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maximum in all steps with extruder speed was about 150 rpm.
In the first step, it comprised producing a mixture of 13% by weight of technical-grade a-
Cypermethrin with 7.5% by weight of technical Piperonyl butoxide (Mixture-1) and another
mixture of 15% by weight of technical-grade Chlorfenapyr with 7.5% by weight of technicalgrade
Piperonyl butoxide (Mixture-2).
Thereafter, 21% of Mixture-1 and 21% of Mixture-2 were each individually combined
with 58% by weight of Linear Low Density Polyethylene (Grade -20 MFI).
The polyethylene (LLDPE) used contains the customary adjuvant (or additives) selected from
antioxidants, UV Stabilizers/absorbers, processing aids, coloring agents, release agents,
lubricants, surfactants, antistatic agents and viscosity modifiers.
The above composition materials were introduced in solid and liquid forms into the feed Zone of
the twin-screw compounding extruder to produce two concentrated Masterbatches of active
ingredients with synergist.
Master batch Analysis (By GC):
a) Master batch-1 (Mixture-1): a-Cypermethrin 13.23% w/w + Piperonyl butoxide (PBO) =
7.43%w/w
b) Master batch-2 (Mixture-2): Chlorfenapyr 15.21% w/w + Piperonyl butoxide (PBO) =
7.60%w/w
These concentrated masterbatches were diluted in a second step to a High Density
Polyethylene (HDPE) material containing 0.6% by weight of technical-grade Alphacypermethrin,
0.8% by weight of technical-grade Chlorfenapyr, 0.7% by weight of technical-grade Piperonyl
butoxide and 0.4% by weight of the additive (Stearic acid).
To this about 5% by weight of Master batch-1, 5% by weight of Master batch-2 above and
89.6% by weight of HDPE were mixed in a tumble mixer and this mixture was extruded using a
close-meshing single-screw monofilament extruder under the above-mentioned conditions. The
polyethylene was supplied to the extruder in pellet form in the feed zone and the additive was
dosed as per the desired quantity into the polymer melt the form of concentrated master batch.
Entire extrusion took place under the below mentioned conditions.
The polyethylene was supplied to the extruder in pellet form in the feed zone and the
13
additive was dosed as per the desired quantity into the polymer melt the form of concentrated
masterbatch. Extrusion took place under the abovementioned conditions.
The polymeric material of the present invention was used to produce insecticide incorporated
monofilament yarn having linear density ranging between 75 - 250 denier, wherein, the polymeric
material was melted in a single-screw extruder with temperature controlled to 200±5°C and
extruded through a suitable monofilament die.
ITN (fabric/yarn) Analysis (By GC): Alpha Cypermethrin 0.613% w/w; Chlorfenapyr =
0.82 %w/w; Piperonyl butoxide= 0.705 %w/w; Linear Density= 131 Denier; Fabric weight = 36.4
g/m2; Bursting Strength of fabric = 421.6kPa
Bioassay Test protocol and results:
The monofilament yarn obtained as above was warp knitted to make the fabric for
performing efficacy test (Bioassay Test) as per WHO test protocol in order to know the
performance utility with respect to existing commercial products. WHO Prequalified treated net
(ITN) products that are coated with active insecticides, when washed often lead to loss of activity
for controlling disease carrying vectors like mosquitoes or similar insects.
Inventor have successfully developed the potent and safe, incorporated Insecticidal Treated Nets
(ITNs) and achieved the WHO objective purpose of WHO threshold criteria for ITNs specifically
Blood Feeding Inhibition (BFI) of = 90% and insects Mortality of = 80%.
A comparative bioefficacy study was performed independently at Tanzania, Ivory Coast,
and in India in their GLP (Good Laboratories Practice) compliance facilities, which have
concluded that newly developed ITNs as per present invention are much superior and safe in
performance even after 20 times Wash – WHO protocol based criteria. Test protocol summary
and their results outcomes are summarized herein below in the Tables.
Washing Protocol: (20 Times Wash (20X) – In-line with WHO protocol)
Wherever washing of ITNs is used, they were followed the below ITNs washing protocol,
wherein ITNs were washed individually in aluminium bowls according to WHOPES phase II
washing protocol (WHO 2013). Nets were washed in 10 litres of tap water having a maximum
hardness of 5 dh and containing 2g/litre of soap ("Savon de Marseille") at an outdoor ambient
temperature between 25 and 29 °C. Each net was agitated for 3 min, left to soak for 4 min and
14
further agitated for 3 min totalling 10 min for one washing cycle. Agitation was done by stirring
the net with a pole at 20 rotations per minute. Rinsing was done twice using clean water (10 litres
per rinsing i.e. 20 litres per net). Nets were dried horizontally in the shade and then stored at
ambient temperature (27 °C ± 2 °C) between washes. The interval between washes was informed
by the phase 1 determination of the regeneration time (RT) of the actives, done in Tanzania. The
time for regeneration of the active ingredients between washes was 1 day for the tested nets in the
present invention.
Insecticidal Activity Tests:
Both Susceptible and Resistant strains of Female malaria mosquitoes (Anopheles
gambiae) were selected for study, and they were fed with sugared water only.
The tested new formulations products A, B and C developed using unique incorporation
technology according to the present invention were tested along with existing WHO Prequalified
Market Product. The below table summarized the features of the products under bioefficacy
evaluation:
Tested
Products
Active Active Synergis
t
Technology
used
Polymer
Matrix
Denier
A Bifenthrin Chlorfenapyr Piperonyl
butoxide
(PBO)
Incorporation
in polymer
matrix
Polyethylene 120
B Bifenthrin Chlorfenapyr - Incorporation
in polymer
matrix
Polyethylene 120
C a-
Cypermethrin
Chlorfenapyr Piperonyl
butoxide
(PBO)
Incorporation
in polymer
matrix
Polyethylene 100
(Q1)
WHO
Prequalified
Market
Product
(Coated)
a-
Cypermethrin
(100mg/m2)
Chlorfenapyr
(200mg/m2)
- Coating on
fiber/yarn
Polyester 100
(Q2)
WHO
Prequalified
Market
Product
(Incorporated)
a-
Cypermethrin
- Piperonyl
butoxide
(PBO)
Incorporation
in polymer
matrix
Polyethylene 130
15
Below Tables summarized the outcome of results with respect to WHO threshold criteria for ITNs
specifically Blood Feeding Inhibition (BFI) of = 90% and insects Mortality of = 80%.
In order to get confidence of data to be generated, the novel formulation of the present inventions
were aimed to be tested against different mosquito species viz., Anopheles arabiensis, Anopheles
gambiae etc along with both resistant and susceptible strains.
Table-1: % Mortality against wild pyrethroid resistant Anopheles arabiensis in Tanzania
% Mortality against wild pyrethroid resistant Anopheles arabiensis in Tanzania
24 Hrs Mortality 72 Hrs Mortality 120 Hrs Mortality
Tested
Products
Unwashed 20 X
washed
Unwashed 20 X
washed
Unwashed 20 X
washed
A 72 57 75 58 76 63
B 75 54 76 55 78 59
(Q1) WHO
Prequalified
Market Product
(Coated)
47 34 52 38 54 46
Table-2: % Mortality against wild pyrethroid resistant Anopheles gambiae in Ivory Coast
% Mortality against wild pyrethroid resistant Anopheles gambiae sl. in Ivory Coast
24 Hrs Mortality 72 Hrs Mortality 120 Hrs Mortality
Tested
Products
Unwashed 20 X
washed
Unwashed 20 X
washed
Unwashe
d
20 X
washed
A 88 82 89 83 91 84
B 87 79 87 80 88 80
(Q1) WHO
Prequalified
Market Product
(Coated)
72 67 73 69 74 70
Table-3: % Mortality against wild pyrethroid resistant Anopheles stephensi in India
% Mortality against wild pyrethroid resistant Anopheles stephensi in India
24 Hrs Mortality 72 Hrs Mortality 120 Hrs Mortality
Tested
Products
Unwashed 20 X
washed
Unwashed 20 X
washed
Unwashe
d
20 X
washed
C 90 88 91 87 93 89
(Q2)WHO
Prequalified
Market Product
21 25 23 28 26 29
16
(Incorporated)
All the ITN products (A, B and C) developed based on the incorporated insecticidal composition
in polymer matrix of polyethylene as per the present invention showed significantly improved
mortality in the pyrethroid resistant Anopheles arabiensis and Anopheles gambiae in comparison
to already marketed coated product.
With regard to Blood Feeding Inhibition (BFI) study performed, following is the summary of
data generated-
Table-4: % Feeding Inhibition against wild pyrethroid resistant Anopheles arabiensis in
Tanzania
% Feeding Inhibition against wild pyrethroid resistant Anopheles arabiensis
Study at Tanzania
Tested Products Unwashed 20 X washed
A (incorporated) 91 82
B (incorporated) 86 90
(Q1)WHO Prequalified Market
Product (Coated)
91 79
Table-5: % Feeding Inhibition against wild pyrethroid resistant Anopheles gambiae in
Ivory Coast
% Feeding Inhibition against wild pyrethroid resistant Anopheles gambiae in Ivory
Coast
Tested Products Unwashed 20 X washed
A 80 81
B 77 83
(Q1)WHO Prequalified Market
Product (Coated)
67 53
Table-6: % Feeding Inhibition against wild pyrethroid resistant Anopheles stephensi in
India
% Feeding Inhibition against wild pyrethroid resistant Anopheles stephensi in India
Tested Products Unwashed 20 X washed
C 86 85
(Q2)WHO Prequalified Market
Product
(Incorporated)
35 31
All the ITN products (A,B and C) developed based on the incorporated insecticidal
composition in polymer matrix of polyethylene as per the present invention showed significantly
improved % feeding inhibition under both washed and unwashed condition in the pyrethroid
17
resistant Anopheles arabiensis and Anopheles gambiae in comparison to already marketed WHO
Prequalified coated product (Q1 and Q2).
In view to assess the safety (as % Personal protection) of products (A, B and C) developed
based on the incorporated insecticidal composition in polymer matrix of polyethylene as per the
present invention, an independent study was performed (at Tanzania as well as Ivory Coast) to
know the personal protection level of users (human), since it is expected that incorporated
products are much safer than coated products being unexposed directly on surface of the
monofilament fiber fabric unlike coated filaments.
A comparative study for % personal protection (both under washed and unwashed
condition) performed has provided the below data as summarized in table-
Table-7: % Personal Protection against wild pyrethroid resistant Anopheles arabiensis in
Tanzania
% Personal Protection against wild pyrethroid resistant Anopheles arabiensis
Study at Tanzania
Tested Products Unwashed 20 X washed
A 89 79
B 83 89
(Q1) WHO Prequalified
Market Product (Coated)
79 27
Table-8: % Personal Protection against wild pyrethroid resistant Anopheles gambiae in
Ivory Coast
% Personal Protection against wild pyrethroid resistant Anopheles Anopheles gambiae
in Ivory Coast
Tested Products Unwashed 20 X washed
A 82 86
B 84 85
(Q1) WHO Prequalified
Market Product (Coated)
77 43
18
Table-9: % Personal Protection against wild pyrethroid resistant Anopheles stephensi in
India
% Personal Protection against wild pyrethroid resistant Anopheles stephensi in India
Tested Products Unwashed 20 X washed
C 87 89
(Q2) WHO Prequalified
Market Product
(Incorporated)
50 57
All the ITN products (A, B and C) developed based on the incorporated insecticidal composition
in polymer matrix of polyethylene as per the present invention tested for personal protection
owing to assess safety profile, they showed significantly improved % Personal protection under
both washed and unwashed condition in the pyrethroid resistant Anopheles arabiensis in
comparison to already marketed WHO Prequalified coated product. This showed exceptional
confidence on products according the present invention for their usability as safe incorporated
ITN product.
While reviewing the data generated compiled in the Table 1, 2,3,4,5,6,7,8 and 9, following
may be inferred -
1. ITN products derived from novel incorporated insecticidal composition in
polyethylene polymer matrix appears to be promising in their activities and
intended role of controlling disease carrying vectors with mosquitoes or similar
insects.
2. ITN products A, B and C derived from novel incorporated insecticidal
composition in polyethylene polymer matrix are enough potent and already
exceeding the WHO threshold criteria for ITNs specifically Blood Feeding
Inhibition (BFI) of = 90% and insects Mortality of = 80%.
3. ITN products A,B and C derived from novel incorporated insecticidal
composition in polyethylene polymer matrix were found significantly superior
compared from existing WHO Prequalified Marketed Product, which is an
insecticidal coated but not a polymeric matrix incorporated product. Further, said
novel incorporated products has better expectations, since highly toxic/hazardous
active insecticide/pesticides unlike WHO Prequalified Marketed coated polyester
Product, are not present on the surface of fabric (knitted fibers) but present in
19
polymer matrix inside, which not only provides the improved shelf life but also
ensure the long term safety from exposure to the user human beings at field and
homes.
4. ITN products A, B and C derived from novel incorporated insecticidal
composition in polyethylene polymer matrix are found to be quite safe for human
use with significant retention of activity.
5. ITN products derived from novel incorporated insecticidal composition in
polyethylene polymer matrix are observed to apparently more retained active
entity in the incorporated polymer matrix based product and quite safe for human
use.
A separate study was also performed independently for understanding the
regeneration time after washing following WHO criteria for the ITN products derived
from novel incorporated insecticidal composition in polyethylene polymer matrix.
Customary tests like Cone Assay and Tunnel tests were performed as per WHO protocol
(WHO Threshold criteria of 95% Knock Down in 60 min i.e. KD60 and or 80% 72 hour
Mortality for Cone Assay).
The result outcomes for the ITN products derived from novel incorporated insecticidal
composition in polyethylene polymer matrix according to the present invention surprised
the finding that all products obtained exceeds the WHO Threshold criteria of for
regeneration time. Below table -10 summarized the outcome data-
Table-10: Regeneration time of Novel ITN products – using wild pyrethroid resistant
Anopheles arabiensis in Tanzania(A & B) and Anopheles stephensi in India (C)
Regeneration time using whole net (ITN) series method
72 Hrs Mortality
Day (0)
Day (1) Day (5) Day (7)
Tested
Products
%
Mortality
%
Feeding
Inhibition
%
Mortality
%
Feeding
Inhibition
%
Mortality
%
Feeding
Inhibition
%
Mortality
%
Feeding
Inhibition
A 100 100 100 100 100 100 99.4 100
B 100 100 100 100 100 100 100 100
C 100 100 100 100 97.5 93.0 100 100
(Q1)WHO
Prequalified
Market
Product
85.1% 99.4% - - - - - -
20
It may be inferred from the above, that even after day 1 (after 24 hours) reuse, it indicates
exceptional potency and Actives role in the incorporated fabric both in terms of % mortality and
% feeding inhibition, though the WHO prequalified market product indicated both % mortality
and Feeding inhibition to the lesser even on Day (0).
ITNs products obtained using incorporate insecticidal composition in polymer matrix
comprising of a pyrethroid insecticide, a pyrrole chemical entity and/or optionally an organic
synergist were found Bio efficacious after 1, 3, 5, 10, 15, and 20 laboratory washes against both
the resistant and susceptible strains.
Based on these results, ITNs products A, B and C demonstrated significantly
bioefficacious and inline with WHO qualification threshold on both the laboratory-reared
resistant strain of Anopheles arabiensis (Kingani strain) and susceptible Anopleles gambiae
(Ifakara strain) mosquitoes.
While the foregoing pages provide a detailed description of the preferred embodiments of
the invention, it is to be understood that the description and examples are for illustrative purpose
only of the principles of the invention and not limiting to its scope. Furthermore, as many changes
can be made to the invention without departing from the scope of the invention, it is intended that
all material contained herein be interpreted as illustrative of the invention and not in a limiting
sense. ,CLAIMS:1. An incorporated insecticidal composition in polymer matrix comprising of a
pyrethroid insecticide, a pyrrole chemical entity and/or optionally an organic synergist
effective for controlling disease carrying vectors.
2. An incorporated insecticidal composition in polymer matrix according to claim-1,
wherein insecticidal composition in polymer matrix is useful for making insect/pests
protective nets or insecticide treated nets (ITNs) or long lasting insecticidal net (LLIN).
3. An incorporated insecticidal composition in polymer matrix according to claim-1,
wherein, polymer matrix is selected from polyethylene or polypropylene.
4. An incorporated insecticidal composition in polymer matrix according to claim -1,
wherein, pyrethroid insecticide is selected from Bifenthrin, lambda-Cyhalothrin, alpha
Cypermethrin or Deltamethrin and said pyrrole chemical entity is Chlorfenapyr and
said organic synergist is Piperonyl butoxide (PBO) or o-cresol derivatives.
5. A method of incorporating the insecticidal composition in polymer matrix comprising
the stepsa.
Mixing the pyrethroid insecticide, a pyrrole entity and an organic synergist each
individually or in combination in the polymer matrix in the melt stage in twin screw
compounding extruder
b. Recovering the master batch granules incorporated with insecticide composition
c. Testing the master batch for incorporated insecticide content, wherein the
concentration of pyrethroid insecticide is in range of 5% to 20% w/w, the
concentration of pyrrole insecticide as Chlorfenapyr is in the range of 5% to
20%w/w and the concentration of organic synergist as Piperonyl butoxide is in the
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range of 0% to 10%w/w.
6. A method of incorporating the insecticidal composition in polymer matrix according
to claim 5, wherein the step a. comprising mixing the pyrethroid insecticide, a pyrrole
entity and an organic synergist each individually providing individual master batch
granules.
7. A method of incorporating the insecticidal composition in polymer matrix according
to claim 5, wherein the step a. comprising mixing insecticide optionally with adjuvant
selected from antioxidants, UV Stabilizers/absorbers, processing aids, coloring agents,
release agents, lubricants, surfactants, antistatic agents and viscosity modifiers or
adjuvant can be incorporated within polymer matrix separately without combining
with insecticide/s.
8. A method of incorporating the insecticidal composition in polymer matrix according
to claim 5, wherein step b of recovering master batch granules comprising cutting and
flash cooling at temperature ranging between 10-20ºC.
9. An incorporated insecticidal composition in polymer matrix according to claim-1,
wherein the insecticide treated nets (ITNs) or long lasting insecticidal net (LLIN) is
produced out by warp knitting from monofilament yarn extruded out of this polymer
matrix.
10. An incorporated insecticidal composition in polymer matrix for insecticide treated nets
(ITNs) or long lasting insecticidal net (LLIN) according to claim-9, wherein the
insecticide incorporated monofilament yarn has linear density ranging between 75 to
200 denier.
11. An incorporated insecticidal composition in polymer matrix for insecticide treated nets
(ITNs) or long lasting insecticidal net (LLIN) according to claim-5, wherein the
incorporation of insecticidal composition is achieved during extrusion process in the
direct master batch mixing or molten state of the polymer matrix using side feeder.