MXPA06009879A - Improved granular formulation of neem seed extract and its process thereof - Google Patents

Abstract

The present invention relates to an improved granular formulation of neem seed extract containing azadirachtins having enhanced storage stability, gradual release of azadirachtins for application to plant rhizosphere comprising of inert particulate as a carrier, at least a lipophilic substance as deactivator/binder, colorant and neem seed extract comprising azadirachtins providing gradual release of azadirachtins and effectively at the point of application. The invention also relates to a process for the preparation of the said formulation by coating the carrier with a lipophilic substance, subsequently impregnating the coated carrier with neem seed extract followed by coating with a colorant and finally lipophilic substance, by spraying and drying at a temperature below 50°C.

Description

IMPROVED GRANULAR FORMULATION OF NEEM SEED EXTRACT AND PROCESS OF THE SAME Field of the Invention The present invention relates to an improved granular formulation, which has increased storage stability, gradual release of azadirachtins for the application < • to the rhizosphere of the plant, the formulation comprising extract, of neem seed, a particulate material of inert carrier, a lipophilic substance and a dye. The invention also relates to a process for the preparation of the granular formulation. BACKGROUND AND PRIOR ART OF THE INVENTION The protection of pest plants is a complex task. Usually different pests affect the growth of various parts of the plant throughout its life cycle. It is a general practice to apply plant protection chemicals or pesticides to protect plants from various pests in order to obtain higher crop yields in agriculture, horticulture, floriculture and forestry. These chemicals are also used to protect plants in gardens, meadows and. domestic plants. Most of the damage due to pests and diseases occurs in the visible aerial parts of the plant and therefore it is a practice to spray the plant protection chemicals on the aerial parts - to control the pests. The conventional plant protection agents mainly act as contact poisons to pests resulting in mortality or their suppression and protection to the plant. The effectiveness of the plant protection agents that act on the base of contact toxicity depends on the type of formulation, the efficiency of the spray mechanisms that provide effective coverage and penetrability of the active compound in the aerial parts of the plant. . It is generally reported that aerial sprays leave 20-30% of product waste due to deviation, during spraying which results in the waste of valuable active ingredients apart from the inherent leakage of toxic compounds to air, water and soil. causing pollution to the environment. These problems can be avoided by using systemic plant protection molecules that can be absorbed by the plant when they are delivered to the rhizosphere of the plant through various delivery systems such as granules, pellets, etc. Most plant protection chemicals are toxic to non-target organisms and to humans apart from their longer persistence in the environment. Due to the increased knowledge of the environmental and toxicity problems of these chemical substances, there has been a demand for alternative molecules that are active against the target pest but safer to humans and non-target organisms, and biodegradable that do not cause harm to the environment. Extracts of various parts of the neem tree (Azadirachta indica A. Juss) such as leaves, bark, seeds, etc. they have long been known to 'have insect and disease control properties. The seed grain in particular possesses the most active lipoids, such as azadirachtins A and B and structurally related compounds such as azadirachtins D, E, F, H, I, K and the like, together with ni bina, salannin, azadiradione and the like. All natural azadirachtins have been reported to have a very high growth-altering activity against Epilachna varivestis, with LC50s in the range of 0.3 to 2.8 ppm (H. Rembold and I. Puhlmann, 1995). More than 'one hundred terpenoid compounds are reported from the neem seed / neem tree fruit. The azadirachtins A have been tested against more than 400 insects and were found to be active as antialimentantes, regulation of the growth of insects, ovicides, etc., thus reducing the population of insects, different from the neurotic insecticide. Being natural, they are highly degradable, leaving no residue in the environment. In addition, neem components are reported to be safer to target organisms and mammals and therefore ideal agents that replace conventional toxic agents used in crops and public health. The various methods have described extracting these active components from various parts of the neem tree in the crude or semi-crude forms to be used in commercially acceptable vehicles in the form of liquid and solid formulations such as powders, water-dispersible granules, etc. The raw neem seed extracts obtained after the removal of the lipid component typically comprise about 20-45% of Azadirachtins A and B and have been shown to be potent regulators of insect growth and feeding deterrents and are formed as ingredients Potential assets in commercial pest control • formulations. These active molecules, however, are rather large and complex, and having functional groups sensitive to acid and base tend to be unstable when they come into contact with the usual formulation ingredients, thus presenting a major limitation for successful development. of commercial formulations of these extracts in stable form. So far, azadirachtins have been formulated widely in liquid forms to be applied as an emulsion or solution to agricultural crops. Various organic solvents and other inorganic additives have been used as carriers in order to make a delivery system effective in cost and efficiency. The use of such carriers in commercial formulations is rather limited since many solvents are reported to be deleterious in causing degradation of azadirachtins. Dureja (1999) has studied the degradation of azadirachtins A in several solvents for 25 days at 29 +/- 1 ° C. The results indicated 50% degradation of azadirachtin A in methanol and acetone, 75-80% in methylene chloride, carbon tetrachloride and chloroform and approximately 85% in ethanol and water. Extracts and formulations containing storage stable azadirachtins and methods of their preparation have been proposed. US Patent No. 4,556,562 reports that the stability of azadirachtins in ethanol emulsions was increased by diluting the concentration of azadirachtins between 2000 and 4000 ppm. and when adjusting the pH between 3.5 and 6.0. U.S. Patent No. 4,946,681 reports greater stability for azadirachtins in aprotic solvent solutions containing less than 2-5% water. U.S. Patent No. 5,001,146 indicates that the stability of azadirachtins is improved by adjusting the concentration of the polar aprotic solvent to at least 50% by volume and by decreasing the water content by less than 15% by volume. I US Patent No. 5,001,146 further indicates that the stability of azadirachtins depends on the type of solvent used, and that the stability requires storage in certain aprotic and alcohol solvents listed. The North American Patent No. 5,736,145 reports a stable aqueous storage composition containing azadirachtins A and US Patent No. 5,827,521 indicates a stable azadirachtin formulation containing aliphatic dihydric alcohols of more than 80.% by volume and optionally with sunscreens and antioxidants. U.S. Patent No. 5,352,697 discloses the increased stability of the azadirachtins in solution by the presence of an epoxide, preferably an epoxidized vegetable oil. All these methods describe the increase in stability of extracts containing azadirachtins in the prepared liquid form of the neem seed grain with organic solvents. European Patent No. 9216109 describes the preparation of a neem seed extract in solid form with greater stability. U.S. Patent No. 5, 635,193 reports that a solid containing azadirachtins is stabilized by limiting moisture and volatile polar solvents to less than 1% and 5% respectively. The highest stability is suggested for the extract if it is formulated with 0.05% to 2% of surfactant and 99% of solid diluent (75% of azadirachtins after • 2 weeks of storage at 54 ° C). But they do not exist. details regarding the type of solid diluents and surfactants. ' The preparation of stable neem seed extracts from. Neem grain was reported in the North American Patent No. 5,695,763, European Patent No. 579,624 and Indian Patent 181,845. Although, several extracts with stable azadirachtins have been reported, the shelf life for azadirachtins in a formulated state is still a problem. The azadirachtins are unstable in several surfactants, organic solvents and in different combinations of solvents and surfactants in liquid formulations which is a serious limitation for the development of a stable commercial product in longer shelf. Normal pesticide formulations contain several solvents made mainly of petroleum, and there is a problem that the use of such solvents. In specialty pesticide formulations, especially proposals for veterinary application in organic farms, and the like, it is disadvantaged. The use of such solvents, at a lower rate, demands large quantities of surfactants and other additives that make the cost of the formulations high. .The use of a wider range of I, '. • ingredients in liquid formulations and the associated problem of instability in such formulations is also a serious problem for the commercial success of culture protection agents containing azadirachtins. In addition, azadirachtins, especially Azadirachtin A, were found to be highly photo-unstable and tend to degrade rapidly when applied to plant surfaces. The mode of action of azadirachtins in providing protection to plants against insects is very different from synthetic chemical molecules, the latter acting mainly due to their toxic property of contact. The azadirachtins act as a repellent, antialimentante and regulator of the growth and therefore they need to be exposed, absorbed or introduced in the systems of the insects for their control. The borer type of insects and insects that have hard-shelled bodies are difficult to control through foliar application due to lack of contact. The compounds that possess systemic properties are ideal for the control of such insects. The azadirachtins are reported to possess systemic property and are easily absorbed by plants when applied to the rhizosphere of the plant. Therefore, a supply system for supplying the azadirachtins in the rhizosphere of the plant will ensure effective protection of the plants of the borer as well as the scaly sucking insects. Although, aqueous emulsions of formulations containing azadirachtins can be applied to the soil, due to their total exposure to water and soil they tend to degrade more quickly and not. available for the longest period of protection. Therefore, the effective and economic use. of azadirachtins is not possible with any of the liquid formulations. existing and proposed 'for foliar applications. There is a need for an efficient supply system to transfer azadirachtins to the rhizosphere of the plant without any significant loss of its content when released slowly for plant protection. This can be accomplished through a granular formulation of the type that has been used to provide systemic plant protection agents in agriculture and horticulture crops. Granules are the most widely used and most versatile of the pesticide supply systems available since their initiation in the late 1940s. In these systems, the granules act as a diluent as well as a carrier for plant protection agents. The large number of particles per unit weight of the granules allows the granules to be applied per unit area I at a rate which is toxic to the plague but which will not cause damage to the desirable life forms and unwanted deviation. The available granule carriers are most natural components, both inorganic and botanical and some are synthetic made from natural (botanical) or synthetic components. But to be effective, they must have properties of (a) adequate capacity for 'containment / sorption of liquid' (b) chemically inert and (c) nature of free flow. The inorganic category of carriers include clays, attapulgite, bentonite, kaolin, sepiolite, kieselguhr, diatomaceous earth, talc, sand from brick fragments, white carbon and vermiculite. The botanical category comprises corn cobs, walnut shells, rice pods, and wood, fibers from natural starch plants and pumice from different particles within the 4 to 80 mesh range (US standard). While low in cost, clays often sometimes need to be treated with a deactivator prior to formulation to prevent decomposition of the active ingredient. Corn cobs have been a primary source of inert granular carriers, but their extensive use and occasional drought conditions lead to inadequate supply and as a costly alternative. The effectiveness of the granule product is dependent not only on the nature of the active ingredient but also on the nature of the inert ingredient used as the carrier acting as the transfer mechanism for the active ingredient. If the carrier does not effectively release the active ingredient, the active compound will never achieve its intended purpose. Importantly, such a carrier must be inert to the active ingredients and must not cause degradation to the active ingredients. Thus, the selection of an effective carrier is an essential step in the development of a successful granular formulation. In fact it is a critical task to choose a suitable carrier for the azadirachtins due to its highly reactive nature with the acidic / basic and ionic nature of these carriers and other additives used in the granulation. The Applicant has tested the adaptability of customary carriers such as sand, bentonite, clay, etc. for granular formulations of azadirachtins. It is noted that azadirachtins are highly susceptible to rapid degradation in contact with these carriers when formulated in conventional manner. This limits the use of these carriers directly for formulations containing azadirachtins. In addition, the azadirachtins - being easily soluble in water, the normal methods of impregnation with these carriers without binders result in the immediate release of the azadi'ractine in the soil as soon as it comes into contact with water, which It is undesirable. The use of known binders such as polyvinyl alcohol, rosin, pressed wax, sugar, clay together with customary carriers such as sand and bentonite have had limitation since they have caused rapid degradation to azadirachtees. Accordingly, there is a need to identify a solid carrier that provides higher stability to the azadirachtins and capable of delivering the azadirachtins as desired in the rhizosphere of the plant. As the azadirachtin molecules are thermoshable, the extrusion methods of granular preparation require several ingredients such as emulsifiers, polymers, binders, drying agents, etc. and rather high temperatures during extrusion will lead to its degradation during the process. Accordingly, various granulation processes described in the prior art that are primarily suitable for synthetic chemical molecules are not ideal for biomolecules such as azadirachtins with available carriers and additives. Several methods of the prior art described in the preparation of granular pesticidal formulations were based on two different processes. 1. The extrusion granulation process, involves mixing the active ingredient, with various additives such as waxes, surfactants, polymers, inorganic salts, etc., melting / mixing in water and extruding the fluid through a mold to form granules of desired diameter. The extracted material is then fed to a dryer "to reduce the moisture content of the granules to produce free flow product 2., The spray formulation process, in which the pesticide is dissolved in an appropriate solvent or in the molten state it is sprayed on the inert particles One of the important characteristics of the granular formulation is its ability to release the pesticide active compound in a controlled manner Several prior art methods have been known to achieve the controlled release of active substances from granulated forms that are achieved through the encapsulation process Encapsulation involves coating the particulate matter for the release of an active agent over a prolonged period, such processes have been developed based on the use of organic polymers of non-polymeric organic materials such as fats and waxes as the coating material.The processes of the typical prior art s are described, for example, in US Pat. Nos. 2800457, 2800458, 3041466, 3415758, 3429827, 3594327, 3639256 and I 3674704. It is well known that biocidal materials can be incorporated into an elastomeric matrix and caused to release a effective with the destruction of the plague. U.S. Patent No. 3417181 teaches that organotin toxicants can be dissolved in an elastomer-type matrix and caused to release through a diffusion-dissolution mechanism when exposed to water.

• Bioactive agents such as organic pesticides required to be soluble in elastomers such as natural rubber, rubber. of styrene-butadiene, etc. (Patents North American Nos. 3-590119, 3426473, 3851053 and 3639583). Prior art methods are known to cause an insoluble organic agent to be emitted from a plastic dispensing unit by using a third phase material that is (a) soluble to some degree in the plastic, and (b) will carry the organic agent in solution or it will serve as a migratory route for the agent to reach the surface of the spout. To achieve these properties for the granules this may require varied chemical substances and conditions such as emulsification, polymerization, crosslinking, etc. using inorganic salts, bases, acids and organic solvents, polymers etc. (US Patents Nos. 2956073, 3116201, 3705938, 3864468). Pesticide granules have been prepared by both macro- and micro-encapsulation processes, placed in ceramic materials, including biodegradable polymers, mixed with porous mineral supports, coated with cellulose derivatives,. combined with poly-urea compounds and included with gypsum and other supports to protect the pesticide from the environment and to ensure controlled release in an attempt to substantially control pest populations. In addition to prior patent documents of the prior art, the following patent documents refer to either the granular formulation comprising azadirachtins and / or their process for preparation. U.S. Patent Nos. 4,065,558, 4341759, 4,370,160, 4,464,317, 4,485,103, 4,732,762, 4,971,796, 5,130,171, 5,229,356, 5,435,821, 5,484,600, 5,556,631, 5,562,914, 5,945,114 6,090,415, EP Patent No. 0200288, 0848906, 0966882, GB Patent No. 2127690, Patent IN No. 189,080, WO 0205641, 02087342 & 9409627. Table Some prior art methods for the preparation of different types of granular formulations The documents of the prior art have been considered in their entirety in the present application. It is clear from the details provided in the above table the limitations associated with both the prior art composition comprising azadirachtin and the process for the preparation of these compositions. The present invention has provided a composition comprising azadirachtins and their process for the preparation of the composition by overcoming the limitations of the prior art. Novelty Thus, there is a need for an effective and stable granular formulation of neem seed extract containing azadirachtins and a process to obtain granules based on azadirachtins in stable form. This objective has been achieved by the applicant by providing an improved granular formulation comprising the neem seed extract containing aradiractins for the purpose of protecting plants from insect damage when applied to the plant kidney. The improved granular formulation has increased storage stability with gradual release of the azadirachtins as the active ingredient from the granules. Also, the carrier used to achieve the efficient granular formulation is a readily available solid material, found compatible with the thermo-unstable azadirachtins only when covered with a lipophilic substance. The surprising results of the present invention provide a combination of increased storage stability and gradual release of azadirachtins in a formulation containing neem seed extract when using a lipophilic substance that imparts the deactivating and binder characteristic that has never been achieved in the formulations granules of the prior art. OBJECTIVES OF THE INVENTION An object of the present invention is to provide an improved granular formulation of neem seed extract comprising essentially Azadirachtins for the purpose of protecting plants from insect damage. Another object of the invention is to provide a granular formulation that can be applied to the rhizosphere of I, ' • • a plant. Yet another object of the invention is to provide a granular formulation having increased storage stability. Another object of the invention is to provide a granular formulation that gradually liberates azadirachtins when applied to the rhizosphere of the plant. Another object of the invention is to provide a granular formulation for systemic application. Still another objective of. The present invention uses a lipophilic substance as a deactivator to protect the azadirachtins from degradation due to their contact with the carrier. Still another object of the invention is to provide a lipophilic substance as a binder that acts as a permeable membrane to establish contact between the water and the neem seed extract used. Another object of the invention is to provide a formulation in which the neem seed extract containing azadirachtins is sandwiched between the impregnated inert particulate material and a coating of lipolytic substances. Still another object of the invention is to provide a safe, biodegradable and environmentally friendly formulation. Another object of the invention is to provide a substitute for toxic and persistent chemical plant protection agents to the formulations. Still another object of the invention wherein the solid carrier is modified by coating a lipophilic substance .. to increase the stability of the azadirachtins of the neem seed extract used in the formulation. Still another object of the invention is to provide a carrier and other ingredients that are naturally occurring, environmentally safe and inert to achieve the desired activity. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an improved granular formulation of neem seed extract having increased storage stability, gradual release of azadirachtins for application. to the rhizosphere of the plant. The formulation comprising sand as a carrier, at least one lipophilic substance as a binder, a dye and neem extract containing azadirachtins that provides the release of azadirachtins gradually and effectively at the point of application. The invention also relates to a process for the preparation of the formulation by coating the carrier I with a lipophilic substance, subsequent to impregnation of the carrier coated with the neem seed extract followed by the coating with a dye and finally the lipophilic substance. - by spraying and drying at a temperature of up to 50 ° C. It will be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide additional explanation of the present invention, as claimed. Description of the Tables: Table 1 - Formulation recipe and percentage of release of Azadiractins in the run-in-water test Table 2 - Azadiractin stability data Table 3 - Mortality of BPH fed in rice seedlings treated with the granular formulations Table 4 - Monitoring of the systemic absorption of Azadirachtins in Rice Seedlings DETAILED DESCRIPTION OF THE PRESENT INVENTION In accordance with the objective, the present invention describes an improved granular formulation having increased storage stability, controlled release of Azadirachtins in the application to the rhizosphere of the plant to prevent plants of damage by insects, the composition comprising: Ingredients Weight / Weight (%) i. Neem Seed Extract 0.03 to 50.00 ii. Carrier '48.50 to 99.30 iii. Coloring 0.01 to 0.04 iv. Lipophilic Substance 0.50 to L.50 In one embodiment of the present invention, the preferred granular formulation comprising: Ingredients is described. Weight / Weight (%), i. Neem seed extract 0.075 to 12.50 ii. Carrier 86.70 to 99.20 iii. Coloring 0.02 to 0.03 iv. Lipophilic Substance 0.60 to 0.75 Another embodiment of the invention provides a process for preparing the granular formulation, wherein the process comprises the steps of: a) optionally washing the carrier with water, drying at about 60 ° C, sifting to obtain the carrier dry, b) coat the dry carrier of step (a) with the lipophilic substance dissolved in an organic solvent, c) impregnate the coated carrier of step (b) with neem seed extract dissolved in a solvent, dry in a hot air stream at a temperature that varies between 40 ° C 3 ¿2z i and 50 ° C, I d) coat with. dye dissolved in a solvent by spraying the impregnated material of step (c), drying at about 40 ° C below 50 ° C, and e) finally coating the material of stage (d) with a lipophilic substance, drying 'approximately 40 ° C to below 50 ° C, to obtain the required granular formulation. The invention uses neem seed extract having an azadirachtin content ranging from 0.03 to 5.0%. The content of azadirachtins is preferably up to 1.0%. The carrier used is selected from siliceous substances preferably sand. The preferable carrier used is river sand. The particle size of the sand used varies between the mesh 12 to 32, preferably mesh size from 16 to 32. The moisture content of the sand used is below 2.0%. The lipophilic substance used for the coating is selected from the group consisting of a low-melting hydrocarbon wax category of vegetable and animal origin, preferably beeswax and paraffin wax. The colorant used is selected from the group consisting of synthetic and natural substance such as crystal violet, methyl violet, natural bixin turmeric and mixtures thereof. The invention provides organic solvent for dissolving the lipophilic substance selected from the group consisting of low boiling hydrocarbons, ethers, ketones, aldehydes, esters, such as n-hexane, petroleum ether, diethyl ether, acetone, ethyl acetate and the like. '••' The extract of neem seed used. it is dissolved in a solvent selected from the group consisting of ethers, ketones, alcohols, aldehydes, esters such as diethyl ether, ethyl acetate, acetone and methanol and the like. The neem extracts containing azadirachtins are prepared from the neem seed and used for the proposed application as a plant protection agent. Since, azadirachtins control plague not through contact toxicity but through the property of regulating the growth of the insect and possess systemic property, these can be effectively utilized with a delivery system, usually in solid granular form, which causes the plant to absorb the azadirachtins when the granules are applied to the rhizosphere of the plant. Insects such as barrenillos and suckers in nature with bodies, hard scales are also effectively controlled with such a method that I make the azadirachtins enter the insect when they feed on the plants treated with the granule. Formulations of conventional liquid azadirachtins fail to control these insects effectively when applied to plants such as sprays. As the azadirachtins are highly active to various carriers due to their acidic or basic nature and ionic nature, the selection of suitable carriers is critical for the development of a granule formulation. stable. Several processes involving the encapsulation or mixing of various ingredients and the preparation of granules by extrusion are rather complex and require expensive equipment and ingredients that make the product very expensive. These processes also have limitations to be used for azadirachtins since they use conditions of - Drastic processes such as high temperature, fusion of various ingredients, chemical substances such as surfactants, polymers, proteinaceous materials, pH modifiers, ionic solvents, water etc. which are highly detrimental to azadirachtins causing degradation in the process. With the intention of 'developing a simple and cost-effective granular formulation for neem extract containing azadirachtins the inventors have initially tested agriculturally accepted carriers such as sand, bentonite etc. The granulation is carried out by spraying the neem-extract solutions containing azadirachtins dissolved in different solvents such as ethyl acetate, methanol, cyclohexanone etc. The evaluation of the stability of the azadirachtins in these formulations - under standard accelerated conditions at 54 ° C - resulted in higher degradation of the azadirachtin which made these carriers unsuitable if formulated by the methods known up to now. In addition, azadirachtins which are highly soluble in water, their release in water is rather rapid which is undesirable for an ideal granular formulation. The inventors have made several formulations using cheaper carriers such as sand, bentonite etc. and several additives, studied their stability and release of azadirachtins when they are in contact with water. The aforementioned limitations for azadirachtins in this way were surprisingly solved while studying the release phenomenon of azadirachtins coated on sand granules with lipophilic substances used as the binder. One of the formulations provided higher stability to azadirachtin that involves the following process. The locally available natural river sand is procured and cleaned with water to free it of mud and low density impurities. The dry sand is screened to obtain particles with a mesh size of 16 to 32. I The sand is coated with a lipophilic substance preferably beeswax or paraffin wax, 1%, preferably 0.5%, much more preferably 0.25 % which is dissolved in a lipophilic solvent such as hydrocarbons by any normal spray method or by direct contact of the wax solution with the sand granules. The hydrocarbon used to dissolve the wax is selected from lower hydrocarbons, hexane, an ether, oil etc. of boiling point give around 60-80 ° C. Wax impregnated granules are dried under the hot air stream to below 50 ° C to obtain free-flowing particles. The sand particles impregnated with wax thus obtained are treated with the neem extract containing azadirachtins. 1.2% equivalent to azadirachtins, much more preferably 0.1% of azadirachtins dissolved in a suitable solvent. The solvent used to dissolve the neem extract containing azadirachtins can be medium to polar in nature such as esters, alcohols, ketones, aldehydes etc. The preferred solvents are ethyl acetate, methanol and acetone. The treatment of the neem extract solution containing azadirachtins to the wax-coated granules can be carried out by direct treatment or by spraying, mixing and drying under a stream of hot air, preferably up to below 50 ° C or under vacuum to obtain free-flowing granules. The azadirachtin-coated particles thus obtained are further treated with the lipophilic substance preferably beeswax or paraffin wax in 1%, preferably 0.5%, much more preferably 0.25% 'which is dissolved in lipophilic solvent' such as hydrocarbons by any normal method of spraying or by direct contact of the wax solution with the granules, of sand. The hydrocarbon used to dissolve the wax is selected from lower hydrocarbons, hexane, petroleum ether, etc. that has a point boiling around 60-80 ° C. The resulting granules are dried by normal drying methods to remove bonded solvents preferably up to below 50 ° C and / or under vacuum. The granules thus obtained retain the azadirachtins without any change during the process of their preparation and have higher stability of storage and gradual release of bioactive compounds (10-15% as observed in the run-in-water test) in the application site and given the desired activity for its proposed use. The amount of bioactive compounds present in the granule formulation can be any effective amount that has proposed activity, such as, but not limited to, reduction or elimination of insect damage to trees and / or crops. Preferably the amount of I azadirachtins present in. The pesticidal formulation is from about 0.03% by weight to about 5.0% by weight based on the weight of the granule formulation, and more. preferably from about 0.03 to about 1.0% by weight based on the weight of the granule formulation. In terms of the neem seed extract, the neem seed extract is preferably present in an amount, ranging from about 0.075 to about 50.0 p / p. % of the granular pesticide formulation. More preferably, the azadirachtins present in the pesticidal formulation vary from about 0.03 to 5.0 w / w%. The method for producing the bioactive compounds such as' azadirachtins is described in US Patent No. 5,695,763, which is incorporated herein in its entirety. In general, azadirachtins are preferably recovered from the seeds of a neem tree by crushing the seeds and then by extracting the azadirachtins and other active ingredients from the ground seeds with water. The extraction of azadirachtins and others. Water's active ingredients are made using a non-aqueous solvent that is non-irascible with water and has a high solubility of azadirachtins that in water, or by using a surfactant that has a turbidity temperature between 20 ° and 80 ° C. The concentrated azadirachtins are then recovered from the second extraction solution. The solution containing azadirachtins is then concentrated to produce a concentrate containing azadirachtins that are added to a liquid hydrocarbon, thereby forming a precipitate comprising azadirachtins which are then recovered for use in pesticidal formulations. The method described in Indian Patent No. 181,845 which may also be adopted for the preparation of neem seed extracts comprising azadirachtins. The azadirachtins can also be recovered according to the method described in US Patents Nos. 5,124,349 and 5,397,571. The first described preparation of neem extract comprising the defatting of the neem seed coarsely milled with a non-polar solvent followed by the extraction of azadirachtins from defatted neem seeds using a polar aprotic solvent. The process described in US Pat. No. 5,397,571 involves extracting ground neem seeds with a co-solvent mixture of a non-polar solvent and a polar solvent to obtain a neem extract having both the hydrophilic azadirachtin-containing portion and the moiety. of hydrophobic neem oil from the seeds. The resulting hydrophobic and hydrophilic extracts are concentrated by removing the respective solvent to obtain the neem extract containing azadirachtins and other lipophilic components. The neem extract is then treated with a lower polar solvent to precipitate the I portion containing the extract azadirachtins. The solid is filtered off, dried to obtain about 10-20% azadirachtins therein. Other conventional methods involving trituration, solid or liquid extraction, chromatography, precipitation and the like can also be used for the preparation of the neem seed extract containing azadirachtins. With respect to the lipophilic organic substances used in the present invention is beeswax, or paraffin wax, preferably paraffin wax which is about 2% by weight or less by weight of the granule formulation and preferably 0.25-1.0. % by weight by weight of • the granules. With respect to the carriers, this is sand, preferably natural sand, and its chemically related particles more preferably river sand of mesh size from 16 to 32. The moisture content of the sand is preferably up to below 2%. The granule formulation can additionally be made distinguishable by incorporating a colorant after impregnation of the neem extract containing azadirachtins. The dyes can be synthetic compounds such as crystal violet, methyl violet, bright blue, indigo carmine, erythrosine, red alura, tatrazine, solar yellow, firm green, carmosine, ponceau 4R, cochinial red A, red 2G, green S, coffee HT, bright black BN, iron oxides, quinoline yellow, lithium BK rubin, etc. or of natural origin such as curcumin, lutein, carotenes, lycopene, carmine, betanin, antoxianina ,. chlorophyll, carbon black, bixin, capsanthin etc. and the weight of which may be less than 1% and more preferably 0.05% by weight of the granule formulation. The dye can be incorporated before the final coating of the wax. The dye is dissolved in methanol or ethyl acetate and sprayed on the granules, covered with neem seed extract, dried under the air stream below 50 ° C and / or under vacuum. The granular formulation described herein can be prepared by conventional mixing / blending techniques such as spraying or direct addition of various ingredients to the solid carrier in appropriate conventional equipment. Preferably, the lipophilic substance is dissolved in a hydrocarbon solvent, preferably in hexane and sprayed or added to the sand granules before and after the treatment of the neem extract containing azadirachtin. The solution of the neem extract containing azadirachtin is prepared by dissolving in a suitable solvent, preferably polar low boiling solvents such as acetone, ethyl acetate, etc. and then that spray is applied directly on sand particles coated with wax. The drying of the coated granules at the end of each wax applying step, the neem extract containing azadirachtins and the dye is carried out at a temperature below 50 ° C and / or under vacuum. The granular azadirotaine formulation of the present invention in the analysis has shown the retention of the azadirachtin content without any change during the manufacturing process. The formulations of granular azadirachtins described herein are stable in storage which is demonstrated by subjecting the accelerated thermal degradation of the formulation. Thus 85% by weight of the azadirachtins originally present remains after 28 days of storage at 54 ° C in a sealed container that is equivalent to two years of shelf life at average temperature storage conditions of 25 ° C. In addition the granular azadirachtin formulation of the present invention meets the desired specification of a commercial agrochemical granular formulation such that a granule must release the active ingredient at less than 15% of its nominal value in 10 minutes when the granules are brought into contact with Water. Thus, the present invention provides an effective, cost-effective process for the preparation of the granular formulation of azadirachtin using very minimal ingredients and less expensive equipment and demonstrates higher stability to azadirachtins during processing and storage after processing.; releasing azadirachtins in amounts that are sufficient for bioactivity and that meet granular specifications in general. The ability of granule formulations of. the present invention to contain all natural substances and still be stored for longer periods has advantage over other commercially available liquid formulations since in many specialty applications, the use of organic solvents is disadvantaged due to environmental problems. The aforementioned characteristics of the present invention thus make the process and the product - unique for the successful commercial application. Additional features and advantages of - present invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the present invention. The objects and other advantages of the present invention will be understood and obtained by means of the elements and combinations particularly indicated in the written description and the appended claims. To achieve these and other advantages, and in accordance with the purpose of the present invention, as encompassed and broadly described herein, the present invention relates to a granular formulation of neem extract containing azadirachtins comprising sand as a carrier, at least one lipophilic substance as a deactivator and agglutinating, bio-active compounds such as azadirachtins and another neem extract containing limonoid. The following examples are for the purpose of illustration of the invention and should not be considered to limit the scope of the present invention. EXAMPLES Example I Encapsulation of azadirachtins in granular formulation Neem seed extracts containing azadirachtins are formulated into granular formulations using various carriers, binders / additives. The critical parameters of encapsulation and stability of the active ingredients are evaluated using suitable methods in order to identify ideal carriers and binders for the neem seed extract. The degree of encapsulation of azadirachtins in all these formulations is determined in accordance with the "water shift test" according to the method prescribed in Bureau Indian Standard specification IS: 6940-1982. According to the method, 10 g of the granules are taken in a 100 ml burette covered with cotton, 50 ml of water are added to the granules: Water is collected from the burette after 15 minutes and analyzed for the content of azadirachtins by HPLC according to the method described in Bureau Indian Standard specification ES: 14299-1995. The percentage of release of azadirachtins from the granules is given in Table 1. • ...

A. Granules of Neem Seed Extract Prepared by Conventional Methods Granule formulations 1 and • 2 of neem extract containing azadirachtins are prepared by the conventional manner as follows. 474 g of sand particles are mixed with 20 g of white clay in a conical 2-liter flask. 1 g of polyvinyl acetate is dissolved in 15 ml of boiling water to which is added 1.22 g of neem seed extract (equivalent to 0.1% of azadirachtins), noigen-1.16 g, crystal violet-0.15 g and sugar-5 g. The contents are completely mixed to obtain a clear solution. The solution is then added slowly to the sand-clay mixture while the contents are stirred completely. After the addition is complete, the wet granules are transferred onto a glass tray and dried at a temperature up to below 50 ° C for 8 hours (Formulation 1). The granules are subjected to the "bleed test" in. water to find the degree of encapsulation. The results indicate 90% release of I azadirachtins from the granulated product. The granules used for insect control generally release about 15% of their active ingredient when they are tested. To further improve the encapsulation in the Formulation 1, the granules are coated with beeswax as described below. 1.25 g of beeswax is dissolved in 15 ml of n-hexane. The wax solution is added dropwise to 250 g of the above granules taken in a conical flask of a lid. The contents are thoroughly mixed for a few minutes and transferred to a glass tray and dried under a stream of air or in hot air above one. temperature below 50 ° C for 2 hours (Formulation 2). The resulting wax-coated granules are subjected to the water bleeding test. The results indicate 72% release of azadirachtins, a slight improvement as against the granules without wax coating. This indicates that conventional methods for the preparation of agrochemical granules using inert carriers such as sand are not suitable for azadirachtins since they readily release azadirachtins in contact with it which is undesirable. Even the coating with wax at levels of 0.25-0.5% has resulted in only slight improvement in the encapsulation. The use of higher amounts of wax than 0.5% to improve the encapsulation could not be possible since the agglomeration of the granule particles is noted. In addition to the low encapsulation, granules have shown shorter shelf life for azadirachtins which indicates that this may be due to the presence of several ingredients used in the preparation of granules that have caused degradation due to their adverse effects on azadirachtin. . Accordingly, the use of various ingredients which is generally observed in the preparation of conventional granules may have limitation when applied for the preparation of azadirachtin granules. B. Studies on the impregnation of the neem seed extract, which contains azadirachtins in granular form. With an objective to identify a process and composition with minimum number of additives but improved encapsulation and stability for the azadirachtins, 3 to 30 granulated compositions were prepared. Carriers such as sand and bentonite, binders or additives such as polyvinyl alcohol (PVA), rosin, beeswax, paraffin wax, pressed wax, turpentine oil, neem oil, pine oil and polyethylene glycol (PEG) were used. . The. compositions of these formulations (100 g each) is given in Table 1 and the process for their preparation is as follows.

Example II: I, '. . Preparation of Formulations: The formulations are prepared according to the procedures mentioned in Example I-A: Example III: Formulations 3-24: These formulations are prepared using sand without pretreatment. Stage 1: Preparation of sand: Sieved river sand, particle size 16-32 mesh, washed with water and dried under hot stream of air (50-70 ° C) until the moisture content attached it reaches below 2%. Commercial bentonite is used directly if washed. Stage 2: Impregnation of the neem seed extract containing azadirachtins: Approximately 98.7 g of the sand or bentonite sifted particles (12-30 mesh) are taken in a conical flask. To this is added slowly approximately 0.3 g of neem seed extract solution (equivalent to 0.1% of Azadirachtins) dissolved in 5 ml of acetyl acetate. The contents are completely mixed and dried under the air stream. Step 3: Coatings of different binders on granules impregnated with neem extract: Granules impregnated with neem seed extract are taken in a conical flask and the solutions of various binders alone or in combination are dissolved in 5 ml of bees - 0.25 - 1 g, rosin - 0.1-0.5 g, turpentine oil - 1 g, Neem oil - 1 g) that are added drop by drop. The contents are thoroughly mixed "and dried under the air stream to obtain free-flowing granules." Example IV: Formulations: 25-30 These formulations are with sand and bentonite granules that are coated with beeswax / wax Before applying the neem seed extract and other binders to improve the encapsulation, the process involves the following stages: Stage 1: Preparation of the river sand: The river sand is sifted to obtain sand particles from Mesh size from 16 to 32, washed with water and dried under the warm air stream until the bound moisture content reaches below 2% Commercial bentonite is used directly without washing Stage 2: Pre-coating of wax on the carrier: To approximately 98 g of sand or bentonite obtained in stage 1, the solution of binders (beeswax, 0.25 g, paraffin wax, 0.25 g) dissolved in approx. 5 ml of n-hexane. The contents are mixed thoroughly for uniform distribution of the wax substance on the surface of the sand, dried in the air stream to obtain free-flowing particles. Stage 3: Impregnation of the neem seed extract containing azadirachtins: 0.3 g of neem seed extract (equivalent to 0.1% of azadirachtins) are dissolved in approximately 5 ml of methanol and the solution is added dropwise to the particles. .coated wax obtained in stage 2. The contents are completely mixed and dried under the air stream, or in a hot air oven at 50 ° C for 2 hours, Stage 4: Post-coating of the wax in the granules impregnated with neem seed extract: The granules impregnated with neem seed extract obtained in stage 3 are slowly treated with respective solutions of wax (beeswax, 0.75 g, paraffin wax, 0.75 g, pressed wax, 0.75 g) ) prepared as in step 2. The contents are thoroughly mixed and dried under the air stream in a hot air oven at a temperature below 50 ° C for 2 hours to obtain free-flowing granules. The use of water from stage 2 forward is avoided as it is known to degrade azadirachtins and also leads to difficulty in drying at low preferred temperatures. Accordingly, the usual binders such as guar gum, gum arabic, etc., which are hydrophilic in nature could not be used due to their insolubility in the solvents. 'The degree of encapsulation is tested using the water shift test' as described, in example IA and the results are given in Table 1.,. Table 1 (Note: Aza = Azadirachtins) The results indicate that granules made by coating neem extract containing azadirachtins directly on the sand (Formulation 3) without any binder gave the rapid release of azadirachtins. Binders such as polyethylene glycol, polyvinyl alcohol have not provided controlled release of azadirachtins such as beeswax and rosin have imparted gradual release to azadirachtins. In addition, granules made with sand or bentonite carriers coated with wax have provided comparatively higher encapsulation. Example V Stability of granules with different carriers and additives that possess higher encapsulation of the neem extract containing azadirachtins: Formulations that have shown improved encapsulation by releasing approximately 50% azadirachtins in the Water Shift test Example 1 (Table 2) are studied for their stability under accelerated conditions at 54 +/- 2 ° C. Approximately 80 g of granules of each formulation are taken in air-tight glass vials and incubated in a hot air oven for 28 'days. The samples are taken outside the oven and. at designated intervals and analyzed for azadirachtins by HPLC according to the method described in Bureau Indian Standard specification ES: 14299-1995. The degradation of azadirachtins in these formulations is given in Table 2. Table 2 NA = Not Analyzed, The results indicate that formulations that are made of sand as a carrier and beeswax as a deactivator / binder have higher stability to azadirachtins than those made of bentonite and rosin carrier, turpentine oil, oil of neem as binder / additives although the latter have shown higher encapsulation of the azadirachtins (Example 1). But in view of the stability of the azadirachtins these additives were found to be unsuitable for use in the formulation. Formulations that consist of sand carrier and beeswax / paraffin wax as deactivator / binder have shown both stability and higher encapsulation. The stability and encapsulation are also improved if the extracts containing azadirachtins are coated in sand granules coated with wax and is one of the inventive concepts in the subject subject of the present application. Example VI A. Efficacy of the granular formulation of extra to neem seed containing azadirachtins against. the insect Nllaparvata lugens (brown plant lobster, BPH) in rice The granular formulation containing azadirachtins, 25, prepared according to the present invention is tested against BPH insects. The insects used for the bioassay are from cultures maintained in the laboratory. Rice seedlings are grown in trays and kept in the laboratory and 30-day-old seedlings are used in the study. Test solutions containing 25 ppm, 50 ppm and 100 ppm azadirachtins are prepared by adding the required amount of granules (5.5, 11 and 22 g respectively) in 200 ml of water taken in bottles (Bottle 1, Bottle 2 and Bottle) 3 respectively). A bunch of rice seedlings is immersed in the treated solutions. For the evaluation of bioefficiency, nine seedlings of each of the jars (1-3) are taken after 24 hours of treatment and planted in clay pots (3 x 3 1. '' Plants) in three replications to every concentration. Plants that are not treated with granules serve as control. The plants are then enclosed in mylar cages (10 cm in diameter and 30 cm in height). Ten newly emerged BPH nymphs are transferred to each of the cages and the top of each mylar cage is covered with wet muslin cloth. The pots are irrigated continuously throughout the study. The mortality of the BPH insects are observed in 12, 32, 5 =, 7 =, 9-, 11 = and 14 £ days after the treatment and the corrected mortality is determined using Abbot's formula. Table 3: Mortality of BPH fed in rice seedlings treated with the granular formulation of the present invention.

* The coted mortality is in parentheses. The results of bioefficiency indicate 93-100% mortality of BPS that is attributed to the granules. B. Systemic absorption of azadirachtins by rice plants treated with azadirachtin granules: Systemic absorption of azadirachtins is monitored in rice seedlings Submerged between the three bottles containing "granulated water." Seedlings are removed from each of the 1 and 3 day flasks are extracted and analyzed for the azadirachtin content by HPLC (Table 4).

The HPLC results indicate absorption of azadirachtins by rice seedlings in proportion to the dosage of the granules that gave 25, 50 and 100 ppm respectively. Example VII 1 The preparation of granules of neem seed extract that I. '-' contain azadirachtins in ton quantities according to the present invention involves the following steps. Stage -1: Preparation of the sand: The sand of required particle size, 1190μ / 550μ (16-32 mesh), is obtained by sieving 4450 kg of sand in a crude river in a screen agitator. This sand is taken in a 'Mild steel tank provided with a mixer and washed with hot water at approximately 70 ° C to remove adhering impurities. The water is discarded and the. Clean sand thus obtained is transfe to a Mild steel dryer. The drying takes place at 60 ° C under normal conditions for a period of 4 hours. You get the 1000 kg clean sand with moisture content in the sand that is < 0.05% 989.3 kg of dry sand is loaded onto a coating tray. Stage -2: Pre-coating with wax: n-Hexane, 58.3 kg (equivalent to 5.83% of the batch size) is taken in a 304 stainless steel mixing vessel. Gradually, with stirring, 2.5 kg of paraffin wax ( equivalent 0.25%) is added and the addition is made at 60 ° C. The paraffin wax is dissolved in the n-hexane completely, typically within one hour. The paraffin wax solution is slowly sprayed at the rate of 14.5 kg / hr onto the sand, rotating on the tray at a speed of 10 rpm. The drying is done simultaneously by means of the hot air blower mechanism by keeping the temperature below 50 ° C, preferably at about 47 ° C to ensure the uniform coating of the paraffin wax on the sand of the coating process. which takes place for four hours. Step -3: Impregnation of the neem seed extract containing .azadiractins: Ethyl acetate, 58.3 kg (equivalent to 5.83% of the batch size) is taken in a 304 stainless steel mixing vessel. Gradually with stirring, approximately 3,245 kg of extract equivalent to 1.0 kg of 100% Azadirachtins (equivalent to 0.12% of the batch size) is added. Stirring is continued until the complete dissolution of the extract in methanol is complete. gets, typically within an hour. The neem seed extract solution thus obtained is slowly sprayed at a rate of 14.5 kg / hr onto the sand granules covered in wax, in a tray rotating at a speed of 10 rpm. The drying is done simultaneously by means of the mechanism of rotation of the hot air blower to maintain the temperature below 50 ° C, preferably about 42 ° C to ensure the uniform impregnation of the neem seed extract on the sand granules covered waxy. This process is carried out for four hours. Stage -4. Coating with coloring agent: Ethyl alcohol, 11.6 kg (equivalent to 1.16% of the batch size) is taken in a 304 stainless steel mixing vessel. Gradually, with stirring, 0.2 kg of methyl violet (equivalent to 0.2%) is added. 0.02% of lot size). Agitation is continued until it dissolves completely, typically for one hour. The solution is gently sprayed at the rate of 3 kg / hr on the granules of sand impregnated with neem seed extract containing Azadirachtins, and the tray rotating at a speed of 10 rpm. The drying is done simultaneously by means of the hot air blower mechanism to keep the temperature below 50 ° C. • To ensure uniform coating of the coloring agent, the process is carried out for four hours. Stage -5, Post-coating wax: n-Hexane, 58. 3 kg (equivalent to 5.83% of the batch size) is taken in a 304 stainless steel mixing vessel. Gradually, with stirring, 5 'kg of paraffin wax (equivalent to 0.5% of the batch size) is added and the Addition is made at 60 degrees centigrade. The paraffin wax is completely dissolved in the n-Hexane, typically within one hour. The solution is gently sprayed at the 14.5 kg / hr ratio on the colored colored sand pellets, rotating at a speed of 10 rpm. The drying is done simultaneously by means of the mechanism of hot air blower to keep the temperature below 5 ° C, - preferably 47 ° C. To ensure the uniform coating of the paraffin wax on the colored coated sand granules, the process is carried out for hours. Stage 6: Packing: The dry formulated product is packed in double thickness polyethylene bags, of a thickness of not less than 0.062 mm each inside cylinders, high density polyethylene, fiberboard or moderate steel cylinders, sizes of the package include 5 ', 10 and 20 kilograms. Main Advantages: 1) Stable increased storage of the granular pest control formulation containing azadirachtins. 2) Gradual release of the azadirachtins from the active constituents of the granular formulation that allows for prolonged efficacy. 3) Effective formulation in cost and a simple process for the preparation of the same. 4) . Ideal Eco-friendly granular formulation for organic agriculture. 5) Easy availability of the solid carriers and other ingredients used in the granular formulation.

Claims (20)

1. I CLAIMS 1. A granular formulation of neem seed extract containing azadirachtins having increased storage stability and gradual release of azadirachtins, the formulation composition characterized in that it comprises: Ingredients Weight / Weight (%) i. Seed extract of. Neem 0.03 to 50.00 ii. Carrier 48.50 to 99.30 iii. Coloring 0.01 to 0.04 iv. Lipophilic Substance 0.50 a.1.50 2. A preferred granular formulation according to claim 1, characterized in that it comprises: Ingredients Weight / Weight (%) i. Neem seed extract 0.075 to 12.5 ii. Carrier 86.7 to 99.20 iii. Coloring 0.02 to 0.03 iv. Lipophilic substance 0.60 to 0.75 3. The granular formulation according to claim 1, characterized in that the content of azadirachtins in the neem seed extract varies between 0.03-5.0 w / w%. 4. The granular formulation according to claim 3, characterized in that the content of azadirachtins in the neem seed extract is preferably up to 1.0 w / w%. 5. The granular formulation according to claim 1, characterized in that the carrier used is selected from siliceous substances preferably sand. 6. The granular formulation according to claim 1, characterized in that the carrier used is preferably river sand. • 7. The granular formulation in accordance with. claim 6, characterized in that the particle size of the sand used varies between the mesh 12 to 32, preferably mesh 16 to 32. 8. The granular formulation according to claim 7, characterized in that the moisture content in the sand is below 2.0%. 9. The granular formulation according to claim 1, characterized in that the. The lipophilic substance used is low melting hydrocarbon wax selected from the group consisting of plant and animal origin, preferably beeswax and paraffin wax. The granular formulation according to claim 1, characterized in that the dye is of synthetic and / or natural origin selected from the group consisting of crystal violet, methyl violet, natural-bixin, turmeric and mixtures thereof. 11. A process for preparing the granular formulation of claim 1, characterized in that the process comprises the steps of: a) optionally washing the carrier with water, drying at about 60 ° C, sifting to obtain the dry carrier, b) coating the dry carrier of stage (a) with. lipophilic substance dissolved in an organic solvent, c) impregnate the coated carrier of step (b) with extract, of neem seed dissolved in a solvent, dry in a stream of hot air at a temperature of about 40 ° C to 50 ° C. ° C, d) coating with dissolved dye in a solvent by spraying the impregnated material of step (c), drying at about 40 ° C to 50 ° C, and e) finally coating the material of step (d). with a lipophilic substance, dry at approximately 40 ° C to 50 ° C, to obtain the required granular formulation. 12. The process according to claim 11, characterized in that in steps (a) and (b) the carrier used is a siliceous sand substance. 13. The process according to claim 11, characterized in that the preferable carrier used is river sand. 14. The process according to claim 13, characterized in that the particle size of the river sand used varies between the mesh 12 and 32, preferably mesh 16 and 32. 15. The process according to claim 13, characterized The moisture content of the river sand is up to below 2.0%. , 16. The process in accordance with the claim 11, characterized in that in steps (b) and (e), the organic solvent used is selected from the group consisting of low boiling hydrocarbons., ethers, ketones, aldehydes, esters, such as n-hexane, petroleum ether, diethyl ether, acetone, ethyl acetate and the like. The process according to claim 11, characterized in that in steps (b) and (e), the lipophilic substance used is low melting hydrocarbon wax, selected from the group consisting of plant and animal origin, preferably wax of bees and paraffin wax. 18. The process according to claim 11, characterized in that in step (c) the neem seed extract used is dissolved in a solvent selected from the group consisting of ethers, ketones, 74 • .... I alcohols, aldehydes, esters such as diethyl ether, ethyl acetate, acetone, methanol and the like. The process according to claim 11, characterized in that in step (c) the neem seed extract used comprises azadirachtins ranging from 0.03% to 5.0% and preferably up to 1.0% weight / weight%. 20. The process according to claim 11, characterized in that in step (d), the dye used is of synthetic and / or natural colors, selected from the group consisting of crystal violet, methyl violet, bixin, turmeric and mixtures thereof.