Process for Preparing Water Soluble Azadiractin Powder Formulation with In-Built and External Inclusion Complexes

Abstract

Process for producing water soluble Azadirachtin containing powder formulation from neem seed kernel with the help of native and external inclusion complex. The process comprises expelling a large proportion of oil from neem seed kernels (NSK) by cold pressing, extracting the so called de-oiled neem seed cake with water to form an aqueous solution in which the azadirachtin is complexed with water soluble polysaccharides and proteins. The enrichment of azadiractin in aqueous solution is achieved by addition of azadiractin containing inclusion complex and spray drying. This helps in retaining all naturally occurring limonoids of neem seed kernel along with native encapsulating agents such as polysaccharide-protein matrix and also achieve water soluble powder with higher amounts of azadirachtin (>6000-60,000 ppm) in it.

Claims

1. A water soluble powder formulation comprising one or more inclusion complexes and a neem seed kernel extract, wherein said neem seed kernel extract comprises azadirachtin, limonoids and polysaccharide-protein matrix, wherein said formulation is a free flowing powder, and wherein said inclusion complexes and said neem seed kernel extract are not chemically bonded.

2. The water soluble powder formulation of claim 1, wherein said inclusion complex comprises a cyclodextrin derivative.

3. The water soluble powder formulation of claim 1, wherein said azadirachtin is present in an amount exceeding 600 ppm.

4. The water soluble powder formulation of claim 1, wherein said azadirachtin is selected from the group comprising: azadirachtin A, or azadirachtin B, or mixtures thereof.

5. The water soluble powder formulation of claim 1, wherein said inclusion complex comprises a cyclodextrin derivative and a polysaccharide-protein mixture.

6. A process for the production of water soluble azadirachtin enriched water soluble powder, the process comprising: (i) removal of husk from neem seeds to obtain neem seeds kernel, (ii) de-oiling by cold pressing neem seeds kernel to remove a first proportion of an oil content thereof, resulting in a de-oiled neem seeds cake, (iii) extracting the cake from the de-oiled neem seeds with water at near neutral pH (iv) separating a liquid phase to obtain clarified aqueous solution of azadirachtin along with polysaccharides and proteins and remaining oil.

7. The process of claim 6, for the production azadirachtin enriched water soluble powder further comprising: (v) concentration of clarified aqueous extract to suitable extent under vacuum so that azadiractin content is nearly doubled; (vi) addition of external azadirachtin containing SoluNeem in different ratios to the clarified aqueous extract so that azadiractin content is increased; (vii) filteration to remove the water insoluble; (ix) spray drying the resultant solution from step vii to obtain enriched water soluble azadiractin powder.

8. The process of claim 6 wherein the cake is extracted with heated water or steam.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is table of findings

[0017] These and other aspects of the present invention will become apparent upon reading the following detailed description in conjunction with the associated drawings.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0018] The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways as defined and covered by the claims and their equivalents. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout.

[0019] Unless otherwise noted in this specification or in the claims, all of the terms used in the specification and the claims will have the meanings normally ascribed to these terms by workers in the art.

[0020] Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of including, but not limited to. Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words herein, above, below, and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.

[0021] A first aspect of a disclosed embodiment may comprise a process for the production of water soluble azadirachtin and its enrichment both by concentrating the aqueous extract and by addition of external azadiractin and finally making a water soluble powder that may contain inclusion complexes, preferably a mixture of cyclodextrin derivatives and polysaccharide-proteins, especially for such production at commercial scale:

[0022] The neem seeds are preferably first dried to a moisture content of from 10-15% by weight to a level of 2-4%, and then the husk is removed to get the neem seed kernel. The neem seed kernel obtained is then pressed to produce the cake from which has been removed a substantial proportion of the oil content of the seeds. Preferably, the pressing is done at a low speed to reduce the temperature build up in the neem seeds during pressing and so minimize heat degradation of the azadirachtin. The pressing is preferably conducted so that at least 70% by weight, more preferably 90% by weight of the oil is removed from the neem seed kernels during the pressing process.

[0023] Generally, the extraction process of this invention is preferably accomplished using demineralised water as solvent, although one of skill would recognize that other polar solvents could be employed.

[0024] The aqueous solution obtained can be cooled and the oil is preferably separated from the water on the basis of the different densities of the oil and water. Preferably, the separation can be undertaken by passing the aqueous solution through a separator where the solution is spun through a series of cones that physically separate the oil and water on the basis of their densities. The oil stream which preferably contains no azadirachtin but does contain the less polar triterpenes and the diterpenes will be kept aside for oil recovery and further processing

[0025] The azadirachtin-rich aqueous solution, which also contains polar triterpenes, polysaccharides and proteins is passed through celite bed to get clear aqueous solution. The azadiractin content in the clear aqueous solution would generally vary from 300 to 1000 ppm depending upon neem seed quality and the proportion of water used for extraction and most preferably 8 volumes of water with respect to deoiled neem cake.

[0026] Another embodiment of this invention is enhancement of azadiractin content in the aqueous layer by concentrating it under vacuum to preferably to volume and then by the addition of external azadiractin powder viz., SoluNeem, stirring and filtration. This way the azadiractin content in the aqueous layer could be enhanced by many fold, preferably having 600 ppm and above. These findings are illustrated in FIG. 1, showing Table 1

[0027] In a still further embodiment, the process can include addition of inclusion complex preferably a mixture of beta-cyclodextrin, beta-methyl cyclodextrins along with polysaccharide-protein complex with limonoids present in neem seed kernels preferably so as to get azadiractin enriched aqueous solution and finally spray drying to get enriched water soluble azadiractin containing powder.

[0028] The invention provides for an efficient process for producing water soluble azadirachtin containing powder formulation from neem seed kernel with the help of native and external inclusion complexes. This process comprises expelling a large proportion of oil from neem seed kernels (NSK) by cold pressing, extracting the so called de-oiled neem seed cake with water to form an aqueous solution in which the azadirachtin is complexed with water soluble polysaccharides and proteins. The enrichment of azadiractin in aqueous solution can be achieved by addition of azadiractin containing inclusion complex and spray drying. This helps in retaining all naturally occurring limonoids of neem seed kernel along with native encapsulating agents such as polysaccharide-protein matrix and also achieves water soluble powder with higher amounts of azadirachtin (>6000-60,000 ppm) in it.

[0029] Specifically, in its most preferred embodiment, the invention discloses a water soluble powder formulation comprising at least one or two inclusion complexes and a neem seed kernel extract, wherein said neem seed kernel extract comprises azadirachtin, limonoids and polysaccharide-protein matrix, wherein said composition is a free flowing powder, and wherein said inclusion complexes and said neem seed kernel extract are not chemically bonded. The said inclusion compound is preferably a cyclodextrin derivative and azadirachtin is preferably present in an amount exceeding 600 ppm. The azadirachtin in the formulation is an azadirachtin A or an azadirachtin B, or both.

[0030] Another preferred inclusion complex is cyclodextrin derivative and polysaccharide-protein mixture thereof.

[0031] The invention also provides for a process for the production of water soluble azadirachtin enriched water soluble powder. The process steps include:

[0032] (i) Removal of husk from the neem seeds to get neem seed kernel

[0033] (ii) de-oiling by cold pressing neem seeds kernel to remove a first proportion of the oil content thereof

[0034] (iii) extracting the so called de-oiled neem seeds cake with water at near neutral pH

[0035] (iv) separating the liquid phase to obtain clarified aqueous solution of azadirachtin along with polysaccharides and proteins and the remaining oil.

[0036] Further, optional step comprise:

[0037] (v) concentration of clarified aqueous extract to suitable extent under vacuum so that azadiractin content would preferably be nearly doubled

[0038] (vi) addition of external azadirachtin containing SoluNeem in different ratios to the clarified aqueous extract so that azadiractin content would be increased many fold

[0039] (vii) filteration to remove the water insolubles

[0040] (ix) spray drying the resultant solution from step vii to obtain enriched water soluble azadiractin powder.

Examples 1

[0041] Neem seeds, 500 kgs, were dehulled and deoiled by cold pressing using standard methodology involving mechanical oil extrusion. 100 kgs of deoiled neem cake was ground and stirred with 800 kg of demineralised water in Stainless steel reactor at room temperature for 5 hours. The slurry was filtered to remove majority of solids. The aqueous layer was finally filtered using Nutsch filter with celite bed to get clear solution of 730 kgs. This clear aqueous solution contained 671 ppm of azadiractin. To this was added different quantities of SoluNeem powder and stirred at room temperature for 4 hours and filtered to remove insolubles. The results are tabulated in Table 1.

Example 2

[0042] To 10 lts of aqueous extract of neem seed kernel when added 60 gms of SoluNeem and filtered. The clear aqueous solution should contain about 6670 ppm of azadiractin.

Example 3

[0043] To 10 lts of aqueous extract of neem seed kernel when added 30 gms of SoluNeem and filtered. The clear aqueous solution should contain about 3670 ppm of azadiractin.

Example 4

[0044] To 10 lts of aqueous extract of neem seed kernel when added 15 gms of SoluNeem and filtered. The clear aqueous solution should contain about 2170 ppm of azadiractin.

[0045] Various embodiments are possible of the invention other than those disclosed above and are easily comprehended by a person skilled in the art. The invention encompasses all such embodiments within its scope.

[0046] The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform routines having steps in a different order. The teachings of the invention provided herein can be applied to other systems, not only the systems described herein. The various embodiments described herein can be combined to provide further embodiments. These and other changes can be made to the invention in light of the detailed description.

[0047] All the above references and U.S. patents and applications are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions and concepts of the various patents and applications described above to provide yet further embodiments of the invention.

[0048] These and other changes can be made to the invention in light of the above detailed description. In general, the terms used in the following claims, should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above detailed description explicitly defines such terms. Accordingly, the actual scope of the invention encompasses the disclosed embodiments and all equivalent ways of practicing or implementing the invention under the claims.

[0049] While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate the various aspects of the invention in any number of claim forms.