Aqueous suspension of nanoparticles comprising an agrochemical active ingredient

• US 6,638,994 B2
• Filed: 03/29/2002
• Issued: 10/28/2003
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Joel Coret, Mathieu Joanicot, Prudʼhomme, Robert K., Regan Crooks
• Original Assignee: Joel Coret, Mathieu Joanicot, Prudʼhomme, Robert K., Regan Crooks
• Inventors: Joanicot, Mathieu, Coret, Joel, Crooks, Regan, PrudʼHomme, Robert K.
• Primary Examiner(s): Cain, Edward J.
• Assistant Examiner(s): WYROZEBSKI LEE, KATARZYNA I
• Application Number:
  US10/112,131
• Publication Number:
  US 20030013799A1
• Time in Patent Office: 578 Days
• Field of Search: 504/116.1, 504/118, 504/121, 504/123, 504/156, 504/172, 504/560, 504/360, 504/361, 504/362, 504/365, 504/366, 514/951, 523/122
• US Class Current: 523/122
• CPC Class Codes: A01N 2300/00 Combinations or mixtures of active ingredients covered by classes A01N27/00 - A01N65/48 with other active or formulation relevant ingredients, e.g. specific carrier materials or surfactants, covered by classes A01N25/00 - A01N65/48
• CPC Class Codes: A01N 25/04 Dispersions, emulsions, suspoemulsions, suspension concentrates or gels foams A01N25/16
• CPC Class Codes: A01N 43/70 Diamino—1,3,5—triazines with only one oxygen, sulfur or halogen atom or only one cyano, thiocyano (—SCN), cyanato (—OCN) or azido (—N3) group directly attached to a ring carbon atom
• CPC Class Codes: A61K 9/14 Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles microspheres A61K9/16; microcapsules A61K9/50; nanocapsules, nanoparticles of the matrix type A61K9/51
• CPC Class Codes: A61K 9/16 Agglomerates; Granulates; Microbeadlets ; Microspheres; Pellets; Solid products obtained by spray drying, spray freeze drying, spray congealing,(multiple) emulsion solvent evaporation or extraction A61K9/20 takes precedence if the final form is a tablet; microspheres with drug-free outer coating, microcapsules A61K9/50; mixture of different granules, microcapsules, (coated) microparticles A61K9/5084; nanoparticles A61K9/51
• CPC Class Codes: A61K 9/19 lyophilised , i.e. freeze-dried, solutions or dispersions lyophilised products with subsequent particle size reduction A61K9/14; granules or pellets made by lyphilisation A61K9/1682; solid oral dosage forms made by lyophilisation A61K9/2095; lyophilisation additives A61K47/00
• CPC Class Codes: A61K 9/5146 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, polyamines, polyanhydrides
• CPC Class Codes: A61K 9/5192 Processes
• CPC Class Codes: B01F 21/00 Dissolving separating by dissolving B01D; dissolving to effect cooling F25D5/00
• CPC Class Codes: B01F 27/91 with propellers
• CPC Class Codes: B01F 35/20 Measuring; Control or regulation
• CPC Class Codes: B01F 35/2211 Amount of delivered fluid during a period
• CPC Class Codes: B01F 35/2213 Pressure
• CPC Class Codes: B01F 35/22142 Speed of the mixing device during the operation
• CPC Class Codes: B01F 35/2215 Temperature
• CPC Class Codes: B01J 13/0021 containing a solid organic phase
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/775 Nanosized powder or flake, e.g. nanosized catalyst

Abstract

The invention relates to an aqueous suspension of particles, said particles comprising an organic active ingredient. A controlled release of the ingredient occurs. The invention is especially suitable for the controlled release of organic agrochemical active ingredients useful in crop sciences, such as pesticides.

Claims

1. An aqueous suspension of nanoparticles, said nanoparticles having a solid core comprising:

an amphiphilic compound comprising at least one hydrophilic moiety and at least one hydrophobic moiety, and

at least 50 parts by weight of an organic water-insoluble agrochemical active ingredient for 100 parts of the amphiphilic compound,

wherein more than 50% of the nanoparticles have a diameter of lower than 1060 nm.

2. An aqueous suspension according to claim 1, wherein the hydrophilic moiety is a hydrophilic polymeric block.

3. An aqueous suspension according to claim 1, wherein the nanoparticles further comprise an organic solvent.

4. An aqueous suspension according to claim 1, wherein the nanoparticles comprise more than 100 parts by weight of the organic water-insoluble agrochemical active ingredient for 100 parts of the amphiphilic compound.

5. An aqueous suspension according to claim 1, wherein the nanoparticles comprise more than 500 parts by weight of the organic water-insoluble agrochemical active ingredient for 100 parts of the amphiphilic compound.

6. An aqueous suspension according to claim 1, wherein the organic water-insoluble agrochemical active ingredient is an insecticide, a nematicide, an herbicide, a fungicide, an aphicide, a miticide, or pesticide.

7. An aqueous suspension according to claim 6, wherein the organic water-insoluble agrochemical active ingredient is atrazine, cymoxanil, chlorothalanil, cyproconazole, and tebuconazole or a mixture thereof.

8. An aqueous suspension according to claim 1, wherein more than 50% of the nanoparticles have a diameter of lower than 600 nm.

9. An aqueous suspension according to claim 1, wherein the hydrophobic moiety is alpha-{2,4,6-tris[1-(phenyl)ethyl]phenyl}-omega-hydroxy group.

10. An aqueous suspension according to claim 9, wherein the hydrophilic polymer block is a poly(oxyethelene), poly(oxypropylene), or a poly(oxyethelene)-poly(oxypropylene) copolymer.

11. An aqueous suspension according to claim 2, wherein the hydrophobic moiety is a hydrophobic polymeric block.

12. An aqueous suspension according to claim 11, wherein:

the amphiphilic compound has a number-average molecular weight comprised between 1000 and 50000 g/mol,

the hydrophobic block(s) has a glass transition temperature lower than 30°

C.

13. An aqueous composition according to claim 11, wherein the amphiphilic compound is a di-block copolymer comprising a hydrophilic block and a hydrophobic block.

14. An aqueous composition according to claim 13, wherein the di-block copolymer is obtained by a “

living”

polymerization process with the use of a transfer agent, comprising the steps of;

a) reacting an ethylenically unsaturated hydrophobic or hydrophilic monomer, at least a free radicals source compound, and a transfer agent, to obtain a first block,

b) reacting the first block, an ethylenically unsaturated hydrophobic or hydrophilic monomer, and, optionally, at least a radical source compound, to obtain a di-block copolymer, and then,

c) optionally, reacting the transfer agent with means to render it inactive.

15. An aqueous suspension according to claim 14, wherein the transfer agent comprises a dithioester group, a thioester-thione group, a dithiocarbamate group, or a xanthate group.

16. An aqueous suspension according to claim 11, wherein the hydrophilic block comprises units deriving from monomers being:

unsaturated ethylenic monocarboxylic acids, unsaturated ethylenic dicarboxylic acids,

monoalkyl esters of unsaturated ethylenic dicarboxylic acids or N-substituted derivatives of monoalkyl esters of unsaturated ethylenic dicarboxylic,

amides of unsaturated carboxylic acids,

ethylenic monomers comprising a sulphonic acid group, their alkali metal or their ammonium salts.

17. An aqueous suspension according to claim 16, wherein the hydrophilic block comprises units deriving from monomers being acrylic acid (AA), methacrylic acid, itaconic acid, maleic acid, fumaric acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate methacrylate, acrylamide (AM), methacrylamide, vinylsulphonic acid, vinylbenzenesulphonic acid, alpha-acrylamidomethylpropanesulphonic acid, 2-sulphoethyl methacrylate, 2-acrylamido-2-methylpropanesulphonic acid (AMPS), or styrenesulphonate (SS).

18. An aqueous suspension according to claim 11, wherein the hydrophobic block comprises units deriving from monomers being:

esters of acrylic acid and of methacrylic acid with hydrogenated or fluorinated C₁-C₁₂ alcohols,

vinyl nitrites having from 3 to 12 carbon atoms,

carboxylic acid vinyl esters,

vinyl halides,

vinylamine amides,

unsaturated ethylenic monomers comprising a secondary, tertiary or quaternary amino group, unsaturated ethylenic monomers comprising a heterocyclic group comprising nitrogen, or

styrene.

19. An aqueous suspension according to claim 18, wherein the hydrophobic block comprises units deriving from monomers being methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl versatate, vinyl propionate vinylformamide, vinylacetamide, vinylpyridines, vinylimidazole, aminoalkyl (meth)acrylates, aminoalkyl(meth)acrylamides, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, di-tert-butylaminoethyl acrylate, di-tert-butylaminoethyl methacrylate, dimethylaminomethylacrylamide or dimethylaminomethylacrylamide methacrylamide.

20. An aqueous suspension according to claim 11, wherein the hydrophobic block is a polybutylacrylate block, and the hydrophilic block is a polyacrylic acid block.

21. An aqueous suspension according to claim 20, wherein the ratio between the weight-average molecular weight of the hydrophilic block and the weight-average molecular weight of the hydrophobic block is from 1 to 5.

22. An aqueous suspension according to claim 21, wherein the weight-average molecular weight of the hydrophobic block is comprised between 1000 g/mol and 10000 g/mol, and the weight-average molecular weight of the hydrophilic block is comprised between 1000 g/mol and 50000 g/mol.

23. An aqueous suspension according to claim 1, obtained by a process comprising mixing water, the organic water-insoluble agrochemical active ingredient dissolved a water-miscible solvent, and the amphiphilic compound.

24. A process for protecting plants or for increasing crop yield, comprising the step of spreading an aqueous suspension according to claim 1.