RU2603460C2 - Method of producing kinetin nanocapsules - Google Patents

Abstract

FIELD: nanotechnology.

SUBSTANCE: invention relates to method of producing kinetin nanocapsules. Said method is characterized by fact, that glycerol ester with one or two molecules of edible fatty acids and one or two molecules of citric acid is added to carrageenan in petroleum ether, mixture is stirred, kinetin powder is added, after formation of independent solid phase benzene is added slowly drop-by-drop, obtained suspension of nanocapsules is filtered, washed with benzene and dried, wherein weight ratio of nucleus/shell of nanocapsules makes 1:3, or 1:1, or 5:1.

EFFECT: invention provides simplifying and accelerating of kinetin nanoencapsulation process and higher weight yield.

1 cl, 1 dwg, 4 ex

Description

The invention relates to the field of nanotechnology, in particular to crop production and cosmetics.

Previously known methods for producing microcapsules. So, in US Pat. 2092155, IPC A61K 047/02, A61K 009/16, published October 10, 1997, Russian Federation, a method for microencapsulation of drugs based on the use of special equipment using ultraviolet radiation is proposed.

The disadvantages of this method are the duration of the process and the use of ultraviolet radiation, which can affect the process of formation of microcapsules.

In US Pat. 2095055, IPC A61K 9/52, A61K 9/16, A61K 9/10, Russian Federation, published November 10, 1997, a method for producing solid non-porous microspheres includes melting a pharmaceutically inactive carrier substance, dispersing the pharmaceutically active substance in a melt in an inert atmosphere, spraying the resulting dispersion in the form of fog in a freezing chamber under pressure in an inert atmosphere at a temperature of from -15 to -50 ° C, and dividing the resulting microspheres into fractions. A suspension intended for administration by parenteral injection contains an effective amount of said microspheres distributed in a pharmaceutically acceptable liquid vector, wherein the pharmaceutically active substance of the microsphere is not soluble in said liquid medium.

The disadvantages of the proposed method: the complexity and duration of the process, the use of special equipment.

In US Pat. 2076765, IPC B01D 9/02, Russian Federation, published April 10, 1997, a method for producing dispersed particles of soluble compounds in microcapsules by crystallization from a solution is proposed, characterized in that the solution is dispersed in an inert matrix, cooled, and dispersed particles are obtained by changing the temperature.

The disadvantage of this method is the difficulty of execution: obtaining microcapsules by dispersion with subsequent change in temperature, which slows down the process.

In US Pat. 2101010, IPC A61K 9/52, A61K 9/50, A61K 9/22, A61K 9/20, A61K 31/19, Russian Federation, published 01/10/1998, a chewing form of the drug with a taste masking having the properties of a controlled release of the drug The preparation contains microcapsules with a size of 100-800 microns in diameter and consists of a pharmaceutical core with crystalline ibuprofen and a polymer coating, including a plasticizer, flexible enough to withstand chewing. The polymer coating is a methacrylic acid based copolymer.

The disadvantages of the invention: the use of a copolymer based on methacrylic acid, as these polymer coatings can cause cancerous tumors; complexity of execution; the duration of the process.

In US Pat. 2139046, IPC A61K 9/50, A61K 49/00, A61K 51/00, Russian Federation, published on 10/10/1999, a method for producing microcapsules as follows. An oil-in-water emulsion is prepared from an organic solution containing dissolved mono-, di-, triglyceride, preferably tripalmitin or tristearin, and possibly a therapeutically active substance, and an aqueous solution containing a surfactant, possibly a portion of the solvent is evaporated, a redispersing agent is added the agent and the mixture are freeze dried. The freeze-dried mixture is then redispersed in an aqueous carrier to separate the microcapsules from organic residues, and the hemispherical or spherical microcapsules are dried.

The disadvantages of the proposed method are the complexity and duration of the process, the use of freeze-drying, which takes a lot of time and slows down the process of obtaining microcapsules.

In US Pat. 2159037, IPC A01N 25/28, A01N 25/30, Russian Federation, published November 20, 2000, a method for producing microcapsules by a polymerization reaction at the phase boundary containing solid agrochemical material 0.1-55 wt. % suspended in a water-miscible organic liquid, 0.01-10 wt. % non-ionic dispersant active at the phase boundary and not acting as an emulsifier.

The disadvantages of the proposed method: complexity, duration, the use of high shear mixer.

In the article “Development of microencapsulated and gel-like products and materials for various industries”, Russian Chemical Journal, 2001, vol. XLV, No. 5-6, p. 125-135, a method for producing microcapsules of drugs by gas-phase polymerization is described, since the authors of the article consider the method of chemical coacervation from aqueous media to be microencapsulated as unsuitable because most of them are water-soluble. The microencapsulation process by gas phase polymerization using n-xylylene includes the following main stages: evaporation of the n-xylylene dimer (170 ° C), its thermal decomposition in a pyrolysis furnace (650 ° C at a residual pressure of 0.5 mm Hg), transfer of reaction products to the “cold” polymerization chamber (20 ° C, residual pressure 0.1 mm Hg), deposition and polymerization on the surface of the protected object. The polymerization chamber is made in the form of a rotating drum, the optimum speed for coating the powder is 30 rpm. The thickness of the shell is regulated by the time of coating. This method is suitable for encapsulation of any solids (with the exception of prone to intense sublimation). The resulting poly-n-xylylene highly crystalline polymer, characterized by high orientation and tight packaging, provides a conformal coating.

The disadvantages of the proposed method are the complexity and duration of the process, the use of gas phase polymerization, which makes the method inapplicable for producing microcapsules of drugs in polymers of protein nature due to denaturation of proteins at high temperatures.

In the article “Development of Micro- and Nanosystems for the Delivery of Medicines”, Russian Chemical Journal, 2008, vol. LII, No. 1, p. 48-57, a method for producing microcapsules with incorporated proteins is presented, which does not significantly reduce their biological activity, carried out by the process of interfacial crosslinking of soluble starch or hydroxyethyl starch and bovine serum albumin (BSA) using terephthaloyl chloride. The proteinase-aprotinin inhibitor, either native or with a protected active center, was microencapsulated when it was introduced into the aqueous phase. The flattened form of lyophilized particles indicates the preparation of microcapsules or particles of a reservoir type. Thus prepared microcapsules were not damaged after lyophilization and easily restored their spherical shape after rehydration in a buffer medium. The pH of the aqueous phase was decisive in the preparation of strong microcapsules in high yield.

The disadvantage of the proposed method for producing microcapsules is the complexity of the process, which, in turn, leads to a decrease in the output of the final capsules.

In US Pat. 2173140, IPC A61K 009/50, A61K 009/127, Russian Federation, published September 10, 2001. A method for producing silicon organolipid microcapsules using a rotary-cavitation unit with high shear forces and powerful sonar acoustic and ultrasonic dispersion ranges is proposed.

The disadvantage of this method is the use of special equipment - a rotary-quittance installation, which has an ultrasonic effect, which affects the formation of microcapsules and can cause adverse reactions due to the fact that ultrasound destructively affects polymers of a protein nature, therefore, the proposed method is applicable when work with polymers of synthetic origin.

In US Pat. 2359662, IPC A61 009/56, A61J 003/07, B01J 013/02, A23L 001/00, published June 27, 2009, Russian Federation, a method for producing microcapsules using spray cooling in a Niro spray cooling tower under the following conditions: air temperature inlet 10 ° C; outlet air temperature 28 ° C; spray drum rotation speed of 10,000 rpm. The microcapsules of the invention have improved stability and provide controlled and / or prolonged release of the active ingredient.

The disadvantages of the proposed method are the duration of the process and the use of special equipment, a set of certain conditions (air temperature at the inlet 10 ° C, air temperature at the outlet 28 ° C, rotation speed of the spray drum 10,000 rpm).

In US Pat. WO / 2009/148058 JP, IPC B01J 13/04, A23L 1/00, A61K 35/20, A61K 45/00, A61K 47/08), A61K 47/26, A61K 47/32, A61K 47/34, A61K 47/36, A61k 9/50, B01J 2/04, B01J 2/06, published December 10, 2009, describes a process for producing microcapsules applicable for industrial production in which a high content of hydrophilic biologically active substance is encapsulated. The proposed microcapsules can be used in food, pharmaceutical and other industries. In the manufacturing process, dispersing compositions are used consisting of hydrophilic biologically active substances and surfactants in solid fat. The temperature is not lower than the melting point of solid fat.

The disadvantages of this method are the complexity and duration of the process of obtaining microcapsules.

In US Pat. WO / 2010/076360 ES, IPC B01J 13/00; A61K 9/14; A61K 9/10; A61K 9/12, published July 8, 2010, proposes a new method for producing solid micro- and nanoparticles with a homogeneous structure with a particle size of less than 10 μm, where the treated solid compounds have a natural crystalline, amorphous, polymorphic and other states associated with the starting compound. The method allows to obtain solid micro- and nanoparticles with substantially spheroidal morphology.

The disadvantage of the proposed method is the complexity of the process, and hence the low yield of the final product.

In US Pat. WO / 2010/014011 NL, IPC A61K 9/50; B01J 13/02; A61K 9/50; B01J 3/02, published February 4, 2010, describes a method for producing microcapsules with a diameter of 0.1 μm to 25 μm, including: a particle core with a diameter of 90 nm to 23 μm containing at least 3% of the active component by weight of the particle; a coating that completely covers the main particles containing at least 20% by weight of a hydrophobic polymer selected from cellulose ethers, cellulose esters, shellac, gluten, polylactide, hydrophobic starch derivatives, polyvinyl acetate, acrylic ester polymers or copolymers and / or methacrylic acid ester and combinations thereof. The active component is not released when introduced into aqueous foods, drinks, food or pharmaceutical compositions. After oral administration, however, the active component is released rapidly.

The disadvantages of this method are the complexity, duration of the process, as well as the use of ultrasound and special equipment, the use of acrylic or methacrylic acid copolymers as microcapsule shells that can cause cancerous tumors.

In US Pat. WO / 2010/119041 EP, IPC A23L 1/00, published October 21, 2010, a method for producing beads containing an active ingredient encapsulated in a gel matrix of a whey protein including denatured protein, serum and active components is proposed. The invention relates to a method for producing beads that contain components such as probiotic bacteria. A method for producing microspheres includes the stage of production of microspheres in accordance with the method of the invention, and the subsequent curing of the microspheres in a solution of an anionic polysaccharide with a pH of 4.6 or lower for at least 10, 30, 60, 90, 120, 180 minutes. Examples of suitable anionic polysaccharides: pectins, alginates, carrageenans. Ideally, whey protein is heat-denaturing, although other denaturation methods are also applicable, such as pressure-induced denaturation. In a preferred embodiment, the whey protein is denatured at a temperature of from 75 ° C to 80 ° C, appropriately for from 30 minutes to 50 minutes. As a rule, whey protein is mixed with heat denaturation. Accordingly, the concentration of whey protein is from 5 to 15%, preferably from 7 to 12%, and ideally from 9 to 11% (weight / volume). As a rule, the suspension of the filtration process is carried out through many filters with a gradual decrease in pore size. Ideally, a fine filter has submicron pore sizes, for example, from 0.1 to 0.9 microns. A preferred method for producing beads is a method using vibratory encapsulators (Inotech, Switzerland) and machines manufactured by Nisco Engineering AG ,. As a rule, nozzles have openings of 100 and 600 microns, and ideally about 150 microns.

The disadvantage of this method is the use of special equipment (vibration encapsulators (Inotech, Switzerland)), the production of microcapsules by protein denaturation, the difficulty of isolating the microcapsules obtained by this method is filtration using multiple filters, which makes the process long.

In US Pat. WO / 2011/003805 EP, IPC B01J 13/18; B65D 83/14; C08G 18/00, published January 13, 2011, describes a method for producing microcapsules that are suitable for use in compositions forming sealants, foams, coatings or adhesives.

The disadvantage of the proposed method is the use of centrifugation to separate from the process fluid, the duration of the process, as well as the use of this method not in the pharmaceutical industry.

In US Pat. according to the application 20110223314, IPC B05D 7/00 20060101 B05D 007/00, B05C 3/02 20060101 B05C 003/02; B05C 11/00 20060101 B05C 011/00; B05D 1/18 20060101 B05D 001/18; B05D 3/02 20060101 B05D 003/02; B05D 3/06 20060101 B05D 003/06 dated 03/10/2011 US, describes a method for producing microcapsules by suspension polymerization, belonging to the group of chemical methods using a new device and ultraviolet radiation.

The disadvantage of this method is the complexity and duration of the process, the use of special equipment, the use of ultraviolet radiation.

In US Pat. WO / 2011/150138 US, IPC C11D 3/37; B01J 13/08; C11D 17/00, published 01.12.2011, describes a method for producing microcapsules of solid water-soluble agents by polymerization.

The disadvantages of this method are the complexity of execution and the duration of the process.

In US Pat. WO / 2011/127030 US, IPC A61K 8/11; B01J 2/00; B01J 13/06; C11D 3/37; C11D 3/39; C11D 17/00, published October 13, 2011, several methods for producing microcapsules are proposed: interfacial polymerization, thermally induced phase separation, spray drying, evaporation of the solvent, etc.

The disadvantages of the proposed methods are the complexity, duration of the processes, as well as the use of special equipment (filter (Albet, Dassel, Germany), a spray dryer for collecting particles (Spray-4M8, Dryer from ProCepT, Belgium)).

In US Pat. WO / 2011/104526 GB, IPC B01J 13/00; B01J 13/14; С09В 67/00; C09D 11/02, published 01.09.2011, a method for producing a dispersion of encapsulated solid particles in a liquid medium is proposed, comprising: a) grinding a composition comprising solid, liquid media and polyurethane dispersants with an acid number from 0.55 to 3.5 mmol per gram dispersant, the composition includes from 5 to 40 parts of a polyurethane dispersant per 100 parts of solid, products, by weight; and b) crosslinking the polyurethane dispersant in the presence of a solid and liquid medium, as for the encapsulation of solid particles, in which the polyurethane dispersant contains less than 10% by weight of repeating elements from polymer alcohols.

The disadvantages of the proposed method are the complexity and duration of the process for producing microcapsules, as well as the fact that the encapsulated particles of the proposed method are useful as dyes in ink, especially inkjet inks, for the pharmaceutical industry this technique is not applicable.

In US Pat. WO / 2011/056935 US, IPC C11D 17/00; A61K 8/11; B01J 13/02; C11D 3/50, published May 12, 2011, describes a method for producing microcapsules with a size of 15 microns or more. Polymers of the group consisting of polyethylene, polyamides, polystyrenes, polyisoprenes, polycarbonates, polyesters, polyacrylates, polyureas, polyurethanes, polyolefins, polysaccharides, epoxies, vinyl polymers and mixtures thereof are proposed as a shell material. The proposed polymer shells are sufficiently impervious to core material and materials in the environment in which the agent is encapsulated; benefits will be used to provide benefits to be obtained. The core of encapsulated agents may include perfumes, silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils, lipids, skin cooling fluids, vitamins, sunscreens, antioxidants, glycerin, catalysts, bleaching particles, particles of silicon dioxide, etc.

The disadvantages of the proposed method are the complexity, duration of the process, the use as shells of microcapsules of polymers of synthetic origin and their mixtures.

In US Pat. WO / 2011/160733 EP, IPC B01J 3/16, published December 29, 2011, describes a method for producing microcapsules that contain shells and cores of water-insoluble materials. An aqueous solution of a protective colloid and a solution of a mixture of at least two structurally different bifunctional diisocyanates (A) and (B) insoluble in water are collected together until an emulsion is formed, then added to a mixture of bifunctional amines and heated to a temperature of at least 60 ° C until microcapsules are formed.

The disadvantages of the proposed method are the complexity, duration of the process, the use as shells of microcapsules of polymers of synthetic origin and their mixtures.

In US Pat. WO / 2011/161229 EP, IPC A61K 8/11; B01J 13/14; B01J 13/16; C11D 3/50, published December 29, 2011, describes a method for producing microcapsules containing a polyurea and perfume shell in oil, where the shell is obtained by the reaction of two structurally different diisocyanates in the form of an emulsion. In the process of obtaining microcapsules, protective colloids are used. During the reaction of isocyanates and amines, a protective colloid must be present. This is preferably polyvinylpyrrolidone (PVP). Protective colloid - a polymer system that in suspension or dispersion prevents adhesion (agglomeration, coagulation, flocculation). This method can be used for perfumes and all kinds of consumer goods. An exhaustive list of consumer goods cannot be listed. Illustrative examples of consumer products include all applications, including liquid detergents, and powder detergents; everything for personal hygiene and hair care, including shampoos, conditioners, comb creams, styling cream, soap, body creams, etc .; deodorants and antiperspirants.

The disadvantages of this method of obtaining microcapsules are the complexity and duration of the process, the use as a shell of microcapsules of diisocyanates, which are obtained as a result of the reaction of two isocyanates.

Pat. WO / 2012/007438 EP, IPC A61K 8/11; A61Q 13/00; B01J 13/16; B01J 13/18, published January 19, 2012, describes a method for producing particles with an average diameter of less than 50 microns, consisting of at least one shell, by the method of stepwise polymerization with the participation of isocyanate monomer. At least one shell is formed by a chain reaction of growth polymerization (preferably free radical polymerization), which is not associated with an isocyanate. The invention also relates to a method for producing such particles in which a shell is formed prior to chain growth of polymerization at a temperature at which a chain reaction of growth is suppressed. The invention also provides fully formulated products, preferably liquids and gels, which contain these particles.

The disadvantages of the proposed method are the complexity and duration of the process, obtaining microcapsules by the chemical method of stepwise polymerization. The particles obtained by this method have a sufficiently large size — 50 μm.

The closest method is the method proposed in US Pat. 2134967 IPC A01N 53/00, A01N 25/28, published 08/27/1999, Russian Federation (1999). A solution of a mixture of natural lipids and a pyrethroid insecticide in a weight ratio of 2-4: 1 in an organic solvent is dispersed in water, which simplifies the microencapsulation method.

The disadvantage of this method is dispersion in an aqueous medium, which makes the proposed method not applicable for the preparation of nanocapsules of water-soluble preparations in water-soluble polymers.

The technical task is to simplify and accelerate the process of obtaining nanocapsules of water-soluble agricultural preparations of kinetin, reduce losses in obtaining nanocapsules (increase in yield by mass).

The solution of the technical problem is achieved by the method of producing kinetin nanocapsules, characterized in that carrageenan is used as the nanocapsule shell, as well as by obtaining the nanocapsules by the physicochemical method of precipitation with a non-solvent using a precipitant benzene.

The result of the proposed method is the preparation of kinetin nanocapsules in carrageenan within 15 minutes. The yield of nanocapsules is more than 90%.

EXAMPLE 1

Obtaining kinetin nanocapsules in the ratio of core: shell 1: 3

To 1.5 g of carrageenan in petroleum ether add 0.01 g of the preparation E472 s (glycerol ester with one or two molecules of food fatty acids and one or two molecules of citric acid, and citric acid, as a tribasic, can be esterified with other glycerides and like oxoacid, other fatty acids. Free acid groups can be neutralized with sodium) as a surfactant). The resulting mixture is placed on a magnetic stirrer and include stirring. 0.5 g of kinetin powder is added in portions to a suspension of carrageenan in petroleum ether. After the formation of an independent solid phase, 5 ml of benzene is added very slowly dropwise. The resulting suspension of nanocapsules is filtered off on a filter, washed with benzene and dried.

Received 2 g of a white powder. The yield was 100%.

EXAMPLE 2

Obtaining kinetin nanocapsules in the ratio of core: shell 1: 1

To 0.5 g of carrageenan in petroleum ether add 0.01 g of the preparation E472 c as a surfactant. The resulting mixture is placed on a magnetic stirrer and include stirring. 0.5 g of kinetin powder is added in portions to a suspension of carrageenan in petroleum ether. After the formation of an independent solid phase, 3 ml of benzene is added very slowly dropwise. The resulting suspension of nanocapsules is filtered off on a filter, washed with benzene and dried.

Received 0.92 g of a white powder. The yield was 92%.

EXAMPLE 3

Preparation of kinetin nanocapsules in a core: shell ratio of 5: 1

To 0.1 g of carrageenan in petroleum ether add 0.01 g of the preparation E472 s as a surfactant. The resulting mixture is placed on a magnetic stirrer and include stirring. 0.5 g of kinetin powder is added in portions to a suspension of carrageenan in petroleum ether. After the formation of an independent solid phase, 3 ml of benzene is added very slowly dropwise. The resulting suspension of nanocapsules is filtered off on a filter, washed with benzene and dried.

Received 0.6 g of a white powder. The yield was 100%.

Claims (1)

A method for producing kinetin nanocapsules, characterized in that glycerol ester with one or two molecules of edible fatty acids and one or two molecules of citric acid is added to carrageenan in petroleum ether, the mixture is stirred, kinetin powder is added, after the formation of an independent solid phase, slowly added dropwise benzene, the resulting suspension of nanocapsules is filtered off, washed with benzene and dried, while the mass ratio of the core: shell in the nanocapsules is 1: 3, or 1: 1, or 5: 1.

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