JP5275561B2 - Water dispersible nanoparticles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide safe nanoparticles comprising a biodegradable polymer, high in storage stability (dispersion stability and the stability of an antioxidant compound included therein) and high in transparency because of being small in particle size. <P>SOLUTION: The water-dispersible nanoparticles are composed of the antioxidant compound and the biodegradable polymer, and preferably also contain a stabilizer for the antioxidant compound. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to water-dispersible nanoparticles. More specifically, the present invention relates to a water-dispersible nanoparticle excellent in dispersion stability and stability of an encapsulated antioxidant compound.

  Fine particle materials are expected to be widely used in biotechnology. In particular, in recent years, the application of nanoparticulate materials produced by the advancement of nanotechnology to foods, cosmetics, pharmaceuticals, etc. has been actively studied, and many research results have been reported.

  For example, in cosmetics, a clearer skin effect has been demanded in recent years. By incorporating various new technologies such as nanotechnology, functionality and usability can be improved and differentiated from other products. Is measured. Skin generally has low drug penetration into the skin due to the presence of the stratum corneum as a barrier. In order to fully exert the skin effect, it is essential to improve the skin permeability of the active ingredient. Moreover, even if it has high effectiveness with respect to the skin, there are many components that are difficult to formulate because of poor storage stability or easy irritation to the skin. In order to solve these problems, various fine particle materials have been developed for the purpose of improving transdermal absorbability, improving storage stability, and reducing skin irritation. Currently, various fine particle materials such as ultra-fine emulsification and liposome have been studied (for example, Non-Patent Document 1).

  Conventionally, an oily component has been added to an aqueous cosmetic, but since the oily component is insoluble or hardly soluble in water, the oily component can be converted into a so-called emulsion by using any emulsifying means. It was common to mix in. Since the emulsion scatters light depending on the particle size, the emulsion and foods and cosmetics to which the emulsion is added may become turbid and may be unfavorable in appearance. The emulsion until the light scattering becomes very small. It has been desired to reduce the particle size of the particles. In addition, the emulsion is generally in a metastable state, the particle size becomes large during storage, and it is a big problem to separate after long-term storage. Adhesion of the oil droplet aggregates in the beverage and neck ring are one of the oil droplet separation phenomena in such an emulsion.

  By the way, carotenoids (also called carotenoids) are oil-soluble natural pigments, and are a general term for pigment components contained in green-yellow vegetables and fruits, and generally have an anti-oxidant effect. Typical examples include beta-carotene, lutein, lycopene, and astaxanthin. is there. For example, astaxanthins (including astaxanthin and esters thereof) are widely distributed in the animal and plant kingdoms in nature, and are mainly used as a color frying agent for farmed fish and chickens. Astaxanthin is known to have an anti-inflammatory action (Patent Document 1), an anti-skin aging action (Patent Document 2), and a whitening action (Non-Patent Document 2) in addition to the antioxidant action. For this reason, the addition to raw materials for foods and cosmetics and processed products thereof has been studied and implemented. However, since it is oil-soluble, it can be added as an emulsified composition with high dispersibility. is necessary. However, carotenoids derived from natural products have an unstable structure, and it has been difficult to stabilize the dispersibility in a high state for a relatively long period of time within a range in which the particle diameter of the emulsified particles can be satisfied.

  Conventionally, not only carotenoids but also the stability of compounds in raw materials such as foods, cosmetics and pharmaceuticals and processed products thereof has been an important industrial issue. These compounds are generally decomposed by causes such as ultraviolet rays, oxygen, enzymes, heat, moisture and light. In particular, there is a problem that antioxidant compounds are oxidatively decomposed before being used in raw materials and processed products thereof. Various means have been attempted to date as a method for stabilizing antioxidant compounds. Patent Documents 3 and 4 describe techniques for examining the dispersion stability of carotenoid pigments.

  As described above, the fine particle materials used in foods and cosmetics are often related to emulsions. In contrast, in recent years, attention has been focused on polymer micelles in pharmaceuticals. Features of polymer micelles include large drug capacity, high water solubility, high structural stability, non-accumulation, and functional separation. Studies have been conducted in which drugs are encapsulated in micelle structures using amphiphilic polymers and administered into blood, and clinical trials have also been conducted (for example, Non-Patent Document 3).

  Since emulsions use electrostatic interactions with surfactants, stability problems such as oil droplet separation are a problem, whereas polymer micelles are structured by covalent bonds and are stable. This is advantageous. Moreover, compared with the synthetic surfactant normally used, if biodegradable polymer, especially natural polymers, such as protein, are used, safety | security is high. Furthermore, if the polymer micelle can be made fine (nanoparticulate), sufficient transparency at the time of water dispersion can be obtained.

Mitsuhiro Nishida, Fragrance Journal, November, 17 (2005) Proceedings of the 19th Academic Conference of the Japan Cosmetic Science Society P.66, 1994 Y. Mizumura et al., Jap. J. Cancer Res., 93, 1237 (2002) JP 2002-308728 A JP 2004-244420 A Japanese Patent Laid-Open No. 9-328419 JP 2005-506841 gazette

  An object of the present invention is to solve the above-described problems of the prior art. That is, the present invention provides nanoparticles comprising a biodegradable polymer that is excellent in storage stability (dispersion stability and stability of the encapsulated antioxidant compound), is safe, and has high transparency due to its small particle size. Providing to provide was a problem to be solved.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that storage stability (dispersion stability and stability of the encapsulated antioxidant compound is improved by mixing the antioxidant compound and the biodegradable polymer. It has been found that water-dispersible nanoparticles with excellent properties can be prepared. The present invention has been completed based on these findings.

  That is, according to the present invention, there are provided water-dispersible nanoparticles composed of an antioxidant compound and a biodegradable polymer.

Preferably, the nanoparticles of the present invention further comprise an antioxidant compound stabilizer.
Preferably, the nanoparticle of the present invention contains 0.1 to 100% by weight of an antioxidant compound based on the weight of the biodegradable polymer.
Preferably, the average particle size is 10 to 1000 nm.

Preferably, the biodegradable polymer is a protein.
Preferably, the protein is at least one selected from the group consisting of collagen, gelatin, acid-treated gelatin, albumin, ovalbumin, ovalbumin, casein, transferrin, globulin, fibroin, fibrin, laminin, fibronectin, or vitronectin.

Preferably, the protein is cross-linked during and / or after nanoparticle formation.
Preferably, a crosslinking treatment is performed using transglutaminase.

Preferably, the antioxidant compound is an oil soluble component.
Preferably, the oil-soluble component is a cosmetic component, functional food component, or pharmaceutical component that is insoluble or sparingly soluble in water.
Preferably, the oil-soluble component includes one or more carotenoids.
Preferably, the carotenoid is astaxanthin.

According to another aspect of the present invention, casein nanoparticles produced by the following steps (a) to (c) are provided.
(A) dissolving casein in a basic aqueous medium having a pH of 8 or higher;
(B) a step of adding at least one antioxidant compound to the solution obtained in step (a); and (c) a step of injecting the solution obtained in step (b) into an acidic aqueous medium having a pH of 3.5 to 7.5. :

According to still another aspect of the present invention, casein nanoparticles produced by the following steps (a) to (c) are provided.
(A) dissolving casein in a basic aqueous medium having a pH of 8 or higher;
(B) adding at least one antioxidant compound to the solution obtained in step (a); and (c) lowering the pH of the solution obtained in step (b) to pH 3.5-7.5:

According to still another aspect of the present invention, a drug delivery agent comprising the above-described nanoparticles of the present invention is provided.
Preferably, the drug delivery agent of the present invention is used as a transdermally absorbable agent, topical therapeutic agent, oral therapeutic agent, intradermal injection, subcutaneous injection, intramuscular injection, intravenous injection, cosmetics, functional food, or supplement. The

  The water-dispersible nanoparticle of the present invention is a nanoparticle composed of a biodegradable polymer such as protein, and has higher structural stability than an emulsion. Moreover, since the water-dispersible nanoparticle of this invention can be manufactured without using a chemical crosslinking agent or a synthetic surfactant, its safety is high. Furthermore, the water-dispersible nanoparticles of the present invention can stably contain an antioxidant compound.

Hereinafter, embodiments of the present invention will be described more specifically.
The water-dispersible nanoparticles of the present invention are characterized by comprising an antioxidant compound and a biodegradable polymer.

  The antioxidant compound used in the present invention is preferably an oil-soluble component. Specific examples of antioxidant compounds that can be used in the present invention include vitamin A, retinoic acid, retinol, acetic acid retinol, retinol palmitate, retinyl acetate, retinyl palmitate, tocopheryl retinoic acid, vitamin C and its derivatives, Examples include kinetin, β-carotene, astaxanthin, lutein, lycopene, tretinoin, vitamin E, α-lipoic acid, coenzyme Q10, polyphenol, SOD, and phytic acid. The nanoparticles of the present invention preferably contain 0.1 to 100% by weight of an antioxidant compound based on the weight of the biodegradable polymer. In the present invention, the antioxidant compound can be selected from cosmetic ingredients, functional food ingredients, or pharmaceutical ingredients that are insoluble or sparingly soluble in water. The antioxidant compound used in the present invention may be used alone or in combination of two or more.

  In the present invention, the antioxidant compound may be added when the biodegradable polymer nanoparticles are formed, or may be added after the nanoparticles are formed.

  The nanoparticles of the present invention may further contain an antioxidant compound stabilizer. Specific examples of stabilizers for antioxidant compounds include tocopherol, ascorbic acid, kinetin, α-lipoic acid, coenzyme Q10, polyphenol, SOD, phytic acid, nordihydroguaiaretic acid (NDGA), 2,6-di An antioxidant such as -t-butyl-4-methylphenol (BHT) and t-butylhydroxyanisole (BHA) can be mentioned. Antioxidant compound stabilizers may be used alone or in combination of two or more.

  The average particle size of the nanoparticles of the present invention is usually 1 to 1000 nm, preferably 10 to 1000 nm, more preferably 30 to 500 nm, and particularly preferably 50 to 400 nm.

  The biodegradable polymer used in the present invention may be a protein or a biodegradable synthetic polymer.

  The type of protein used in the present invention is not particularly limited, but a protein having a lysine residue and a glutamine residue is preferable, and a protein having a molecular weight of about 10,000 to 1,000,000 is preferably used. The origin of the protein is not particularly limited, but it is preferable to use a human-derived protein. Specific examples are listed as proteins, but the present invention is not limited to these compounds. At least one selected from the group consisting of collagen, gelatin, acid-treated gelatin, albumin, ovalbumin, casein, transferrin, globulin, fibroin, fibrin, laminin, fibronectin, or vitronectin can be used. In addition, the origin of the protein is not particularly limited, and any of cows, pigs, fish, and gene recombinants can be used. As the genetically modified gelatin, for example, those described in EU1014176A2 and US Pat. No. 6,992,172 can be used, but are not limited thereto. Among them, casein, acid-treated gelatin, collagen, or albumin is preferable, and casein or acid-treated gelatin is most preferable. When casein is used in the present invention, the origin of casein is not particularly limited, and may be derived from milk or bean, α-casein, β-casein, γ-casein, κ-casein and theirs. Mixtures can be used. Casein can be used alone or in combination of two or more.

  The proteins used in the present invention may be used alone or in combination of two or more. Examples of the biodegradable synthetic polymer include polylactic acid and lactic acid / glycolic acid copolymer (PLGA).

  In the present invention, the protein can be crosslinked during and / or after the formation of the nanoparticles. The above crosslinking treatment can be performed using an enzyme. The enzyme used for the cross-linking treatment is not particularly limited as long as the cross-linking action of protein is known, and transglutaminase is preferable among them.

  Transglutaminase may be derived from a mammal or a microorganism, and a genetic recombinant can be used. Specifically, Activa series manufactured by Ajinomoto Co., Inc., transglutaminases derived from mammals that have been released as reagents, for example, guinea pig liver-derived trans from Oriental Yeast Co., Ltd., Upstate USA Inc., Biodesign International, etc. Examples include glutaminase, goat-derived transglutaminase, rabbit-derived transglutaminase, and human-derived recombinant transglutaminase.

  The amount of the enzyme used for the crosslinking treatment in the present invention can be appropriately set according to the type of protein, but is typically about 0.1 to 100% by weight based on the weight of the protein. It can be added, and preferably about 1 to 50% by weight can be added.

  The time for the cross-linking reaction by the enzyme can be appropriately set according to the kind of protein and the size of the nanoparticle, but it can be reacted normally for 1 hour to 72 hours, preferably 2 hours to 24 hours. Can react.

  The temperature of the cross-linking reaction by the enzyme can be appropriately set according to the type of protein and the size of the nanoparticle, but it can be reacted normally at 0 to 80 ° C., preferably 25 to 60 ° C. Can react at ℃.

  The enzyme used for this invention can be used individually or in combination of 2 or more types.

  The nanoparticles of the present invention should be prepared according to the method described in Japanese Patent Application Laid-Open No. 6-79168 or by C. Coester, Journal Microcapsulation, 2000, Vol. 17, p. 187-193. However, it is preferable to use an enzyme instead of glutaraldehyde as a crosslinking method.

  Moreover, in this invention, it is preferable to perform an enzyme crosslinking process in an organic solvent. The organic solvent used here is preferably a water-soluble organic solvent such as ethanol, isopropanol, acetone, or THF.

  One or more components selected from phospholipids, anionic polysaccharides, cationic polysaccharides, anionic proteins, or cationic proteins can be added to the water-dispersible nanoparticles of the present invention.

  Specific examples are listed as phospholipids that can be used in the present invention, but the present invention is not limited to these compounds. Examples include phosphatidylcholine (lecithin), phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, sphingomyelin and the like.

  The anionic polysaccharide that can be used in the present invention is a polysaccharide having an acidic polar group such as a carboxyl group, a sulfate group, or a phosphate group. Specific examples are listed below, but the present invention is not limited to these compounds. Examples thereof include chondroitin sulfate, dextran sulfate, carboxymethyl cellulose, carboxymethyl dextran, alginic acid, pectin, carrageenan, fucoidan, agaropectin, porphyran, caraya gum, gellan gum, xanthan gum, and hyaluronic acid.

  The cationic polysaccharide that can be used in the present invention is a polysaccharide having a basic polar group such as an amino group. Specific examples are listed below, but the present invention is not limited to these compounds. Examples thereof include glucosamine such as chitin and chitosan and galactosamine as a constituent monosaccharide.

  Anionic proteins that can be used in the present invention are proteins and lipoproteins whose isoelectric point is more basic than physiological pH. Specific examples are listed, but the present invention is not limited to these compounds. Examples include polyglutamic acid, polyaspartic acid, lysozyme, cytochrome C, ribonuclease, trypsinogen, chymotrypsinogen, α-chymotrypsin and the like.

  The cationic proteins used in the present invention are proteins and lipoproteins whose isoelectric point is on the acidic side of physiological pH. Specific examples are listed, but the present invention is not limited to these compounds. Examples include polylysine, polyarginine, histone, protamine, and ovalbumin.

According to the present invention, casein nanoparticles produced by the following steps (a) to (c) are provided.
(A) dissolving casein in a basic aqueous medium having a pH of 8 or higher;
(B) a step of adding at least one antioxidant compound to the solution obtained in step (a); and (c) a step of injecting the solution obtained in step (b) into an acidic aqueous medium having a pH of 3.5 to 7.5. :

Furthermore, according to this invention, the casein nanoparticle produced by the following process (a) to (c) is provided.
(A) dissolving casein in a basic aqueous medium having a pH of 8 or higher;
(B) adding at least one antioxidant compound to the solution obtained in step (a); and (c) lowering the pH of the solution obtained in step (b) to pH 3.5-7.5:

  In the present invention, casein nanoparticles of a desired size can be produced by making the casein basic conditions, breaking the micelle structure, dissolving in water, and insolubilizing again while forming the nanoparticles. Further, the active substance can be encapsulated in the casein nanoparticles by utilizing the interaction between the hydrophobic active substance and the casein hydrophobic portion. Furthermore, it was found that these particles exist stably in an aqueous solution.

  The method for producing casein nanoparticles of the present invention includes a method of dissolving casein in a basic aqueous medium solution and injecting the casein into a basic aqueous medium solution, and dissolving casein in a basic aqueous medium solution and stirring the pH. A method of lowering is mentioned.

  As a method of dissolving casein in a basic aqueous medium liquid and injecting it into the basic aqueous medium, it is convenient and preferable to use a syringe. However, as long as the method satisfies the injection speed, solubility, temperature, and stirring state, it is particularly preferable. Not limited. In general, the injection rate can be from 1 mL / min to 100 mL / min. The temperature of the basic aqueous medium can be appropriately set, but can be normally 0 ° C. to 80 ° C., and preferably 25 ° C. to 70 ° C. Although the temperature of an aqueous medium can be set suitably, it can be normally 0 to 80 degreeC, Preferably it can be 25 to 60 degreeC. The stirring speed can be set as appropriate, but it can be normally set to 100 rpm to 3000 rpm, and preferably 200 rpm to 2000 rpm.

  As a method of lowering the pH while dissolving casein in a basic aqueous medium solution and stirring, it is simple and preferable to add an acid, but it is particularly limited as long as the method satisfies the solubility, temperature, and stirring state. do not do. The temperature of the basic aqueous medium can be appropriately set, but can be normally 0 ° C. to 80 ° C., and preferably 25 ° C. to 70 ° C. The stirring speed can be set as appropriate, but it can be normally set to 100 rpm to 3000 rpm, and preferably 200 rpm to 2000 rpm.

  As the aqueous medium used in the present invention, an organic acid or base, an aqueous solution of an inorganic acid or inorganic base, or a buffer solution can be used.

  Specifically, citric acid, ascorbic acid, gluconic acid, carboxylic acid, tartaric acid, succinic acid, acetic acid or phthalic acid, trifluoroacetic acid, morpholinoethanesulfonic acid, 2- [4- (2-hydroxyethyl) -1- Piperazinyl] organic acids such as ethanesulfonic acid; organic bases such as tris (hydroxymethyl), aminomethane, ammonia; inorganic acids such as hydrochloric acid, perchloric acid, carbonic acid; sodium phosphate, potassium phosphate, calcium hydroxide, Although the aqueous solution using inorganic bases, such as sodium hydroxide, potassium hydroxide, and magnesium hydroxide, is mentioned, It is not limited to these.

  The concentration of the aqueous medium used in the present invention is preferably about 10 mM to about 1M. More preferably, it is about 20 mM to about 200 mM.

  The pH of the basic aqueous medium used in the present invention is preferably 8 or more, and preferably 8 to 12. More preferably, the pH is 10-12. Casein does not dissolve at a pH lower than pH 8, but if the pH is too high, there is a concern about hydrolysis or a handling risk, so the above range is preferable.

  In the present invention, the temperature at which casein is dissolved in a basic aqueous medium having a pH of 8 or higher is preferably from 0 to 80 ° C, more preferably from 10 to 60 ° C. More preferably, it is 20-40 degreeC.

  The pH of the acidic aqueous medium used in the present invention is preferably 3.5 to 7.5. More preferably, the pH is 4-6. Outside the above range, the particles are dissolved at a pH higher than 7.5, and the particle size tends to be larger at 3 or less.

  The nanoparticles of the present invention contain an antioxidant compound. When the antioxidant compound is an active ingredient, the nanoparticles of the present invention containing such an active ingredient can be administered to a disease site. That is, the nanoparticle of the present invention is useful as a drug delivery agent.

  Preferable methods for administering the nanoparticles of the present invention include transcutaneous / transmucosal absorption and injection into blood vessels / intracavities / lymph. More preferred is transdermal and transmucosal absorption.

  In the present invention, use of the drug delivery agent is not particularly limited, but transdermal absorption agent, topical therapeutic agent, oral therapeutic agent, intradermal injection, subcutaneous injection, intramuscular injection, intravenous injection, cosmetics, function Sex foods or supplements are listed.

  In the present invention, the drug delivery agent can include additives. Although it does not specifically limit as an additive, A moisturizer, a softener, a transdermal absorption promoter, a soothing agent, an antiseptic | preservative, a coloring agent, a thickener, a fragrance | flavor, or a pH adjuster etc. are mentioned.

  Specific examples are listed as humectants that can be used in the present invention, but the present invention is not limited to these compounds. Kantene, Diglycerin, Distearyldimonium hectorite, Butylene glycol, Polyethylene glycol, Propylene glycol, Hexylene glycol, Yokuinin extract, Vaseline, Urea, Hyaluronic acid, Ceramide, Lipidure, Isoflavone, Amino acid, Collagen, Mucopolysaccharide, Fucodyne, Lactoferrin, sorbitol, chitin / chitosan, malic acid, glucuronic acid, placenta extract, seaweed extract, button pi extract, achacha extract, hypericum extract, coleus extract, masaki extract, koka extract, maikai flower extract, chorei extract, hawthorn extract, rose Marie extract, Duke extract, chamomile extract, nettle extract, litchi extract, yarrow extract, aloe extract, maroni extract Asunaroekizu, Fucus extract, Osmo-in extract, oat extract, tuberosa polysaccharide, Cordyceps extract, barley extract, orange extract, Rehmannia glutinosa, pepper extract, such as Yokuininekisu and the like.

  Specific examples are listed as softening agents that can be used in the present invention, but the present invention is not limited to these compounds. Glycerin, mineral oil, emollient ingredients (for example, isopropyl isostearate, polyglyceryl isostearate, isotridecyl isononanoate, octyl isononanoate, oleic acid, glyceryl oleate, cocoa butter, cholesterol, mixed fatty acid triglycerides, dioctyl succinate, sucrose acetate stearate , Cyclopentasiloxane, sucrose distearate, octyl palmitate, octyl hydroxystearate, aralkyl behenate, sucrose polybehenate, polymethylsilsesquioxane, myristyl alcohol, cetyl myristate, myristyl myristate, hexyl laurate) Can be mentioned.

  Specific examples are listed as transdermal absorption enhancers that can be used in the present invention, but the present invention is not limited to these compounds. Ethanol, isopropyl myristate, citric acid, squalane, oleic acid, menthol, N-methyl-2-pyrrolidone, diethyl adipate, diisopropyl adipate, diethyl sebacate, diisopropyl sebacate, isopropyl palmitate, isopropyl oleate, oleic acid Examples include octyldodecyl, isostearyl alcohol, 2-octyldodecanol, urea, vegetable oil, and animal oil.

  Specific examples are listed as soothing agents that can be used in the present invention, but the present invention is not limited to these compounds. Examples include benzyl alcohol, procaine hydrochloride, xylocaine hydrochloride, and chlorobutanol.

  Specific examples are listed as preservatives that can be used in the present invention, but the present invention is not limited to these compounds. Benzoic acid, sodium benzoate, paraben, ethyl paraben, methyl paraben, propyl paraben, butyl paraben, potassium sorbate, sodium sorbate, sorbic acid, sodium dehydroacetate, hydrogen peroxide, formic acid, ethyl formate, sodium dichlorite, Examples include propionic acid, sodium propionate, calcium propionate, pectin degradation products, polylysine, phenol, isopropylmethylphenol, orthophenylphenol, phenoxyethanol, resorcin, thymol, thiram, and tea tree oil.

  Specific examples are listed as coloring agents that can be used in the present invention, but the present invention is not limited to these compounds. Examples include krill pigment, orange pigment, cacao pigment, kaolin, carmine, gunjo, cochineal pigment, chromium oxide, iron oxide, titanium dioxide, tar pigment, chlorophyll and the like.

  Specific examples are listed as thickeners that can be used in the present invention, but the present invention is not limited to these compounds. Quince seed, carrageenan, gum arabic, caraya gum, xanthan gum, gellan gum, tamarind gum, locust bean gum, tragacanth gum, pectin, starch, cyclodextrin, methylcellulose, ethylcellulose, carboxymethylcellulose, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, Examples include sodium polyacrylate.

  Specific examples are listed as perfumes that can be used in the present invention, but the present invention is not limited to these compounds. Musk, Acacia Oil, Anise Oil, Ylang Ylang Oil, Cinnamon Oil, Jasmine Oil, Sweet Orange Oil, Spearmint Oil, Geranium Oil, Thyme Oil, Neroli Oil, Meat Oil, Cypress Oil, Fennel Oil, Peppermint Oil, Bergamot Oil, Lime And oil, lavender oil, lemon oil, lemongrass oil, rose oil, rosewood oil, anisaldehyde, geraniol, citral, cybeton, muscone, limonene, vanillin and the like.

  Specific examples of the pH adjusting agent that can be used in the present invention are listed, but the present invention is not limited to these compounds. Examples include sodium citrate, sodium acetate, sodium hydroxide, potassium hydroxide, phosphoric acid, and succinic acid.

The dosage of the nanoparticles of the present invention can be appropriately set according to the type and amount of the active ingredient, the weight of the patient, the state of the disease, etc., but in general, 10 μg to About 100 mg / kg can be administered, and preferably about 20 μg to 50 mg / kg can be administered. When used transdermally or transmucosally, about 1 μg to 50 mg / cm ² can be administered, and preferably about 2.5 μg to 10 mg / cm ² can be administered.
The following examples further illustrate the present invention, but the scope of the present invention is not limited to these examples.

Example 1:
15 mg of casein (milk-derived, Wako Pure Chemical Industries, Ltd.) is dissolved in 1.5 mL of pH 9 phosphate buffer. 9 mg of astaxanthin (manufactured by Wako Pure Chemical Industries) is dissolved in 1 mL of ethanol. After mixing these two solutions and evaporating ethanol, 1 mL was injected into 10 mL of pH 5 phosphate buffer water using a microsyringe under the external stirring conditions of 40 ° C. and 800 rpm. Particles were obtained. The average particle size of the above particles was 274 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation.

Example 2:
15 mg of casein (milk-derived, Wako Pure Chemical Industries, Ltd.) is dissolved in 1.5 mL of pH 9 phosphate buffer. 9 mg of astaxanthin (manufactured by Wako Pure Chemical Industries) and 2.75 mg of tocopherol are dissolved in 1 mL of ethanol. After mixing these two solutions and evaporating ethanol, 1 mL was injected into 10 mL of pH 5 phosphate buffer water using a microsyringe under the external stirring conditions of 40 ° C. and 800 rpm. Particles were obtained. The average particle diameter of the above particles was 293 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation.

Example 3:
15 mg of casein (milk-derived, Wako Pure Chemical Industries, Ltd.) is dissolved in 1.5 mL of pH 9 phosphate buffer. 9 mg of astaxanthin (manufactured by Wako Pure Chemical Industries) and 2.75 mg of tocopherol are dissolved in 1 mL of ethanol. After mixing these two solutions and evaporating ethanol, 1 mL was injected into 10 mL of pH 5 phosphate buffer water using a microsyringe under the external stirring conditions of 40 ° C. and 800 rpm. Particles were obtained. The average particle diameter of the above particles was 293 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation. 100 mg of ascorbic acid was added to this dispersion.

Example 4:
PLGA (milk-derived Wako Pure Chemical) 15 mg, astaxanthin (Wako Pure Chemical) 9 mg and tocopherol 1.8 mg are dissolved in acetone 1.5 mL. When 1 mL of this solution was injected into 10 mL of water using a microsyringe under the external stirring conditions of 40 ° C. and 800 rpm, PLGA nanoparticles were obtained. The average particle size of the above particles was 52 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation. Acetone was evaporated using a rotary evaporator, and then water was added so that the liquid volume became 11 mL. 100 mg of ascorbic acid was added to this dispersion. The average particle size of the above particles was 52 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation.

Example 5;
15 mg of acid-treated gelatin (milk-derived, manufactured by Wako Pure Chemical Industries) and 7.5 mg of transglutaminase preparation (Activa TG-S, manufactured by Ajinomoto Co., Inc.) are dissolved in 1.5 mL of water. When this solution was mixed and 1 mL was injected into 10 mL of ethanol using a microsyringe under the external stirring conditions of 40 ° C. and 800 rpm, gelatin nanoparticles were obtained. The obtained dispersion was allowed to stand at an external temperature of 55 ° C. for 5 hours to obtain crosslinked gelatin nanoparticles. The average particle size of the particles was 76 nm as measured using a light scattering photometer (DLS-7000, manufactured by Otsuka Electronics Co., Ltd.). 6 mg of astaxanthin (manufactured by Wako Pure Chemical Industries, Ltd.) and 1.8 mg of tocopherol were dissolved in the above dispersion, 5 mL of water was added, and ethanol was evaporated using a rotary evaporator. Water was added so that the liquid volume was 11 mL. 100 mg of ascorbic acid was added to this dispersion. The average particle size of the above particles was 359 nm as measured using a light scattering photometer and a Microtrack manufactured by Nikiso Corporation.

Example 6:
The casein nanoparticles prepared in Examples 1, 2, and 3 were allowed to stand in a high-temperature bath at 50 ° C., and a 10-day stability test was performed. As Comparative Example 1, an astaxanthin olive oil emulsion was used. The amount of astaxanthin was calculated from the absorption spectrum (Abs. 500 nm) (FIG. 1).

  Comparison with olive oil emulsion shows that the casein nanoparticles are more stable. Furthermore, the combination with an antioxidant (antioxidant compound stabilizer) showed higher stability than commercially available emulsions.

Example 7:
The nanoparticles encapsulating astaxanthin prepared in Examples 3, 4, and 5 were left in a high-temperature bath at 50 ° C., and a 7-day stability test was performed. The amount of astaxanthin was calculated from the absorption spectrum (Abs. 500 nm). The results are shown in FIG.

  As can be seen from the results in FIG. 2, when casein, gelatin, and PLGA were compared, the residual ratio was 80% or more in any system, and the stability of the antioxidant compound was improved.

FIG. 1 shows the results of the thermal stability test of astaxanthin in the nanoparticles of Examples 1 to 3 and the emulsion of the comparative example. FIG. 2 shows the results of a thermal stability test of astaxanthin on the nanoparticles of Examples 3 to 5.

Claims (3)

A water-dispersible nanoparticle composed of astaxanthin and a lactic acid / glycolic acid copolymer (PLGA) , further comprising tocopherol . The nanoparticle according to claim 1, comprising 0.1 to 100% by weight of astaxanthin relative to the weight of lactic acid / glycolic acid copolymer (PLGA). The nanoparticle according to claim 1 or 2 , wherein the average particle size is 10 to 1000 nm.