JP2018052922A - Plga microparticles, plga microparticle production method, and plga microparticle production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide PLGA microparticles suitable for filtration sterilization.SOLUTION: A PLGA microparticle contains lactic acid-glycolic acid copolymer (PLGA), in which relative Span Factor (R. S. F.) satisfies a formula (1) and an average volume-based particle diameter is 80 nm or less. 0<(R. S. F.)≤1.20...formula (1) [(R. S. F.) is defined by (D90-D10)/D50, D90 represents a cumulative 90 volume% from the small particle side of the cumulative particle size distribution, D50 represents a cumulative 50 volume% from the small particle side of the cumulative particle size distribution, D10 represents a cumulative 10 volume% from the small particle side of the cumulative particle size distribution.]SELECTED DRAWING: Figure 6

Description

  The present invention relates to PLGA fine particles, a method for producing PLGA fine particles, and an apparatus for producing PLGA fine particles.

  In recent years, research on drug delivery systems has been actively conducted as a technique for efficiently and safely administering medicinal ingredients to diseased sites. Among them, the drug-encapsulated nanoparticles can pass through fine pores such as capillaries by adjusting the size to several tens nm to several hundreds nm. Therefore, the demand for these nanoparticles is increasing.

  As a material suitable for the nanoparticles, a material having high biocompatibility and capable of eluting the contained drug in a sustained release manner is preferable. As such a material, for example, a lactic acid polymer (PLA) or a lactic acid / glycolic acid copolymer (PLGA) is used (for example, see Patent Documents 1 and 2). Among them, since the PLGA can store the encapsulated drug for a long period of time, many studies have been conducted.

  As a method for producing drug-encapsulated PLGA fine particles, a production method using an underwater emulsion solvent diffusion method (EDS method) is known (see, for example, Patent Documents 1 and 2). The EDS method is a method of obtaining nanoparticles by dissolving an organic polymer in an organic solvent which is a good solvent and then diffusing it in a poor solvent such as water.

In addition, when the nanoparticles are used for medical purposes, sterilization treatment by heating, radiation irradiation, filtration or the like is essential. With regard to the PLGA particles, the glass transition point is as low as 30 ° C. to 50 ° C., melting by heating occurs, and sterilization by heating is unsuitable. Also, radiation irradiation is unsuitable because it may alter the properties of the nanoparticles. Therefore, when PLGA fine particles are used for medical purposes, filtration sterilization is preferably selected as the sterilization treatment.
Therefore, PLGA fine particles suitable for filtration sterilization are demanded.

  An object of the present invention is to provide PLGA fine particles suitable for filtration sterilization.

The PLGA fine particles of the present invention are
Contains lactic acid / glycolic acid copolymer (PLGA),
Relative Span Factor (RSF) satisfies the following formula (1),
The average volume reference particle diameter is 80 nm or less.
0 <(R.S.F) ≦ 1.20 ..Formula (1)
Here, (RSF) is defined by (D90-D10) / D50.
D90 represents the cumulative 90 volume% from the small particle side of the cumulative particle size distribution, D50 represents the cumulative 50 volume% from the small particle side of the cumulative particle size distribution, and D10 represents from the small particle side of the cumulative particle size distribution. Cumulative 10 volume% is represented.

  According to the present invention, PLGA fine particles suitable for filter sterilization can be provided.

FIG. 1 is a cross-sectional view showing an example of a liquid column resonance droplet discharge means. FIG. 2 is a schematic view of an example of an apparatus for producing PLGA fine particles. FIG. 3 is a schematic diagram of an example of an apparatus for producing PLGA fine particles. FIG. 4A is a schematic diagram of another example of an apparatus for producing PLGA fine particles. 4B is an enlarged view of the vicinity of the solution discharge means of the PLGA fine particle manufacturing apparatus of FIG. 4A. FIG. 5 is a schematic diagram of another example of a PLGA fine particle production apparatus. FIG. 6 is a graph showing the particle size distribution of the particles produced in Example 1.

(PLGA fine particles)
The PLGA fine particles of the present invention contain at least a lactic acid / glycolic acid copolymer (PLGA), preferably contain a physiologically active substance, and further contain other components such as a dispersant and an additive as necessary. .

  In the PLGA fine particles, for example, other components such as a physiologically active substance are dispersed in a lactic acid / glycolic acid copolymer (PLGA) matrix.

The present inventors have intensively studied to provide PLGA fine particles suitable for filtration sterilization.
The filtration sterilization is a method of removing bacteria such as microorganisms present in the sterilized material by filtration, and a membrane filter having a diameter of 0.2 μm is usually used. Therefore, PLGA nanoparticles having a particle diameter of more than 200 nm cannot sufficiently pass through a filter for filtration sterilization.
Therefore, some PLGA particles produced in Japanese Patent No. 4856752 and Japanese Patent Application Laid-Open No. 2006-131577 have an average particle diameter of 200 nm or less.
However, it is necessary to use a membrane filter having a diameter of 0.1 μm in order to remove bacteria having a plastic shape such as mycoplasma or smaller bacteria. In this case, the present inventors have found that the size of the PLGA nanoparticles need not be 100 nm or less, and the particle size distribution is also important. The present inventors have found that when the particle size distribution is wide, large particles that do not pass through the filter increase and the sterilization rate decreases.
As a result of repeated studies, the present inventors have found a particle size distribution capable of performing sufficient filtration sterilization, and have completed the present invention.

<Characteristics of PLGA fine particles>
<< Average volume-based particle diameter >>
The average volume reference particle diameter of the PLGA fine particles is 80 nm or less, preferably 10 nm or more and 50 nm or less, more preferably 10 nm or more and 40 nm or less, and particularly preferably 10 nm or more and 30 nm or less.

The average volume-based particle diameter of the PLGA fine particles can be measured using a concentrated analyzer (“FPAR-1000”, manufactured by Otsuka Electronics Co., Ltd.) by a dynamic light scattering method.
In the present invention, the average volume reference particle diameter of the PLGA fine particles is 80 nm or less. When the average volume reference particle diameter exceeds 80 nm, it becomes easy to clog when applied to a filter sterilization filter. Further, when targeting cancer or the like, the average volume reference particle diameter is more preferably 10 nm or more and 30 nm or less.

<< Relative Span Factor (RSF) >>
In the PLGA fine particles, a relative span factor (RSF) satisfies the following formula (1).
0 <(R.S.F) ≦ 1.20 ..Formula (1)
Here, (RSF) is defined by (D90-D10) / D50.
D90 represents the cumulative 90 volume% from the small particle side of the cumulative particle size distribution, D50 represents the cumulative 50 volume% from the small particle side of the cumulative particle size distribution, and D10 represents from the small particle side of the cumulative particle size distribution. Cumulative 10 volume% is represented.
When (R.S.F) is greater than 1.20, large particles that do not pass through the filter increase and the sterilization rate decreases.

  (R. S. F) can be measured using a dense analyzer ("FPAR-1000", manufactured by Otsuka Electronics Co., Ltd.) by a dynamic light scattering method.

<Lactic acid / glycolic acid copolymer (PLGA)>
The lactic acid / glycolic acid copolymer (PLGA) is a copolymer having a structural unit derived from lactic acid and a structural unit derived from glycolic acid.
Hereinafter, the “lactic acid / glycolic acid copolymer” may be referred to as “PLGA”.

  The weight average molecular weight of the lactic acid / glycolic acid copolymer (PLGA) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 2,000 to 250,000, and 2,000 to 100. Is more preferable, 3,000 to 50,000 is more preferable, and 5,000 to 10,000 is particularly preferable.

  The molar ratio (L: G) of the structural unit (L) derived from lactic acid and the structural unit (G) derived from glycolic acid in the lactic acid / glycolic acid copolymer (PLGA) is not particularly limited. The ratio can be appropriately selected according to the purpose, but is preferably 1:99 to 99: 1, more preferably 25:75 to 99: 1, still more preferably 30:70 to 90:10, and 50:50 to 85. : 15 is particularly preferable.

The lactic acid / glycolic acid copolymer (PLGA) can be produced, for example, by heating lactic acid and glycolic acid under a weak reduced pressure using an ion exchange resin as a catalyst for condensation polymerization.
In the production of the lactic acid / glycolic acid copolymer (PLGA), lactide may be used instead of lactic acid.

  The lactic acid / glycolic acid copolymer (PLGA) may be a commercially available product. The said commercial item can be purchased from Wako Pure Chemical Industries, Ltd. or Taki Chemical Co., Ltd., for example.

  There is no restriction | limiting in particular as content of the said lactic acid-glycolic acid copolymer (PLGA) in the said PLGA microparticles | fine-particles, Although it can select suitably according to the objective, 1 mass% or more is preferable and 1 mass% or more 100 More preferably, it is 10 mass% or more, 99 mass% or less, More preferably, 30 mass% or more and 95 mass% or less, More preferably, 50 mass% or more and 90 mass% or less are especially preferable.

<Bioactive substances>
There is no restriction | limiting in particular as said physiologically active substance, According to the objective, it can select suitably, For example, a pharmaceutical compound, a functional food compound, a functional cosmetic compound etc. are mentioned.
The PLGA fine particles containing the pharmaceutical compound can be suitably used, for example, in medicine.
The PLGA fine particles containing the functional food compound can be suitably used for food, for example.
The PLGA fine particles containing the functional cosmetic compound can be suitably used for cosmetics, for example.

<< medicine >>
The said medicine contains the said pharmaceutical compound, and also contains other components, such as a dispersing agent and an additive, as needed.

There is no restriction | limiting in particular as said pharmaceutical, According to the objective, it can select suitably, For example, a tablet, a capsule, a suppository, other solid dosage forms etc .; Aerosol for intranasal thru | or pulmonary administration, etc .; Examples thereof include liquid preparations such as injection preparations, intraocular preparations, otic preparations, and oral preparations.
In addition, the PLGA fine particles can be produced as functional fine particles or pharmaceutical compositions imparted with functionality by containing, for example, a dispersant, an additive and the like.

  The functional fine particles are not particularly limited and may be appropriately selected depending on the purpose. For example, immediate-release fine particles, sustained-release fine particles, pH-dependent release fine particles, pH-independent release fine particles, enteric properties Examples thereof include coating fine particles, controlled release coating fine particles, and nanocrystal-containing fine particles. These may be used individually by 1 type and may use 2 or more types together.

The pharmaceutical composition is not particularly limited and may be appropriately selected depending on the intended purpose. For example, large intestine delivery preparation, lipid microsphere preparation, dry emulsion preparation, self-emulsifying preparation, dry syrup, powder for nasal administration Preparations, powder preparations for pulmonary administration, wax matrix preparations, hydrogel preparations, polymer micelle preparations, mucoadhesive preparations, gastric suspension preparations, liposome preparations, solid dispersion preparations, and the like. These may be used individually by 1 type and may use 2 or more types together.
The drug may be a pharmaceutical composition or a drug substance.

<< Pharmaceutical compounds >>
The pharmaceutical compound used for the medicine is not particularly limited as long as it achieves the form of the functional fine particles or the pharmaceutical composition, and can be appropriately selected according to the purpose, such as a poorly water-soluble compound. Is mentioned.
The poorly water-soluble compound means a compound having a water / octanol partition coefficient log P value of 3 or more. The water / octanol partition coefficient can be measured in accordance with JIS Z 7260-107 (2000) flask shaking method.
In addition, the pharmaceutical compound includes any form such as a salt and a hydrate as long as it is effective as a medicine.

  The poorly water-soluble compound is not particularly limited and may be appropriately selected depending on the intended purpose. , Chloramphenicol, indomethacin, nimodipine, dihydroergotoxin, cortisone, dexamethasone, naproxen, tulbuterol, beclomethasone propionate, fluticasone propionate, pranlukast, tranilast, loratidine, tacrolimus, amprenavir, bexarotene, calcitrol , Digoxin, doxel calciferol, dronabinol, etoposito, isoto Chinoin, lopinavir, ritonavir, progesterone, saquinavir, sirolimus, tretinoin, valproic acid, amphotericin, fenoldopam, melphalan, paricalcitol, propofol, voriconazole, ziprasidone, docetaxel, haloperidol, lorazepam, Tenipojido, testosterone, and the like valrubicin. Among these, cyclosporine is preferable.

<< Functional food compound >>
There is no restriction | limiting in particular as said functional food compound, According to the objective, it can select suitably, For example, vitamin A, vitamin D, vitamin E, lutein, zeaxanthin, lipoic acid, flavonoid, fatty acid (for example, omega-3) Fatty acid, omega-6 fatty acid, etc.). These may be used individually by 1 type and may use 2 or more types together.

<< Food >>
The food contains the functional food compound, and further contains other components such as a dispersant and an additive as necessary.

  The food is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ice cream, ice sherbet, shaved ice, and other frozen desserts; buckwheat, udon, harsame, gyoza peel, cucumber peel, Chinese noodles , Noodles such as instant noodles; candy, candies, gum, chocolate, tablet confectionery, snack confectionery, biscuits, jelly, jam, cream, baked confectionery, bread etc .; crabs, salmon, clams, tuna, sardines, shrimp, bonito , Mackerel, whale, oyster, saury, squid, red scallop, scallop, abalone, sea urchin, salmon roe, tocobushi and other marine products; fishery and livestock products such as kamaboko, ham and sausage; dairy products such as processed milk and fermented milk; salad oil , Tempura oil, margarine, mayonnaise, shortening, whipped cream, dressing, etc. Seasonings such as sauces and sauces; curry, stew, oyakodon, rice bowl, miso cooked, Chinese rice bowl, bonito, tempura, eel rice, hayashi rice, oden, mabodorf, beef bowl, meat sauce, egg soup, omelet rice, dumplings, shumai, Examples include retort pouch foods such as hamburger and meatballs; various forms of health foods and nutritional supplements.

<< Functional cosmetic compound >>
The functional cosmetic compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alcohols, fatty alcohols, polyols, aldehydes, alkanolamines, alkoxylated alcohols (for example, , Polyethylene glycol derivatives such as alcohols and fatty alcohols), alkoxylated amides, alkoxylated amines, alkoxylated carboxylic acids, amides including salts (eg, ceramides, etc.), amines, salts and alkyl substitutions Derivatives-containing amino acids, esters, alkyl substituted and acyl derivatives, polyacrylic acids, acrylamide copolymers, adipic acid copolymer water, aminosilicones, biological polymers and derivatives thereof, butylene copolymers, carbohydrates (e.g. Police Calides, chitosan, derivatives thereof, etc.), carboxylic acids, carbomers, esters, ethers, and polymer ethers (eg, PEG derivatives, PPG derivatives, etc.), glyceryl esters and derivatives thereof, halogen compounds , Heterocyclic compounds containing salts, hydrophilic colloids and derivatives containing salts and gums (for example, cellulose derivatives, gelatin, xanthan gum, natural rubbers, etc.), imidazolines, inorganic substances (clay, TiO ₂ , ZnO) Etc.), ketones (for example, camphor, etc.), isethionates, lanolin and its derivatives, organic salts, phenols containing salts (for example, parabens), phosphorus compounds (for example, phosphoric acid derivatives, etc.), Polyacrylates and acrylate copolymers, proteins and enzyme derivatives (e.g. Collagen), synthetic polymers including salts, siloxanes and silanes, sorbitan derivatives, sterols, sulfonic acids and derivatives thereof, and waxes. These may be used individually by 1 type and may use 2 or more types together.

<< cosmetics >>
The cosmetic contains a functional cosmetic compound, and further contains other components such as a dispersant and an additive as necessary.

There is no restriction | limiting in particular as said cosmetics, According to the objective, it can select suitably, For example, skin care cosmetics, makeup cosmetics, hair care cosmetics, body care cosmetics, fragrance cosmetics etc. are mentioned.
The skin care cosmetic is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a cleansing composition for removing makeup, a facial cleanser, an emulsion, a lotion, a cosmetic liquid, a skin moisturizer, a pack, a shaving Cosmetics (for example, shave foam, pre-shave lotion, after-shave lotion, etc.).
There is no restriction | limiting in particular as said makeup cosmetics, According to the objective, it can select suitably, For example, a foundation, a lipstick, a mascara, etc. are mentioned.
The hair care cosmetics is not particularly limited and may be appropriately selected depending on the intended purpose. For example, hair shampoo, hair rinse, hair conditioner, hair treatment, hair conditioner (for example, hair gel, hair set lotion, hair liquid, hair mist) Etc.).
There is no restriction | limiting in particular as said body care cosmetics, According to the objective, it can select suitably, For example, a body soap, sunscreen cosmetics, massage cream etc. are mentioned.
There is no restriction | limiting in particular as said fragrance cosmetics, According to the objective, it can select suitably, For example, perfume (for example, perfume, parfum, etc.), eau de parfum (for example, perfume colon etc.), eau de toilette (for example, perfume de toilette) , Palfuntoire, etc.) and cologne (for example, colon, fresh colon, etc.).

  There is no restriction | limiting in particular as content of the said bioactive substance in the said PLGA microparticles | fine-particles, Although it can select suitably according to the objective, 5 to 95 mass% is preferable, and 5 to 50 mass% is preferable. Is more preferable.

<Dispersant>
The dispersant can be suitably used for dispersing the physiologically active substance.
The dispersant may be a low molecular weight dispersant or a high molecular weight dispersant polymer.
The low molecular weight dispersant means a compound having a weight average molecular weight of less than 15,000, and the high molecular weight dispersant polymer includes a repeating covalent bond between one or more monomers, and has a weight average molecular weight. Means 15,000 or more compounds.

  The low molecular weight dispersant is not particularly limited as long as it is acceptable as a physiologically active substance such as a pharmaceutical, and can be appropriately selected according to the purpose. For example, lipids, saccharides, cyclodextrins, Examples include amino acids and organic acids. These may be used individually by 1 type and may use 2 or more types together.

  The lipids are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include medium-chain or long-chain monoglycerides, diglycerides or triglycerides, phospholipids, vegetable oils (for example, soybean oil, avocado oil, squalene). Oil, sesame oil, olive oil, corn oil, rapeseed oil, safflower oil, sunflower oil, etc.), fish oil, seasoning oil, water-insoluble vitamins, fatty acids, and mixtures thereof, and their derivatives. These may be used individually by 1 type and may use 2 or more types together.

  The saccharide is not particularly limited and may be appropriately selected depending on the intended purpose.For example, glucose, mannose, idose, galactose, fucose, ribose, xylose, lactose, sucrose, maltose, trehalose, turanose, raffinose, malto Examples include triose, acarbose, water-soluble cellulose, synthetic cellulose, or sugar alcohols such as glycerin, sorbitol, lactitol, maltitol, mannitol, xylitol, erythritol, or polyol, or derivatives thereof. These may be used individually by 1 type and may use 2 or more types together.

<Other ingredients>
There is no restriction | limiting in particular as said other component, Although it can select suitably according to the objective, The thing which can be conventionally used for a pharmaceutical is preferable.
Examples of the other components include excipients, flavoring agents, disintegrating agents, fluidizing agents, adsorbents, lubricants, flavoring agents, fragrances, coloring agents, antioxidants, masking agents, antistatic agents, and wetting agents. Agents and the like. These may be used individually by 1 type and may use 2 or more types together.

(Production method of PLGA fine particles)
The method for producing PLGA fine particles of the present invention includes at least a particle forming step, and further includes other steps as necessary.
The method for producing the PLGA fine particles is suitable as a method for producing the PLGA fine particles of the present invention.

The production method of the PLGA fine particles is a method classified into an emulsion solvent diffusion method in water (EDS method) which is a spheroidizing means by mutual diffusion using a difference in surface tension between a good solvent and a poor solvent.
In the EDA method using PLGA, a solution containing PLGA is poured into water, which is a poor solvent for PLGA, or an aqueous organic solvent and brought into contact with each other, so that the solution containing PLGA is diffused. When PLGA comes into contact with a poor solvent, it crystallizes to obtain spherical fine particles.

<Particle formation process>
The particle forming step is a step in which a PLGA solution is discharged from one or more discharge holes into a liquid which is a poor solvent for lactic acid / glycolic acid copolymer (PLGA) to form PLGA fine particles. There is no restriction, and it can be appropriately selected according to the purpose, but it is preferable to include liquid flow treatment and liquid circulation treatment.

<< PLGA solution >>
The PLGA solution is not particularly limited as long as it is a solution in which PLGA is dissolved in a good solvent for PLGA, and can be appropriately selected according to the purpose.
The PLGA solution is obtained by dissolving a lactic acid / glycolic acid copolymer (PLGA) in a good solvent for PLGA.
There is no restriction | limiting in particular as said good solvent, According to the objective, it can select suitably, For example, alcohol, a ketone, ether, acetonitrile etc. are mentioned.
Examples of the alcohol include alcohols having 1 to 4 carbon atoms. Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, propanol, butanol and the like.
As said ketone, a C3-C6 ketone etc. are mentioned, for example. Examples of the ketone having 3 to 6 carbon atoms include acetone, methyl ethyl ketone, and cyclohexanone.
As said ether, C2-C6 ether etc. are mentioned, for example. Examples of the ether having 2 to 6 carbon atoms include dimethyl ether, methyl ethyl ether, diethyl ether and the like.
These may be used alone or in combination of two or more.
As said solvent, the solvent which used alcohol and the ketone together is preferable, and the solvent which used ethanol and acetone together is more preferable.

Here, in the present invention, the “good solvent” means a solvent having a high solubility of the PLGA. The “poor solvent” means a solvent having a low solubility of the PLGA or a solvent that does not dissolve the PLGA.
For example, “good solvent” and “poor solvent” can be defined by the mass of PLGA that can be dissolved in 100 g of solvent at a temperature of 25 ° C. In the present invention, the “good solvent” is preferably a solvent capable of dissolving 0.1 g or more of the PLGA. On the other hand, the “poor solvent” is preferably a solvent that can dissolve only 0.05 g or less of the PLGA.

There is no restriction | limiting in particular as content of the said PLGA in the said PLGA solution, Although it can select suitably according to the objective, For example, as a density | concentration (content) when using the mixed solvent of acetone and ethanol, 5.0 mass% or less is preferable, and 0.1 mass% or more and 5.0 mass% or less are more preferable. When the concentration is 5.0% by mass or less, aggregation can be prevented and particle size distribution can be prevented from being deteriorated.
In addition, the particle diameter of the produced PLGA fine particles can be controlled to some extent by adjusting the content of the PLGA in the PLGA solution.

<< Discharge hole >>
The discharge hole is not particularly limited as long as it has a hole with an inner diameter of less than 1.0 mm, and can be appropriately selected according to the purpose.
The inner diameter is preferably 1.0 μm or more and less than 1.0 mm.
When the hole is not a perfect circle, the hole may have an area corresponding to a perfect circle having a diameter of less than 1.0 mm.

The discharge hole may or may not be contained in the poor solvent, but the inclusion prevents the PLGA solution from drying in the discharge hole, and the PLGA in the discharge hole. This is preferable in that discharge failure due to drying of the solution can be prevented. In other words, the discharge hole is preferably in contact with the poor solvent.
There is no restriction | limiting in particular as distance which puts the said discharge hole in the said poor solvent, Although it can select suitably according to the objective, 1.0 mm-10 mm are preferable, and 2.0 mm-5.0 mm are more preferable. . In other words, the discharge hole is preferably immersed in the poor solvent by 1.0 mm to 10 mm, and more preferably 2.0 mm to 5.0 mm.

<<< Solution Discharge Unit >>>
The discharge hole is formed in, for example, a solution discharge unit.
Examples of the solution discharge means include the following means.
(I) a flat plate nozzle discharge means for discharging the solution by applying pressure to the solution from a hole vacant on the flat plate, such as an ink jet nozzle; (Iii) Discharging means for applying vibration to a solution and discharging it from a hole as a droplet

Examples of the discharge means (iii) include a membrane vibration type discharge means, a Rayleigh split type discharge means, a liquid vibration type discharge means, and a liquid column resonance type discharge means. Further, the solution may be simultaneously discharged under pressure, and these means may be combined.
Examples of the membrane vibration type discharge means include discharge means described in Japanese Patent Application Laid-Open No. 2008-292976.
Examples of the Rayleigh split type discharge means include discharge means described in Japanese Patent No. 4647506.
Examples of the liquid vibration type discharge means include discharge means described in Japanese Patent Application Laid-Open No. 2010-102195.
Among these, a means for applying pressure to the liquid column resonance type discharge means using the liquid column resonance method is more preferable.

The liquid column resonance method is not particularly limited and can be appropriately selected according to the purpose. For example, a standing wave by liquid column resonance is applied by applying vibration to a PLGA solution contained in the liquid column resonance liquid chamber. And the PLGA solution is discharged from the discharge holes formed in the amplitude direction of the standing wave in a region that becomes the antinode of the standing wave.
The liquid column resonance method can be suitably performed by a liquid column resonance droplet discharge means.

<< poor solvent >>
There is no restriction | limiting in particular as said poor solvent, Although it can select suitably according to the objective, Water is preferable. In order to further ensure the stability of the prepared PLGA fine particles, the poor solvent may contain a stabilizer.

  There is no restriction | limiting in particular as said stabilizer, According to the objective, it can select suitably, For example, a hydroxypropyl cellulose (HPC), a hydroxypropyl methylcellulose (HPMC), and polyvinyl alcohol (PVA) are preferable. Moreover, it is preferable that the density | concentration of the stabilizer to add is 5 mass% or less.

  As a liquid which is the said poor solvent, PVA aqueous solution etc. are mentioned, for example.

<< Liquid flow treatment >>
The liquid flow treatment is not particularly limited as long as it is a treatment that causes the liquid to flow when the PLGA solution is discharged into the liquid that is the poor solvent, and may be appropriately selected according to the purpose. However, the flow rate of the liquid is preferably 0.3 m / s or more, and more preferably 1.0 m / s.
By performing the liquid flow treatment, coalescence of the PLGA fine particles can be suppressed.

  Examples of the liquid flowing means for flowing the liquid include a stirring member that stirs the liquid. There is no restriction | limiting in particular as said stirring member, According to the objective, it can select suitably, For example, a stirring blade etc. are mentioned.

<< Liquid circulation treatment >>
In the particle forming step, it is preferable to discharge the PLGA solution into the liquid being circulated from the discharge holes into the liquid in terms of preventing the coalescence of PLGA fine particles.
Therefore, it is preferable to perform a liquid circulation treatment for circulating the liquid.
In the liquid circulation treatment, for example, the liquid is circulated in the poor solvent containing member having a circulation path by using a pump as a circulation member.

<<< good solvent removal treatment >>>
When the liquid is circulated, the good solvent of the PLGA is accumulated in the liquid. When the good solvent is accumulated in the liquid, coalescence between PLGA fine particles is likely to occur. In that respect, it is preferable to perform a good solvent removal treatment for removing the good solvent contained in the circulated liquid from the liquid.
The good solvent removal treatment is not particularly limited as long as the good solvent can be removed from the liquid, and can be appropriately selected according to the purpose. For example, the liquid is heated and the liquid is Examples include a method of evaporating the good solvent and removing it from the liquid by at least one of reducing the pressure.

<Other processes>
As said other process, a good solvent removal process, a filter sterilization process, etc. are mentioned, for example.

<< Good solvent removal process >>
The good solvent removal step is not particularly limited as long as it is a step of taking out the good solvent from the produced PLGA fine particles, and can be appropriately selected according to the purpose. For example, the liquid containing the PLGA fine particles is subjected to a decompression treatment. For example, a method may be mentioned in which only the good solvent of the PLGA is volatilized to obtain a suspension containing the PLGA fine particles.

<< Filter sterilization process >>
The filtration sterilization step is not particularly limited as long as it is a step of filtering the suspension after the good solvent removal step with a sterilization filter, and can be appropriately selected according to the purpose.
The suspension used for filtration may or may not be diluted with the poor solvent.
Prior to the filtration, it is preferable to apply ultrasonic waves to the suspension. By doing so, aggregation of the PLGA fine particles in the suspension is eliminated, and the PLGA fine particles easily pass through the filter.

There is no restriction | limiting in particular as said sterilization filter, According to the objective, it can select suitably, For example, a nylon membrane filter etc. are mentioned.
There is no restriction | limiting in particular as filtration accuracy of the said sterilization filter, Although it can select suitably according to the objective, 0.1 micrometer-0.45 micrometer are preferable.
A commercially available product may be used as the sterilizing filter. As commercially available products, for example, LifeASSUR ^TM nylon membrane filter cartridge (filtration precision, 0.1 [mu] m), and the like.

(PLGA fine particle production equipment)
The apparatus for producing PLGA fine particles of the present invention has at least a PLGA solution container and a solution discharge means, preferably has a poor solvent storage member and a liquid flow means, and further has other members as necessary. .

  The PLGA fine particle production apparatus of the present invention will be described below, but the same terms as those described in the PLGA fine particle production method of the present invention are the same as those of the PLGA fine particles of the present invention unless detailed description is given below. It has the same meaning as the term explained in the production method, and examples and preferred embodiments of the term include the illustration and preferred embodiment explained in the production method of the PLGA fine particles.

<PLGA solution container>
The PLGA solution container is not particularly limited as long as it is a container that accommodates a PLGA solution, and can be appropriately selected according to the purpose, and may or may not be flexible. Also good.
The material of the PLGA solution container is not particularly limited and may be appropriately selected depending on the purpose. For example, the PLGA solution container may be made of resin or metal. Good.
The structure of the PLGA solution container is not particularly limited and may be appropriately selected depending on the purpose. For example, the PLGA solution container may be a sealed container or a non-sealed container. Also good.

  In the PLGA solution, a lactic acid / glycolic acid copolymer (PLGA) is dissolved in a good solvent for the PLGA.

<Solution discharging means>
The solution discharge means is not particularly limited as long as it has one or more discharge holes having an inner diameter of less than 1.0 mm, and can be appropriately selected according to the purpose.
The solution discharge means is connected to the PLGA solution container. The method for connecting the solution discharge means and the PLGA solution container is not particularly limited as long as the PLGA solution can be supplied from the PLGA solution container to the solution discharge means. For example, a pipe (a pipe, a tube, etc.) etc. are mentioned.

  The solution discharge means preferably includes a vibration applying member that applies vibration to the PLGA solution.

<Poor solvent containing member>
The poor solvent containing member is not particularly limited as long as it is a member that contains a liquid that is a poor solvent for the PLGA, can be appropriately selected according to the purpose, and may have flexibility, It doesn't have to be flexible.
There is no restriction | limiting in particular as a material of the said poor-solvent accommodation member, According to the objective, it can select suitably, For example, the said poor-solvent accommodation member may be resin, and may be metal. Good.

  The poor solvent in the poor solvent containing member may be stirred or not stirred when the PLGA fine particles are produced, but is preferably stirred.

The discharge hole of the solution discharge means may or may not be contained in the poor solvent in the poor solvent housing member, but it is not included in the PLGA solution in the discharge hole. This is preferable in that the drying of the PLGA solution in the discharge holes can be prevented and the discharge failure due to the drying of the PLGA solution can be prevented. In other words, it is preferable that the discharge hole of the solution discharge means is in contact with the poor solvent in the poor solvent containing member.
There is no restriction | limiting in particular as distance which puts the said discharge hole of the said solution discharge means in the said poor solvent in the said poor solvent accommodation member, Although it can select suitably according to the objective, 1.0 mm-10 mm are Preferably, 2.0 mm to 5.0 mm is more preferable. In other words, it is preferable to immerse the discharge hole of the solution discharge means in the poor solvent in the poor solvent housing member by 1.0 mm to 10 mm, and more preferably 2.0 mm to 5.0 mm.

  The poor solvent containing member preferably has a circulation path through which the liquid can be circulated. The circulation path that can circulate the liquid may be, for example, a circulation path composed of only piping, or may be a circulation path having a piping and a tank.

<< good solvent removal member >>
When the liquid is circulated, the good solvent of the PLGA is accumulated in the liquid. When the good solvent is accumulated in the liquid, coalescence between PLGA fine particles is likely to occur. In that respect, it is preferable to have a good solvent removing member for removing the good solvent contained in the circulated liquid from the liquid.
The good solvent removing member is not particularly limited as long as the good solvent can be removed from the liquid, and can be appropriately selected according to the purpose. For example, a heating unit for heating the liquid, the liquid And a decompression section for decompressing the pressure. When at least one of the heating unit and the decompression unit is used, the good solvent can be evaporated and removed from the liquid.

<Liquid fluid means>
The liquid flow means is not particularly limited as long as it is a means for flowing the liquid that is the poor solvent in the poor solvent containing member, and can be appropriately selected according to the purpose. Examples of the stirring member include stirring.

  By using the liquid flow means, coalescence of the PLGA fine particles can be suppressed.

The PLGA fine particles obtained by the PLGA fine particles of the present invention and the PLGA fine particle production method of the present invention or the PLGA fine particle production apparatus are PLGA fine particles suitable for filtration sterilization.
The filtration sterilization is a method of removing bacteria such as microorganisms present in the sterilized product by filtration, and a membrane filter having a diameter of 0.1 μm is usually used. Therefore, PLGA nanoparticles having a particle diameter of 200 nm or more cannot sufficiently pass through a filter for filtration sterilization.

The liquid column resonance droplet discharge means, which is an aspect of the solution discharge means, will be described below.
FIG. 1 is a schematic cross-sectional view of the liquid column resonance droplet discharge means 11. The liquid column resonance droplet discharge means 11 includes a liquid common supply path 17 and a liquid column resonance liquid chamber 18. The liquid column resonance liquid chamber 18 communicates with a liquid common supply path 17 provided on one of the wall surfaces at both ends in the longitudinal direction. Further, the liquid column resonance liquid chamber 18 is provided on a wall surface facing the discharge hole 19 and a discharge hole 19 for discharging the droplet 21 to one wall surface of the wall surfaces connected to both ends. Vibration generating means 20 for generating high-frequency vibrations to form a standing wave. The vibration generating means 20 is connected to a high frequency power source (not shown).

  The PLGA solution 14 passes through the liquid supply pipe by a liquid circulation pump (not shown) and flows into the liquid common supply path 17 of the liquid column resonance droplet forming unit, and the liquid column resonance liquid chamber of the liquid column resonance droplet discharge means 11. 18 is supplied. In the liquid column resonance liquid chamber 18 filled with the PLGA solution 14, a pressure distribution is formed by the liquid column resonance standing wave generated by the vibration generating means 20. Then, the droplet 21 is ejected from the ejection hole 19 arranged in a region where the amplitude of the liquid column resonance standing wave is large and the pressure fluctuation is large and which is an antinode of the standing wave. The region that becomes the antinode of the standing wave due to the liquid column resonance is a region other than the node of the standing wave, and a region having a sufficient amplitude for the pressure fluctuation of the standing wave to discharge the liquid is preferable. A region of ± 1/4 wavelength from the position where the amplitude of the pressure standing wave is maximized (the node as the velocity standing wave) toward the position where the amplitude is minimized is more preferable.

  As long as the region is an antinode of a standing wave, even if there are a plurality of discharge holes, substantially uniform droplets can be formed from each, and moreover, the droplets can be discharged efficiently. And clogging of the discharge holes is less likely to occur. The PLGA solution 14 that has passed through the liquid common supply path 17 flows through a liquid return pipe (not shown) and is returned to the PLGA solution 14. When the amount of the PLGA solution 14 in the liquid column resonance liquid chamber 18 decreases due to the discharge of the liquid droplet 21, a suction force due to the action of the liquid column resonance standing wave in the liquid column resonance liquid chamber 18 acts, and the liquid common supply path The flow rate of the PLGA solution 14 supplied from 17 increases. Then, the PLGA solution 14 is replenished into the liquid column resonance liquid chamber 18. When the PLGA solution 14 is replenished in the liquid column resonance liquid chamber 18, the flow rate of the PLGA solution 14 passing through the liquid common supply path 17 is restored.

  Each of the liquid column resonance liquid chambers 18 in the liquid column resonance droplet discharge means 11 has a frame formed of a material having such a high rigidity that does not affect the resonance frequency of the liquid at a driving frequency such as metal, ceramics, or silicone. It is formed by bonding. Further, as shown in FIG. 1, the length L between the wall surfaces at both ends in the longitudinal direction of the liquid column resonance liquid chamber 18 is determined based on the liquid column resonance principle. Further, it is preferable that a plurality of liquid column resonance liquid chambers 18 are arranged for one droplet forming unit in order to dramatically improve productivity. The number of liquid column resonance liquid chambers 18 is not particularly limited and is preferably 1 or more and 2,000 or less. In addition, for each liquid column resonance liquid chamber, a flow path for supplying liquid is connected from the common liquid supply path 17, and the common liquid supply path 17 communicates with a plurality of liquid column resonance liquid chambers 18. .

Further, the vibration generating means 20 in the liquid column resonant droplet discharging means 11 is not particularly limited as long as it can be driven at a predetermined frequency, but a form in which a piezoelectric body is bonded to the elastic plate 9 is preferable. The frequency is preferably 150 kHz or more and more preferably 300 kHz or more and 500 kHz or less from the viewpoint of productivity. The elastic plate constitutes a part of the wall of the liquid column resonance liquid chamber so that the piezoelectric body does not come into contact with the liquid. Examples of the piezoelectric body include piezoelectric ceramics such as lead zirconate titanate (PZT). In general, the piezoelectric body is often used by being laminated because the displacement is small. In addition, piezoelectric polymers such as polyvinylidene fluoride (PVDF), single crystals such as quartz, LiNbO ₃ , LiTaO ₃ , and KNbO ₃ can be used. Furthermore, it is preferable that the vibration generating means 20 is arranged so that it can be individually controlled for each liquid column resonance liquid chamber. In addition, the block-shaped vibrating member made of one material is partially cut in accordance with the arrangement of the liquid column resonance liquid chambers, and each liquid column resonance liquid chamber can be individually controlled via an elastic plate. preferable.

  Furthermore, it is preferable to employ a configuration in which the discharge holes 19 are provided in the width direction in the liquid column resonance liquid chamber 18 because a large number of openings of the discharge holes 19 can be provided and the production efficiency is increased. Further, since the liquid column resonance frequency varies depending on the arrangement of the discharge holes 19, it is desirable to appropriately determine the liquid column resonance frequency after confirming the discharge of the droplet.

  For the mechanism of droplet formation in liquid column resonance, see, for example, paragraphs [0011] to [0020] of Japanese Patent Application Laid-Open No. 2011-194675.

Next, an example of a PLGA fine particle production apparatus of the present invention will be described with reference to the drawings.
FIG. 2 is a schematic view showing an example of a PLGA fine particle production apparatus. The PLGA manufacturing apparatus 1 mainly includes a PLGA solution container 13, a solution discharge means 2, and a poor solvent storage member 61. The solution discharge means 2 supplies the PLGA solution container 13 containing the PLGA solution 14 and the PLGA solution 14 contained in the PLGA solution container 13 to the solution discharge means 2 through the liquid supply pipe 16, and further returns to the solution. A liquid circulation pump 15 that pumps the PLGA solution 14 in the liquid supply pipe 16 to return to the PLGA solution container 13 through the pipe 22 is connected, and the PLGA solution 14 can be supplied to the solution discharge means 2 at any time.
The solution discharge means 2 includes, for example, a liquid column resonance droplet discharge means 11 shown in FIG.

The PLGA solution 14 is discharged as droplets 21 from the solution discharge means 2 into the poor solvent 62 accommodated in the poor solvent accommodating member 61.
When the droplet 21 comes into contact with the poor solvent 62, the PLGA solution is diffused, and when the PLGA comes into contact with the poor solvent, it is crystallized to obtain spherical fine particles.

Next, another example of the PLGA fine particle production apparatus of the present invention will be described with reference to the drawings.
FIG. 3 is an example of an apparatus for producing PLGA fine particles including a stirring member.
The PLGA fine particle manufacturing apparatus in FIG. 3 is a schematic view when a PLGA solution is discharged to a poor solvent 62 in a poor solvent containing member 61 that is a glass container. The discharge unit of the solution discharge unit 2 discharges the PLGA solution to the poor solvent 62 while being immersed in the poor solvent 62.
The PLGA fine particle manufacturing apparatus in FIG. 3 includes a stirring member 50 having a stirring blade 51. The stirring blade 51 is immersed in the poor solvent 62 in the poor solvent housing member 61.
When discharging the PLGA solution to the poor solvent 62 by the solution discharge means 2, the stirring blade 51 is rotated and the poor solvent 61 is stirred to prevent coalescence of the PLGA fine particles formed from the droplets 21. it can.

Next, still another example of the apparatus for producing PLGA fine particles of the present invention will be described with reference to the drawings.
As a method for preventing the coalescence of PLGA fine particles formed by the PLGA solution being in contact with the poor solvent, it is most preferable to impart a poor solvent flow to the discharge portion of the solution discharge means. In that respect, the embodiment of FIGS. 4A and 4B is preferred.
FIG. 4A is a schematic view of an example of an apparatus for producing PLGA fine particles capable of imparting a poor solvent flow to the discharge portion of the solution discharge means.
The apparatus for producing PLGA fine particles in FIG. 4A includes a solution discharge means 2, a poor solvent housing member 61, a stirring member 50, and a pump 31.
The poor solvent accommodating member 61 has a circulation path capable of circulating the liquid, and includes a tank 63 as a part of the poor solvent accommodating member 61 in the middle of the circulation path.
4B is an enlarged view of the vicinity of the solution ejection means 2 (broken line portion) in FIG. 4A.
The poor solvent 62 introduced into the tank 63 is circulated through the poor solvent containing member 61 by the pump 31 through the solution discharge means 2. At that time, the PLGA solution is discharged into the poor solvent 62 from the discharge hole of the solution discharge means 2. By applying a flow to the liquid that is the poor solvent 62, coalescence of the PLGA fine particles formed by the droplets 21 is suppressed. The flow rate of the poor solvent 62 in the discharge hole of the solution discharge means 2 is preferably 0.3 m / s or more, and more preferably 1.0 m / s.
The tank 63 is provided with a stirring member 50 having a stirring blade 51, and the liquid that is the poor solvent 62 is stirred by the stirring blade 51, whereby the coalescence of PLGA fine particles can be further suppressed.

Next, still another example of the apparatus for producing PLGA fine particles of the present invention will be described with reference to the drawings.
As the amount of the good solvent in the liquid increases, coalescence of PLGA fine particles increases and the particle diameter tends to become coarse. In order to prevent this, it is preferable to remove the good solvent from the liquid and keep the amount of the good solvent in the liquid small.
FIG. 5 is a schematic diagram of an example of an apparatus for producing PLGA fine particles including a good solvent removing member that removes the good solvent.
The PLGA fine particle manufacturing apparatus of FIG. 5 includes a solution discharge means 2, a poor solvent housing member 61, a stirring member 50, a pump 31, a heating unit 33 and a decompression unit 36 (vacuum pump) as good solvent removal members. Have
The configuration in the vicinity of the solution discharge means 2 is the same as in FIGS. 4A and 4B.
The poor solvent accommodating member 61 has a circulation path capable of circulating the liquid, and includes a tank 63 as a part of the poor solvent accommodating member 61 in the middle of the circulation path.
The poor solvent 62 introduced into the tank 63 is circulated through the poor solvent containing member 61 by the pump 31 through the solution discharge means 2. At that time, the PLGA solution is discharged into the poor solvent 62 from the discharge hole of the solution discharge means 2. By applying a flow to the liquid that is the poor solvent 62, coalescence of the PLGA fine particles formed by the droplets 21 is suppressed.
Furthermore, the good solvent contained in the liquid which is the poor solvent 62 can be removed by providing the tank 63 with the heating unit 33 and the decompression unit 36. For example, while the liquid that is the poor solvent 62 is heated by the heating unit 33, the pressure of the liquid is reduced by the pressure reducing unit 36. If it does so, the good solvent whose boiling point is lower than a poor solvent will evaporate. The evaporated good solvent is ablated by the condenser 35 and recovered through the recovery pipe 37.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Preparation of PLGA solution>
A lactic acid / glycolic acid copolymer (PLGA7510, manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in a mixed solvent having a mass ratio of acetone and ethanol of 1: 1 using a stirrer so that the mass becomes 0.3% by mass. A solution was obtained.
Further, 0.15 g of polyvinyl alcohol (PVA, 363170, manufactured by Aldrich) was dissolved in 49.85 g of ion-exchanged water to prepare a 0.3 mass% PVA aqueous solution which is a poor solvent for PLGA, and the glass shown in FIG. It put in the manufactured poor solvent accommodating member 24.

<Preparation of PLGA fine particles>
1 g of the PLGA solution is charged into the poor solvent (0.3 mass% PVA aqueous solution) in which the rotation speed of the stirring device 23 shown in FIG. 3 is 200 rpm using the liquid column resonance discharge means shown in FIG. A liquid in which PLGA nanoparticles were formed was obtained. At this time, the temperature of the poor solvent was 25 ° C.
Nozzle diameter: 8.0 μm
Supply pressure: 0.03 MPa
Solution discharge means: Liquid column resonance Drive frequency: 150 kHz
Applied voltage to piezoelectric: 5.0V
Depth of immersion of nozzle in poor solvent: 3.0 mm

<Good solvent removal>
Next, while the liquid was stirred at 200 rpm, the good solvent (acetone and ethanol) was removed by a reduced pressure treatment at −50 kPa for 24 hours to obtain a suspension containing PLGA fine particles (PLGA fine particle suspension). .

<Evaluation of particle size distribution>
About the obtained PLGA fine particle suspension, an average volume reference particle diameter and (RSF) are measured using a dynamic light scattering method with a concentrated analyzer (“FPAR-1000”, manufactured by Otsuka Electronics Co., Ltd.). did. The results are shown in Table 1. The particle size distribution is shown in FIG.
The concentration of PLGA fine particles in the PLGA fine particle suspension used for the measurement was adjusted to 0.1 mass%. The integration time per one time was 180 seconds, and the average volume reference particle diameter (nm) was determined by the Contin method. The average value of the values measured three times was defined as the average volume reference particle diameter (nm) in the present invention.
The measured average volume reference particle size and (RSF) were evaluated according to the following criteria.
〔Evaluation criteria〕
Average volume reference particle size A: Average volume reference particle size of 10 nm or more and 50 nm or less ○: Average volume reference particle size of greater than 50 nm, 80 nm or less ×: Average volume reference particle size of greater than 80 nm

(R.S.F)
A: (R.S.F) is greater than 0 and less than or equal to 1.00. O: (R.S.F.) is greater than 1.00 and less than or equal to 1.20. large

<Sterilization rate evaluation>
The prepared PLGA fine particle suspension was filtered using a nylon membrane filter for sterilization with a pore size of 0.1 μm (PSA, manufactured by 3M). Further, after the filtrate after sterilization by filtration was sufficiently dried in a drying furnace at 50 ° C., the weight of the remaining PLGA was measured, and the sterilization rate was calculated. The results are shown in Table 1.
The sterilization rate was calculated by the following formula and used as a criterion for evaluation.
[Calculation formula]
Sterilization rate (%) = [(weight of PLGA dried after filtration) / (weight of PLGA in suspension before filtration)] × 100
〔Evaluation criteria〕
◎: Sterilization rate is 90% or more ○: Sterilization rate is 70% or more and less than 90% ×: Sterilization rate is less than 70%

(Example 2)
In Example 1, the PLGA concentration of the PLGA solution was changed from 0.3% by mass to 1.0% by mass, and the nozzle diameter was changed from 8.0 μm to 50 μm. Fine particles were obtained.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Example 3)
In Example 1, PLGA fine particles were obtained in the same manner as in Example 1 except that the nozzle diameter was changed from 8.0 μm to 100 μm.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

Example 4
In Example 1, PLGA fine particles were obtained in the same manner as in Example 1 except that the nozzle diameter was changed from 8.0 μm to 500 μm.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Example 5)
In Example 1, except that cyclosporine (trade name: Cyclosporin A, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the PLGA solution at a ratio of 5% by mass with respect to the mass of PLGA. PLGA fine particles were obtained.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Example 6)
In Example 1, PLGA fine particles were obtained in the same manner as in Example 1 except that the solution discharging means was changed from the liquid column resonance method to a method of discharging the solution without applying vibration from the flat plate nozzle.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Example 7)
In Example 6, the nozzle diameter was changed from 8.0 μm to 50 μm, the PLGA concentration of the PLGA solution was changed from 0.3% by mass to 1.0% by mass, and cyclosporine (trade name: Cyclosporin A in the PLGA solution was further changed. (Manufactured by Tokyo Chemical Industry Co., Ltd.) was added in a proportion of 5 mass% with respect to the mass of PLGA, to obtain PLGA fine particles in the same manner as in Example 6.
In the same manner as in Example 6, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Example 8)
In Example 6, PLGA fine particles were obtained in the same manner as in Example 6 except that the apparatus was changed to the configuration shown in FIGS. 4A and 4B.
As a specific apparatus configuration, the tank 63 was a 300 mL hot water heatable tank, and 25 ° C. hot water was passed through. The stirring member 50 was a paddle type stirrer and the stirring blade 51 was rotated at 200 rpm. The pump 31 used a Nikuni UOD to feed a poor solvent. When the flow rate of the poor solvent in the discharge hole of the solution discharge means 2 was measured, it was 1.0 m / s.
In the same manner as in Example 6, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

Example 9
In Example 6, PLGA fine particles were obtained in the same manner as in Example 6 except that the apparatus was changed to the configuration shown in FIG.
As a specific device configuration, the tank 63 used a 300 mL hot water heatable tank, and 40 ° C. hot water was passed through. The stirring member 50 was a paddle type stirrer and the stirring blade 51 was rotated at 200 rpm. The pump 31 used a Nikuni UOD to feed a poor solvent. When the flow rate of the poor solvent in the discharge hole of the solution discharge means 2 was measured, it was 1.0 m / s. The condenser 35 was operated using Kurose KMSB, and the vacuum pump as the decompression unit 36 was operated using Osaka Air Machinery Co., Ltd. CV-2E. The temperature of the poor solvent during operation was 25 ° C. PLGA fine particles were produced while removing the good solvent in the liquid which was a poor solvent.
In the same manner as in Example 6, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, PLGA fine particles were obtained in the same manner as in Example 1 except that the solution discharging means was changed from the liquid column resonance method to a Teflon tube having an inner diameter of 1.0 mm.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Comparative Example 2)
In Comparative Example 1, PLGA fine particles were obtained in the same manner as in Comparative Example 1, except that the PLGA concentration of the PLGA solution was changed from 0.3% by mass to 1.0% by mass.
In the same manner as in Comparative Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 2, PLGA fine particles were obtained in the same manner as in Comparative Example 2, except that the inner diameter of the Teflon tube was changed from 1.0 mm to 2.5 mm.
By the same method as in Comparative Example 2, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

(Comparative Example 4)
In Example 1, the solution discharge means was changed from the liquid column resonance method to a Teflon tube having an inner diameter of 5.0 mm, and the PLGA concentration of the PLGA solution was changed from 0.3 mass% to 0.1 mass%. In the same manner as in Example 1, PLGA fine particles were obtained.
In the same manner as in Example 1, the average volume reference particle diameter, (RSF) was measured, and the sterilization rate was evaluated. The results are shown in Table 1.

  Table 1 shows the results of Examples and Comparative Examples.

Aspects of the present invention are as follows, for example.
<1> Contains a lactic acid / glycolic acid copolymer (PLGA),
Relative Span Factor (RSF) satisfies the following formula (1),
PLGA microparticles having an average volume reference particle size of 80 nm or less.
0 <(R.S.F) ≦ 1.20 ..Formula (1)
Here, (RSF) is defined by (D90-D10) / D50.
D90 represents the cumulative 90 volume% from the small particle side of the cumulative particle size distribution, D50 represents the cumulative 50 volume% from the small particle side of the cumulative particle size distribution, and D10 represents from the small particle side of the cumulative particle size distribution. Cumulative 10 volume% is represented.
<2> The PLGA fine particles according to <1>, wherein the average volume reference particle diameter is 10 nm or more and 50 nm or less.
<3> The PLGA microparticle according to any one of <1> to <2>, which contains a physiologically active substance.
<4> A PLGA solution obtained by dissolving a lactic acid / glycolic acid copolymer (PLGA) in a good solvent for PLGA is used to remove the poor PLGA from one or more discharge holes having an inner diameter of less than 1.0 mm. A method for producing PLGA fine particles, comprising a particle forming step of forming PLGA fine particles by discharging into a liquid as a solvent.
<5> The method for producing PLGA fine particles according to <4>, wherein vibration is applied to the PLGA solution, and the PLGA solution is discharged into the liquid from the discharge hole.
<6> The method for producing PLGA fine particles according to any one of <4> to <5>, wherein the liquid is caused to flow when the PLGA solution is discharged into the liquid that is the poor solvent. is there.
<7> The method for producing PLGA fine particles according to <6>, wherein the flow rate of the liquid is 0.3 m / s or more.
<8> The method for producing PLGA fine particles according to any one of <4> to <5>, wherein the PLGA solution is discharged into the liquid from the discharge hole into the liquid being circulated.
<9> The method for producing PLGA fine particles according to <8>, further including a good solvent removal treatment for removing the good solvent contained in the circulated liquid from the liquid.
<10> a PLGA solution container that contains a PLGA solution in which a lactic acid / glycolic acid copolymer (PLGA) is dissolved in the good solvent of PLGA;
A solution ejection means connected to the PLGA solution container and having one or more ejection holes having an inner diameter of less than 1.0 mm;
An apparatus for producing PLGA fine particles, comprising: a poor solvent containing member that contains a liquid that is a poor solvent for PLGA.
<11> The PLGA fine particle manufacturing apparatus according to <10>, wherein the solution discharge unit includes a vibration applying member that applies vibration to the PLGA solution.
<12> The PLGA fine particle production apparatus according to any one of <11> to <12>, further including a liquid flow unit configured to flow the liquid.
<13> The PLGA fine particle production apparatus according to any one of <11> to <12>, wherein the poor solvent containing member has a circulation path through which the liquid can be circulated.
<14> The PLGA fine particle production apparatus according to <13>, further including a good solvent removing member that removes the good solvent contained in the circulated liquid.

  The PLGA fine particles according to <1> to <3>, the method for producing PLGA fine particles according to <4> to <9>, and the apparatus for producing PLGA fine particles according to <10> to <14>, The above-described problems can be solved and the object of the present invention can be achieved.

DESCRIPTION OF SYMBOLS 1 PLGA manufacturing apparatus 2 Solution discharge means 9 Elastic plate 11 Liquid column resonance droplet discharge means 13 PLGA solution container 14 PLGA solution 15 Liquid circulation pump 16 Liquid supply pipe 17 Liquid common supply path 18 Liquid column resonance liquid chamber 19 Discharge hole 20 Vibration generating means 21 Droplet 22 Liquid return pipe 33 Heating part 35 Condenser 36 Depressurizing part 37 Recovery pipe 50 Stirring member 51 Stirring blade 61 Poor solvent housing member 62 Poor solvent

Japanese Patent No. 4856752 JP 2006-131577 A

Claims (14)

Contains lactic acid / glycolic acid copolymer (PLGA),
Relative Span Factor (RSF) satisfies the following formula (1),
PLGA fine particles having an average volume reference particle size of 80 nm or less.
0 <(R.S.F) ≦ 1.20 ..Formula (1)
Here, (RSF) is defined by (D90-D10) / D50.
D90 represents the cumulative 90 volume% from the small particle side of the cumulative particle size distribution, D50 represents the cumulative 50 volume% from the small particle side of the cumulative particle size distribution, and D10 represents from the small particle side of the cumulative particle size distribution. Cumulative 10 volume% is represented.   The PLGA fine particles according to claim 1, wherein the average volume reference particle diameter is 10 nm or more and 50 nm or less.   The PLGA microparticle according to claim 1, which contains a physiologically active substance.   A PLGA solution obtained by dissolving lactic acid / glycolic acid copolymer (PLGA) in a good solvent of PLGA is a poor solvent of PLGA from one or more discharge holes having an inner diameter of less than 1.0 mm. A method for producing PLGA fine particles, comprising a particle forming step of forming PLGA fine particles by discharging into a liquid.   The method for producing PLGA fine particles according to claim 4, wherein vibration is applied to the PLGA solution, and the PLGA solution is discharged into the liquid from the discharge hole.   The method for producing PLGA fine particles according to any one of claims 4 to 5, wherein the liquid is caused to flow when the PLGA solution is discharged into the liquid that is the poor solvent.   The method for producing PLGA fine particles according to claim 6, wherein the flow rate of the liquid is 0.3 m / s or more.   The method for producing PLGA fine particles according to any one of claims 4 to 5, wherein the PLGA solution is discharged from the discharge hole into the liquid being circulated.   The method for producing PLGA fine particles according to claim 8, comprising a good solvent removal treatment for removing the good solvent contained in the circulated liquid from the liquid. A PLGA solution container containing a PLGA solution in which a lactic acid / glycolic acid copolymer (PLGA) is dissolved in a good solvent of the PLGA;
A solution ejection means connected to the PLGA solution container and having one or more ejection holes having an inner diameter of less than 1.0 mm;
An apparatus for producing PLGA fine particles, comprising: a poor solvent containing member that contains a liquid that is a poor solvent for PLGA.   The apparatus for producing PLGA fine particles according to claim 10, wherein the solution discharge means includes a vibration applying member that applies vibration to the PLGA solution.   The apparatus for producing PLGA fine particles according to any one of claims 11 to 12, further comprising a liquid flow means for flowing the liquid.   The apparatus for producing PLGA fine particles according to claim 11, wherein the poor solvent containing member has a circulation path through which the liquid can be circulated.   The apparatus for producing PLGA fine particles according to claim 13, further comprising a good solvent removing member that removes the good solvent contained in the circulated liquid.