JP3191004B2 - Manufacturing method of microsphere - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing microspheres.

[0002]

2. Description of the Related Art As a conventional technique, for example, EP-A 481,732
Include drugs and polylactic acid and glycolic acid / hydroxycarboxylic acid [HOCH (C ₂ -C ₈ alkyl) COOH]
Sustained-release preparations consisting of copolymers are described. As a preparation method of the preparation, a W / O emulsion in which an aqueous solution of a physiologically active peptide is used as an internal aqueous phase and an organic solvent solution of a biodegradable polymer is used as an oil phase is added to water or the like, and is gradually released from the W / O / W emulsion. An underwater drying method for producing water-soluble microspheres is described. Also, Japanese Patent Application Laid-Open No. 60-100516 (EP-A 1452)
40) and JP-A-62-201816 (EP-A 190833) describe a method for producing microcapsules from a water-soluble drug and a polymer by a method of drying in water.

[0003]

In the underwater drying, the rate of desolvation of the microsphere is not a satisfactory rate.
If the solvent removal is insufficient, the spheres tend to aggregate with each other, which causes problems in the dispersibility of the spheres and the needle penetration during administration. If the solvent is sufficiently removed, the drying time in water becomes very long, and the incorporation rate of the drug in the obtained microspheres decreases, which is not satisfactory.

[0004]

[Means for Solving the Problems] In view of such circumstances,
As a result of intensive studies, it was found that by drying in water under specific conditions, the rate of desolvation of microspheres can be increased and the rate of incorporation of drugs into microspheres can be significantly improved. Completed the invention. That is, the present invention provides a process for preparing microspheres by in-water drying method from W / O / W emulsion or O / W emulsions, the amount of microspheres per external aqueous phase 1 m ³ is about 0.1
About 500 kg, and the ratio of the cubic root of the volume (unit: m ³ ) of the external water phase to the square root of the area of the liquid surface (unit: m ² ) in contact with the gas phase is 1: about 0.2
To about 4.5, and the ratio of W / O /
Replaces W emulsion or O / W emulsion, gas movement speed near liquid level is about 0.1 to about 300m /
A gas is blown onto a W / O / W emulsion or an O / W emulsion so that the time is reduced to seconds, and the gas is replaced so that the number of replacement times is about 0.5 times / minute or more. is there.

In the present specification, amino acids, protecting groups, etc.
When abbreviated, it is based on the abbreviation by IUPAC-IUB Commission on Biochemical Nomenclature or the abbreviation commonly used in the art, and there may be optical isomers with respect to amino acids. In this case, the L-form is indicated unless otherwise specified. Also,
The abbreviations used herein have the following meanings. NAcD2Nal: N-acetyl-D-3- (2-naphthyl) alanyl D4ClPhe: D-3- (4-chlorophenyl) alanyl D3Pal: D-3- (3-pyridyl) alanyl NMeTyr: N-methyltyrosyl DLys (Nic): D- (epsilon-N-nicotinoyl) lysyl Lys (Nisp) :( epsilon-N-isopropyl) lysyl DhArg (Et ₂ ): D- (N, N′-diethyl) homoarginyl

[0006] In the present specification, the weight average molecular weight of the biodegradable polymer is 120,000, 52,000, 22,
It is a molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) using nine kinds of polystyrenes of 000, 9,200, 5,050, 2,950, 1,050, 580 and 162 as reference substances. The degree of dispersion is calculated from the weight average molecular weight thus measured. The measurement was performed using GPC column KF804Lx2 (manufactured by Showa Denko), R
I monitor L-3300 (manufactured by Hitachi, Ltd.) was used, and chloroform was used as a mobile phase.

[0007] The microspheres of the present invention are microparticles (microspheres) containing a physiologically active substance (hereinafter sometimes abbreviated simply as a drug) and a biodegradable polymer.
Specific examples thereof include, for example, microcapsules containing one drug core in one particle,
Examples include polynuclear microcapsules containing a large number of drug cores in individual particles, and fine particles in which the drug is dissolved or dispersed in a biodegradable polymer as a solid solution in molecular form.

The physiologically active substance is not particularly limited, but includes physiologically active peptides, antitumor agents, antibiotics, antipyretics, analgesics, anti-inflammatory agents, antitussive expectorants, sedatives, muscle relaxants, antiepileptic agents, antiulcer agents , Antidepressants, antiallergic agents, inotropic agents,
Antiarrhythmic agent, vasodilator, antihypertensive diuretic, antidiabetic agent, antilipidemic agent, anticoagulant, hemostatic agent, antituberculous agent, hormonal agent, narcotics antagonist, bone resorption inhibitor, bone formation promoter And angiogenesis inhibitors. The bioactive peptide is composed of two or more amino acids, and preferably has a molecular weight of about 200 to about 80,000. The bioactive peptide is preferably LH-RH (luteinizing hormone releasing hormone) or an analog thereof. Analogs of LH-RH include LH-RH agonists or LH-RH antagonists. Examples of the LH-RH agonist include a compound represented by the formula: (Pyr) Glu-R ₁ -Trp-Ser-R ₂ -R ₃ -R ₄ -Arg-Pro-R ₅ (I) wherein R ₁ is His, Tyr , Trp or p-NH ₂ -Phe; R ₂ is Tyr
Or Phe; R ₃ is a Gly or D type amino acid residue; R ₄ is Le
u, Ile or Nle; R ₅ is _{Gly-NH-R 6 (R} 6 is a hydrogen atom or a hydroxyl or without alkyl group) or NH-R ₇
(R ₇ represents a hydrogen atom, an alkyl group having or not having an amino or hydroxyl group, or ureido (-NH-CO-NH ₂ ))] (hereinafter abbreviated as peptide (I)) Or a salt thereof.

In the above formula (I), the D-type amino acid residue in R ₃ is, for example, an α-D-amino acid having up to 9 carbon atoms (eg, D-Leu, Ile, Nle, Val, Nval, Abu , Phe, Ph
g, Ser, Thr, Met, Ala, Trp, α-Aibu), etc., which are appropriately substituted (eg, tert-butyl, tert-butoxy, tert-butoxycarbonyl, methyl, dimethyl,
Trimethyl, 2-naphthyl, indolyl-3-yl, 2-methylindolyl, benzyl-imidazo-2-yl, etc.). In the formula (I), as the alkyl group for R ₆ or R ₇ , for example, a C _1-4 alkyl group is preferable, and examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. Butyl. Examples of the salt of peptide (I) include acid salts (eg, carbonate, bicarbonate, acetate, trifluoroacetate, propionate, succinate, etc.), metal complex compounds (eg, copper complex) , A zinc complex, etc.). Peptide (I) or a salt thereof is described, for example, in US Pat. No. 3,853,837.
No. 4,008,209, No. 3,972,859, British Patent No. 1,
423,083, Proceedings of the National Academy of Sciences of the United States of America
e National Academy of Sciences of the United State
s of America), Vol. 78, pp. 6509-6512 (1981), or a method analogous thereto.

The peptide (I) is preferably the following (a)
To (j). (A) Leuprorelin [in formula (I), R ₁ = His, R ₂ = Tyr, R ₃ = D-Leu, R ₄ = Leu, R ₅ = NHCH
Is ₂ -CH ₃ peptide]; (b) gonadorelin (Gonadre
lin)

Embedded image [German Patent No. 2213737]; (c) Buserelin (Buser
elin)

Embedded image [U.S. Pat. No. 4,024,248, German Patent No. 2,438,352, JP-A-51-41359]; (d) Triptoreli
n)

Embedded image [U.S. Pat. No. 4,010,125, JP-A-52-31073]; (e)
Goserelin

Embedded image [U.S. Pat. No. 4,100,274, JP-A-52-136172]; (f)
Nafarelin

Embedded image (U.S. Pat.No.4234571, JP-A-55-164663, JP-A-63
-264498, JP-A-64-25794]; (g) Histrelin

Embedded image (H) Deslorelin

Embedded image [U.S. Pat. No. 4,659,967, U.S. Pat. No. 4,218,439];
(I) Meterelin

Embedded image [WO9118016]; (j) Lecirelin

Embedded image [Belgian Patent No. 897455, JP-A-59-59654] and the like. In the above formulas (c) to (j), the amino acid corresponding to R ₃ in the formula (I) is a D-form. Peptide (I) or a salt thereof is particularly preferably leuprorelin or leuprorelin acetate. Here, leuprorelin acetate is an acetate of leuprorelin.

Examples of LH-RH antagonists include, for example, US Pat. Nos. 4,086,219, 4,124,577 and 4,25.
Nos. 3,997 and 4,317,815, or formulas

Embedded image Wherein X represents hydrogen or tetrahydrofurylcarboxamide, Q represents hydrogen or methyl, A represents nicotinoyl or N, N′-diethylamidino, and B represents isopropyl or N, N′-diethylamidino. [Hereinafter sometimes abbreviated as peptide (II)] or a salt thereof. In the formula (II), X
Is preferably tetrahydrofurylcarboxamide, and more preferably (2S) -tetrahydrofurylcarboxamide. A is preferably nicotinoyl. B is preferably isopropyl. When the peptide (II) has one or more asymmetric carbon atoms, two or more optical isomers exist. Such optical isomers and mixtures thereof are also included in the present invention.

The peptide (II) or a salt thereof can be produced by a method known per se. Examples of such a method include, for example, JP-A-3-016955, Journal of Medicinal Chemistry,
35, p. 3942, (1992), and the like. As the salt of peptide (II), a pharmacologically acceptable salt is preferably used. Such salts include inorganic acids (eg, hydrochloric acid, sulfuric acid,
Salts with organic acids (eg, carbonic acid, bicarbonate, succinic acid, acetic acid, propionic acid, trifluoroacetic acid, etc.). The salt of the peptide (II) is more preferably a salt with an organic acid (eg, carbonic acid, bicarbonate, succinic acid, acetic acid, propionic acid, trifluoroacetic acid, etc.). The salt of peptide (II) is particularly preferably a salt with acetic acid. These salts may be any of mono- or tri-salts.

Preferred examples of the peptide (II) or a salt thereof are shown below.

Embedded image [Wherein m represents a real number of 1 to 3] (3) NAcD2Nal-D4ClPhe-D3Pal-Ser-Tyr-DhArg (Et ₂ ) -Le
u-hArg (Et ₂ ) -Pro-DAlaNH ₂ (4) NAcD2Nal-D4ClPhe-D3Pal-Ser-Tyr-DhArg (Et ₂ ) -Le
u-hArg (Et ₂ ) -Pro-DAlaNH ₂ .n (CH ₃ COOH) wherein n represents a real number of 1 to 3. Peptide (II) or a salt thereof is particularly preferably the above (1), (2).

Examples of the physiologically active peptide include insulin, somatostatin, and somatostatin derivatives (Sandostatin, US Pat. Nos. 4,087,390 and 4,093,574).
No. 4,100,117 and 4,253,998), growth hormone, prolactin, adrenocorticotropic hormone (ACT
H), ACTH derivatives (eg, eviratide), melanocyte stimulating hormone (MSH), thyroid hormone-releasing hormone [represented by the structural formula of (Pyr) Glu-His-ProNH ₂ , sometimes abbreviated as TRH] And its derivatives (see JP-A-50-121273 and JP-A-52-116465),
Thyroid stimulating hormone (TSH), luteinizing hormone (L
H), follicle-stimulating hormone (FSH), vasopressin, vasopressin derivative {see desmopressin [Journal of the Japan Endocrine Society, Vol. 54, No. 5, pp. 676-691 (1978)]}, oxytocin, calcitonin, parathyroid hormone (PT
H), glucagon, gastrin, secretin, pancreozimine, cholecystokinin, angiotensin, human placental lactogen, human chorionic gonadotropin (HC
G), enkephalins, enkephalin derivatives (see U.S. Pat. No. 4,277,394, European Patent Application Publication No. 31567), endorphins, kyotorphins, interferons (eg, α-type, β-type, γ-type, etc.), interleukins (E.g. 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, etc.), tuftsin, thymopoietin, thymosin, thymostimulin, thymic humoral factor (THF),
Blood thymic factor (FTS) and its derivatives (US Patent No.
No. 4,229,438), and other thymic factors [Ayumi Yakuhin, Vol. 125, No. 10, pp. 835-843 (1983)], tumor necrosis factor (TNF), colony-inducing factor (CSF, GC)
SF, GMCSF, MCSF, etc.), motilin, dynorphin, bombesin, neurotensin, caerulein,
Bradykinin, urokinase, asparaginase, kallikrein, substance P, insulin-like growth factors (IGF-I, IGF-II), nerve growth factor (NG
F), cell growth factors (EGF, TGF-α, TGF-
β, PDGF, acidic FGF, basic FGF, etc., bone morphogenetic factor (BMP), neurotrophic factor (NT-3, NT-4,
CNTF, GDNF, BDNF, etc.)
Factor VIII, factor IX, lysozyme chloride, polymyxin B, colistin, gramicidin, bacitracin and erythropoietin (EPO), thrombopoietin (TP
O), peptides having endothelin antagonism (European Patent Publication Nos. 436189, 457195, and 496452)
And JP-A-3-94692 and JP-A-3-130299).

Examples of the antitumor agent include bleomycin, methotrexate, actinomycin D, mitomycin C, vinblastine sulfate, vincristine sulfate,
Daunorubicin, adriamycin, neocarzinostatin, cytosine arabinoside, fluorouracil, tetrahydrofuryl-5-fluorouracil, krestin,
Picibanil, lentinan, levamisole, bestatin, azimexone, glycyrrhizin, poly I: C, poly A: U, poly ICLC and the like. As antibiotics, for example, gentamicin, dibekacin, canendomycin, lividomycin, tobramycin, amikacin, fradiomycin, sisomicin, tetracycline hydrochloride, oxytetracycline hydrochloride, lolitetracycline, doxycycline hydrochloride, ampicillin, piperacillin, ticarcillin, cephalothin, cephaloridine, Cefotiam, cefsulodin, cefmenoxime, cefmetazol, cefazolin, cefotaxime, cefoperazone, ceftizoxime, moxalactam, thienamycin, sulfazecin, azuleonam and the like. Antipyretics, analgesics, and anti-inflammatory agents include, for example, salicylic acid, sulpyrine, flufenamic acid, diclofenac,
Indomethacin, morphine, pethidine hydrochloride, levorphanol tartrate, oxymorphone and the like can be mentioned.

Examples of antitussive expectorants include ephedrine hydrochloride, methylephedrine hydrochloride, noscapine hydrochloride, codeine phosphate, dihydrocodeine phosphate, alloclamide hydrochloride, clofedanol hydrochloride, picoperidamine hydrochloride, cloperastine, protochlorol hydrochloride, isoproterenol hydrochloride , Salbutamol sulfate, terbutaline sulfate, and the like. Examples of the sedative include chlorpromazine, prochlorperazine, trifluoroperazine, atropine sulfate, methylscopolamine bromide and the like. Examples of the muscle relaxant include pridinol methanesulfonate, tubocurarine chloride, pancuronium bromide and the like. Examples of antiepileptic drugs include phenytoin,
Ethosuximide, acetazolamide sodium, chlordiazepoxide and the like can be mentioned. Examples of the anti-ulcer agent include metoclopromide and histidine hydrochloride. Examples of the antidepressant include imipramine, clomipramine, noxiptiline, phenelzine sulfate and the like.

Examples of the antiallergic agent include diphenhydramine hydrochloride, chlorpheniramine maleate, tripelenamine hydrochloride, methdilazine hydrochloride, clemizole hydrochloride, diphenylpyraline hydrochloride, methoxyphenamine hydrochloride and the like. Examples of the cardiotonic agent include transpyoxocamphor, theophyllol, aminophylline, and ethylrefrin hydrochloride. Examples of antiarrhythmic agents include propranol, alprenolol,
Bufetrol, oxyprenolol and the like. Examples of vasodilators include oxyfedrine hydrochloride, diltiazem, tolazoline hydrochloride, hexobendine,
Bamethane sulfate and the like can be mentioned. As antihypertensive diuretics,
Examples include hexamethonium bromide, pentolinium, mecamylamine hydrochloride, ecarazine hydrochloride, clonidine and the like. Examples of the therapeutic agent for diabetes include glymidine sodium, glipizide, phenformin hydrochloride, buformin hydrochloride, metformin and the like. Examples of antilipidemic agents include pravastatin sodium,
Simvastatin, clinofibrate, clofibrate, simfibrate, bezafibrate and the like can be mentioned. Examples of the anticoagulant include heparin sodium and the like. Examples of the hemostatic agent include thromboplastin, thrombin, menadione sodium bisulfite, acetomenaphthone, ε-aminocaproic acid, tranexamic acid, sodium carbazochrome sulfonate, adrenochrome monoaminoguanidine methanesulfonate, and the like.

Examples of antituberculous agents include isoniazid,
Ethambutol, para-aminosalicylic acid and the like. Hormonal agents include, for example, prednisolone, sodium prednisolone, dexamethasone sodium sulfate, betamethasone sodium phosphate, hexestrol phosphate, hexestrol acetate, methimazole and the like. Examples of the narcotic antagonist include levallorphan tartrate, nalorphine hydrochloride, naloxone hydrochloride and the like. Examples of the bone resorption inhibitor include ipriflavone and the like. Examples of the bone formation promoter include polypeptides such as BMP, PTH, TGF-β, and IGF-1, and (2R, 4S)-(−)-N- [4- (diethoxyphosphorylmethyl) phenyl] -1, 2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxamide, 2- (3-pyridyl) -ethane-1,1-diphosphonic acid, etc. No. Examples of the angiogenesis inhibitor include, for example, angiogenesis inhibitory steroid [Science No. 221].
Volume 719 (1983)], fumagillin (see European Patent Publication No. 325199), fumagillol derivatives (European Patent Publication Nos. 357061, 359036 and 3866).
No. 67, No. 415294).

The physiologically active substance may be itself or a pharmacologically acceptable salt. For example, when the physiologically active substance has a basic group such as an amino group, an inorganic acid (eg, hydrochloric acid, sulfuric acid, nitric acid, etc.) or an organic acid (eg, carbonic acid,
And succinic acid). When the physiologically active substance has an acidic group such as a carboxy group, an inorganic base (eg, an alkali metal such as sodium or potassium) or an organic base compound (eg, an organic amine such as triethylamine, a basic amino acid such as arginine) ) Are used.

In the present invention, the bioactive substance is preferably a bioactive peptide, more preferably LH-RH or an analog thereof, particularly preferably leuprorelin or leuprorelin acetate.

As the biodegradable polymer, a biodegradable polymer having a free carboxyl group at a terminal is preferably used. Here, the biodegradable polymer having a free carboxyl group at the terminal is GPC
It is a biodegradable polymer in which the number average molecular weight determined by measurement and the number average molecular weight determined by terminal group quantification are almost the same. The number average molecular weight by terminal group quantification is calculated as follows.
About 1 to 3 g of the biodegradable polymer is added to acetone (25 m
l) and methanol (5 ml), and the carboxylic group in this solution was rapidly titrated with a 0.05N alcoholic potassium hydroxide solution under stirring at room temperature (20 ° C.) using phenolphthalein as an indicator. The number average molecular weight is calculated from the following equation. Number average molecular weight by terminal group determination = 20,000 × A / B A: mass of biodegradable polymer (g) B: amount of 0.05N alcoholic potassium hydroxide solution added by the end of titration (ml) For example, one type In a polymer synthesized from the above α-hydroxy acids by a noncatalytic dehydration polycondensation method and having a free carboxyl group at a terminal, the number average molecular weight by GPC measurement and the number average molecular weight by terminal quantification are almost the same. On the other hand, a polymer synthesized from a cyclic dimer by a ring-opening polymerization method using a catalyst and having substantially no free carboxyl group at the terminal has a number-average molecular weight determined by GPC of the terminal group.
It greatly exceeds the number average molecular weight measured. By this difference, a polymer having a free carboxyl group at a terminal can be clearly distinguished from a polymer having no free carboxyl group at a terminal.

While the number average molecular weight determined by terminal group quantification is an absolute value, the number average molecular weight determined by GPC is determined by various analysis and analysis conditions (eg, the type of mobile phase, column type, reference material, selection of slice width, This is a relative value that varies depending on the selection of a baseline or the like. For this reason, it is difficult to associate both with a unique numerical value. For example, the number average molecular weight determined by GPC and the number average molecular weight determined by terminal group quantification almost agree with each other when the number average molecular weight determined by terminal group quantification is determined by the number determined by GPC measurement. About 0.4 times to about 2 times the average molecular weight
Times, preferably about 0.5 to about 2 times, more preferably about 0.8 to about 1.5 times. Also, the expression that the number average molecular weight determined by the terminal group determination greatly exceeds the number average molecular weight determined by the GPC measurement means that the number average molecular weight determined by the end group determination exceeds about twice the number average molecular weight determined by the GPC measurement. Specific examples of the biodegradable polymer having a free carboxyl group at its terminal include, for example, α-hydroxy acids (eg, glycolic acid, lactic acid, hydroxybutyric acid, etc.), hydroxydicarboxylic acids (eg, malic acid, etc.),
Polymers, copolymers, or mixtures thereof, poly-α-cyanoacrylates, polyamino acids (eg, hydroxytricarboxylic acids (eg, citric acid, etc.)) synthesized by non-catalytic dehydration polycondensation from at least one kind thereof , Poly-γ-benzyl-L-glutamic acid, etc.), maleic anhydride copolymers (eg, styrene-maleic acid copolymers) and the like.

In the biodegradable polymer described above,
The type of polymerization may be random, block, or graft. When the α-hydroxy acids, hydroxydicarboxylic acids, and hydroxytricarboxylic acids have an optically active center in the molecule, D-, L-, and DL-
Any of the bodies can be used. The biodegradable polymer having a free carboxyl group at the terminal is preferably (1) a lactic acid-glycolic acid polymer (a homopolymer such as polylactic acid or polyglycolic acid, or a copolymer of lactic acid and glycolic acid). Or (2) (A) glycolic acid and a general formula

Embedded image (Wherein, R represents an alkyl group having 2 to 8 carbon atoms) with a hydroxycarboxylic acid represented by the formula (B):
Biodegradable polymer mixed with polylactic acid.

When a lactic acid-glycolic acid polymer is used as the biodegradable polymer, its composition ratio (lactic acid / glycolic acid) (mol%) is preferably about 100/0 to about 40/60. The composition ratio is more preferably about 90/10 to about 50/50.
It is. The weight average molecular weight of the lactic acid-glycolic acid polymer is preferably from about 5,000 to about 25,000. The weight average molecular weight is more preferably from about 7,000 to about 20,000. The dispersity (weight average molecular weight / number average molecular weight) of the lactic acid-glycolic acid polymer is preferably from about 1.2 to about 4.0. The degree of dispersion is more preferably from about 1.5 to about 3.5. The lactic acid-glycolic acid polymer can be produced according to a known production method, for example, a production method described in JP-A-61-28521.

The decomposition / elimination rate of a lactic acid-glycolic acid polymer greatly varies depending on the composition or molecular weight. However, in general, the lower the glycolic acid fraction, the slower the decomposition / elimination. Alternatively, the release period can be extended by increasing the molecular weight. Conversely, the release period can be shortened by increasing the glycolic acid fraction or decreasing the molecular weight. In order to form a long-term (for example, 1 to 4 months) sustained release preparation, a lactic acid-glycolic acid polymer having the above composition ratio and weight average molecular weight is preferable. When a lactic acid-glycolic acid polymer that decomposes faster than the lactic acid-glycolic acid polymer in the range of the above composition ratio and weight average molecular weight is selected, it is difficult to suppress the initial burst, and conversely, the above composition ratio and weight average molecular weight When a lactic acid-glycolic acid polymer having a lower decomposition rate than that of the lactic acid-glycolic acid polymer is selected, a period in which an effective amount of the drug is not released is likely to occur.

In the above general formula (III), examples of the linear or branched alkyl group having 2 to 8 carbon atoms represented by R include ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl and the like. -Butyl, pentyl, isopentyl, neopentyl, tert-pentyl, 1-
Ethylpropyl, hexyl, isohexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl,
2-ethylbutyl and the like. Preferably, a linear or branched alkyl group having 2 to 5 carbon atoms is used. Specific examples include, for example, ethyl, propyl, isopropyl, butyl, isobutyl and the like. Particularly preferably, R is ethyl.

The hydroxycarboxylic acid represented by the general formula (III) includes, for example, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxycaproic acid, 2-hydroxyisocaproic acid , 2-hydroxycapric acid and the like. Of these, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxy-3-methylbutyric acid, and 2-hydroxycaproic acid are particularly preferred. The hydroxycarboxylic acid represented by the general formula (III) is particularly preferably 2-hydroxybutyric acid. These hydroxycarboxylic acids may be any of D-form, L-form and D, L-form, but those having D-form / L-form (mol%) in the range of about 75/25 to about 25/75. Is preferred. The D-form / L-form (mol%) is more preferably about 60/40 to about 40/60, particularly preferably about 55/45 to about 45/55.

In a copolymer of glycolic acid and a hydroxycarboxylic acid represented by the general formula (III) (hereinafter abbreviated as glycolic acid copolymer (A)), the copolymerization mode is random, block, or graft. Any of Preferably, it is a random copolymer. One or more hydroxycarboxylic acids represented by the general formula (III) may be used in an appropriate ratio. In the glycolic acid copolymer (A), the composition ratio of glycolic acid to the hydroxycarboxylic acid represented by the general formula (III) is preferably about 10 to about 75 mol%, and the remainder is hydroxycarboxylic acid. . More preferably, the glycolic acid is from about 20 to about 75 mole%, the balance being hydroxycarboxylic acid. Particularly preferably, glycolic acid is about
40 to about 70 mol%, the balance being hydroxycarboxylic acid. These glycolic acid copolymers having a weight average molecular weight of about 2,000 to about 50,000 are used. The weight average molecular weight is preferably from about 3,000 to about 40,000, more preferably from about 8,000 to about 30,000. The degree of dispersion of these glycolic acid copolymers (weight average molecular weight /
Number average molecular weight) is preferably from about 1.2 to about 4.0, particularly preferably from about 1.5 to about 3.5. The glycolic acid copolymer (A) can be produced according to a known production method, for example, a method described in JP-A-61-28521.

The polylactic acid of the above (B) includes L-form,
Any of the D-form and a mixture thereof may be used.
Those having an L-form (mol%) in the range of about 75/25 to about 20/80 are preferred. The D-form / L-form (mol%) is more preferably about 60/40 to about 25/75, particularly preferably about 55/45 to about 25/75. The weight average molecular weight of the polylactic acid is
Preferably it is from about 1,500 to about 30,000. The weight average molecular weight is more preferably from about 2,000 to about 20,000, particularly preferably from about 3,000 to about 15,000. The polylactic acid preferably has a degree of dispersion of about 1.2 to about 4.0, particularly preferably about 1.5 to about 3.5. As a method for producing polylactic acid, a method of ring-opening polymerization of lactide, which is a dimer of lactic acid, and a method of dehydrating and polycondensing lactic acid are known. In order to obtain a relatively low molecular weight polylactic acid used in the present invention, a method of directly dehydrating and polycondensing lactic acid is preferred. Such a method is performed, for example, according to the method described in JP-A-61-28521 or a method similar thereto.

The glycolic acid copolymer (A) and the polylactic acid (B) are used in a mixing ratio (% by weight) represented by (A) / (B) of about 10/90 to about 90/10. Is done. The mixing ratio (% by weight) is preferably about 20/80 to about 8
0/20, more preferably about 30/70 to about 70/30.
If any one of (A) and (B) is too large, (A)
Alternatively, only a preparation having almost the same drug release pattern as when the component (B) is used alone can be obtained, and a linear release pattern in the latter half of the release by the mixed base cannot be expected. Decomposition / elimination rates of the glycolic acid copolymer (A) and polylactic acid greatly vary depending on the molecular weight or composition, but generally, the decomposition / elimination rate of the glycolic acid copolymer (A) is reduced.
Since the elimination rate is higher, the release period can be lengthened by increasing the molecular weight of the polylactic acid to be mixed or decreasing the mixing ratio represented by (A) / (B). Conversely, the release period can be shortened by reducing the molecular weight of the polylactic acid to be mixed or by increasing the mixing ratio represented by (A) / (B).
Further, the release period can be adjusted by changing the type and ratio of the hydroxycarboxylic acid represented by the general formula (III).

The biodegradable polymer having a terminal free carboxyl group is more preferably a lactic acid-glycolic acid polymer. Above all, a lactic acid-glycolic acid polymer having a composition ratio (lactic acid / glycolic acid) (mol%) of 100/0 is polylactic acid, and when microspheres are produced using the polylactic acid, the obtained microspheres are obtained. Spheres can release bioactive substances stably over a long period of about 3 months or more. Therefore, the biodegradable polymer having a free carboxyl group at the terminal is particularly preferably polylactic acid.

In the present invention, the W / O / W emulsion and the O / W emulsion each include (i) an aqueous solution, dispersion or suspension of a physiologically active substance as an internal aqueous phase, and an organic solvent of a biodegradable polymer. A W / O emulsion having a solution as an oil phase is obtained, or (ii) a physiologically active substance is dissolved or suspended in an organic solvent solution of a biodegradable polymer to obtain an oil phase, and the (i) or (ii) Is added to water (outer aqueous phase), and dispersed and emulsified.

The above-mentioned (i), that is, a W / O emulsion in which an aqueous solution, dispersion or suspension of a physiologically active substance is used as an internal aqueous phase and an organic solvent solution of a biodegradable polymer is used as an oil phase is as follows. Manufactured. First, a physiologically active substance is dissolved, dispersed or suspended in water to produce an internal aqueous phase. The concentration of the physiologically active substance in an aqueous solution, dispersion or suspension is
For example, 0.001-90% (w / w), preferably 0.01-80% (w / w)
It is. The amount of the physiologically active substance used varies depending on the type of the physiologically active substance, the desired pharmacological effect and the duration of the effect, but is about 0.01 to about 50% (w / w) with respect to the biodegradable polymer. Preferably from about 0.1 to about 40% (w / w), particularly preferably from about 1 to about 30% (w / w). If necessary, drug retention of gelatin, agar, sodium alginate, polyvinyl alcohol or basic amino acids (eg, arginine, histidine, lysine) in the internal aqueous phase to increase the incorporation of bioactive substances into the microspheres Substances may be added. The amount of the drug-retaining substance to be added is usually 0.01 to 10 times the weight of the physiologically active substance. The internal aqueous phase may be freeze-dried once into a powder state, and then dissolved by adding water so as to have an appropriate concentration.

Separately, the biodegradable polymer is dissolved in an organic solvent to produce an oil phase. Examples of the organic solvent include halogenated hydrocarbons (eg, dichloromethane, chloroform, chloroethane, trichloroethane, carbon tetrachloride, etc.), fatty acid esters (eg, ethyl acetate, butyl acetate, etc.), aromatic hydrocarbons (eg, benzene, toluene) , Xylene, etc.), of which dichloromethane is preferred. The concentration of the biodegradable polymer in the organic solvent varies depending on the type of the biodegradable polymer, the molecular weight, and the type of the organic solvent, but is usually 0.01 to 90% (w / w), preferably 0.01 to 70% (w / w). w / w)
It is. It is better to dissolve so that there is no undissolved matter. An aqueous solution, dispersion or suspension (inner aqueous phase) of the above-mentioned physiologically active substance is added to the organic solvent solution (oil phase) of the biodegradable polymer obtained in this way, and dispersed by a homomixer or the like. Emulsify to produce a W / O emulsion.

On the other hand, the above (ii), that is, the oil phase obtained by dissolving or suspending a physiologically active substance in an organic solvent solution of a biodegradable polymer is produced as follows. First, an organic solvent solution of a biodegradable polymer is prepared. As the organic solvent, the same organic solvent as that used in producing the W / O emulsion is used. The concentration of the biodegradable polymer in the organic solvent solution is
Although it depends on the molecular weight of the biodegradable polymer and the type of organic solvent, it is usually about 0.01 to about 70% (w / w), preferably about 1 to about 60% (w / w). Next, the physiologically active substance is dissolved or suspended in an organic solvent solution of the biodegradable polymer to produce an oil phase. The amount of the physiologically active substance used is such that the ratio of the physiologically active substance to the biodegradable polymer is W /
What is necessary is just to select so that it may become the same as that of manufacturing O emulsion (i). Further, the physiologically active substance used in (ii) is preferably water-insoluble or hardly water-soluble.

Next, the above-mentioned (i) W / O emulsion or (ii) oil phase is added to the external aqueous phase, and dispersed and emulsified by using a homomixer or the like, and the resulting mixture is respectively W / O / W emulsion or O / W. Produce an emulsion. The amount of the outer aqueous phase used is usually from 1 to 10,000 times, preferably from 10 to 2000 times, particularly preferably from 50 to 50 times the above (i) or (ii).
0 times the volume. An emulsifier is usually added to the external aqueous phase. The emulsifier may be any as long as it can generally form a stable W / O / W emulsion or O / W emulsion. Examples of the emulsifier include an anionic surfactant, a nonionic surfactant, and polyoxyethylene castor oil. Derivatives, polyvinylpyrrolidone, polyvinylalcohol, carboxymethylcellulose, lecithin, gelatin, hyaluronic acid and the like are mentioned, with polyvinyl alcohol being preferred. The concentration of the emulsifier in the external aqueous phase is usually 0.001 to 20
% (W / w), preferably 0.01 to 10% (w / w), particularly preferably
0.05 to 5% (w / w).

The thus obtained W / O / W emulsion or O / W emulsion (hereinafter sometimes abbreviated to simply as emulsion) is subjected to an underwater drying method to obtain an organic solvent contained in these emulsions. To produce microspheres. Hereinafter, various preferable conditions for performing the underwater drying method will be described in detail.
The relationship between the external aqueous phase and the microspheres is represented, for example, by the relationship between the volume of the external aqueous phase and the amount of the microspheres (the total weight of the bioactive substance, the drug-retaining substance and the biodegradable polymer), The amount of microspheres per 1 m ^{3 of the} external water phase is about 0.1 to about 500 kg, preferably about 0.5 to about 100 k.
g, more preferably about 1.0 to about 20 kg.

The underwater drying method is carried out in a suitable container, preferably a closed container protected from the outside. The relationship between the container and the external aqueous phase is expressed, for example, by the relationship between the capacity of the external aqueous phase and the area where the external aqueous phase contacts the gas phase. In the present invention, the ratio of the cubic root of the volume of the external aqueous phase (unit: m ³ ) to the square root of the area of the liquid surface in contact with the gas phase (unit: m ² ) is 1:
About 0.2 to about 4.5, preferably 1: about 0.5 to about 3.0. In addition, depending on the size and shape of the container, the amount of microspheres in the external water phase per 1 m ^{2 of} the liquid surface in contact with the gas phase is as follows:
Preferably about 0.01 to about 7000 kg, more preferably about 0.02
From about 100 kg, particularly preferably from about 0.05 to about 20 kg.

The emulsion is preferably fluidized. The flow of the emulsion can be carried out by circulation or stirring. For example, circulation is performed by sucking a part of the emulsion from the bottom of the container by a pump, passing the pipe through a pipe, and returning the emulsion into the container from the top of the container. The stirring may be performed by a stirring means in a reactor used for ordinary chemical synthesis or the like, and can be performed by a stirring blade or a magnet stirrer. In this case, it is preferable to carry out the process so that the emulsion in the container flows uniformly. The above-mentioned degree of circulation or stirring is represented by the number of times of replacement of the emulsion. The number of replacements is indicated by the reciprocal of the average residence time. For example, when the emulsion is circulated using a pump, the number of times of replacement of the emulsion is a value obtained by dividing the circulating flow rate per minute by the amount of the emulsion in the container.
When the emulsion is stirred, the number of times of replacement of the emulsion is a value obtained by dividing the average angular velocity of the emulsion by 2π. In the underwater drying method of the present invention, the replacement frequency of the emulsion is about 0.01 to about 10 times / minute, preferably about 0.1 to about 10 times / minute.
It is about 10 times / minute, more preferably about 0.5 to about 10 times / minute.

It is preferred that a gas be present above the liquid level of the emulsion. The gas may be any gas that does not adversely affect the underwater drying method. Examples of such a gas include air, carbon dioxide gas, nitrogen gas, and argon gas.
Helium gas and the like can be mentioned. Since the gas existing above the liquid surface of the emulsion contains the organic solvent evaporated from the emulsion, it is desirable to take out a part of the gas and replace it with a new one that does not contain the organic solvent. The replacement of the gas is performed, for example, by blowing the gas toward the liquid surface of the emulsion. As the gas blown to the liquid surface of the emulsion, the same kind of gas as the gas on the liquid surface of the emulsion is usually used. Such a gas is blown from one or more places near the liquid surface at a flow rate of about 10 to about 1000 liters / minute, for example, from a hole having an inner diameter of about 0.2 to about 1.5 cm. The gas flow rate is preferably from about 50 to about 500 l / min, more preferably from about 100 to about 400 l / min. The pressure of the gas is, for example, about 0.3 to about 4.0 kg / c.
m ² , preferably from about 0.5 to about 3.0 kg / cm ² . further,
The velocity of gas movement near the liquid level of the emulsion is approximately
0.1 to about 300 m / sec, preferably about 10 to about 200 m / sec, more preferably about 50 to about 150 m / sec. In the gas replacement, the number of replacements of the gas in the container is about 0.5 times / minute or more, preferably about 0.5 to about 10 times / minute, more preferably about 1 to about 1 / minute.
It is performed so as to be 0 times / minute. By employing the above various conditions, the underwater drying method is usually completed in a short time of about 0.5 to about 5 hours.

The microspheres thus obtained are recovered by centrifugation or a sieve or the like, and if necessary, a sugar or sugar alcohol, an inorganic salt or the like, preferably mannitol, sorbitol or the like for preventing aggregation of the microspheres. And then freeze-dried. The mixing ratio (weight ratio) of the microspheres and the anti-agglomeration agent is 50: 1 to 1: 1, preferably 20: 1 to 1: 1,
More preferably, it is 10: 1 to 5: 1. The method of adding the anti-agglomeration agent is not particularly limited as long as the microspheres and the anti-agglomeration agent are uniformly mixed, and examples thereof include a method of dispersing the microspheres in an aqueous solution of the anti-agglomeration agent.

The microsphere of the present invention can be administered to a living body as it is, or can be administered after being molded into various preparations. Examples of such preparations include injections, implants, oral preparations (eg, powders, granules, capsules, tablets, syrups, emulsions, suspensions, etc.), nasal preparations, suppositories (eg, , Rectal suppositories, vaginal suppositories, etc.). These preparations can be produced by a known method generally used in the field of preparations. For example, injections are produced by dispersing microspheres in an aqueous or oily dispersion medium. Examples of the aqueous dispersion medium include isotonic agents (eg, sodium chloride, glucose, D-mannitol, sorbitol, glycerin, etc.) and dispersants (eg, Tween 8) in distilled water.
0, HCO-50, HCO-60 (Nikko Chemicals), carboxymethylcellulose, sodium alginate), preservatives (eg, benzyl alcohol, benzalkonium chloride, phenol, etc.), soothing agents (eg, glucose, calcium gluconate) , Procaine hydrochloride, etc.). Examples of the oily dispersion medium include olive oil, sesame oil, peanut oil, soybean oil, corn oil, and medium-chain fatty acid glycerides. The injection may be filled in a chamber of a prefilled syringe. Further, the above-described dispersion medium and microspheres may be separately filled in different chambers of a syringe having two chambers, that is, a double chamber prefilled syringe (DPS).

Formulations for oral administration include, for example, microspheres, excipients (eg, lactose, sucrose, starch, etc.), disintegrants (eg, starch, calcium carbonate, etc.), binders (eg,
Add starch, gum arabic, carboxymethylcellulose, polyvinylpyrrolidone, hydroxypropylcellulose, etc.) and lubricants (eg, talc, magnesium stearate, polyethylene glycol 6000, etc.) and press-mold and then, if necessary, taste It can be produced by coating by a method known per se for the purpose of masking, enteric coating or sustaining. Examples of the coating agent include hydroxypropylmethylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, polyoxyethylene glycol, Tween 80, Bruronic F68, cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, hydroxymethylcellulose acetate succinate, and Eudragit (manufactured by Rohm). ,
West Germany, methacrylic acid / acrylic acid copolymer) and pigments (eg, titanium oxide, red iron oxide, etc.) are used.

The preparation for nasal administration may be solid, semi-solid or liquid. A solid nasal administration preparation may be, for example, microspheres as they are, but usually, microspheres contain excipients (eg, glucose, mannitol, starch, microcrystalline cellulose, etc.), thickeners (eg,
It can be produced by adding and mixing natural gums, cellulose derivatives, acrylic acid polymers and the like. For example, a liquid nasal preparation can be produced in the same manner as in the case of the injection described above. In addition, all of these nasal administration preparations include a pH regulator (eg, carbonic acid, phosphoric acid, citric acid, hydrochloric acid, sodium hydroxide, etc.), a preservative (eg,
Paraoxybenzoic acid esters, chlorobutanol, benzalkonium chloride, etc.).

The suppository may be oily or aqueous, and may be solid, semi-solid or liquid. Suppositories are usually prepared using an oily, aqueous or aqueous gel base. Examples of the oily base include glycerides of higher fatty acids (eg, cocoa butter, witepsols (Dynamite Nobel), etc.), intermediate fatty acids [eg,
Miglyols (Dynamite Nobel) and vegetable oils (eg, sesame oil, soybean oil, cottonseed oil, etc.). Examples of the aqueous base include polyethylene glycols and propylene glycol. Examples of the aqueous gel base include natural gums, cellulose derivatives, vinyl polymers, acrylic acid polymers and the like.

The microsphere of the present invention is preferably used as an injection. The particle size of the microspheres may be within a range that satisfies dispersibility and needle penetration when used as an injection. For example, the average diameter is from about 1 to about
It is 300 μm, preferably about 5 to about 100 μm.

The microspheres of the present invention and preparations containing the microspheres (hereinafter, abbreviated as microsphere preparations) have low toxicity and can be used safely. The dosage of the microsphere preparation depends on the type and content of the bioactive substance as the main drug, dosage form, duration of release of the bioactive substance, animals to be administered (eg, mice, rats,
Warm-blooded mammals such as horses, cattle and humans) and the purpose of administration, but may be any effective amount of the main drug. For example, as a dose per adult (50 kg body weight), the weight of the microsphere can be appropriately selected from the range of about 1 mg to about 10 g, preferably about 10 mg to about 2 g. The volume of the dispersion medium when the microsphere preparation is an injection can be appropriately selected from the range of about 0.5 to about 3 ml. In particular, when the bioactive substance is, for example, peptide (I), (II) or a salt thereof, hormones such as prostate cancer, prostatic hyperplasia, breast cancer, endometriosis, uterine fibroids, central precocious puberty, etc. A microsphere preparation useful as a prophylactic / therapeutic agent or a contraceptive for a dependent disease can be obtained. In particular, in a microsphere preparation, when the physiologically active substance is peptide (I) or a salt thereof, the preparation is an injection, and the preparation is used as a prophylactic or therapeutic agent for the above-mentioned diseases, the adult (body weight) of the preparation
50 kg) The dose per one person is preferably about 1 to about 10 mg as peptide (I) or a salt thereof.
0 mg, more preferably about 1 to about 10 mg.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples and Experimental Examples, but the present invention is not limited to these without departing from the gist thereof. In addition,% shows weight% unless otherwise specified.

【Example】

Example 1 65.0 g of leuprorelin acetate and 10.3 g of gelatin were weighed into an eggplant-type kolben, and 66 ml of water for injection was added and completely dissolved. To this, 521.9 g of a lactic acid-glycolic acid copolymer [lactic acid / glycolic acid = 75/25 (mol%), weight average molecular weight: about 11,000] dissolved in 873.6 g of dichloromethane (methylene chloride) was added, and an auto mini mixer was added. For 10 minutes to obtain a W / O emulsion. 20
After injecting 150 liters of 0.1% aqueous solution of polyvinyl alcohol (Gohsenol EG40) (hereinafter abbreviated as PVA aqueous solution) (outer aqueous phase) into a 0 liter tank, the above-mentioned W / O emulsion was added to the aqueous solution, and the mixture was stirred and emulsified. And
A W / O / W emulsion was obtained. Although there was adhesion to the inside of the Kolben and the inside of the pipe, the W / O emulsion actually injected into the tank was 99% or more. W obtained
The / O / W emulsion was dried in water for 3 hours under the following conditions. Container size: The amount of 200 l gas-phase: the amount a 50 liter external aqueous phase: the amount of microspheres 150 liters external aqueous phase 1 m ³ per: The amount of microspheres 4.0kg external aqueous phase: contacting the vapor phase 1.2 kg per 1 m ^{2 of} liquid surface ratio Ratio of cubic root of external water phase capacity (unit: m ³ ) to square root of liquid surface area (unit: m ² ) that comes into contact with gas: 1: 1.3 Number of emulsion replacement: 1.3 times / minute (200 liters /
Min) The moving speed of the gas near the liquid surface: 100 m / sec The number of times of replacement of the gas above the liquid surface: 6 times / min The flow of the emulsion is the circulation of the emulsion, that is, the flow of the emulsion from the bottom of the tank through a pipe. This was done by removing the part and returning it to the top of the liquid phase by a pump through a pipe. The flow of gas near the liquid surface is compressed air at a flow rate of 300 l / min from a pipe having an inner diameter of 6 mm at an angle of about 30 degrees with respect to the liquid surface from about 10 cm above the liquid level. It was done by doing. After drying in water, collect the resulting microspheres,
Mannitol (94.1 g) was added and freeze-dried to obtain microsphere powder.

Example 2 Lactic acid / glycolic acid copolymer [lactic acid / glycolic acid copolymer] was added to an aqueous solution in which 0.5 g of thyroid hormone releasing hormone (TRH) was dissolved in 0.2 g of water.
Glycolic acid = 75/25 (W / W), weight average molecular weight: about 1
4,000], a dichloromethane (4.9 ml) solution containing 4.5 g was added to obtain a W / O emulsion. The whole amount of this W / O emulsion was dispersed in 1 liter of a 0.1% PVA aqueous solution (outer aqueous phase) to obtain a W / O / W emulsion. The W / O /
The W emulsion was dried in water for 3 hours under the following conditions. Container size: The amount of 2.5 liters gas phase: the amount of 1.5 liters external aqueous phase: the amount of microspheres per liter external aqueous phase 1 m ^3: The amount of microspheres 5kg external aqueous phase: contacting the vapor phase 0.09 kg per 1 m ^{2 of} liquid level Ratio of cubic root of external water phase capacity (unit: m ³ ) to square root of liquid surface area (unit: m ² ) in contact with gas: 1: 2.4 Number of emulsion replacement: 1.9 Times / minute (average angular velocity 3.8π
/ Min) Movement speed of gas near the liquid surface: 100m / sec Number of times of replacement of gas above the liquid surface: 5 times / min In addition, the emulsion flows by stirring the emulsion in the tank using a stirrer. Was performed. In addition, the flow of gas near the liquid level starts from about 5 cm above the liquid level,
This was performed by blowing nitrogen at a flow rate of 100 liters / minute from a pipe having an inner diameter of 3 mm at an angle of about 20 degrees with respect to the liquid surface. After drying in water, the microspheres were collected by centrifugation and lyophilized. By performing nitrogen blowing, compared with microspheres prepared without performing,
Drug incorporation into microspheres increased by 4%.

Example 3 119.3 g of leuprorelin acetate and 18.7 g of gelatin were weighed into an eggplant-type kolben, and 120 ml of water for injection was added to completely dissolve it. Lactic acid-glycolic acid copolymer [lactic acid / glycolic acid = 75/25 (mol%), weight average molecular weight: about 11,000] dissolved in 1602.8 g of dichloromethane 95
7.2 g was added and the mixture was stirred and emulsified for 10 minutes with an auto homomixer to obtain a W / O emulsion. After injecting 200 liters of 0.1% PVA aqueous solution (outer aqueous phase) into a 360 liter tank, the above-mentioned W / O emulsion was added to the aqueous solution,
The mixture was stirred and emulsified to obtain a W / O / W emulsion. Although there was adhesion to the inside of the Kolben and the inside of the pipe, the W / O emulsion actually injected into the tank was 99% or more. The obtained W / O / W emulsion was dried in water for 3 hours under the following conditions. Container size: 360 liters Volume of gas phase: 160 liters Volume of external water phase: 200 liters Volume of microspheres per 1 m ^{3 of} external water phase: about 5.5 kg Volume of microspheres in external water phase: gas phase Approximately 2.2 kg per 1 m ^{2 of} liquid level in contact The ratio of the cubic root of the volume of the external aqueous phase (unit: m ³ ) to the square root of the area of the liquid surface in contact with gas (unit: m ² ): 1: 1.2 Emulsion replacement Number of times: once / minute (200 liters /
(Min) The moving speed of the gas near the liquid surface: 100 m / sec The number of times of replacement of the gas above the liquid surface: 1.8 times / min The flow of the emulsion and the flow of the gas are described in Example 1.
Was performed in the same manner as described above. After drying in water, the obtained microspheres were collected, mannitol (172.6 g) was added, and lyophilized to obtain microsphere powder.

Example 4 86.7 g of leuprorelin acetate was weighed into an eggplant-type kolben, and 100 ml of water for injection was added to completely dissolve it. To this, 765.1 g of polylactic acid (weight average molecular weight: about 14,000) dissolved in 1280 g of dichloromethane was added, and the mixture was emulsified and stirred with an auto homomixer for 13.5 minutes to obtain a W / O emulsion. After injecting 200 liters of 0.1% PVA aqueous solution (outer aqueous phase) into a 360 liter tank, the above-mentioned W / O emulsion was added to the aqueous solution, followed by stirring and emulsification, and
/ W emulsion was obtained. Although there is adhesion inside the Kolben and inside the pipe, the W /
The O emulsion was over 99%. W / O / obtained
The W emulsion was subjected to underwater drying in the same manner as in Example 3, except that the amount of microspheres per m ^{3 of} the external aqueous phase was about 4.2 kg and the flow rate of the gas was 350 liter / min.
After drying in water, the obtained microspheres were collected, mannitol (134.3 g) was added, and lyophilized to obtain microsphere powder.

Example 5 The emulsion was replaced at a frequency of 0.13 times / minute (20 liters / minute).
Min), and dried in water in the same manner as in Example 1 to produce microspheres. The microspheres were collected, mannitol (94.1 g) was added, and lyophilized to obtain microsphere powder. Example 6 Microspheres were produced by drying in water in the same manner as in Example 1 except that the emulsion was flowed by stirring the emulsion in the tank, and the number of replacements of the emulsion was changed to 1.3 times / minute (200 liters / minute). did. The microspheres were collected, mannitol (94.1 g) was added, and lyophilized to obtain microsphere powder. Example 7 Same as Example 1 except that the number of replacements of gas on the liquid surface was set to 1.3 times / min (200 liter / min from a pipe having an inner diameter of 12 mm) and the moving speed of gas near the liquid surface was set to 15 m / sec. And dried in water to produce microspheres. The microspheres were collected, mannitol (94.1 g) was added, and lyophilized to obtain microsphere powder.

Example 8 80.5 g of leuprorelin acetate and 12.6 g of gelatin were weighed into an eggplant-type colben, and 80 ml of water for injection was added to completely dissolve it. Lactic acid-glycolic acid copolymer [lactic acid / glycolic acid = 75/25 (mol%), weight average molecular weight: about 11,000] dissolved in 1081.9 g of dichloromethane 64
6.1 g was added, and the mixture was stirred and emulsified for 10 minutes with an auto homomixer to obtain a W / O emulsion. After injecting 135 liters of a 0.1% PVA aqueous solution (outer aqueous phase) into a 300 liter tank, the above-described W / O emulsion was added to the aqueous solution,
The mixture was stirred and emulsified to obtain a W / O / W emulsion. Although there was adhesion to the inside of the Kolben and the inside of the pipe, the W / O emulsion actually injected into the tank was 99% or more. The obtained W / O / W emulsion was dried in water for 3 hours under the following conditions. Container size: 300 liters Volume of gas phase: 165 liters Volume of external water phase: 135 liters Quantity of microspheres per 1 m ^{3 of} external water phase: about 5.5 kg Cubic root of capacity of external water phase (unit: m ³ ) And the square root of the area of the liquid surface in contact with the gas (unit: m ² ): 1: 1.4 Emulsion replacement frequency: 2.2 times / minute (300 liters / minute)
(Min) The moving speed of the gas near the liquid surface: 100 m / sec The number of times of replacement of the gas above the liquid surface: 1.8 times / min The flow of the emulsion and the flow of the gas are described in Example 1.
Was performed in the same manner as described above. After drying in water, the resulting microspheres were collected using a centrifuge.

Comparative Example The replacement frequency of the emulsion was 0.8 times / minute (100 liters / minute).
) And dried in water in the same manner as in Example 8, except that the compressed air was not blown onto the liquid surface, and the microspheres were collected.

Experimental Example 1 For the microspheres and microsphere powders obtained in Examples 5, 6 and 7, the solvent content at the end of drying in water and the uptake rate of the main drug at the end of lyophilization were respectively shown in Table 1. Shown in

[Table 1] As is clear from Table 1, according to the production method of the present invention, it is possible to produce microspheres having a low solvent content and a high uptake rate of the main drug.

Experimental Example 2 Table 2 shows the solvent content of the microspheres obtained in Example 8 and Comparative Example at the end of drying in water and the operability at the time of recovery.

[Table 2] As is evident from Table 2, by spraying the emulsion with gas during drying in water, it is possible to produce microspheres having a low solvent content and excellent operability at the time of recovery.

[0056]

According to the production method of the present invention, the solvent content of the microsphere can be reduced in a short time by increasing the desolvation rate of the microsphere during drying in water. In addition, microspheres having a low solvent content and a high uptake rate of the main drug can be produced. Furthermore, microspheres with excellent operability at the time of recovery can be manufactured. Moreover, when the microspheres obtained by the production method of the present invention are used as pharmaceutical injections, they are excellent in dispersibility and needle penetration.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-54760 (JP, A) JP-A-63-233926 (JP, A) JP-A-62-201816 (JP, A) JP-A 60-2018 100516 (JP, A) JP-A-6-145046 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61K 9 / 52,47 / 34,38 / 22 B01J 13/04

Claims (10)

(57) [Claims] 1. A method for producing microspheres from a W / O / W emulsion or an O / W emulsion by an underwater drying method, wherein the amount of microspheres per 1 m ³ of the external aqueous phase is about 0.
1 to about 500 kg, and the ratio of the cubic root of the volume of the external water phase (unit: m ³ ) to the square root of the area of the liquid surface in contact with the gas phase (unit: m ² ) is 1: about 0.2 to about 4.5 such that the number of replacements is about 0.01 to about 10 times / min.
/ O / W emulsion or O / W emulsion is replaced, and the moving speed of gas near the liquid surface is about 10 to about 300.
W / O / W emulsion or O /
A method for producing microspheres, comprising blowing a gas into a W emulsion and replacing the gas so that the number of replacement times is about 0.5 times / minute or more. 2. The method according to claim 1, wherein the amount of microspheres per m ^{3 of the} external aqueous phase is about 0.5 to about 100 kg. ^3. The cubic root of the volume (unit: m ³ ) of the external aqueous phase;
^{2. The} method according to claim 1, wherein the ratio of the square root of the area of the liquid surface in contact with the gas phase (unit: m < ² >) is 1: about 0.5 to about 3.0. 4. The method according to claim 1, wherein the moving speed of the gas near the liquid surface is about 10
The method of claim 1 wherein the speed is from about 200 m / sec. 5. The method according to claim 1, wherein the moving speed of the gas near the liquid surface is about 50.
The method of claim 1 wherein the rate is from about 150 m / sec. 6. The method according to claim 1, wherein the microsphere contains a bioactive substance and a biodegradable polymer. 7. The method according to claim 6, wherein the physiologically active substance is a physiologically active peptide. 8. The method according to claim 7, wherein the physiologically active peptide is LHRH or an analog thereof. 9. The method according to claim 6, wherein the biodegradable polymer is a biodegradable polymer having a free carboxyl group at a terminal. 10. The method according to claim 9, wherein the biodegradable polymer having a terminal free carboxyl group is a lactic acid-glycolic acid polymer.