JPH11269097A - New particle, its production and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain particles having excellent biodegradability, capable of having multifunctions and useful as a carrier for medicines by including a block copolymer comprising a specific hydrophobic segment and a specific hydrophilic segment as a base material. SOLUTION: The particles contains a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment as a base material. The block copolymer is preferably a polymer of the formula: X-B-Y X is H, R-CO [R is a (substituted) hydrocarbon or the like], A (A is a polyamino acid residue) or the like; Y is OH, OR<2> (R<2> is the same as R<1> ), A or the like; B is a group obtained by removing H from the terminal hydroxyl group of the biodegradable polymer and OH from the terminal carboxyl group}, and the particles are preferably nano-sized particles, especially preferably polymer micelles having an average particle diameter of about 10-200 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to fine particles containing a block copolymer having a hydrophobic / hydrophilic segment, a method for producing the same, a medicament containing the fine particles, a novel base for fine particles and a novel block copolymer. And so on.

[0002]

2. Description of the Related Art Microcapsules capable of sustained release of a drug over a long period of time are currently used in clinical practice as microparticle preparations. This technique uses biodegradable polylactic acid (hereinafter sometimes referred to as PLA).
Alternatively, it can be achieved by using a lactic acid / glycolic acid copolymer (hereinafter sometimes referred to as PLGA) as a base and encapsulating a drug in fine particles. This PLA or PLGA has extremely excellent biodegradability, and various studies on these polymers have been reported. Kawashima et al. Have reported a study on a technique for using this polymer to form fine particles down to nano-size, but the particle size obtained is only a few hundred nanometers (International Journal of Pharmaceuticals ( Int. J. Pharm.), Volume 149, pp. 43-49, 199.
7 years). Also, studies on changing the pharmacokinetics by adding a hydrophilic group to the surface of the nano-sized fine particles have been actively conducted. For example, by coating the surface of a liposome preparation using microparticles or a lipid bilayer prepared from PLGA or polystyrene with a poloxamer-based surfactant or the like, a reticuloendothelial system (hereinafter abbreviated as RES) such as liver and spleen. ) Can be avoided, and the retention in blood has been prolonged (Adv. Drug Deliv. Rev.), Vol. 17, 31-4.
8, p. 1995). However, these methods have a problem that it takes a lot of time for coating, and that the reproducibility is poor such that the behavior in a living body changes depending on the amount of coating.

On the other hand, recently, researches for changing the composition of a polymer serving as a carrier have been increasing. For example, an AB or An-B-An type block copolymer obtained by covalently bonding a hydrophilic polymer such as polyethylene oxide and a hydrophobic polymer such as polylactic acid is exemplified. Polymeric micelles and nanoparticles using these materials are prepared based on the amphiphilic properties of hydrophilic / hydrophobic segments (Japanese Patent Application Laid-Open No. 9-208494; International Journal of -Pharmaceuticals (Int. J. Pharm.), 132, 195-206,
1996; Journal of Material Science Material in Medicin (J. Mater. Sci. Mate)
r. Med.), 5, 308-313, 1994).
Kataoka et al. Provide a polymer micelle in which both ends of a block polymer having polyethylene oxide as a hydrophilic segment and PLA as a hydrophobic segment are substituted with functional groups (WO97 / 06202). But,
Since polyethylene oxide is not biodegradable, the chain length of the segments that can be used is very limited.
Further, since polyethylene oxide has no properties other than being hydrophilic, the field of application as a drug carrier is also limited. Langer et al. Provide a block polymer in which citric acid is bound to the carboxyl terminus of PLGA and hydrophilic segments such as polyethylene oxide and polysaccharide are bound to three carboxyl termini (WO95 / 03356). Polyamino acids are described as hydrophilic segments, but only gelatin, fibrinogen and albumin are listed.

[0004]

As described above, fine particles using a block copolymer have been developed, but no fine particles having a function by themselves have been obtained by paying attention to the hydrophilic segment.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a biodegradable hydrophilic segment composed of a synthetic polyamino acid and a biodegradable hydrophobic segment. By synthesizing a block copolymer bonded to a segment, using this block copolymer, we succeeded in producing, for the first time, fine particles in which a hydrophobic drug was encapsulated in a hydrophobic domain of an inner core. The present inventors have found that the obtained microparticles are excellent in biodegradability and are drug carriers capable of imparting multiple functions. The present inventors have further studied based on these findings, and have completed the present invention.

That is, the present invention relates to (1) fine particles based on a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment, and (2) a block copolymer having the formula XB- Y wherein X is H-, R-CO-, A- or (AQ ¹
-) NW ¹ -CO- (R is an optionally substituted hydrocarbon group, A- is a polyamino acid residue, Q ¹ is O, CO,
NR ¹ (R ¹ represents a hydrogen atom or a hydrocarbon group which may be substituted) or S, W ¹ represents a spacer, n represents an integer of 1 or more), Y represents —OH, —OR ² , -A
Or -QW ² (-Q ² -A) m (R ² represents an optionally substituted hydrocarbon group, Q represents O or NR ³ (R ³ represents a hydrogen atom or an optionally substituted hydrocarbon Indicates a group)
Q ² represents O, CO, NR ⁴ (R ⁴ represents a hydrogen atom or an optionally substituted hydrocarbon group) or S,
Represents a polyamino acid residue, W ² represents a spacer, m represents an integer of 1 or more), and B represents a group obtained by removing H from a terminal hydroxyl group and removing OH from a terminal carboxyl group of a biodegradable polymer. Provided that X is H- or R-CO-,
(Except when Y is —OH or —OR ² )], (3) fine particles according to (1), which are nano-sized particles, and (4) average. (3) The fine particles according to (3) having a particle diameter of about 10 nm to about 200 nm, (5) the fine particles according to (1), which are polymer micelles, and (6) the biodegradable polymer is an aliphatic polyester. (8) the fine particles according to (1) or (2), (7) the fine particles according to (6), wherein the aliphatic polyester is a polymer derived from one or more polylactides; ) 1 aliphatic polyester
Fine particles according to item (6), which is a polymer derived from one or more kinds of α-hydroxycarboxylic acids;
(9) The fine particles according to (8), wherein the polymer is a lactic acid polymer or a lactic acid-glycolic acid copolymer, (10) the biodegradable polymer has a number average molecular weight of about 500 to about 100,
(1) The fine particles according to (1) or (2), wherein (11) the number of constituent amino acids of the polyamino acid is about 1,
(1) The fine particles according to (1) or (2), wherein one or all of the functional groups of the amino acid are protected with a protecting group or modified with a modifying group. The fine particles according to item 1) or (2), wherein (1)
3) the fine particle according to item (1) or (2), wherein the polyamino acid is an amino acid homopolymer composed of one kind of amino acid; (13) The microparticle according to (12), wherein the modifying group is a sugar residue, (16) the microparticle according to (15), wherein the sugar residue is a glucosyl group, (17) The fine particles according to (12), wherein the modifying group is a pteroic acid derivative,
(18) The fine particles according to (1) or (2), wherein the polyamino acid is a synthetic polyamino acid; (19) the fine particle according to (1), wherein the content of the hydrophilic segment in the block copolymer is about 1 to about 80% by weight; (1) The fine particle according to (1) or (5), wherein the hydrophobic segment is in the core of the fine particle and the hydrophilic segment is in the outer shell of the fine particle, and (21) the fine particle is the hydrophilic segment. (1) The microparticle according to (1) or (5), wherein the hydrophobic segment is in the outer shell of the microparticle, (22) the microparticle according to (1), which contains the drug, and (23) the drug is a hormone. (22) The microparticle according to (23), wherein the hormone is a corticosteroid, (25) the microparticle according to (23), wherein the hormone is a corticosteroid.
(2) The fine particles according to (20), which contain a hydrophobic drug.
6) The fine particles according to item (21), containing a hydrophilic drug.
(27) The second (2) wherein the hydrophilic drug is a water-soluble polypeptide.
(28) The microparticle according to (27), wherein the water-soluble polypeptide is a cytokine.
(30) A medicine comprising the fine particles according to any of (1) to (28), (30) a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment, and a drug A method for producing fine particles containing a drug, characterized by mixing
(1) The method according to (30), wherein the solvent is removed from a mixture of the block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment and a drug, and (32). A base for fine particles containing a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment; and (33) a formula X′-BY ′ wherein X ′ is H-, R'-CO-, A'- or (A'-
Q ¹ '-) n'W ¹ ' -CO- (R 'is a C _1-6 alkyl group,
A′- is an amino acid homopolymer residue, Q ¹ ′ is O,
CO, NH or S, W ¹ ′ represents a C _1-6 alkylene group (excluding propylene), n ′ represents an integer of 1 or more), Y ′ represents —OH, —OR ² ′, − A 'or -Q'-
W ² '(-Q ² -A') m '(R ² ' is a C _1-6 alkyl group,
Q ′ is O or NH, Q ² ′ is O, CO, NH or S
, -A 'is an amino acid homopolymer residue, W ² ' is C _1-6
B is an alkylene group (however, excluding propylene), m 'is an integer of 1 or more), B is H from the terminal hydroxyl group of the biodegradable polymer to O from the terminal carboxyl group.
A group excluding H is shown. Provided that X is H- or R'-C
O-, except when Y is -OH or -OR ² ')
A block copolymer represented by the formula: (34) Q ¹ is O,
(1) CO or NR ¹ , Q ² is O, CO or NR ⁴ , and (35) Q ¹ ′ is O, C
(33) The block polymer according to the above (33), wherein O or NH represents Q, O ² , CO or NH.

The base of the fine particles of the present invention is a biodegradable block copolymer having a hydrophobic segment and a hydrophilic segment. In the specification of the present application, the term "biodegradable" refers to a property that, after administration into a living body, is compatible with a living tissue and does not show any damage to the living body. Means the property excreted outside the body. As used herein, the term "hydrophobic segment" refers to a biodegradable polymer that is particularly poorly soluble or insoluble in water or a derivative derived therefrom, and a hydrophilic segment that is the other component of the block copolymer. A higher molecular weight polymer that is more hydrophobic. As used herein, the term “hydrophilic segment” refers to a polymer or a derivative thereof that is soluble or slightly soluble in water but relatively hydrophilic to the hydrophobic segment of the block copolymer. In the specification of the present application, “fine particles” refers to particles having an average particle diameter of 200 μm or less and generally called microparticles, microspheres, microcapsules, nanoparticle, nanospheres, nanocapsules, and the like. The average particle size is 1
Fine particles smaller than a micrometer are particularly called nano-sized particles. In the present specification, the “polymer micelle” is a part of the “fine particles” referred to in the present specification, and refers to fine particles having a different main composition between an outer shell portion and an inner core portion in the fine particles.

As the block copolymer used in the fine particles of the present invention, a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment is used.
It is a block copolymer in which a hydrophilic segment is covalently bonded to the end of a biodegradable hydrophobic segment, and these may have a bond directly or via a spacer. As such a block copolymer,
For example, the formula X—B—Y (I) wherein X is H—, R—CO—, A— or (AQ ¹
-) NW ¹ -CO- (R is an optionally substituted hydrocarbon group, A- is a polyamino acid residue, Q ¹ is O, CO,
NR ¹ (R ¹ represents a hydrogen atom or a hydrocarbon group which may be substituted) or S, W ¹ represents a spacer, n represents an integer of 1 or more), Y represents —OH, —OR ² , -A
Or -QW ² (-Q ² -A) m (R ² represents an optionally substituted hydrocarbon group, Q represents O or NR ³ (R ³ represents a hydrogen atom or an optionally substituted hydrocarbon Indicates a group)
Q ² represents O, CO, NR ⁴ (R ⁴ represents a hydrogen atom or an optionally substituted hydrocarbon group) or S,
Represents a polyamino acid residue, W ² represents a spacer, m represents an integer of 1 or more), and B represents a group obtained by removing H from a terminal hydroxyl group and removing OH from a terminal carboxyl group of a biodegradable polymer. Provided that X is H- or R-CO-,
Y and block copolymers are used represented by unless a -OH or -OR ^2]. As described above, the polyamino acid that is a hydrophilic segment may be bound to one end or both ends of a biodegradable polymer that is a hydrophobic segment, and may be added to one end by passing through an appropriate spacer. One or more hydrophilic segments may be attached.

It is used as a hydrophobic segment of the block copolymer used in the present invention, and is represented by B in the above formula in "a group obtained by removing H from a terminal hydroxyl group of a biodegradable polymer and OH from a terminal carboxyl group of the biodegradable polymer". The “biodegradable polymer” is not particularly limited, but usually a polymer that is hardly soluble or insoluble in water is used. Specific examples of the biodegradable polymer include the following. 1. Aliphatic polyesters: (1) α-hydroxycarboxylic acids (eg, glycolic acid, lactic acid, 2-hydroxybutyric acid, 2-hydroxyvaleric acid, 2-hydroxycaproic acid, 2-hydroxycapric acid, etc.), hydroxydicarboxylic acids ( For example, a homopolymer (homopolymer), a copolymer (copolymer), or a mixture thereof synthesized from one or more kinds of malic acid and the like and hydroxytricarboxylic acids (for example, citric acid and the like). (2) Polylactides (for example, glycolide, lactide, benzylmalolactoneto, malite benzyl ester, 3-[(benzyloxycarbonyl) methyl]
-1,4-dioxane-2,5-dione) and the like, and a homopolymer, a copolymer, a mixture thereof, or the like. (3) Polylactones (for example, homopolymers, copolymers or the like synthesized from one or more of β-propiolactone, δ-valerolactone, ε-caprolactone, N-benzyloxycarbonyl-L-serine-β-lactone, etc.) These mixtures and the like can be copolymerized with glycolide and lactide, which are cyclic dimers of α-hydroxy acids, etc. 2. Polyanhydrides: For example, poly [1,3-bis (p- 2. Carboxyphenoxy) methane], poly (terephthalic acid-sebacic anhydride, etc.) 3. Polycarbonates: for example, poly (oxycarbonyloxyethylene), spiroortho polycarbonate, etc. 4. Polyorthoesters: for example, poly {3, 9-bis (ethylidene-2,4,8,10-tetraoxaspiro [5, 5] Undecane-1,6-hexanediol
Such. 5. Poly-α-cyanoacrylates: For example,
Poly-α-isocyanoacrylate and the like. 6. Polyphosphazenes: For example, polydiaminophosphazene and the like. 7. Polydepsipeptide: For example, a polymer of 3- [4- (benzyloxycarbonylamino) butyl] -6-methylmorpholine-2,5-dione, or a lactone (eg, ε-caprolactone, etc.), a lactide ( For example, copolymers with glycolide, lactide, etc.). These biodegradable polymers may be mixed and used at an appropriate ratio. The type of polymerization may be any of random, block, and graft.

[0010] Among the above biodegradable polymers,
For example, aliphatic polyesters [eg, α-hydroxycarboxylic acids (eg, glycolic acid, lactic acid, hydroxybutyric acid, etc.), hydroxydicarboxylic acids (eg,
A polymer, a copolymer or a mixture thereof, or a polylactide, etc.) synthesized from one or more of malic acid and the like, and hydroxytricarboxylic acids (for example, citric acid and the like). In particular, homopolymers or copolymers synthesized from one or more kinds of α-hydroxycarboxylic acids (eg, glycolic acid, lactic acid, hydroxybutyric acid, etc.), or polylactides are preferable from the viewpoint of biocompatibility and biodegradability. preferable. Further, these copolymers may be appropriately mixed and used. α-Hydroxycarboxylic acids or polylactides are D-forms,
Any of L-form and D, L-form may be used, but D-form / L
-Those having a form (mol / mol%) in the range of about 75/25 to about 25/75 are preferred. As the D-form / L-form (mol / mol%), those having a range of about 60/40 to about 30/70 are widely used. Examples of copolymers of α-hydroxycarboxylic acids include, for example, copolymers of glycolic acid and other α-hydroxy acids, and examples of α-hydroxy acids include lactic acid, 2-hydroxybutyric acid, and the like. Is used. Specifically, examples of the α-hydroxycarboxylic acids include lactic acid-glycolic acid copolymer and 2-lactic acid.
Hydroxybutyric acid-glycolic acid copolymer and the like are preferable, and particularly lactic acid-glycolic acid copolymer (hereinafter, sometimes referred to as lactic acid-glycolic acid, unless otherwise specified,
Lactic acid and glycolic acid homopolymers and copolymers) are commonly used. The composition ratio of lactic acid-glycolic acid copolymer (lactic acid / glycolic acid) (mol / mol%)
Although not particularly limited as long as the object of the present invention is achieved, those having about 100/0 to about 30/70 are used. Lactic acid-
The glycolic acid copolymer and polylactide preferably have a number average molecular weight of about 500 to about 100,000, and more preferably about 1,000 to 50,000.

The number average molecular weight in the present specification is an average molecular weight calculated by a method not considering weighting of molecular size, and can be used for calculating the number of polymer terminal groups. Generally, it can be determined by quantifying the terminal group of the polymer, but it can also be determined as a molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) using polystyrene as a reference substance. The measurement was performed using GPC column KF804Lx2 (manufactured by Showa Denko), R
GLC system HLC-8120GPC with I monitor
(Manufactured by Tosoh Corporation) and chloroform as a mobile phase. Further, it can also be determined from ¹ H-NMR. For example, when a homopolymer of lactic acid is dissolved in CDCl ₃ and measured, a signal of a terminal group and a signal derived from lactic acid (CH; δ = 5.17 ppm, CH ₃ ; δ = 1.58 ppm).

The “polyamino acid” used as a hydrophilic segment of the block copolymer used in the present invention and represented by A- and -A in the above formula has a significant toxicity in vivo. Unless present, the compounds are not limited to existing compounds in the living body, and usually use biodegradable polyamino acids.
Further, the polyamino acid is preferably a peptide or a polypeptide. The polyamino acid preferably has about 1,000 or less constituent amino acids, more preferably about 10 to about 10 amino acids.
About 500 polyamino acids are used. The polyamino acid may be natural or unnatural. The constituent amino acids are not particularly limited, but include, for example, glutamic acid, aspartic acid, arginine, lysine, histidine, cysteine, tyrosine, phenylalanine, tryptophan, and the like. The constituent amino acids may be a single type of polymer, or two or more types of amino acids may be covalently bonded in a block or random manner. Even in the case of two or more amino acids, the composition ratio of each amino acid is appropriately determined and is not limited. The amino acid may be any of D-form, L-form and racemic-form. As the polyamino acid, an amino acid homopolymer composed of one kind of amino acid is particularly preferable. As the constituent amino acids in this case, for example, glutamic acid, aspartic acid, arginine, lysine, cysteine and the like are preferable, and glutamic acid is particularly preferable.

The functional groups of the constituent amino acids may be partially or entirely substituted with protecting groups or modifying groups. When the functional group is a carboxyl group, the protecting group is not particularly limited, and examples thereof include a benzyl group, a p-nitrobenzyl group, a p-chlorobenzyl group, an o-cyanobenzyl group, and a p-dimethylamino group. Azobenzyl group, 4-picolyl ester group, anthraquinone-2-methyl ester group, p-sulfobenzyl ester group, t-butyl ester group, p-methoxybenzyl ester group, diphenylmethyl ester group, pentamethylbenzyl ester group,
2,4,6-trimethylbenzyl ester group, 3,4-
Examples include a methylenedioxybenzyl ester group, a cyclopentyl ester group, a phthalimidomethyl ester group, and a benzyloxymethyl ester group. When the functional group is an amino group, the protecting group is not particularly limited, but includes, for example, a benzyloxycarbonyl group,
p-phenylazobenzyloxycarbonyl group, p-methoxyphenylazobenzyloxycarbonyl group, benzyl group, 2-ethynyleneisopropyloxycarbonyl group, allyloxycarbonyl group, 4,5-diphenyl-
4-oxazolin-2-one group, o-nitrophenoxyacetyl group, 2- (o-nitrophenoxy) isopropylcarbonyl group, 1-piperidineoxycarbonyl group,
Piperidinooxycarbonyl group, 1,1-dimethyl-2
-Propynyloxycarbonyl group, isopropylideneaminooxycarbonyl group, allyloxycarbonyl group,
Isonicotinyloxycarbonyl group, α, α-dimethyl-4pyridylmethyloxycarbonyl group, 2-dimethylcarbamoylbenzyloxycarbonyl group, 4-dimethylcarbamoylbenzyloxycarbonyl group, [β-
(Phenylethyl) oxy] carbonyl (homobenzyloxycarbonyl) group, N-trityl group, p-trimethylammonium chloridebenzyloxycarbonyl group, benzenesulfonyl group, phenyloxycarbonyl group, p-methylphenyloxycarbonyl group, p-toluene Sulfonyl group, p-chlorobenzyloxycarbonyl group, p-bromobenzyloxycarbonyl group, p-
Nitrobenzyloxycarbonyl, isopropyloxycarbonyl, ethyloxycarbonyl, 2-dimethylethyloxycarbonyl, diisopropylmethyloxycarbonyl, cyclopentyloxycarbonyl, cyclohexyloxycarbonyl, furfuryloxycarbonyl, p-methylbenzyl Oxycarbonyl group, p-phenylbenzyloxycarbonyl group, 1,
4-dimethylpiperidine-4-oxycarbonyl group, t
-Butyloxycarbonyl group, p-methoxybenzyloxycarbonyl group, p-decyloxybenzyloxycarbonyl group, diphenylmethyloxycarbonyl group, 3
-Hydroxy-3-methylbutyloxycarbonyl group,
2-benzylisopropyloxycarbonyl group, pentacarbonyl (phenylcarbene) curonium group, 3-nitro-2-pyridinethiomethylcarbonyl group, α, α-
Dimethyl-3,5-dimethoxybenzyloxycarbonyl group, Tpt-oxycarbonyl group, 4-chlorobutyryl group, t-amyloxycarbonyl group, isobornyloxycarbonyl group, diphenylphosphinyl group, diphenylphosphinothioyl group, Dimethylphosphinothioyl group, 1-adamantyloxycarbonyl group, 1-adamantyloxycarbonyl fluoride group, 1-adamantyloxychloride group, 1- (1-adamantyl)
-1-methylethoxycarbonyl group, 1-methylcyclohexyloxycarbonyl group, 3-dimethylamino-
1,1-diphenylpropyloxycarbonyl group, 1,
1-diphenylpropionyloxycarbonyl group, 3,
5-di-t-butyl-4-oxo-1-phenyl-2,
5-cyclohexadienyl group, triphenylmethyl group,
o-nitrophenylsulfenyl group, triphenylmethylsulfenyl group, 2,4,5-trichlorophenylsulfenyl group, 2,4-dinitrophenylsulfenyl group, pentachlorophenylsulfenyl group, 2-nitro-4-methoxy Phenylsulfenyl group, 2-hydroxy-5-chlorobenzylidene group, 1-hydroxynaphthylmethylene group, 2-benzoyl-1-methylvinyl group,
2-acetyl-1-methylvinyl group, 2-hydroxy-
5-methyl-α-phenylbenzylidene group, 5,5-dimethyl-3-oxocyclohexen-1-yl group, 2-
Phenylisopropyloxycarbonyl group, 2- (p-
Ethoxyphenyl) isopropyloxycarbonyl group,
2- (p-biphenylyl) isopropyloxycarbonyl group, di- (p-methoxyphenyl) methyloxycarbonyl group, 2- (p-methylphenyl) isopropyloxycarbonyl group, 1,1-diphenylpropyloxycarbonyl group, 1-diphenylethyloxycarbonyl group, di- (p-methylphenyl) methyloxycarbonyl group, 2- (p-phenylazophenyl) isopropyloxycarbonyl group, 2- (m, m-di-t-butylphenyl) isopropyl Oxycarbonyl group, 3-nitro-2-pyridinesulfenyl group, 1- (3,5-di-
(t-butylphenyl) -1-methylethoxycarbonyl group.

When the functional group is a thiol group, the protecting group is not particularly limited. Examples thereof include a benzyl group, a 4-methoxybenzyl group, a 4-methylbenzyl group, and a 3,4-dimethylbenzyl group. 2,2,4-trimethylbenzyl group, trityl group, diphenylmethyl group, acetamidomethyl group, trimethylacetamidomethyl group, 3-nitro-2-pyridylsulfenyl group, carbomethoxysulfenyl group, methylphenylcarbamoylsulfenyl group , An ethyl mercapto group, a t-butyl mercapto group, a benzyloxymethyl group, a ferrocenylmethyl group, a 2-ferrocenylpropan-2-yl group, a 9-fluorenylmethyl group, a dimethylphosphinothioyl group, and the like. No. When the functional group is a hydroxyl group, the protective group is not particularly limited, and examples thereof include a benzyl group, a t-butyl group, an acetyl group, a t-butylsilyl group, a t-butyldiphenylsilyl group, and a phenoxyacetyl. Group, 4-bromobenzyl group, 4-chlorobenzyl group, 4-picolyl group and the like. In addition, as a modifying group for the functional group, a recognition element sugar or the like is used. As described in JP-A-7-206903, the recognition element sugar is a glycosyl group capable of recognizing a target organ, tissue, cell or tumor. Although not particularly limited, for example, galactose, glucose,
Mannose, fucose and the like are used, and oligosaccharides composed of a single or plural types of sugars may be used. Further, folic acid may be used alone as a modifying group, or may be mixed in such a manner that it is bonded to sugar or the like. Further, when folic acid is bound as a modifying group, pteroic acid (pteroic
acid) or a derivative thereof (eg, glutamic acid covalently linked to pteroic acid) may be attached to the amino terminal group of polyglutamic acid. The functional group may form a salt with an alkali metal, an alkaline earth metal, an inorganic acid, an organic acid, or the like, and the salt to be formed is not particularly limited. Examples thereof include sodium, potassium, and calcium. , Hydrochloric acid, acetic acid, sulfuric acid, butyric acid, phosphoric acid and the like. Among the above, as the modifying group, for example, saccharides such as glucose and pteroic acid derivatives are preferable. The content of the hydrophilic segment in the block copolymer is determined by the presence or absence and type of the constituent amino acid and the modifying group of the terminal group thereof, the type of the hydrophobic segment, etc., and varies depending on the individual polymer molecule. 80% by weight, more preferably about 20-70
% By weight.

The term "polyamino acid residue" refers to a residue obtained by removing OH from the carboxyl terminal or removing H from the amino terminal of the above-mentioned polyamino acid. The term "amino acid homopolymer residue" refers to a residue obtained by removing OH from the carboxyl terminal or a residue obtained by removing H from the amino terminal of the above amino acid homopolymer. Here, when Q ¹ is O or NR ¹ , the polyamino acid residue represented by A- is a residue obtained by removing OH from the carboxyl terminal of a polyamino acid (preferably, removing OH from the carboxyl terminal of an amino acid homopolymer). Residue). On the other hand, when Q ¹ is CO,
The polyamino acid residue represented by A- represents a residue obtained by removing H from the amino terminal of a polyamino acid (preferably, a residue obtained by removing H from the amino terminal of an amino acid homopolymer).
When Q ¹ is S, the polyamino acid residue represented by A- may represent either a residue obtained by removing OH from the carboxyl terminal of the polyamino acid or a residue obtained by removing H from the amino terminal of the polyamino acid. . When Q ² is CO, the polyamino acid residue represented by -A represents a residue obtained by removing H from the amino terminal of a polyamino acid (preferably, a residue obtained by removing H from the amino terminal of an amino acid homopolymer). . On the other hand, when Q ² is O or NR ³ , the polyamino acid residue represented by -A is
It shows the residue obtained by removing OH from the carboxy terminus of a polyamino acid (preferably, the residue obtained by removing OH from the carboxyl terminus of an amino acid homopolymer). When Q ² is S, A-
May be any of a residue obtained by removing OH from the carboxyl terminus of a polyamino acid and a residue obtained by removing H from the amino terminus of the polyamino acid.

[0016] In the above formula, the spacer represented by W ¹ and W ^2, for example, a divalent hydrocarbon group which may be substituted is used, specifically, for example, C _1-15 Alkylene groups (eg, methylene, ethylene, propylene,
Tetramethylene, 3,3-dimethylpentamethylene, etc.), C _2-15 alkenylene group (eg, vinylene, propynylene, methylpropynylene, dimethylpropynylene, etc.), C _3-10 cycloalkylene group (eg, cyclopropylene, , 3-cyclopentylene, 3-cyclohexene-1,2-ylene, etc.), C _6-14 arylene group (for example,
And divalent C _1-15 hydrocarbon groups such as phenylene and naphthylene. Among them, a C _1-10 alkylene group (, C
_2-10 alkenylene group, C _3-7 cycloalkylene group, C
_A divalent C _1-10 hydrocarbon group such as a _6-10 arylene group is preferred, and a C _1-6 alkylene group such as methylene and ethylene is particularly preferred. The hydrocarbon group has 1 to 3 C
_{A 1-4} alkyl group (eg, methyl, ethyl, etc.), a C _2-4 alkenyl group (eg, ethynyl, etc.), a C _3-10 cycloalkyl group (eg, cyclohexyl, etc.) or a C _6-10 aryl group (eg, Phenyl). The spacer is a C _1-4 such as ethylene _monooxy.
Alkylene monooxy and the like and polymers thereof may be used.
Furthermore, trivalent hydrocarbon groups (for example, trivalent C _1-12 alkylidine such as trivalent C _1-12 alkylidine such as methylidine, ethylidine, propylidine, butyridine, pentyridine, hexylidine, isobutyridine, isohexylidine, and isopentyridine).
(A C _1-12 hydrocarbon group) or a versatile spacer in which a tetravalent carbon atom and a divalent hydrocarbon group are combined.

Examples of the hydrocarbon group represented by R, R ¹ , R ² , R ³ or R ⁴ include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group and an aralkyl group. Among them, a C _1-24 hydrocarbon group is preferred. Examples of the alkyl group include a C _1-24 alkyl group (eg, methyl, ethyl, n-propyl, isopropyl, n-butyl, 1-methylpropyl, isobutyl, t-butyl, n-pentyl, 1-methylbutyl,
n-hexyl, 4-methylpentyl, n-heptyl, 1
-Propylbutyl, n-octyl, 1-methylheptyl, 1-propylpentyl, n-nonyl, 1-propylhexyl, 1-methyloctadecyl, hexylethyl, etc.).
_1-6 alkyl groups are preferred. The alkyl group further comprises 1
3 to 2 C _2-6 alkenyl groups (eg, vinyl, etc.), C _2-6 alkynyl groups (eg, ethynyl, etc.),
It may have a C _3-6 cycloalkyl group (for example, cyclohexyl), a C _6-10 aryl group (for example, phenyl) or a C _7-14 aralkyl group (for example, benzyl). Examples of these include vinyl ethyl, benzyl ethyl and the like. Examples of the alkenyl group include a C _2-6 alkenyl group (eg, vinyl, 1-propenyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-
Methylpropen-1-yl, 1-methylpropen-1-
Yl, 1-methylallyl, 2-methylallyl, etc.). The alkynyl group includes, for example, C
_{A 2-6} alkynyl group (eg, ethynyl, 1-propynyl, 2-propynyl, etc.) and the like are used. As the cycloalkyl group, for example, a C _3-10 cycloalkyl group (eg, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, etc.) and the like are used. As the aryl group, for example, a C _6-14 aryl group (eg, phenyl, tolyl, naphthyl, etc.) is used. Examples of the aralkyl group include a C _7-16 aralkyl group (eg, benzyl,
And phenethyl). The alkenyl group, alkynyl group, cycloalkyl group, aryl group and aralkyl group have 1 to 3 C _1-10 alkyl groups,
_It may be substituted with a _2-10 alkenyl group, a C _3-10 cycloalkyl group, a C _6-10 aryl group or a C _7-14 aralkyl group. Among the above, the hydrocarbon group represented by R, R ¹ , R ² , R ³ or R ⁴ is preferably, for example, a C _1-6 alkyl group such as methyl and ethyl. R ¹ , R ³
Alternatively, R ⁴ is preferably a hydrogen atom or a C _1-6 alkyl group such as methyl and ethyl, and particularly preferably a hydrogen atom.

N and m each represent an integer of 1 or more, for example, preferably an integer of 1 to 10, more preferably an integer of 1 to 3, and particularly preferably 1. For example, when n is 2, represented by ^{X (A-Q 1 -)} nW 1 - is

Embedded image When m is 3, -W ² (-Q ²
-A) m is

Embedded image Is represented by

Specifically, as a spacer represented by W ¹ , when n is 2, for example,

Embedded image And the like. When n is 3, for example,

Embedded image Are preferred.

[0020] In the above formulas, Q ^1, O, CO or NR ¹ are preferred, as Q ² is, O, CO or NR ⁴
Is preferred. When X represents (A-Q ^1- ) nW ¹ -CO-, Q ¹ is preferably O, CO or NH. A
-, W ¹ and n are preferably the same as described above. When Y represents -QW ² (-Q ² -A) m, Q is preferably O or NH, and particularly preferably O.
As Q ² , O, CO or NH is preferable.
H is preferred. As W ² , A and m, the same as described above are preferable. Among the above, X is H-
Or R-CO- is preferred. B is preferably a lactic acid polymer or a lactic acid-glycolic acid polymer. The ^{Y, -Q-W 2 (-Q} 2 -A) m is preferable. In particular, in the above formula, B is lactic acid polymer, X is Ra-CO- (Ra represents an alkyl group), Y is ^{-O-W 2 a (NH -Aa} )
A block copolymer of n (wherein, W ² a represents an alkynyl group, Aa represents an amino acid homopolymer, and n represents an integer of 1 or more) is preferably used. As Ra, a C _1-6 alkyl group such as a methyl group and an ethyl group is preferably used. The alkynyl group represented by W ² a, methylene, C _1-6 alkylene group such as ethylene is preferably used. As the constituent amino acids of the amino acid homopolymer represented by Aa, for example, glutamic acid, aspartic acid, arginine, lysine, cysteine and the like are preferably used, and glutamic acid is particularly preferable. Further, the functional groups of these constituent amino acids may be protected with benzyl, or may be modified with a glycosyl group or a pteroic acid derivative. As such constituent amino acids, for example, γ-benzyl-glutamic acid and the like are preferable. n is preferably 1.

Among the block copolymers used in the fine particles of the present invention, among the block copolymers of the formula X'-BY ', wherein X' is H-, R'-CO-, A'- or (A'-
The ^{- ') n'W 1' -CO- (} R ' is C _1-6 alkyl group, Q ¹
A'- is an amino acid homopolymer residue, Q ¹ 'is O, C
O, NH or S, W ¹ ′ represents a C _1-6 alkylene group (excluding propylene), n ′ represents an integer of 1 or more), Y ′ represents —OH, —OR ² ′, − A 'or -Q'-
W ² '(-Q ² -A') m '(R ² ' is a C _1-6 alkyl group,
Q ′ is O or NH, Q ² ′ is O, CO, NH or S
, -A 'is an amino acid homopolymer residue, W ² ' is C _1-6
B is an alkylene group (however, excluding propylene), m 'is an integer of 1 or more), B is H from the terminal hydroxyl group of the biodegradable polymer to O from the terminal carboxyl group.
A group excluding H is shown. Provided that X is H- or R'-C
O-, except when Y is -OH or -OR ² ')
Is a novel polymer.

As the C _1-6 alkyl group represented by R ′,
For example, methyl, ethyl, n-propyl, i-propyl and the like are used, and among them, a C _1-3 alkyl group such as methyl is preferable. As the amino acid homopolymer residue represented by A'- or -A ', the same amino acid homopolymer residue represented by A- or -A described above is used. As the C _1-6 alkylene group (excluding propylene) represented by W ¹ ′ or W ² ′, methylene, ethylene, n-butylene and the like are used, and methylene and ethylene are particularly preferable. Among the above, X 'is preferably R'-CO-. B is preferably a lactic acid polymer or a lactic acid-glycolic acid polymer. Y 'The ^{-Q'-W 2' (-Q 2} '-A') m ' is preferably, Q' O as is, Q ² 'NH as is, -A' as a polyglutamic acid residue or A poly (γ-benzyl-glutamic acid) residue, methylene or ethylene as W ² ′,
m ′ is preferably 1.

As specific block copolymers used for the fine particles of the present invention, those shown in the following [Table 1] to [Table 6] are used.

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

The fine particles of the present invention may contain a drug. The drug may be water-soluble or fat-soluble.
Further, it may be any of synthetic compounds, fermentation products, peptides, proteins, steroid compounds, genes, viruses, saccharides (polysaccharides), fatty acids, lipids (or derivatives), vitamins, coenzymes (or derivatives), etc. ,
They may be natural products, synthetic products, semi-synthetic products, or products of genetic engineering. Furthermore, drugs used in any field such as medicines, agricultural chemicals, and fertilizers may be used, but in particular, medicines are preferably used. Examples of such drugs include renal disease therapeutic / prophylactic agents (eg, diabetic nephropathy therapeutic / prophylactic agents, glomerulonephritis therapeutic agents, urinary incontinence therapeutic / prophylactic agents, pollakiuria therapeutic / prophylactic agents, etc.). , Nootropics (for example,
Alzheimer's drug, senile dementia drug, cerebral infarction drug, transient ischemic attack drug, etc., pain drug, cardiovascular drug (eg, hypertension drug, thrombotic drug,
Drugs for heart failure, drugs for ischemic heart disease, drugs for myocardial infarction,
Drugs for treating angina pectoris, drugs for treating peripheral circulatory disorders, etc., drugs for treating bone and joint diseases (eg, drugs for treating osteoporosis, rheumatoid arthritis, etc.), drugs for treating infectious diseases (eg, bacteria, viruses, A
IDS, hepatitis B, hepatitis C or shingles), diabetes, arteriosclerosis, hyperlipidemia, allergic disease (eg, asthma, atopic dermatitis) Drugs, gastrointestinal ulcer drugs (eg, gastric ulcer drug, duodenal ulcer drug, pancreatitis drug, etc.), cancer drugs (eg, prostate cancer drug, breast cancer drug, etc.), vaccines, test drugs (eg, , Fluorescent dyes, and the like), but are not limited thereto. The drug may be either hydrophilic or hydrophobic. As described below, the fine particles of the present invention have a hydrophobic segment of the block copolymer in the core of the fine particles and a hydrophilic segment in the outer shell of the fine particles. The sex segment may be present in the outer shell of the fine particle, and furthermore, both segments may be randomly present in the particle and have no domain structure. Therefore, it is preferable to select a relatively hydrophobic drug when the core of the microparticles is composed of a hydrophobic segment, and to select a relatively hydrophilic drug when the core of the microparticles is composed of a hydrophilic segment. When each segment is present, a drug having either a hydrophilic property or a hydrophobic property can be selected.

Examples of hydrophobic drugs include, but are not limited to, corticosteroids (eg, dexamethasone acetate, dexamethasone, dexamethasone valerate, dexamethasone palmitate, dexamethasone propionate, dexamethasone sodium metasulfobenzoate, Epinephrine, cortisone acetate, triamcinolone acetate, triamcinolone, triamcinolone acetonide, norepinephrine, paramethasone acetate, haloresone acetate, hydrocortisone, hydrocortisone butyrate, hydrocortisone butyrate propionate, hydrocortisone acetate, fludrocortisone acetate, prednisolone butyl valerate, zovalone prednisone valonate , Prednisolone acetate, betamethasone, betamethasone valerate,
Betamethasone dipropionate, betamethasone butyrate, betamethasone acetate / betamethasone sodium phosphate, methylprednisolone acetate, etc., drugs for tumors (eg, fluorouracil, methotrexate, tegafur, tegafur / uracil, mitomycin C, cisplatin, carbone, dacarbazine, mercapto) Purines, actinomycin D, doxorubicin hydrochloride, tamoxifen citrate, etc., gout treatments (eg, allopurinol, colchicine, sulfinpyrazone, probenecid, benzbromarone, etc.), central nervous system drugs (eg, idebenone, aniracetam, etc.), Cardiovascular drugs (eg, pinbocetin), antihypertensive drugs (eg, delapril hydrochloride, manidipine hydrochloride), drugs for hyperlipidemia (eg, clofibrate, Nma oryzanol), bronchodilators (e.g., theophylline, hydrochloric methoxyphenamine, tulobuterol hydrochloride), antiallergic agents (e.g., emedastine, tranilast, terfenadine),
Drugs for urinary incontinence and pollakiuria (eg, tachykinin antagonists),
Drugs for improving brain metabolism / psychiatric symptoms (eg, idebenone), fluorescent dyes (eg, pyrene, alkylpyrenes, acylpyrenes, bispyrenylalkanes, bispyrenoylalkanes, pyrenesulfonylalkylamines, pyrenyloxoalkyl fatty acids For example, pyrene-based fluorescent dyes such as ethyl esters, naphthalene-based fluorescent dyes, polyene-based fluorescent dyes, coumarin-based fluorescent dyes, anthracene-based fluorescent dyes, stilbene-based fluorescent dyes, and rhodamine-based fluorescent dyes are used. The hydrophilic drug is not particularly limited, but for example, a water-soluble polypeptide or the like is used. As the water-soluble polypeptide, for example, those which have a hormonal action and are endocrine are preferred. Such water-soluble polypeptides include, for example, cytokines, hematopoietic factors, various growth factors, enzymes and the like.
Among them, cytokines are preferable, and for example, lymphokines (eg, interferon α, interferon β, interferon γ, interleukin (IL-2
To IL-12)) and monokine (interleukin-1, tumor necrosis factor (TNF), etc.).

Other drugs include luteinizing hormone-releasing hormone (also called LH-RH or gonadotropin-releasing hormone, Gn-RH) and LH-.
RH derivatives (for example, LH-RH agonist, LH-R
H antagonists), insulin, somatostatin, somatostatin derivatives (eg, sandostatin; USP
4,087,390, 4,093,574, 4,100,117 and 4,253,998),
Growth hormone (GH), growth hormone releasing hormone (G
H-RH), prolactin, erythropoietin (EP
O), adrenocortical hormone (ACTH), ACTH derivative (eg, eviratide), melanocyte stimulating hormone (MS
H), thyroid hormone releasing hormone ((pyr) Glu-His-Pro
NH ₂ ; TRH), its salts and derivatives (Japanese Patent Laid-Open No. 50-1)
No. 21273, JP-A-52-116465), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH), vasopressin, vasopressin derivatives (eg, desmopressin), oxytocin, calcitonin, glucagon , Gastrin, secretin, pancreozymine, cholecystokinin, angiotensin, human placental lactogen, human chorionic gonadotropin (HCG), enkephalin, enkephalin derivative (eg, USP 4,277,394, EP-31567), endorphin, kyotorphin, tuftsin , Thymopoietin, thymosin, thymothymulin, thymic humoral factor (T
HF), blood thymic factor (FTS) and its derivatives (US
P4,229,438), colony-inducing factors (eg, CSF, GCS
F, GMCSF, MCSF), motilin, deinorphin, bombesin, neurotensin, caerulein, bradykinin, atrial natriuretic factor, nerve growth factor (NGF), cell growth factor (eg, EGF, TGF-
β, PDGF, acidic FGF, basic FGF), neurotrophic factors (eg, NT-3, NT-4, CNTF, GDNF,
BDNF), peptides having endothelin antagonistic activity and analogs (derivatives) thereof (EP-436189, EP-457195,
EP-496452, JP-A-3-94692, JP-A-3-94692
No. 130299), insulin receptor, insulin-like growth factor (IGF) -1 receptor, IGF-
2 receptor, transferrin receptor, epidermal growth factor, lowdensity lipoprotein (LD
L) Receptor, macrophage scavenger receptor, GLUT-4 transporter, growth hormone receptor, and MHC-I (major histocompatibility class) having activity to inhibit internalization of leptin receptor.
Peptide derived from the α1 domain of the I antigen complex (Procedings of the National Academy of Sciences of USA
eedings of the NationalAcademy of Sciences of the
United States of America), Vol. 91, pp. 9086-9090 (1994); Vol. 94, pp. 11692-11697 (1997))
And their analogs (derivatives), as well as fragments or derivatives of these fragments.

The drug used in the present invention may be itself or a pharmacologically acceptable salt. Such salts include, when the drug has a basic group such as an amino group, an inorganic acid (eg, hydrochloric acid, sulfuric acid, nitric acid, boric acid, etc.),
Salts with organic acids (eg, carbonic acid, bicarbonate, succinic acid, acetic acid, propionic acid, trifluoroacetic acid, etc.) and the like can be mentioned.
When the drug has an acidic group such as a carboxyl group, inorganic bases (eg, alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium) and organic bases (eg, organic amines such as triethylamine, Salts with basic amino acids such as arginine). Further, the drug may form a metal complex compound (eg, a copper complex, a zinc complex, etc.).

Preferred examples of the above-mentioned drugs include LH
LH-RH derivatives which are effective for prostate cancer, prostatic hyperplasia, endometriosis, uterine fibroids, precocious puberty, sex hormone-dependent diseases such as breast cancer and contraception, and salts thereof. Can be Specific examples of the LH-RH derivative or a salt thereof include, for example, Treatment With G
nRH analogs: Treatment with GnRH analogs: Controver
sies and perspectives) [The Parthenon Publishing Group
1996), Published Japanese Translation of PCT International Publication No. 3-503165,
Peptides described in JP-A-3-101695, JP-A-7-97334 and JP-A-8-259460 are exemplified. As LH-RH derivatives, LH-
Examples of the RH agonist or LH-RH antagonist include LH-RH antagonists, for example, of the general formula [I] X-D2Nal-D4ClPhe-D3Pal-Ser-AB-Leu-C-Pro-DAlaNH2 Is N (4H2-furoyl) Gly or NAc, A is NMeTy
r, Tyr, Aph (Atz), a residue selected from NMeAph (Atz),
B is DLys (Nic), DCit, DLys (AzaglyNic), DLys (AzaglyF
ur), DhArg (Et ₂ ), a residue selected from DAph (Atz) and DhCi, and C represents Lys (Nisp), Arg or hArg (Et ₂ ), respectively.) Is used. Examples of the LH-RH agonist include, for example, a compound represented by the general formula [II] 5-oxo-Pro-His-Trp-Ser-Tyr-Y-Leu-Arg-Pro-Z wherein Y is DLeu, DAla, DTrp, DSer (tBu), D2Nal and DHis (ImBzl), Z is Gly-NH ₂
The physiologically active peptide represented by the following or a salt thereof is used. In particular, Y is DLeu and Z is NH-C
A ₂ H ₅ peptides are preferred. These peptides can be produced by the method described in the literature or the gazette or a method analogous thereto.

The meanings of the abbreviations used in the present specification are as follows. Abbreviation Name N (4H2-furoyl) Gly: N-tetrahydrofuroylglycine residue NAc: N-acetyl group D2Nal: D-3- (2-naphthyl) alanine residue D4ClPhe: D-3- (4-chloro) phenylalanine Residue D3Pal: D-3- (3-pyridyl) alanine residue NMeTyr: N-methyltyrosine residue Aph (Atz): N- [5 '-(3'-amino-1'H-1', 2 ' , 4'-Triazolyl)] phenylalanine residue NMeAph (Atz): N-methyl- [5 '-(3'-amino-1'H-1', 2 ', 4'-triazolyl)] phenylalanine residue DLys (Nic): D- (eN-nicotinoyl) lysine residue Dcit: D-citrulline residue DLys (AzaglyNic): D- (azaglycylnicotinoyl) lysine residue DLys (AzaglyFur): D- (azaglycylfuranyl) ) Lysine residue DhArg (Et2): D- (N, N′-diethyl) homoarginine residue DAph (Atz): DN- [5 ′-(3′-amino-1′H-1 ′, 2 ′, 4'-triazolyl)] phenylalanine residue DhCi: D-homocitrulline residue Lys (Nisp): (eN-isopropyl) lysine Residue hArg (Et2): (N, N'- diethyl) relates other amino homoarginine residue, when displaying by abbreviations, IUPAC-IU
B Commission of Biochemical Nomenclature
(European Journal of Biochemistry, Vol. 138, 9
To page 37 (1984)) or a common abbreviation in the relevant field, and when an amino acid may have an optical isomer, the L-form is indicated unless otherwise specified.

The block copolymer used for the fine particles of the present invention can be produced, for example, as in the following (1) and (2), but is not limited thereto. (1) Starting from a primary amino group directly or via a spacer at the end of a biodegradable polymer which is a hydrophobic segment as a starting material, the N-amino acid of the amino acid which is a constituent component of the polyamino acid which is a hydrophilic segment is used as a starting material. A method for producing a block copolymer by ring-opening polymerization of carboxy anhydride (NCA). (2) A block copolymer is produced by an amide bond between a primary amino group or a carboxyl group, which is directly or via a spacer, on a biodegradable polymer as a hydrophobic segment and a terminal of a polyamino acid as a hydrophilic segment. Method. Hydrophobic segment having a primary amino group at the end can be represented by the formula B-Z ¹ (or _{^{B-Q-W 2 -NH 2}} ). In the formula, preferred examples of the group represented by Z ¹ include, for example, an aminomethyloxy group, a 2-aminoethyloxy group, a 1-aminopropane-2-oxy group, a 1-aminopropane-3-oxy group, 1-aminobutane-2-oxy group, 1-amino-3-butene-2-oxy group, 2-aminobutane-1-oxy group, 2-aminobutane-3-oxy group, 3-aminobutane-1-oxy group, 1 -Aminobutane-4-oxy group, 1-amino-2
-Methylpropane-2-oxy group, 2-amino-2-methylpropane-1-oxy group, 1-aminopentane-5
-Oxy group, 2-aminohexane-1-oxy group, 3-
Aminoheptane-4-oxy group, 1-aminooctane-
2-oxy group, 5-aminooctane-4-oxy group, 3
-Aminononane-4-oxy group, 1,2-diaminopropane-3-oxy group, 1,3-diaminopropane-2-
Oxy group, 1-amino-2,2-bis (aminomethyl)
Propane-1-oxy group, 1,2-diaminopropane-
2-oxy group, 2- (2-aminoethyl) aminoethyloxy group, 3- (2-aminoethyl) aminopropane-
2-oxy group, 3-aminopropane-1,2-dioxy group, 2-aminopropane-1,3-dioxy group, 2-amino-2-methylpropane-1,3-dioxy group, 2-
An amino-2-propylpropane-1,3-dioxy group,
2-amino-2- (1-methyl) ethylpropane-1,
3-dioxy group, aminomethane-tris (methoxy)
Group, 2-aminoethane-tris (methoxy) group, 2,2
-Bis (aminomethyl) propane-1,3-dioxy group, aminomethylamino group, 1-aminobutylamino group, 1-amino-2-methylpropylamino group, 1-amino-3-methylbutylamino group, 1 -Amino-2-phenylethylamino group, 2-aminoethylamino group, 3
-Amino-4-phenylbutylamino group, 3-amino-
5-methylhexylamino group, 3-aminopropylamino group, 2-aminoethylthio group, 2-amino-2-methylethyloxy group, 2-amino-2- (1-methylethyl) ethyloxy group, 2-amino -2- (2-methylpropyl) ethyloxy group, 2-amino-2- (1-methylpropyl) ethyloxy group, 2-amino-2-benzylethyloxy group, 2-aminobutane-1,3-dioxy group, -Amino-2- (4-aminobutyl) ethyloxy group, 2,6-diaminohexane-1,5-dioxy group, 2-amino-2- (3-guanidinopropyl) ethyloxy group, 2-amino-2- ( Carbamoylmethyl)
Ethyloxy group, 2-amino-2- (2-carbamoylethyl) ethyloxy group, 2-amino-2- (2-methylthioethyl) methylethyloxy group, 2-amino-2
-(Oxyphenylmethyl) methylethyloxy group, 2
-Amino-2- (5-imidazolylmethyl) ethyloxy group, 2-amino-2- (3-indolylmethyl) ethyloxy group and the like. B represents a biodegradable polymer, and the same as described above is used.

The polymer having a carboxyl group at the terminal (hereinafter sometimes referred to as a carboxyl-terminated polymer) may be prepared by a known method (for example, aliphatic polyesters among biodegradable polymers as hydrophobic segments). , Ring-opening polymerization method, condensation polymerization method, etc.). Among the biodegradable polymers which are hydrophobic segments, those having a primary amino group at the terminal can be prepared by a ring-opening polymerization method from a starting material in which the primary amino group is protected, or via a spacer to a carboxyl-terminated polymer. For example, a method of converting to an amino terminal is used. The production of a polymer having a primary amino group at the terminal using a ring-opening polymerization method is carried out by a ring-opening polymerization reaction from a hydroxyl group using a compound in which the amino group of an amino alcohol is protected as described below as a starting material.
For example, in monooxyamine, 2-aminoethanol (glycinol), 1-aminopropan-2-ol (isopropanolamine), 2-aminopropan-1
-Ol (alaninol), 1-aminobutan-2-ol, 1-amino-3-buten-2-ol, 2-aminobutan-1-ol, 2-aminobutan-3-ol, 1-amino-2-methylpropane -2-ol, 2
-Amino-2-methylpropan-1-ol, 2-amino-4-methylpentan-1-ol (leucinol), 2-aminohexane-1-ol, 3-aminoheptane-4-ol, 1-aminooctane -2-ol, 5-aminooctane-4-ol, 3-aminononan-4-ol, 1-aminopropan-3-ol, 3
-Aminobutan-1-ol, 1-aminobutane-4-
All, 1-aminopentan-5-ol, 1-aminopropane-2,3-diol, 2-aminopropane-
1,3-diol (serinol), 2-amino-2-methylpropane-1,3-diol, 2-amino-2-hydroxymethylpentan-1-ol, 2-amino-2
-Hydroxymethyl-3-methylbutan-1-ol,
Tris (hydroxymethyl) aminomethane, 1,2-diaminopropan-3-ol, 1,3-diaminopropan-2-ol and the like can be mentioned. The protecting group for the amino group in the starting materials may be any protecting group that is commonly used, and the same protecting groups as described above are used.

As a raw material of the biodegradable polymer produced by the present ring-opening polymerization reaction, there may be mentioned cyclic diesters and lactones formed by dehydrating two molecules of α-hydroxy acid. The cyclic diester may be formed from the same or different α-hydroxy acids, but is preferably derived from two molecules of the same α-hydroxy acid. Specific cyclic diesters include DL-, L-,
D-lactide, glycolide and the like. As the lactones, for example, α-lactone, β-lactone, γ-lactone, δ-lactone, ε-lactone and the like are used. Using one or more of these polymer raw materials, ring-opening polymerization is carried out from the hydroxyl group of a compound in which the amino group of the amino alcohol as the starting material is protected. Examples of the catalyst used in the present ring-opening polymerization reaction include organotin-based catalysts (eg, tin octylate, di-n-butyltin dilaurate, tetraphenyltin, etc.), aluminum-based catalysts (eg, triethylaluminum, etc.), and zinc-based catalysts. A catalyst (for example, diethyl zinc or the like) is used. The mixing ratio between the amino acid-protected compound of the amino alcohol, which is the starting material, and the polymer material is determined by the molecular weight of the target hydrophobic segment. The molecular weight of the resulting polymer increases. As the polymerization method, a bulk polymerization method in which the reactants are melted or a solution polymerization method in which the reactants are dissolved in an appropriate solvent (eg, toluene, benzene, decalin, dimethylformamide, etc.) may be used. Although the polymerization temperature is not particularly limited, in the case of bulk polymerization, the temperature is at or above a temperature at which the reactants are brought into a molten state at the start of the reaction, usually about 100 ° C. to about 300 ° C., and in the case of solution polymerization, it is usually room temperature to When the reaction temperature is about 100 ° C. and exceeds the boiling point of the reaction solution, the reaction may be carried out by refluxing with a condenser or in a pressure vessel.
The polymerization time is appropriately determined in consideration of the polymerization temperature, other reaction conditions, physical properties of the target polymer, and the like, and is, for example, about 10 minutes to about 72 hours. After the reaction, if necessary, the reaction mixture is mixed with a suitable solvent (eg, chloroform,
Dissolve in acetone, dichloromethane, etc.), and if necessary, terminate the polymerization with an acid (eg, hydrochloric acid, acetic anhydride, sulfuric acid, lactic acid, glycolic acid, acetic acid, etc.), and then add the desired product by a conventional method. Solvent that does not dissolve (eg, alcohols such as methanol, ethanol, isopropanol, propanol, butanol, water, ether, etc.)
It suffices to precipitate by, for example, dripping into the inside and to isolate it.

One end of the polymer purified and precipitated is a hydroxyl group, and since this hydroxyl group may start a side reaction in a later NCA polymerization reaction, it is protected by the following method. Although it does not specifically limit as a protective group, For example, the acyl derivative which has said hydrocarbons (for example, acetyl, formyl, benzoyl, etc.)
Is mentioned. For example, as a reaction for introducing an acetyl group into a hydroxyl group at the terminal of a polymer, a polymer having a hydroxyl group is dissolved in an appropriate solvent (for example, chloroform, dichloromethane, ethyl acetate, acetone, etc.), and acetic anhydride is added. The amount added is not particularly limited, but is usually from equimolar to about 10 times the molar amount of the hydroxyl group. The reaction temperature is not particularly limited as long as the ester bond of the polymer main chain is not cleaved, but is usually 0 ° C to about 20 ° C. The reaction time is not particularly limited because it is appropriately selected depending on conditions such as the reaction temperature and the solution concentration, but is usually about 5 minutes to about 72 hours. Additives can be added to this reaction to further improve the reaction efficiency. As the additive, for example, dimethylaminopyridine, pyridine, triethylamine and the like are used. These additives can be added alone or in combination of two or more. After the reaction, if necessary, a concentration operation is performed, and then the resultant is dropped in a solvent (eg, alcohol such as methanol, ethanol, isopropanol, propanol, butanol, alcohol, water, ether, etc.) which does not dissolve the target substance by a conventional method. Then, it may be precipitated and isolated.

The deprotection reaction of an amino group from a polymer having an amino group protected at one end and an acetylated hydroxyl group at the other end is appropriately selected depending on the type of protecting group to be deprotected. The polymer is dissolved in a suitable solvent (for example, chloroform, dichloromethane, trifluoroacetic acid, dioxane, ethyl acetate, acetic acid, etc.), and the deprotection reaction is performed according to a conventional method. The deprotection reaction varies depending on the intended protecting group, and examples thereof include a hydrogenolysis reaction and an acid decomposition reaction. However, the reaction is not particularly limited as long as the ester bond of the polymer main chain is not mainly cleaved. For example, in the hydrogenolysis reaction, after the polymer is dissolved in an appropriate solvent, the deprotection reaction can proceed with hydrogen or a substance capable of supplying hydrogen. At this time, an acid (for example, acetic acid, hydrochloric acid, trifluoroacetic acid, phosphoric acid, lactic acid, glycolic acid, butyric acid, etc.) can be added for the purpose of increasing the reaction efficiency. Although the reaction temperature is not particularly limited, it is usually 0 ° C. to 20 ° C., and when the temperature is higher than the boiling point of the solvent, it can be refluxed with a condenser. The reaction time is not particularly limited because it is appropriately selected depending on the reaction temperature, the type of the protecting group, the additive and the like, but is usually about 5 minutes to about 150 minutes.
Time. In the acid decomposition reaction, the polymer is dissolved in an acidic solvent (for example, trifluoroacetic acid, glacial acetic acid in which hydrobromic acid is dissolved, dilute hydrochloric acid, hydrogen fluoride, trifluoromethanesulfonic acid, methanesulfonic acid, or the like) or an appropriate solvent. The acid can be added after dissolving in a solvent. The reaction can also be promoted by adding an appropriate additive (eg, thioanisole, anisole, ethanediol, methionine, etc.). Although the reaction temperature is not particularly limited, it is generally about -20 ° C to about 50 ° C, and the reaction time is appropriately selected depending on the reaction temperature, the type of protective group, the type of additive, the amount of additive and the like. However, it is usually from about 1 minute to about 200 hours. After the deprotection reaction, if necessary, a concentration operation is performed, and then the resulting product is dropped in a solvent (for example, alcohols such as methanol, ethanol, isopropanol, propanol, and butanol, water, and ether) in which these compounds are not dissolved by a conventional method. It may be deposited and isolated. A salt with an acid may be formed at the amino terminus of the polymer after the deprotection reaction. In this case, a basic substance (for example, pyridine) is added to the precipitation solvent to such an extent that the ester bond of the polymer main chain is not cleaved. , Triethylamine, sodium bicarbonate, etc.) to remove the acid that has formed a salt. According to the above method, a hydrophobic segment having a primary amino group at the terminal and protecting the hydroxyl group terminal at the other end can be obtained.

A method for converting a polymer having an amino group at a terminal from a previously prepared carboxyl-terminated polymer via a spacer is performed as follows. By reacting the hydroxyl terminal of the biodegradable polymer obtained by a known method (for example, obtained by a non-catalytic dehydration condensation polymerization method from an α-hydroxycarboxylic acid or the like) with an active acyl compound, the hydroxyl of the biodegradable polymer is Protect the ends. Biodegradable polymer obtained by this,
By subjecting a compound having two protected amino groups to a condensation reaction with a dehydrating agent and / or a functional group activator, if desired, a polymer having a terminal-protected amino group can be obtained. . Amino groups and carboxyl groups involved in the condensation reaction may be activated by a known method, or the carboxyl group may be activated during the condensation reaction. The activation may be performed by a method known per se. Examples of such a method include, for example, an activated ester [substituted phenols (for example, pentachlorophenol, 2,4,5-trichlorophenol, 2,4-
Dinitrophenol, p-nitrophenol, etc.), N-
Esters with substituted imides (for example, N-hydroxy-5-norbornene-2,3-dicarboximide, N-hydroxysuccinimide, N-hydroxy-1,2,3-benzotriazole), etc. A method for forming a carboxylic anhydride, an azide or the like for an acid, an acid chloride method, a redox method (Mukoyama method), a mixed acid anhydride method, an N, N-dicyclohexylcarbodiimide method, an N, N-dicyclohexylcarbodiimide-additive method, Method using Woodwork reagent K, benzotriazol-1-yl-oxy-tris (dimethylamino)
-A method using phosphonium hexafluorophosphate (BOP reagent).

The condensation reaction can be usually performed in a solvent that does not inhibit the reaction. Such solvents include amides such as dimethylformamide, tetrahydrofuran,
Ethers such as dioxane; halogenated hydrocarbons such as dichloromethane and chloroform; alcohols such as ethanol and methanol; sulfoxides such as dimethyl sulfoxide; esters such as ethyl acetate;
Methylpyrrolidone, N-methylmorpholine, water and the like. The reaction temperature is preferably from about -30C to about 50C, more preferably from about 0C to about 40C. The reaction time is
For example, from about 10 minutes to about 24 hours. The protecting group of the polymer obtained by the above condensation reaction can be eliminated by a method known per se. As such a method, any method capable of removing the protecting group without affecting the ester bond or the amide bond may be used.Specifically, for example, oxidation, reduction, A method such as acid treatment may be used. Here, examples of the oxidation method include oxidation with iodine, heavy metals (eg, mercury salts, silver salts, thallium salts, and the like). As the reduction method, for example, a catalyst (for example, palladium carbon, palladium black, platinum oxide, etc.)
, A reduction with sodium in liquid ammonium, a reduction with dithiothreitol, and the like. As the acid treatment method, for example, an inorganic acid (eg, hydrogen fluoride, hydrogen bromide, hydrogen chloride, etc.) or an organic acid (eg, trifluoroacetic acid, methanesulfonic acid,
Acid treatment with trifluoromethanesulfonic acid or the like or a mixture thereof. At the time of the acid treatment, it is preferable to appropriately add a cation scavenger (for example, anisole, phenol, thioanisole, etc.).

The method of synthesizing the hydrophilic segment is not particularly limited, and a method of preliminarily synthesizing the hydrophilic segment and then covalently bonding to the hydrophobic segment, and a method of polymerizing the hydrophilic segment using the hydrophobic segment as a starting material are used. Can be The most efficient method for polymerizing a polyamino acid, which is a hydrophilic segment more than a primary amino group of a hydrophobic segment having a primary amino group, includes a ring-opening polymerization reaction of an amino acid with N-carboxy anhydride (NCA). Can be NCA synthesis of amino acids is performed by a well-known method, and is generally obtained by acting phosgene on an α-amino acid. This NCA is susceptible to attack by nucleophiles and is easily opened with water or a base to obtain carbamic acid, which is immediately decarboxylated to produce a starting amino acid. Then, these amino acids react one after another with NCA to form a polymer. That is, the desired block copolymer can be obtained by reacting with a hydrophobic segment having an amino group which is an initiator of NCA polymerization. The NCA of the amino acid constituting the polyamino acid serving as the hydrophilic segment is not particularly limited. , Lysine, arginine, histidine, D-form, L-form, D, L-form, and the above-mentioned protecting group in the thiol group of cysteine. NCA that combines
Examples include NCA in which the above-described protecting group is bonded to the hydroxyl group of tyrosine, phenylalanine, and NCA of tryptophan. These may be used alone or as a mixture of two or more amino acids NCA.

The amount ratio of the amino acid NCA to be reacted with the primary amino-terminated polymer, which is a hydrophobic segment, is appropriately determined in accordance with the desired ratio of the hydrophilic / hydrophobic segment. The reaction solvent between the polymer of the hydrophobic segment having an amino terminus and the amino acid NCA is not particularly limited as long as it is a suitable solvent that can dissolve or suspend the polymer and the amino acid NCA so that both substances can react. For example, chloroform, dioxane, dichloromethane, ethyl acetate, tetrahydrofuran, dimethylformamide, dimethylacetamide, benzene, toluene, hexane, carbon tetrachloride, acetone, cyclohexane and the like can be used alone or in combination of two or more. It is necessary to use these reaction solvents immediately after strictly performing a dehydration operation. In addition, it is necessary to use a completely dry apparatus in a dry box in order to avoid mixing of water in the reaction environment. Although the reaction temperature is not particularly limited, it is generally about -20 ° C to about 50 ° C. When the temperature becomes higher than the boiling point of the solvent, the solvent can be refluxed with a condenser. The reaction time is not particularly limited because it is appropriately selected depending on the reaction temperature, the type of amino acid NCA, the solvent, and the like, but is usually about 5 minutes to about 150 hours. After the reaction, if necessary, a concentration operation is performed, and then the solution is dropped in a solvent (eg, alcohol such as methanol, ethanol, isopropanol, propanol, butanol, alcohol, water, ether, etc.) which does not dissolve the target compound by a conventional method. And then isolated. This makes it possible to obtain a block copolymer in which a hydrophobic segment and a hydrophilic segment, which is a polyamino acid having a protected side chain functional group, are constituted by amide bonds.

The deprotection reaction of the block copolymer in which the side chain functional group of the polyamino acid which is a hydrophilic segment is protected may be carried out according to a conventional method depending on the type of the protecting group.
All or a part of the protecting group may be appropriately deprotected depending on the purpose. The deprotected block copolymer is precipitated and isolated by dropping into a solvent in which the target substance is not dissolved after the reaction (eg, alcohol such as methanol, ethanol, isopropanol, propanol, butanol, water, ether, etc.). I just need. In addition, when a water-miscible solvent having a high boiling point is selected as a good solvent for the polymer,
This solvent can also be removed by using a dialysis method against a large amount of water. Thereby, a block copolymer in which a hydrophobic segment and a hydrophilic segment are covalently bonded can be obtained. Alternatively, the previously prepared biodegradable polymer, which is a hydrophobic segment, and the polyamino acid, which is a hydrophilic segment, can be bonded together in a blocked state. For example, the hydrophobic segment having a primary amino group and the polyamino acid having a carboxyl group are reacted by a known method to form an amide bond. Alternatively, conversely, a hydrophobic segment having a carboxyl group and a polyamino acid having an amino group are reacted by a known method to form an amide bond. In these methods, coupling via a specer may be used, and the above-mentioned W is used as the specer. The block copolymer in which Q ^{1 and} / or Q ² is S can be produced according to a method known per se or a method analogous thereto. For example, a block copolymer in which Q ^{1 and} / or Q ² is O can be converted to a block copolymer in which Q ² is S according to a method known per se or a method analogous thereto. The block copolymer obtained by the above method is called AB
It is called a block copolymer. Since the AB block copolymer contains a hydrophilic segment and a hydrophobic segment in the molecule, the balance between hydrophilicity and hydrophobicity can be appropriately adjusted by appropriately selecting the type of the segment or the average molecular weight. Can be. Therefore, in these AB block copolymers, due to the difference in the solubility of each segment in a solvent, low-solubility segments associate to form a nucleus (core) (or sometimes referred to as an inner core), around which a high-solubility The polymeric micelle morphology can be formed where the segments form a shell (or sometimes referred to as an outer core). Such fine particles having a plurality of AB block copolymers having a core / shell structure are referred to as polymer micelles. And
Nano-sized particles are simply referred to as nanoparticles.

In order to prepare a polymer micelle containing an AB block copolymer as a constituent component, for example, a dialysis method, a water drying method or an ultrasonic irradiation treatment method is used, and these are used alone or in combination. (1) Preparation method (dialysis method) After dissolving one kind or a mixture of two or more kinds of AB block copolymer in a solvent, the solution is put into a dialysis tube and dialyzed in water to prepare a polymer micelle. The solvent used here is not particularly limited as long as it can dissolve the AB block copolymer and is miscible with water.
Methanol, ethanol, benzene, toluene, dimethylacetamide, dimethylformamide, dimethylsulfoxide, tetrahydrofuran, dioxane, acetone, acetonitrile and the like are used, but any of these may be used alone or in combination. AB
Even if it is not a good solvent for the block copolymer, AB
It can be added to the solvent to the extent that the block copolymer does not precipitate. The ratio between the AB block copolymer and the solvent is not particularly limited, but may be about 0.01 mg / ml to about 10 g / m
l, preferably selected from the range of about 0.1 mg / ml to about 1 g / ml, more preferably from about 1 mg / ml to about 100 mg / ml. As the dialysis membrane, an appropriate molecular weight fraction size may be selected depending on the molecular weight of the AB block copolymer to be used, and a cellulose membrane or the like is often used, but is not limited to this. Further, additives may be added to the outer aqueous phase or the dialysis solution. Examples of the additive include a pH adjuster (for example, a phosphate buffer, a carbonate buffer, an acetate buffer, dilute hydrochloric acid, and sodium hydroxide), an anionic surfactant, a nonionic surfactant, and polyoxyethylene. Emulsifiers such as castor oil derivatives, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, lecithin, gelatin, hyaluronic acid and saccharides such as mannitol are used. The concentration at the time of use can be appropriately selected from the range of about 0.00001% to about 20% (W / V) with respect to the external aqueous phase. The pH adjustment of the outer aqueous phase depends on the type of polyamino acid which is a hydrophilic segment of the block copolymer to be used, but it is usually preferable to select a pH at which a functional group is in a free state. For example, when the polyamino acid is a homopolymer of polyglutamic acid, when the pH of the external aqueous phase is lower than the pKa of glutamic acid, the side chain functional groups do not dissociate, and it becomes difficult to form polymer micelles. Conversely, when the pH of the outer aqueous phase is higher than pKa, the side chain functional groups become free and polymer micelles are easily formed. However, there is an upper limit to the pH, and it is considered that there is an optimum pH. For example, in the case of polyglutamic acid, the most preferred pH of the outer aqueous phase is 5.5.
~ 6.5. The volume ratio of the external aqueous phase to the solvent when performing dialysis is usually selected from about 1 to about 10,000 times.
More preferably, it is selected from about 5 times to about 1,000 times. The dialysis time is usually about 5 minutes to about 24 hours once, but a polymer micelle is prepared by repeating the liquid exchange operation of the outer aqueous phase one or more times. The preparation temperature is preferably from about 0C to about 100C, more preferably from about 5C to about 50C. The polymer micelle thus prepared can be obtained in a dialysis membrane in a transparent to slightly cloudy state.

(2) Preparation method (in-water drying method) After dissolving one or a mixture of two or more AB block copolymers in a solvent, water (referred to as A) is added little by little with stirring, and the solvent is removed in water. To prepare polymer micelles. The solvent used here is not particularly limited, but for example, methanol, ethanol, benzene,
Toluene, dimethylacetamide, dimethylformamide, dimethylsulfoxide, tetrahydrofuran, dioxane, acetone, acetonitrile, or a mixture thereof with water is used, but any of these may be used alone or in combination. Among them, a combination of tetrahydrofuran, acetone and water is preferably used. Since a good solvent for a polymer naturally changes depending on the polymer composition, a solvent is selected according to the polymer to be used. The concentration of AB block copolymer in the solvent can be adjusted from about 0.0001% (W / V) to about 50% (W / V). To the water to be added, the additive in the external aqueous phase described in the above section (1) Preparation method (dialysis method) may be similarly added. The amount of water (A) can be arbitrarily selected with respect to the organic solvent, but is selected from about 1 to about 10,000 times.
More preferably, it is selected from about 5 times to about 1,000 times. The preparation temperature is preferably from about 0C to about 100C, more preferably from about 5C to about 50C. Further, it is also possible to apply an external shearing force at the time of drying in water or to remove the solvent by an evaporator or the like according to a conventional method under reduced pressure conditions. The external shear force includes, for example, a turbine-type stirrer, a homogenizer, and the like.

(3) Preparation method (ultrasonic irradiation method) One or a mixture of two or more AB block copolymers are dispersed in water at a concentration of 0.0001% to 50% (W / V) or in an appropriate solvent. The AB block copolymer is dissolved and dispersed in a large amount of water. Although it cannot be unconditionally determined according to the shape of the apparatus and the amount of processing, for example, 1 W to about 200 W
Ultrasonic irradiation is performed at W, preferably 1 W to about 10 W for 1 second to about 24 hours, more preferably 1 minute to about 5 hours.
The conditioning temperature is in the range of about 0 ° C to about 100 ° C, but is preferably about 5 ° C to 50 ° C. Compositional fractionation is performed in order to remove unnecessary substances generated during preparation such as free drug and large particles, and a method such as filter filtration or centrifugation is used. The pore size of the filter can be properly selected depending on the desired preparation, but is preferably several hundred nm or less. The conditions of the centrifugal separation operation may be in accordance with the purpose, but the centrifugal force is usually about 500 G to about 1 G.
Preferably, the centrifugation time is about 1 minute to about 10 hours.

In the present invention, the form of polymer micelles that can be formed by the AB block copolymer having a hydrophobic / hydrophilic segment can be arbitrarily changed depending on the preparation method. When polymer micelles are prepared in a large amount of aqueous solution after dissolving or dispersing the AB block copolymer in an organic solvent, it becomes O / W type and has a form in which a hydrophilic segment is arranged in an outer shell with a hydrophobic segment as an inner core. . On the other hand, when the AB block copolymer is dissolved or dispersed in an aqueous solution and then polymer micelles are prepared in a large amount of an organic solvent, the polymer becomes W / O type, the hydrophilic segment is the core, and the hydrophobic segment is the outer shell. It becomes the form which was arranged. Usually, for example, it is a core / shell type fine particle having a hydrophobic segment as an inner core and a hydrophilic segment as an outer shell. In that case A
It is presumed that the hydrophobic segments of the B block copolymer aggregate and aggregate at a high density to form a core, and the hydrophilic segments extend outward from the particle surface or form a helical structure. When the functional group is protected or modified, the presence of partial aggregation of the aqueous segment is also considered. These preparation methods can also be changed according to the purpose. For example, when a drug is encapsulated, it is determined by physical properties such as solubility and stability of the drug in water or an organic solvent.

The average particle size of the polymer micelle obtained by the above method is about 1 nm to about 1 nm in a state of being dispersed in water.
It is preferably from 000 nm, more preferably from about 10 nm to 1,000 nm, particularly preferably from about 10 nm to about 200 nm. The determinants of these particle diameters are the composition of the AB block copolymer and the method of preparing it. Also, since the particle size changes depending on the purpose of use,
It is not limited to these. The particle diameter can be measured by a known method, and for example, a light scattering measurement method, microscopic observation, or the like is used. In any of the above-mentioned preparation methods, after the formation of the polymer micelles, freeze-drying or vacuum drying is performed in a state of being dispersed in water, and can be stored as a dry powder. Additives can be added for the purpose of suppressing aggregation during the drying operation. Examples of additives include water-soluble polysaccharides such as mannitol, lactose, glucose, starches (eg, corn starch), hyaluronic acid and alkali metal salts thereof, proteins such as glycine, fibrin, collagen, sodium chloride, and phosphorus. Inorganic salts such as sodium hydrogen oxyoxide are used. The amount of the additive is preferably about 0.01 to 50% by weight, more preferably about 0.1 to 25% by weight, and particularly preferably 0.1 to 10% by weight, based on the whole fine particles.

In the present invention, as the polymer micelle prepared using the AB block copolymer, a polymer in which a hydrophobic segment is disposed in the inner core and a hydrophilic segment is disposed in the outer shell is a polyamino acid which is a hydrophilic segment. This is preferable in that an effect other than the above can be exhibited. As an effect other than being hydrophilic, for example,
When the constituent amino acids are dissociated with a functional group such as aspartic acid, glutamic acid, lysine, or arginine, the amino acids can be positively or negatively charged, and can be expected to exhibit specific translocation into the body after administration in vivo. In addition, the present polymer micelles can be specifically recognized by receptors for various amino acids present in the body. In addition, by binding a recognition element to the hydrophilic segment, it is possible to further impart targeting ability in a living body. Since the polymer micelle can be prepared under relatively mild conditions, it is suitable for entrapping unstable drugs. The particle size and the like can be adjusted by appropriately changing the molecular weight of the hydrophobic segment and the hydrophilic segment. It is considered that the drug-encapsulated preparation can also regulate blood retention. It can also be used for solubilizing hydrophobic compounds in water.

Since the polymeric micelle is a preparation characterized in that it usually has a hydrophobic segment as a core, it is preferable that the drug to be encapsulated is hydrophobic. Specific organs (eg, kidney, liver, lung, pancreas,
For example, those that can enhance drug efficacy by directing them to the brain, and those that can enhance drug efficacy by prolonging their retention in the blood are preferable. The drug is stably encapsulated in the core portion of the fine particles composed of hydrophobic segments. be able to. The method for encapsulating a drug of the present invention enables preparation of a polymer micelle that is added to a polymer solution, has a drug and a hydrophobic segment as nuclei, and has a hydrophilic segment disposed on the surface. At this time, an appropriate solvent can be added to efficiently trap the drug. For example, a method of adding a solvent such as chloroform or dichloromethane to stabilize the hydrophobic environment in the polymer and encapsulating the drug can be considered. Alternatively, a method is also conceivable in which a polymer micelle is prepared in advance using a polymer, and a drug dissolved in a solvent is later added to the polymer micelle solution to allow the drug to permeate the polymer micelle core.
In this case, the permeation efficiency can be increased by appropriately changing the pH, salt concentration, etc. of the solution. Examples of the hydrophobic drug to be encapsulated are the same as those described above. Contrary to the above-mentioned polymer micelles, polymer micelles having a hydrophilic segment as a core and a hydrophobic segment as a shell are also preferable, which encapsulate a hydrophilic drug in the polymer micelle core, and provide sustained release and drug release. It shows stability. As the hydrophilic drug, the same one as described above is used. This polymeric micelle can also be administered by the dosage form described below. Nanoparticles and microparticles containing the AB block copolymer can be produced according to a method known per se or a method analogous thereto (for example, an in-water drying method, a phase separation method, or a spray drying method).

The content of the block copolymer in the fine particles of the present invention is usually about 10 to 1 relative to the whole fine particles.
00% by weight, preferably about 30-100% by weight.
When a drug is contained in the fine particles of the present invention, the content of the drug in the fine particles of the present invention is usually about 0.0001 to 90% by weight, preferably about 0.001% by weight, based on the whole fine particles.
To 80% by weight, more preferably about 0.01 to 50% by weight. The fine particles of the present invention include, for example, dispersants (surfactants such as Tween-80 and HCO-60; polysaccharides such as carboxymethylcellulose, sodium alginate and sodium hyaluronate; protamine sulfate; polyethylene glycol 400 and the like); Preservatives (eg, methylparaben, propylparaben, etc.),
Isotonicity agents (eg, sodium chloride, mannitol, sorbitol, glucose, etc.), fats (eg, sesame oil, corn oil, etc.), phospholipids (eg, lecithin, etc.), excipients (eg, lactose, corn starch, mannitol) , Cellulose, etc.), binders (eg, sucrose,
It may be mixed with gum arabic, methylcellulose, carboxymethylcellulose, dextrin and the like, disintegrants (for example, calcium carboxymethylcellulose) and the like. When an additive such as a dispersant is contained in the fine particles of the present invention, the content of the additive in the fine particles of the present invention is usually about 0.001 to 30 with respect to the whole fine particles.
%, Preferably about 0.01 to 5% by weight. If additives are included, the proportion of drug or polymer will vary from the above.

The microparticles containing the drug of the present invention can be administered intravenously, subcutaneously, intramuscularly, intradermally, instilled, intraocularly (including direct administration to the vitreous retina), or indirectly. It can be used by dispersing it in a solution for the purpose, etc., it can be used pulmonary or nasal administration as a dry powder, or it can be transdermally used as a powder or dispersed in an appropriate dispersion medium It can also be administered as a needleless injection.
Further, transdermal administration adapted to be dispersed in a gel and the like is also conceivable. Here, the preferable gel includes, for example, a hydrogel (for example, PVA gel, N-isopropylacrylamide gel, etc.). Further, the fine particles containing the drug of the present invention are formulated into various dosage forms as a raw material,
Injection or implant for intramuscular, subcutaneous, organ, etc.
Transmucosal agent for nasal cavity, rectum, uterus, etc., oral agent (for example,
Capsules (eg, hard capsules, soft capsules and the like), solid preparations such as granules and powders, and liquid preparations such as syrups, emulsions and suspensions]. For example,
In order to make the microparticles containing the drug of the present invention into injections, these may be used as dispersants (eg, Tween 80, HC
Surfactants such as O-60, polysaccharides such as sodium hyaluronate, carboxymethylcellulose, sodium alginate, etc., preservatives (eg, methylparaben, propylparaben, etc.), isotonic agents (eg, sodium chloride, mannitol, sorbitol) , Glucose, proline, etc.) or an oily suspension by dispersing with vegetable oils such as sesame oil and corn oil.
To make the microparticles containing the drug of the present invention into a sterile formulation,
Examples include a method of sterilizing the entire production process, a method of sterilizing with a gamma ray, and a method of adding a preservative, but are not particularly limited.

Since the microparticles containing the drug of the present invention have low toxicity, they can be used in mammals (eg, humans, cows, pigs, dogs, cats,
Mouse, rat, rabbit, etc.). The dosage of the microparticles containing the drug of the present invention varies depending on the type and content of the drug as the main drug, dosage form, target disease, target animal, and the like, but may be any effective amount of the drug. The dose of the main drug at one time, for example, about 0.01 mg per adult
In the range of 10 mg / kg body weight, more preferably about 0.0
It can be appropriately selected from the range of 5 mg to 5 mg / kg body weight. The dose of drug-containing microparticles per dose is
Preferably, about 0.05 mg to 50 mg per adult
/ Kg body weight range, more preferably about 0.1 mg to 3
It can be appropriately selected from the range of 0 mg / kg body weight. For example, when the drug is adrenocortical hormone and betamethasone, which is a drug effective for patients with renal disease, is administered by injection to adult patients, the dose of the active ingredient is about 0.1 to 5 m
Used in g / kg body weight. The frequency of administration should be once every few weeks, once a month, or once every few months (eg, once every 3 months, 4 months, 6 months, etc.). ,
It can be appropriately selected depending on the target disease, the target animal, and the like.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference examples, examples, comparative examples,
The present invention will be described more specifically with reference to test examples, but these do not limit the present invention.

[0056]

EXAMPLES Reference Example 1 Production of poly (DL-lactide) having an amino group terminal protected with a Z group A 391 mg purified product of recrystallization of benzyl N- (2-hydroxyethyl) -carbamate was prepared in a glass three-necked flask. Within 65 ℃, 18
After drying under reduced pressure for an hour, the atmosphere was replaced with nitrogen, and 10 g of a purified recrystallized DL-lactide was added, followed by melting at 130 ° C. Furthermore, a toluene solution of tin 2-ethylhexanoate recrystallized and purified (1.
(52.5 mg / ml) and reacted at 150 ° C. for 3 hours. After allowing to cool, the mixture was dissolved in 25 ml of chloroform and dropped into 2 L of ice-cooled ethanol to precipitate and purify the polymer. Repeat this precipitation operation
The polymer was dried under reduced pressure, and the polymer was dried under reduced pressure to obtain a white powder of poly (DL-) having 2- (N-benzyloxycarbonyl) aminoethanol ester-bonded to the terminal carboxyl group.
Lactide). Number average molecular weight by GPC (hereinafter, referred to as
Mn) was 6,375, and weight average molecular weight (hereinafter, abbreviated as Mw) was 12,833. ¹ H NMR of polymer
(CDCl ₃ ), the signal δ derived from poly (DL-lactide) δ = 1.58 ppm (doublet, CH ₃ ), 5.17 ppm (quarte
(t, CH) and phenyl signal δ = 7.35 ppm.
The number average molecular weight determined from these peak area ratios based on the terminal group determination method was Mn = 5470.

Reference Example 2 Production of poly (DL-lactide) in which both terminals were protected with Z group and acetyl group Of the dry polymer obtained in Reference Example 1, 11.7 g was dissolved in 20 ml of chloroform, and dimethyl was added under ice cooling. Aminopyridine
3 ml of a chloroform solution in which 52.42 mg was dissolved was added, and then 1.006 ml of acetic anhydride and 0.861 ml of pyridine were added, followed by stirring with a stirrer at room temperature for 15 hours. After the reaction, the polymer was dropped into 2 L of ice-cooled ethanol to precipitate and purify the polymer. After the precipitation operation was repeated twice, the powder was dried and poly (DL-lactide) having 2- (N-benzyloxycarbonyl) aminoethanol at the terminal carboxyl group and an acetyl group at the other hydroxy terminal was ester-bonded to a white powder. I got G
Mn = 7741 and Mw = 13031 by PC. From ¹ H-NMR (CDCl ₃ ) of the polymer, an acetyl signal δ = 2.13 ppm, a phenyl signal δ = 7.35 ppm, and a signal δ = 1.58 ppm (do) derived from poly (DL-lactide)
ublet, CH ₃ ), 5.17 ppm (quartet, CH).

Reference Example 3 Production of poly (DL-lactide) having an amino terminal and protected at one terminal by an acetyl group 10.685 g of the dry polymer obtained in Reference Example 2 was dissolved in 20 ml of trifluoroacetic acid. Then, 2 ml of thioanisole was added, and the mixture was stirred with a stirrer at room temperature for 4 days. After the reaction, the polymer was dropped into 2 L of ice-cooled ethanol to precipitate and purify the polymer. After repeating the precipitation operation twice, the precipitated polymer was redissolved in chloroform, filtered through a 0.45 μm filter, and dried. Chloroform the dried polymer obtained above.
After dissolving in 20 ml, the mixture was added dropwise to 1 L of ice-cold ethanol containing 0.3 V / V% to precipitate a polymer, followed by drying. The dried polymer was redissolved in 15 ml of chloroform, dropped into 1 L of ice-cooled ethanol, and the polymer was precipitated and dried.Aminoethanol was attached to the terminal carboxyl group and an acetyl group was attached to the other hydroxy terminal of the white powder. Poly (DL-lactide) was obtained. According to GPC, Mn was 9,007 and Mw was 13,240. From ¹ H-NMR (CDCl ₃ ) of the polymer, the disappearance of the phenyl signal δ = 7.35 ppm, the acetyl signal δ = 2.13 ppm, and the signal δ = 1.58 ppm derived from poly (DL-lactide) (doublet, CH ₃ ), 5.17ppm (quarte
t, CH). Confirmation of the terminal amino group was performed by the following method. Polymer chloroform solution (50mg / m
l) The same amount of PITC (phenyl isothiocyanate) in chloroform solution (12.5 μL / ml) was reacted at room temperature for 1 hour. Gel Permeation Chromatography (G
The sample was measured after reaction with PITC in PC). In the peak area at the polymer elution position, it was confirmed that PITC having ultraviolet absorption at UV 254 nm reacted with the terminal amino group by comparing with the peak area before the labeling reaction.

Example 1 Preparation of AB block copolymer containing poly (DL-lactide) and poly (γ-benzyl-L-glutamic acid) 3.157 g of the dry polymer obtained in Reference Example 3 was mixed with 33 ml of an equal volume mixture of dioxane and dichloromethane. , And 3.67 g of gamma-benzyl-L-glutamic acid NCA (manufactured by Wako Pure Chemical Industries) was dissolved in 33 ml of an equal mixture of dioxane and dichloromethane. The reaction was carried out by stirring with a stirrer at room temperature for 5 days under dry conditions. After the reaction, a concentration operation was performed, followed by dissolution in 15 ml of tetrahydrofuran, followed by a precipitation operation in 800 ml of ice-cooled ethanol. The precipitated polymer is collected by filtration with a 0.5 μm PTFE filter, dried under reduced pressure, and the carboxyl group end of the polyamino acid block in which all side chain carboxyl groups of polyglutamic acid in white powder are protected with benzyl groups, and the hydroxy end is an acetyl group. An AB block copolymer was obtained in which the carboxyl group of the poly (DL-lactide) protected by amide bond with the amino terminal side of the hydrophobic segment in which the carboxyl group was ester-bonded with ethanolamine. GPC measurement using tetrahydrofuran as a mobile phase confirmed that the AB block copolymer was a synthetic polymer having one peak. From ¹ H-NMR (DMSO) of the polymer, a signal δ derived from benzyl of poly (γ-benzyl-L-glutamic acid) δ = 7.24-7.33 ppm (phenyl), 5.0-5.1 ppm
The signal δ = 1.48 ppm (doublet, CH ₃ ) and 5.2 ppm (quartet, CH) derived from (CH ₂ ) and poly (DL-lactide) were confirmed. The γ-benzyl-L-glutamic acid content in one molecule of the synthetic polymer calculated from these peak area ratios was 27.2.
Residue. Further, since the present block copolymer is hardly soluble in chloroform, a change in physical properties of poly (DL-lactide) before the reaction is apparent.

Example 2 Preparation of AB block copolymer having poly (DL-lactide) and poly (L-glutamic acid) 2.917 g of the dry polymer obtained in Example 1 was dissolved in 40 ml of N, N-dimethylformamide (DMF) After purging with nitrogen, 996 mg of palladium carbon was added, and hydrogen was added using a bubbler while stirring with a stirrer. The catalytic reduction operation with hydrogen was performed at room temperature for 29.5 hours. After the reaction, a concentration operation was performed to remove DMF as much as possible, then dispersed in purified water, placed in a dialysis tube (molecular weight cut-off 6000-8000), and placed in 2 L
The dialysis operation was performed on the outer aqueous phase, and the outer aqueous phase was replaced four times to remove DMF. 1.09 g of white powder obtained by vacuum drying the polymer remaining in the tube after dialysis in 20 ml
Shake in chloroform for 10 minutes and filter (PF02
(0, ADVANTEC) to remove chloroform-dissolved components. The polymer remaining on the filter is vacuum-dried, and the carboxyl group end of polyglutamic acid in white powder and the hydrophobic group in which the carboxyl group of poly (DL-lactide) in which the hydroxy end is protected with an acetyl group are ester-bonded to ethanolamine. An AB block copolymer having an amide bond on the amino terminal side of the acidic segment was obtained. ^{1 of} polymer
From H-NMR (DMSO), disappearance of the peak of benzyl which was a protecting group and signal δ = 1.48 ppm (doublet, CH ₃ ) and 5.2 ppm (quartet, CH) derived from poly (DL-lactide)
It was confirmed. Further, the content of glutamic acid in the present block copolymer can be measured by the following method. 0.347 mg of the obtained AB block copolymer was treated with 6N hydrochloric acid in 110
After hydrolysis at 24 ° C. for 24 hours, the residue was dissolved in 1 ml of 0.02N hydrochloric acid and measured with an amino acid analyzer to find that it was 26.2% (W / W%). The molecular weight in terms of polystyrene measured by GPC using polystyrene as a reference substance was Mn = 982,148 and Mw = 1,66.
It was 0,110. The measurement was performed using GPC columns α-3000 and α-500.
0 were connected in series (manufactured by Tosoh Corporation), RI Monitor SE-61 (manufactured by Showa Denko) was used, and DMF was used as a mobile phase. GP
The peak of the polymer obtained from C was a single peak.

Example 3 Preparation of Polymer Micelles 10.4 mg of the block copolymer obtained in Example 2 was added to DMF 2m
l, dissolved in 2 ml of THF, and dialyzed into a dialysis tube (spectra
/ Por, molecular weight fraction 3500) and dialyzed against 500 ml of 0.05M phosphate buffer (pH 6.0). After the phosphate buffer solution, which is the outer aqueous phase, is exchanged six times in 24 hours, the particle size of the polymer micelles in the dialysis tube is reduced to the submicron particle sizer NICOMP MODEL3.
70 (Particle Sizing System)
s company). The result was that about 7% of aggregates having an average particle diameter of 156 nm were mixed in polymer micelles having an average particle diameter of 42.7 nm.

Comparative Example 1 Production of Polymer Micelles 10.1 mg of the block copolymer obtained in Example 2 was added to DMF2m
l, dissolved in 2 ml of THF, and dialyzed into a dialysis tube (spectra
/ Por, molecular weight fraction 3500), and dialyzed against 500 ml of 0.05 M phosphate buffer (pH 4.0). The phosphate buffer solution, which is the outer aqueous phase, was exchanged 6 times in 24 hours. Precipitation of the polymer component was observed immediately after dialysis, and after completion of the dialysis, about 80% of the block copolymer became a precipitate. It was found that the dialysis operation at pH 4 hardly formed polymer micelles. This suggests that the side chain carboxyl group of polyglutamic acid, which is a hydrophilic segment in the block copolymer used, was not dissociated at pH 4.

Example 4 Production of Polymer Micelles An AB block copolymer synthesized in the same manner as in Example 2 (glutamic acid content: 41.1%, Mn = 236,017, Mw = 265,14)
5) 9.2 mg was dissolved in 2 ml of DMF and 2 ml of THF, placed in a dialysis tube (spectra / por, molecular weight fraction 3500), and dialyzed against 500 ml of a 0.05 M phosphate buffer (pH 6.0). The phosphate buffer, which is the outer aqueous phase, is 6
After performing the liquid exchange, the particle size of the polymer micelle in the dialysis tube is reduced to the submicron particle sizer NICOM.
P Model370 (Particle Size)
As a result, the production of polymer micelles having an average particle diameter of 53.8 nm was confirmed.

Example 5 Preparation of betamethasone valerate-encapsulated polymer micelles Using the same AB block copolymer as in Example 4 above,
A method for preparing a polymeric micellar preparation of betamethasone valerate was performed as follows. Betamethasone valerate is a hydrophobic steroid, but its solubility in water is 1.5 μg / ml. Add the amount of AB block copolymer 50, 100, 200mg
Was dissolved in DMF together with betamethasone valerate (10 mg), THF was added to make the solvent amount 10 ml, and then placed in a dialysis tube (spectra / por, molecular weight fraction 3500), and 1 L of 0.05 M phosphate buffer ( (pH 6.0). The outer aqueous phase was subjected to liquid exchange six times in 24 hours. The concentration of betamethasone valerate in the supernatant from which the insoluble betamethasone valerate was removed by centrifugation of the solution in the precipitation tube (5000 g x 30 min) was measured, and the recovery rate for 10 mg added was calculated. The recovery rate of betamezone valerate encapsulated and recovered in polymer micelles was 30%, 100m
The g addition amount was 41%, and the 200 mg addition amount was 50.1%. 200mg
The concentration of betamethasone valerate in water at the added amount was 17
It was 1.2 μg / ml, which was 100 times or more before encapsulation in the polymer micelle. This makes it possible to solubilize the poorly soluble hydrophobic compound in the AB block copolymer,
It was found to be proportional to the amount of block copolymer.

Test Example 1 About 0.4 ml of the aqueous solution of betamethasone valerate-containing polymer micelle (103.5 μg / ml) described in Example 5 was applied to about 0.4 ml of the aqueous solution of this polymer micelle from the tail vein of an ICR mouse weighing about 40 g at 27 G. Was administered iv using an injection needle. The dose was 1 mg / kg. The betamethasone valerate content in the kidney homogenate and liver homogenate 5 minutes after administration was 1.457 μg / g, 1.
It was 652 μg / g, and the content in the kidney homogenate was about 0.882 times that in the liver homogenate. On the other hand, betamethasone valerate was dissolved in dimethylsulfoxide and then 0.2 ml of a solution (0.4 mg / ml) to which 9 times the amount of mouse serum was added was administered iv from the tail vein of an ICR mouse weighing about 40 g (dose of 2 m
g / kg), and the kinetics were examined. Five minutes after the administration, the content of betamethasone valerate in the kidney homogenate was about 0.57 times that in the liver homogenate. Compared to the control experiment, the rate of transfer to the kidney was higher in the polymer micelle-administered group.

Example 6 Using the same AB block copolymer as in Example 5 above,
The preparation method of the pyrene polymer micelle preparation was performed as follows. Pyrene is a hydrophobic fluorescent dye, but its solubility in water is less than 0.1 ng / ml. AB block copolymer
50.8 mg and 5.03 mg of pyrene are dissolved in 5 ml of DMF, and 2 ml of THF is added.
6.0). The external aqueous phase was subjected to liquid exchange five times in 24 hours. Centrifuge the liquid in the dialysis tube (5000g x
The concentration of pyrene in the supernatant obtained after 30 min) was 15.9 μg / m
l, the solubility in aqueous solution is 1
It was more than 100,000 times. In addition, this polymer micelle is used as a submicron particle sizer NICOMP MODEL3.
70 (Particle Sizing System)
As a result, the production of polymer micelles having an average particle diameter of 56.5 nm was confirmed. This proved that the AB block copolymer solubilized a sparingly soluble hydrophobic compound.

Example 7 Using the same AB block copolymer as in Example 5 above,
A polymer micelle preparation of pyrene was prepared as follows.
To 54.7 mg of the AB block copolymer, 1 ml of a pyrene DMF solution (2 mg / ml), 5 ml of DMF, and 5 ml of THF were added and dissolved.
3500) and dialyzed against 2 L of 0.05 M phosphate buffer (pH 6.0). The phosphate buffer, which is the outer aqueous phase, contains 24
Liquid exchange was performed five times per hour. 0.8 μl of the solution in the dialysis tube
The filtrate obtained by filtration with a 0.2 μm filter and then with a 0.2 μm filter has a pyrene concentration of 8.7 μg / ml.
ICOMP MODEL370 (Particle S
As a result, the production of polymer micelles having an average particle diameter of 62.4 nm was confirmed.
The average particle size of the polymer micelles obtained by freeze-drying the above-mentioned pyrene-containing polymer micelle solution was 58.5 nm, and it was found that there was no aggregation or collapse of the polymer micelles due to freeze-drying. all right.

Example 8 Using the same AB block copolymer as in Example 5 above,
A polymer micelle preparation of pyrene was prepared as follows.
AB block copolymer 50.4mg and weight average molecular weight 17,000
5.2mg of polylactic acid and 1ml of pyrene in DMF (2mg / ml)
After adding 5 ml of DMF and 5 ml of THF to dissolve, the mixture was placed in a dialysis tube (spectra / por, molecular weight fraction 3500), and dialyzed against 1 L of 0.05 M phosphate buffer (pH 6.0). The phosphate buffer, which was the outer aqueous phase, was exchanged five times in 24 hours. The concentration of pyrene in the filtrate obtained by filtering the liquid in the dialysis tube through a 0.2 μm filter was 17.6 μg / ml, and the polymer micelle was converted to a submicron particle sizer NICOMP MODEL370 (Particlel).
As a result, the production of polymer micelles having an average particle diameter of 81.1 nm was confirmed. As compared with Example 7 above, the pyrene content increased about twice and the particle size increased about 1.3 times. This is considered to be due to the fact that the added polylactic acid was present in the inner core of the polymer micelle and pyrene was efficiently encapsulated in the more hydrophobic region.

Test Example 2 The pyrene-containing polymer micelle solution (pyrene content: 8.7 μg / ml) before the freeze-drying operation described in Example 7 and the pyrene-containing polymer micelle solution described in Example 8 (pyrene content: 17.6 μg / ml) m
l) was administered iv to rats. Dosage is 0.05mg /
kg and 0.1 mg / kg. Pyrene 10% D as control experiment
It was dissolved at 18 μg / ml in MF / physiological saline solution and administered iv to 0.1 mg / kg. After administration, blood was collected from the jugular vein and the blood pyrene concentration was measured up to 2 hours later. Table 7 shows the ratio (%) to the dose assuming that the total blood volume of the rat was 60 mg / kg. From Table 7, it was found that the concentration in the blood was maintained by making the micelle into a polymer in response to the solution administration.
In the polymer micelles to which polylactic acid was added, the blood concentration was further maintained, indicating that the micelles were stabilized.

[0070]

[Table 7]

[0071]

Industrial Applicability The biodegradable polymer of the present invention can solubilize a hydrophobic compound in an aqueous solution, and the obtained fine particles have an average particle size of 100 nm or less, and can be sufficiently administered intravenously. Can be expected to stabilize. Furthermore, since the surface of the fine particles of the present invention is covered with a polyamino acid, there is a possibility that the fine particles have an organ directing ability in a living body. Becomes Further, the fine particles of the present invention can be expected to obtain various properties in the future by changing the type of constituent amino acids or by bonding a modifying group.

Claims (33)

[Claims] 1. Fine particles based on a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment. 2. A method according to claim 1, wherein the block copolymer is of the formula X—B—Y, wherein X is H—, R—CO—, A— or (AQ ¹
-) NW ¹ -CO- (R is an optionally substituted hydrocarbon group, A- is a polyamino acid residue, Q ¹ is O, CO,
NR ¹ (R ¹ represents a hydrogen atom or a hydrocarbon group which may be substituted) or S, W ¹ represents a spacer, n represents an integer of 1 or more), Y represents —OH, —OR ² , -A
Or -QW ² (-Q ² -A) m (R ² represents an optionally substituted hydrocarbon group, Q represents O or NR ³ (R ³ represents a hydrogen atom or an optionally substituted hydrocarbon Indicates a group)
Q ² represents O, CO, NR ⁴ (R ⁴ represents a hydrogen atom or an optionally substituted hydrocarbon group) or S,
Represents a polyamino acid residue, W ² represents a spacer, m represents an integer of 1 or more), and B represents a group obtained by removing H from a terminal hydroxyl group and removing OH from a terminal carboxyl group of a biodegradable polymer. Provided that X is H- or R-CO-,
Y particulate of claim 1 wherein the polymer represented by unless a -OH or -OR ^2]. 3. The fine particles according to claim 1, which are nano-sized particles. 4. The fine particles according to claim 3, having an average particle size of about 10 nm to about 200 nm. 5. The fine particles according to claim 1, which are polymer micelles. 6. The fine particles according to claim 1, wherein the biodegradable polymer is an aliphatic polyester. 7. The fine particles according to claim 6, wherein the aliphatic polyester is a polymer derived from one or more polylactides. 8. The fine particles according to claim 6, wherein the aliphatic polyester is a polymer derived from one or more α-hydroxycarboxylic acids. 9. The fine particles according to claim 8, wherein the polymer is a lactic acid polymer or a lactic acid-glycolic acid copolymer. 10. The microparticle according to claim 1, wherein the biodegradable polymer has a number average molecular weight of about 500 to about 100,000. 11. The microparticle according to claim 1, wherein the number of constituent amino acids of the polyamino acid is about 1,000 or less. 12. The microparticle according to claim 1, wherein one or all of the functional groups of the amino acid are protected with a protecting group or modified with a modifying group. 13. The microparticle according to claim 1, wherein the polyamino acid is an amino acid homopolymer comprising one kind of amino acid. 14. The microparticle according to claim 13, wherein the amino acid is glutamic acid, aspartic acid, arginine, lysine or cysteine. 15. The microparticle according to claim 12, wherein the modifying group is a sugar residue. (16) the sugar residue is a glucosyl group;
Fine particles as described. 17. The method according to claim 1, wherein the modifying group is a pteroic acid derivative.
2. Fine particles according to 2. 18. The microparticle according to claim 1, wherein the polyamino acid is a synthetic polyamino acid. 19. The fine particles according to claim 1, wherein the content of the hydrophilic segment in the block copolymer is about 1 to about 80% by weight. 20. The microparticle according to claim 1, wherein the hydrophobic segment is in the core of the microparticle and the hydrophilic segment is in the outer shell of the microparticle. 21. Fine particles according to claim 1 or 5, wherein the hydrophilic segment is in the core of the fine particle and the hydrophobic segment is in the outer shell of the fine particle. 22. The microparticle according to claim 1, which contains a drug. 23. The microparticle according to claim 22, wherein the drug is a hormone. 24. The microparticle according to claim 23, wherein the hormone is a corticosteroid. 25. The microparticle according to claim 20, which contains a hydrophobic drug. 26. The microparticle according to claim 21, which contains a hydrophilic drug. 27. The microparticle according to claim 26, wherein the hydrophilic drug is a water-soluble polypeptide. 28. The microparticle according to claim 27, wherein the water-soluble polypeptide is a cytokine. 29. A pharmaceutical comprising the fine particles according to any one of claims 1 to 28. 30. A process for producing drug-containing fine particles, comprising mixing a drug with a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment. 31. The method according to claim 30, wherein a solvent is removed from a mixture of a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment and a drug. 32. A fine particle base comprising a block copolymer having a biodegradable polymer as a hydrophobic segment and a polyamino acid as a hydrophilic segment. 33. A compound of the formula X'-BY 'wherein X' is H-, R'-CO-, A'- or (A'-
Q ¹ '-) n'W ¹ ' -CO- (R 'is a C _1-6 alkyl group,
A'- is an amino acid homopolymer residue, Q ¹ 'is O, C
O, NH or S, W ¹ ′ represents a C _1-6 alkylene group (excluding propylene), n ′ represents an integer of 1 or more), Y ′ represents —OH, —OR ² ′, − A 'or -Q'-
W ² '(-Q ² -A') m '(R ² ' is a C _1-6 alkyl group,
Q ′ is O or NH, Q ² ′ is O, CO, NH or S
, -A 'is an amino acid homopolymer residue, W ² ' is C _1-6
B is an alkylene group (however, excluding propylene), m 'is an integer of 1 or more), B is H from the terminal hydroxyl group of the biodegradable polymer to O from the terminal carboxyl group.
A group excluding H is shown. Provided that X is H- or R'-C
O-, except when Y is -OH or -OR ² ')
A block copolymer represented by the formula: