JP2003321398A - Polysaccharide complex and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polysaccharide complex prepared by causing a polyion complex which has no danger of virus infection or the like, is excellent in biodegradability and biocompatibility, and is formed from a polysaccharide material consisting of constituting monosaccharides with a clear chemical structures to carry a drug component and a highly safe and simple method for producing the complex in an aqueous system; and a polysaccharide complex in which anionic carboxyl groups and cationic amino groups for forming a polyion complex can be controlled, the release rate of the drug is controlled, and the physical properties of the carrier can be controlled and a method for producing the polysaccharide complex. <P>SOLUTION: The polysaccharide complex comprises: an oxidized polysaccharide formed by introducing a carboxy group or its salt group to the 6-position of a pyranose ring of a polysaccharide by oxidation; chitosan; and at least one drug component. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD [0001] The present invention relates to a polysaccharide complex in which a drug component is supported on a polysaccharide derived from a natural product which is excellent in biodegradability and biocompatibility, and is simple in an aqueous system. The present invention relates to a manufacturing method.

[0002]

2. Description of the Related Art In the fields of medical care, medicine, agricultural chemicals, etc., there is a demand for a system for releasing an effective amount of a drug at a specific site for a necessary time in order to fully exert its drug efficacy and suppress side effects. Extremely high. Conventionally, various attempts have been made to support a drug component on a carrier.

The carrier substance is required not only to control the release rate of the drug but also to have biodegradability and biocompatibility. As this carrier, a polyion complex material composed of a polycationic substance and a polyanionic substance can be easily prepared in an aqueous system and a substance insoluble in water can be obtained. Therefore, various proposals have been made in the past (Japanese Patent Application Laid-Open No. HEI 06-242242). 6-
No. 100468, Japanese Patent Laid-Open No. 7-33682, Japanese Patent Laid-Open No. 11-130697, Japanese Patent Laid-Open No. 2002-638, etc.). For example, natural products such as hyaluronic acid, chondroitin, chitin, chitosan, sodium alginate,
There are polyion complexes using polysaccharides such as pectin and dextran, and multiderivatives such as carboxymethyl cellulose, gelatin, polyamino acids and polypeptides and proteins, and synthetic polymers such as polyacrylic acid.

However, the synthetic polymer can control the cationic group or anionic group in the molecule, and it is easy to prepare a polyion complex having various physical properties, but on the other hand, it is poor in biodegradability and biocompatibility. Limited range. In addition, natural materials with excellent biodegradability and biocompatibility, protein materials are at risk of virus infection of human or animal origin, and natural polysaccharides are cationic or anionic functional groups because they are natural products. However, it has a drawback that it is difficult to form a polyion complex corresponding to various required physical properties. Furthermore, in conventional polysaccharide derivatives such as carboxymethyl cellulose, even though the degree of substitution can be controlled, the distribution of substituents within the molecule or between molecules varies, and the mechanism of degradation and metabolism in vivo is not clear. Had the problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to form a polysaccharide material composed of constituent monosaccharides having a clear chemical structure, having no risk of virus infection, excellent biodegradability and biocompatibility. Another object of the present invention is to provide a polysaccharide complex in which a drug component is supported on a polyion complex, and a simple and highly safe production method in an aqueous system. A further object of the present invention is to control the anionic carboxyl group forming a polyion complex and the cationic amino group, and to easily control the release rate of the drug and the physical properties of the carrier itself, and a polysaccharide complex thereof. It is to provide a manufacturing method.

[0006]

According to the invention of claim 1, an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at the 6-position of the pyranose ring of the polysaccharide by oxidation and chitosan, and at least one or more drug components are used. It is a polysaccharide complex characterized in that

A second aspect of the present invention is the polysaccharide complex according to the first aspect, wherein a polyion complex structure is formed by the oxidized polysaccharide and the chitosan.

The invention of claim 3 is obtained by a method in which the oxidized polysaccharide is oxidized with an oxidizing agent in the presence of an N-oxyl compound catalyst in an aqueous system of a polysaccharide dissolved or dispersed in water. The polysaccharide complex according to claim 1 or 2, wherein the primary hydroxyl group at the 6-position in the pyranose ring of the polysaccharide is selectively oxidized.

According to the invention of claim 4, as the chitosan,
The polysaccharide complex according to any one of claims 1 to 3, wherein the ratio of glucosamine as the constituent monosaccharide and N-acetylglucosamine is in the range of 45:55 to 55:45.

The invention of claim 5 is the polysaccharide complex according to any one of claims 1 to 4, wherein the drug component is a drug component.

The invention of claim 6 is characterized in that the drug component is any one of an agricultural chemical, an antibacterial agent, an antifungal agent, an insect repellent, and an aromatic agent. It is a polysaccharide complex.

[0012] According to the invention of claim 7, an oxidized polysaccharide in which a carboxyl group or a salt thereof is introduced at the 6-position of the pyranose ring of the polysaccharide and chitosan are added to an aqueous solution in which at least one drug component is dissolved or dispersed. The method for producing a polysaccharide complex is characterized in that a polyion complex is formed by adding it to make it insoluble in water, and at the same time, the drug component is included.

The invention of claim 8 provides an aqueous solution in which an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at the 6-position of the pyranose ring of the polysaccharide and chitosan and at least one drug component are dissolved or dispersed together. By neutralizing with an acid or an alkali, a polyion complex of oxidized polysaccharide and chitosan is formed to make it insoluble in water,
A method for producing a polysaccharide complex, which comprises incorporating the drug component.

According to a ninth aspect of the present invention, an aqueous solution in which an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at the 6-position of the pyranose ring of the polysaccharide and chitosan are dissolved or dispersed is prepared in advance, and one of them is prepared. Alternatively, at least one or more kinds of drug components are dissolved or dispersed separately from both or both aqueous solutions, and the respective aqueous solutions are mixed to form a polyion complex to be insoluble in water, and the drug components are included. Is a method for producing a polysaccharide complex.

According to a tenth aspect of the present invention, the oxidized polysaccharide is
It is obtained by a method of oxidizing a polysaccharide dissolved or dispersed in water in an aqueous system using an oxidizing agent in the presence of a catalyst for an N-oxyl compound, and is 1-position at 6-position in the pyranose ring of a natural polysaccharide.
The method for producing a polysaccharide complex according to any one of claims 7 to 9, wherein the primary hydroxyl group is selectively oxidized.

The invention of claim 11 is characterized in that the chitosan has a ratio of glucosamine and N-acetylglucosamine as constituent monosaccharides in the range of 45:55 to 55:45. 10. The method for producing a polysaccharide complex according to any one of 10.

The invention of claim 12 is the method for producing a polysaccharide complex according to any one of claims 7 to 11, wherein the drug component is a drug component.

The invention of claim 13 is characterized in that the drug component is any one of an agricultural chemical, an antibacterial agent, an antifungal agent, an insect repellent, and an aromatic agent. It is a method for producing a polysaccharide complex.

[0019]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below.
The polysaccharide complex of the present invention comprises, as a polyanion component, an oxidized polysaccharide obtained by introducing a carboxyl group or a salt thereof at the 6-position of the pyranose ring of the polysaccharide by a highly selective oxidation method, and N-acetylglucosamine which is a constituent monosaccharide. And chitosan having a controlled ratio of glucosamine as a polycation component to form a polyion complex of both and to contain at least one or more drug components.

First, the oxidative polysaccharide serving as a polyanion component for forming a polyion complex in the present invention will be described. The oxidized polysaccharide used in the present invention is a polysaccharide having a uronic acid structure in which the 6-position of the pyranose ring of a natural polysaccharide is selectively oxidized and a carboxyl group or a salt thereof is introduced. As a natural polysaccharide of the raw material,
The type, origin, etc. are not particularly limited,
Cellulose, chitin, starch and the like, in which almost a single constituent monosaccharide is linearly linked, are particularly preferable from the viewpoints of procuring raw materials, easiness of oxidation treatment, and safety of uronic acid produced by oxidation.

Unlike the introduction of a carboxyl group by derivatization into a polysaccharide such as carboxymethylation, the oxidized polysaccharide used in the present invention has only one carboxyl group at the 6-position selectively in one pyranose ring. Introduced, intermolecular,
Since it has a uniform distribution in the molecule and does not introduce a substituent into the hydroxyl group through an ester bond or an ether bond, it is less affected by steric hindrance when forming a polyion complex. Further, there is no influence of the substituent after being decomposed in vivo. For example, the one in which cellulose is oxidized is called cellouronic acid, and glucuronic acid is β-
They are connected by 1,4 bonds. Oxidized starch is called amilouronic acid, and glucuronic acid is α-1,4.
They are linked together. The one in which chitin is oxidized is called chitouronic acid or 6-oxychitin, and N-acetylglucosaminouronic acid (N-acetylglucosamine 6-
Carbon atoms at which the position carbon becomes a carboxyl group) are linked by β-1,4 bonds.

Although uronic acids such as alginic acid, pectin, and hyaluronic acid exist in nature, mainly heteropolysaccharides are present, and uncontrollable parts such as distribution of sugar residues and influence of side chains introduced due to natural products. Therefore, it is not preferable as the polyanion component of the present invention. One feature of the polyanion component used in the present invention is that it is an oxidized polysaccharide in which the proportion of uronic acid is controlled by controlling the degree of oxidation.

The oxidation method for obtaining the oxidized polysaccharide of the present invention will be described below. The oxidation method in the present invention is characterized by treating a polysaccharide dissolved or dispersed in water in an aqueous system in the presence of a catalyst such as an N-oxyl compound, and selecting the 6-position of the pyranose ring of the polysaccharide. Oxidize,
A carboxyl group or a salt thereof can be introduced.

The oxidized polysaccharide of the present invention can be obtained by oxidizing the starting polysaccharide with an oxidizing agent in the presence of an N-oxyl compound (oxoammonium salt). As the N-oxyl compound, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (hereinafter referred to as TE
(Referred to as MPO) and the like. In this oxidation method, the carboxyl group can be introduced uniformly and efficiently depending on the degree of oxidation. The amount of the N-oxyl compound is sufficient as a catalyst. For example, with respect to the number of moles of the monosaccharide constituting the polysaccharide,
10 ppm to 5% is sufficient, but 0.05% to 3% is preferable.

Examples of the oxidizing agent include halogen, hypohalous acid, halogenous acid, perhalogenic acid or salts thereof, halogen oxides, nitrogen oxides, peroxides, and the like, which can promote the desired oxidation reaction. Any oxidizing agent can be used as long as it is.

Further, in the present oxidation method, if the oxidation reaction is carried out in the coexistence with bromide or iodide, the oxidation reaction can proceed smoothly even under mild conditions, and the introduction efficiency of the carboxyl group can be greatly improved. The amount of the bromide or iodide used can be selected within a range that can accelerate the oxidation reaction, and is, for example, 0 to 100% with respect to the number of moles of the constituent monosaccharide of the polysaccharide. However, from the viewpoint of reaction efficiency, 1 to 50% is preferable.

In the method for oxidizing a polysaccharide according to the present invention, it is particularly preferable to use TEMPO as an N-oxyl compound and sodium hypochlorite as an oxidizing agent in the presence of sodium bromide.

For the purpose of increasing the selectivity of the oxidation of the constituent monosaccharide residue to the primary hydroxyl group and suppressing side reactions, the reaction temperature may be room temperature or lower, more preferably 5 ° C. or lower. desirable. Furthermore, it is preferable to keep the system alkaline during the reaction. At this time, the pH is preferably maintained at 9 to 13, more preferably 10 to 12.

Here, this oxidation method is characterized in that the degree of oxidation can be controlled by the amount of alkali added when the pH is maintained at a constant value. When 1 mol of the alkali is added to 1 mol of the sugar residue, the primary hydroxyl group at the 6-position in all sugar residues is oxidized to a carboxyl group. Therefore,
By reducing the addition amount of alkali and the above-mentioned oxidizing agent and reducing the introduction amount of the carboxyl group, the contact points between the oxidized polysaccharide and chitosan when forming the polyion complex are reduced, and the physical properties of the polysaccharide complex are controlled. It is possible to

Further, when the crystallinity of the polysaccharide as the raw material is high, the oxidation efficiency becomes poor. However, the oxidation efficiency can be improved by once dissolving it in each soluble solvent and subjecting it to a regeneration treatment. .

Further, the 6-position carboxyl group of the oxidized polysaccharide is more stable when it exists as a salt such as sodium salt, and the salt of these oxidized polysaccharides has high water solubility. A desalted COOH-type oxidized polysaccharide can be obtained by adding an acid such as hydrochloric acid to the aqueous solution of the oxidized polysaccharide salt or by treating with an ion exchange resin. In particular, the above-mentioned amylouronic acid and chitouronic acid (or 6-oxychitin)
Shows water solubility even in COOH type.

Next, chitosan, which is a polycation component for forming a polyion complex in the present invention, will be described. N-acetylglucosamine,
Glucosamine is a β-1,4 glycoside-linked polysaccharide,
Generally, those with a high proportion of glucosamine are chitosan and N-
Chitin has a high proportion of acetylglucosamine. Chitin exists as a skeletal substance of crabs and shrimps and in the cell wall of fungi and is obtained through purification processes such as decalcification, deproteinization, removal of lipids and pigments, and chitosan can be used simultaneously with these processes. Alternatively, it is generally obtained by further hydrolyzing the chitin obtained in the above step with an acid or an alkali and performing a deacetylation treatment.
In addition, the constituent monosaccharides N-acetylglucosamine and glucosamine also exist in vivo and are easily decomposed both inside and outside the body, and their safety is high.

As the chitosan used in the present invention, the above-mentioned general chitosan can be applied, and the raw material, the purification method, the degree of polymerization, etc. are not particularly limited. The proportion of glucosamine in the constituent monosaccharides is preferably 20 to 100%. Since glucosamine has a cationic free amino group, this ratio is an important factor in controlling the physical properties of the polysaccharide complex of the present invention.

The proportion of N-acetylglucosamine and glucosamine, that is, the proportion of N-acetyl group and amino group, is that of deacetylation by hydrolysis with an acid or alkali, or conversely, N-acetylation using acetic anhydride or the like. It can be controlled by the method. The proportion of amino groups can be controlled by the reaction time of hydrolysis in the deacetylation reaction and by the addition amount of the reagent in the N-acetylation reaction.

Here, chitosan forms a salt in a dilute acid solution and dissolves, but it is insoluble in water when it is neutral to alkaline. However, it is known that glucosamine and N-acetylglucosamine are soluble in water in a wide pH range in the range of 45:55 to 55:45. When preparing this water-soluble chitosan, it is important to carry out N-acetylation or deacetylation in a homogeneous system.

Since this water-soluble chitosan is soluble in water in a wide pH range, it can be dissolved not only in an acidic solution but also in an alkaline aqueous solution of the uronate, and even in an alkaline aqueous solution, uronic acid and chitosan can be uniformly distributed. Composites can be produced.

Further, the water-soluble chitosan dissolved in water without a counter ion and the complex in which a polyion complex is formed by using the COOH type of uronic acid do not require the work of removing the counter ion. Can be shortened and there is no effect of salt in the body.

Here, the ratio of glucosamine to N-acetylglucosamine of chitosan is generally the degree of deacetylation or the degree of N-acetylation ((N-acetylation degree (%)) =
It is called 100%-(degree of deacetylation (%)),
Infrared spectroscopy by colloid titration or KBr tablet method (I
R) or dissolved in an acidic solution and subjected to nuclear magnetic resonance spectroscopy (N
MR) or the like.

Next, the drug component used in the present invention is not particularly limited in kind and form as long as it can be carried by the polyion complex of the present invention, but it is not limited to pharmaceuticals, agricultural chemicals and antibacterial agents. , Drug agents such as fungicides, insect repellents, and aromatic agents are preferably used. These drug components can be used alone or in combination of two or more.

For example, the pharmaceutical ingredients include anti-inflammatory drugs, antiepileptic drugs, sleep sedatives, antipyretic analgesics, stimulants, stimulants,
Antiphlogistic, central nervous system drug, skeletal muscle relaxant, autonomic nerve drug, autonomic nerve blocker, peripheral nervous system drug, ophthalmic drug, sensory organ drug, cardiotonic drug, arrhythmic drug, diuretic, antihypertensive drug , Vasodilator, vasoconstrictor, vasodilator, arteriosclerosis drug, cardiovascular drug, respiratory stimulant, antitussive expectorant, respiratory drug, peptic ulcer drug, stomach digestive drug, antacid , Laxatives, choleretic agents, digestive agents, hormonal agents, urinary tract disinfectants, uterine constrictors, genitourinary agents, anal agents, vitamins, nutritional tonics, blood and body fluid agents, liver disease agents , Antidote, addictive drug, gout remedy, enzyme preparation, diabetes drug, cell stimulant, tumor drug, antibiotic, chemotherapeutic drug, arthritis drug and the like.

Examples of pesticide components include organic phosphorus-based, organic fluorine-based, organic chlorine-based, carbamate-based insecticides and fungicides such as antibiotics, and soil modifiers. Examples of antibacterial and antifungal agents include organic, inorganic and natural antibacterial agents.

The polysaccharide complex of the present invention comprises the above-mentioned three components of oxidized polysaccharide, chitosan and drug component as essential components.
In addition, it contains a component for adjusting the physical properties of the complex, a component for adjusting the drug efficacy, a component for controlling the release of the drug, and a component secondarily generated when forming the polyion complex. It doesn't matter if it is out. The above-mentioned three essential components may be used alone or in combination of two or more. Further, the mixing ratio of each component is not particularly limited as long as it is within the range of forming a polyion complex, and should be adjusted according to the required physical properties.

In order to form a complex between the oxidized polysaccharide and chitosan forming a complex, it is preferable to dissolve the complex in a suitable solvent to form a polyion complex. In the present invention, it is particularly preferable to use water as a medium, and an organic solvent such as alcohol or acetone can be added if necessary. The concentration of the oxidized polysaccharide or chitosan or the drug in the solution is not particularly limited as long as it is within the range where these complexes are formed, and can be selected according to the required properties of the complex. The method for forming the polyion complex of the polysaccharide complex of the present invention will be exemplified below.

First, the first method is to add a powder or an aqueous solution of the above-mentioned oxidized polysaccharide or a salt thereof and a powder or an aqueous solution of the above-mentioned chitosan or a salt thereof to an aqueous solution in which a drug component is dissolved or dispersed. And chitosan form a polyion complex and become insoluble in water. At this time, the drug component previously present in the solution is incorporated into the polysaccharide complex to obtain the polysaccharide complex of the present invention including the drug component. If necessary, washing with water can remove salts of counterions. Further, in order to obtain a uniform polysaccharide complex, it is preferable to mix with sufficient stirring.

In the second method, first, an acidic or alkaline solution in which the oxidized polysaccharide, the chitosan, and the drug component are dissolved or dispersed together is prepared, and neutralized with an acid or an alkali while stirring well. As a result, a polyion complex of oxidized polysaccharide and chitosan is formed to make it insoluble in water, and a polysaccharide component of the present invention can be obtained by incorporating a drug component. If necessary, the salt generated by neutralization can be removed by washing with water. The neutralization method is not particularly limited,
It can be selected according to the required properties of the composite.

Oxidized polysaccharides dissolve in a wide pH range, and therefore dissolve in acidic solutions. Therefore, an acidic aqueous solution in which both polysaccharides are dissolved can be prepared by adding powdered or acidic oxidative polysaccharides to an acidic aqueous solution of chitosan and dissolving them. On the contrary, since water-soluble chitosan having a degree of deacetylation of 45 to 55% is soluble in water in a wide pH range, it is dissolved by adding powder or water-soluble chitosan to an alkaline aqueous solution of oxidized polysaccharide. Then, an alkaline aqueous solution in which both polysaccharides are dissolved can be prepared. Therefore, it is also possible to select acidic and alkaline liquid properties according to the characteristics of the drug component to be added.

The polysaccharide complex obtained by this method is
Since the polyion complex is formed from the solution in which both the cationic and anionic polysaccharides are uniformly dispersed, the distribution of the contained polysaccharides becomes a more uniform complex. Further, since this polysaccharide complex has a porous structure, it is characterized in that it has a large tensile elongation when swollen in water.

Further, the third method is characterized in that an aqueous solution in which the oxidized polysaccharide and the chitosan are dissolved or dispersed is prepared separately in advance, and the respective aqueous solutions are mixed to form a polyion complex. To do. At this time, the drug component is prepared separately from one or both of both polysaccharide solutions or both aqueous solutions, and mixed to obtain a polysaccharide complex including the drug component.

Here, the degree of deacetylation of chitosan is 4
When 5 to 55% of water-soluble chitosan was used as a COOH type in which the counterion was previously removed as an oxidizing polysaccharide, when each aqueous solution was mixed to form a polyion complex, no counterion salt was formed and the salt was removed. It is particularly preferable because it requires no work and there is no effect of salt in vivo.

The method of mixing the aqueous solution is not particularly limited and can be selected according to the required properties of the complex. For example, a method of casting one solution of oxidized polysaccharide or chitosan to form a dry film, and then casting the other solution thereon to form a polyion complex at the interface thereof can be applied.

The three methods of producing the polysaccharide complex of the present invention have been described in detail above. Furthermore, after forming a polyion complex from the oxidized polysaccharide and the chitosan, a drug solution is applied to the drug solution. The drug component may be supported on the polysaccharide complex by dipping or sticking the drug component.

Further, the polysaccharide complex of the present invention can be dried if necessary. Since the dried composite does not dissolve in water but swells, it is possible to swell the dried composite with a solvent such as water to change its shape, to bond it, or to stack it. The shape of the polysaccharide complex may be sponge-like, plate-like, film-like, granule-like,
Fibers, gels, flakes, powders, etc. can be arbitrarily selected.

The polysaccharide complex of the present invention thus obtained is, for example, as shown in FIG. 1, COO ⁻ derived from oxidized polysaccharide.
And a drug component is contained in the matrix of a polysaccharide complex in which an ion complex structure is formed by NH ³⁺ derived from chitosan. The polysaccharide complex of the present invention comprises uronic acids having high biocompatibility with natural polysaccharides and N-
Consists of acetylglucosamine and glucosamine, which are easily biodegraded or metabolized, and therefore are orally administered drugs, drugs for transdermal absorption, and medical materials used in vivo in surgery, etc., and agricultural chemicals, foods, It can be used as cosmetics. Further, the polysaccharide complex of the present invention is a polysaccharide complex containing N
A carboxyl group and an amino group that form a polyion complex, which is composed of an oxidized polysaccharide that is oxidized in the presence of an oxyl compound catalyst, has high regioselectivity, and is easy to control the degree of oxidation, and chitosan that is easy to deacetylate. As a result, it is easy to control the drug loading performance and release characteristics, the physical characteristics of the polysaccharide complex, and the like, and it is possible to meet various required characteristics. Further, due to such characteristics, it can be applied to a drug delivery system.

[0054]

EXAMPLES The present invention will be specifically described below based on examples.

<Production Example 1> (Preparation of oxidized starch (amyluronate sodium salt)) As the raw material starch, commercially available corn starch was used. 5 g of starch is dissolved by heating in 100 ml of water and cooled. An aqueous solution in which 0.1 g of TEMPO and 1.25 g of sodium bromide were dissolved was added to this starch solution. Next, the reaction system is cooled and an aqueous solution of sodium hypochlorite (C
50 g (1 = 5%) was added to start the oxidation reaction. The reaction temperature was always kept below 5 ° C. Although the pH in the system decreases during the reaction, 0.5N-NaOH aqueous solution is sequentially added,
The pH was adjusted to 10.75. Then, when the amount of alkali added corresponding to the number of moles of 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and water: alcohol = 2: 8 is formed. After thorough washing with the solution, dehydration with acetone and drying under reduced pressure at 40 ° C. to obtain white powdery oxidized starch (sodium amilouronate) with an oxidation degree of 100% (FIG. 2).

<Production Example 2> (Preparation of oxidized cellulose (sodium cellouronate)) As the raw material cellulose, commercially available regenerated cellulose was used. 5 g of cellulose was suspended in 350 ml of water. An aqueous solution in which 0.1 g of TEMPO and 1.25 g of sodium bromide were dissolved was added to this cellulose solution. Next, the reaction system is cooled and an aqueous solution of sodium hypochlorite (Cl = 5
%) 50 g was added to start the oxidation reaction. The reaction temperature was always kept below 5 ° C. During the reaction, the pH of the system decreases, but 0.5N-NaOH aqueous solution is sequentially added to adjust the pH to 1
It was adjusted to 0.75. Then, when the amount of alkali added corresponding to the number of moles of 100% of the total number of moles of the primary hydroxyl group at the 6-position is reached, ethanol is added to stop the reaction, and water: alcohol = 2: 8 is formed. After thorough washing with the solution, dehydrate with acetone and dry under reduced pressure at 40 ° C.
Oxidized cellulose having a 100% degree of oxidation (cellouronic acid sodium salt) was obtained as a white powder (FIG. 3).

<Production Example 3> (Preparation of oxidized cellulose (sodium salt) having an oxidation degree of 60%) The same adjustment as in Preparation 1 of oxidized cellulose was repeated except that the amount of the sodium hypochlorite aqueous solution was changed to 30 g, to carry out the oxidation reaction. Started. 0.5N-N added to maintain pH
The reaction was stopped when the aOH aqueous solution reached 37 ml (60 mol% sodium hydroxide based on the number of moles of glucose residues). Thereafter, washing similar to the preparation of oxidized cellulose was repeated to obtain oxidized cellulose (sodium salt) having an oxidation degree of 60%.

<Production Example 4> (Preparation of oxidized chitin (sodium chitouronate)) Chitin, which is a raw material, is a commercially available product obtained through processes such as decalcification, deproteinization, removal of lipids and pigments from crab moss. Chitin was used. Chitin was immersed in 10 g of a 45% aqueous sodium hydroxide solution of 150 g, and the mixture was stirred at room temperature or lower for 2 hours.
To this, 850 g of crushed ice and the surroundings were cooled with ice water or the like, and added with stirring. Chitin is almost dissolved by this alkaline treatment. The sample was neutralized with hydrochloric acid, washed thoroughly with water, and then not dried. An aqueous solution in which 0.1 g of TEMPO and 1.25 g of sodium bromide were dissolved was added to 100 g of this 5% chitin suspension to prepare a chitin concentration of about 2 wt% based on the total solid weight. Next, the reaction system was cooled, and 35 g of an aqueous solution of sodium hypochlorite (Cl = 5%) was added to start the oxidation reaction. The reaction temperature was always kept below 5 ° C. Although the pH in the system was lowered during the reaction, 0.5N-NaOH aqueous solution was sequentially added to adjust the pH to 10.75. Then, with respect to the total number of moles of the primary hydroxyl group at the 6-position, when the amount of alkali added corresponding to the number of moles of 100% is reached, ethanol is added,
After stopping the reaction, thoroughly washing with a solution of water: alcohol = 2: 8, dehydration with acetone, and drying under reduced pressure at 40 ° C., white powdery chitin oxide (sodium chitouronate) with an oxidation degree of 100%. Was obtained (FIG. 4).

<Production Examples 5 to 8> (Preparation of COOH type of oxidized polysaccharide) The oxidized polysaccharides of the above Production Examples 1 to 4 are isolated as sodium salts. This powder was made into a 2% aqueous solution, and the pH was adjusted to 1 with hydrochloric acid. Precipitation filtration with excess ethanol, water: acetone =
After sufficiently desalting with a solution of 1: 7, it was dehydrated with acetone, dried under reduced pressure at 40 ° C., and each of the above-mentioned oxidized polysaccharides (amiuronic acid, cellouronic acid, oxidation degree 60%).
COOH type of oxidized cellulose and chitouronic acid) was obtained.

<Production Example 9> (Preparation of chitosan having a degree of N-acetylation of 30%) 5 g of chitosan having a degree of deacetylation of 100% was dissolved in 95 g of 10% acetic acid, diluted with 500 g of methanol, and stirred to obtain acetic anhydride. 0.95 g was added, and the mixture was stirred at room temperature for 15 hours. 2N
-Flakes precipitate when neutralized by adding an aqueous NaOH solution. Therefore, the flakes are filtered out, and methanol and water: acetone =
After thoroughly washing with a solution of 1: 7, it was dehydrated with acetone and dried under reduced pressure at 40 ° C to give flaky N-.
Chitosan having an acetylation degree of 30% was obtained (FIG. 5).

<Production Example 10> (Preparation of water-soluble chitosan having a degree of N-acetylation of 50%) 5 g of chitosan having a degree of deacetylation of 100% was mixed with 95% of 10% acetic acid.
g, and diluted with 500 g of methanol, 1.59 g of acetic anhydride was added with stirring, and the mixture was stirred at room temperature for 15 hours. When 2N-NaOH aqueous solution is added to neutralize, flakes are precipitated. Therefore, the flakes are filtered and thoroughly washed with a solution of methanol and water: acetone = 1: 7.
It was dehydrated with acetone and dried under reduced pressure at 40 ° C. to obtain flaky chitosan having a degree of N-acetylation of 50% (FIG. 6,
(Fig. 7). This chitosan was water-soluble and had a pH of 8.2 in a 1 wt% aqueous solution. Further, it was dissolved even if pH was changed by adding acid or alkali.

<Production Example 11> (Preparation of chitosan having N-acetylation degree of 60%) 5 g of chitosan having a deacetylation degree of 100% was dissolved in 95 g of 10% acetic acid, diluted with 500 g of methanol, and stirred to obtain acetic anhydride. When 1.90 g was added, it gelled in about 1 hour, but it was allowed to stand at room temperature for 15 hours. After adding 2N-NaOH aqueous solution to neutralize and filter, thoroughly wash with a solution of methanol and water: acetone = 1: 7, dehydrate with acetone, and dry under reduced pressure at 40 ° C. to form flaky N.
-Chitosan with an acetylation degree of 60% was obtained (Fig. 8).

<Test Example 1> Oxidized polysaccharides of Production Examples 2, 4 and 6, N-acetylated chitosan of Production Examples 9 and 10, microcrystalline cellulose powder, and further sodium salt of carboxymethyl cellulose having a substitution degree of 0.7. Was evaluated for biodegradability by aerobic microorganisms in soil by the following method. The results are shown in Fig. 9. It can be seen that, while carboxymethyl cellulose sodium salt is hardly decomposed, the oxidized polysaccharide and chitosan, which are the raw materials of the present invention, are decomposed almost like cellulose.

(Biodegradability Evaluation Method) A standard compost (YK-manufactured by Yawata Bussan Co., Ltd.) adjusted to a water content of 60% was used as a test soil by using a microbial oxidative decomposition analyzer (MODA) manufactured by Yawata Bussan Co., Ltd. 2) A mixture of 250 cc and 250 cc of sea sand adjusted to have a water content of 18% was used. Sample 1
0 g was uniformly mixed with the test soil and packed in a column-shaped reaction tube, and the temperature in the reaction tube was kept constant at 35 ° C. Furthermore, decarbonated air saturated with water vapor is added to the bottom of the reaction tube by 40
It was vented at a rate of ml / min, and was piped from the top of the reaction tube without gas leakage, passed through a sulfuric acid water bath to remove ammonia gas, passed through a hygroscopic tube filled with silica gel and calcium chloride to remove water, and then soda talc. And is guided to an absorption tube filled with soda lime. Since all the carbon dioxide generated by aerobically biodegrading the sample is absorbed by the absorption tube, the amount of carbon dioxide generated by the biodegradation can be quantified from the weight change of the absorption tube. In addition, the blank test of only the test soil containing no sample was simultaneously performed, and the amount of carbon dioxide generated in the blank test was subtracted to obtain the amount of carbon dioxide generated by decomposition. The theoretically generated amount of carbon dioxide was calculated from the carbon content in 10 g of the sample, and the ratio of the amount of generated carbon dioxide to the theoretical amount was taken as the degree of biodegradation and shown in FIG.

Example 1 A 1 wt% aqueous solution 1 of water-soluble chitosan having a N-acetylation degree of 50% prepared in Production Example 10
200 mg of L-ascorbic acid was dissolved in 00 ml. When this solution was mixed with 50 ml of a COOH-type 2 wt% aqueous solution of amylouronic acid prepared in Production Example 5 while stirring, a gel was formed to obtain the polysaccharide complex of Example 1. The supernatant was sampled and the concentration of ascorbic acid in the supernatant was measured by the indophenol method. As a result, it was 0.001%, and it was confirmed that most of the added ascorbic acid was incorporated into the polysaccharide complex. .
The polysaccharide complex was completely dissolved in acidic and alkaline aqueous solutions.

Example 2 3 g of chitosan having a degree of N-acetylation of 30% prepared in Production Example 9 and 2 g of amilouronate sodium salt prepared in Production Example 1 were dissolved in 100 ml of 0.1N hydrochloric acid solution. D-Limonene 10 was added to this solution.
0 mg was added, and the mixture was stirred and dispersed in the solution. Then, a 0.2N-NaOH aqueous solution was added to adjust the pH to 7, and a gel was produced to obtain the polysaccharide complex of Example 2. Here, the oil droplets of limonene dispersed in the supernatant were significantly reduced, and it was confirmed that most of them were incorporated in the polysaccharide complex. Also, take out the polysaccharide complex, put it in a glass bottle,
It was left without a lid, but a citrus odor was confirmed even after one month.

Example 3 20 mg of allethrin, which is an insecticide component, was dissolved in 0.5 ml of ethyl acetate to prepare purified water 1
It was dispersed in 00 ml. While stirring in this dispersion, 2 g of water-soluble chitosan having a N-acetylation degree of 50% prepared in Production Example 10 and CO of chitouronic acid prepared in Production Example 8 were stirred.
1 g of OH type was added to form a gel, and the polysaccharide complex of Example 3 was obtained. The amount of ethyl acetate solution floating on the supernatant was significantly reduced, and it was confirmed that most of the added allethrin was incorporated into the polysaccharide complex.

<Example 4> Production Example 1 while stirring in 100 ml of a 0.5% slurry of silver zeolite as an antibacterial agent
Chitosan 2.5 with N-acetylation degree of 60% prepared in 1.
g and 1 g of COOH type of oxidized cellulose having an oxidation degree of 60% prepared in Production Example 7 were added to form a gel, and the polysaccharide complex of Example 4 was obtained. The turbidity of the supernatant decreases,
It was confirmed that most of the silver zeolite was incorporated into the polysaccharide complex.

Example 5 3 g of commercially available chitosan having a deacetylation degree of 75% and 2 g of the atrium salt of chitouronate prepared in Production Example 4 were dissolved in 100 ml of 0.1N hydrochloric acid solution. 20 mg of allethrin, which is an insecticide component, was dissolved in 1 ml of ethyl acetate and dispersed in the above-mentioned oxidized polysaccharide and chitosan solution. Further, a 0.2N-NaOH aqueous solution was added to adjust the pH to 7, and a gel was produced to obtain the polysaccharide complex of Example 5. The amount of ethyl acetate solution floating on the supernatant was significantly reduced, and it was confirmed that most of the added allethrin was incorporated into the polysaccharide complex.

Example 6 A 1 wt% aqueous solution of water-soluble chitosan having a N-acetylation degree of 50% prepared in Production Example 10 5
0 ml was cast and dried to obtain a film having a thickness of 50 μm. 1 ml of a 5 wt% aqueous solution of L-ascorbic acid was cast thereon, and subsequently 10 ml of a 2.5 wt% aqueous solution of the COOH type chitouronic acid prepared in Production Example 8.
Was cast and dried to obtain the polysaccharide composite film of Example 6. The obtained film was free of salts such as sodium chloride and sodium acetate, the outermost surface on one side was mostly chitosan, and the outermost surface on the other side was uronic acid.
A composite film containing ascorbic acid was obtained.
Although this polysaccharide complex film swelled in water, it did not dissolve but completely dissolved in acid and alkali.

[0071]

INDUSTRIAL APPLICABILITY According to the present invention, a medicinal component, an agrochemical component, an antibacterial agent, an antifungal agent, an insecticide, an aromatic agent component, etc., which are useful in the fields of medicine / pharmaceuticals, agricultural chemicals, foods, and cosmetics, are carried. A water-insoluble polysaccharide complex can be easily and inexpensively obtained by a simple method. In addition, the polysaccharide complex of the present invention is a polyion complex composed of a natural polysaccharide and an oxidized polysaccharide having a uronic acid structure whose chemical structure is controlled, and a chitosan composed of N-acetylglucosamine and glucosamine, and thus easily produced. Since it decomposes and has a high biocompatibility, it can be used as an orally administered drug, a drug for percutaneous absorption, a medical material used in vivo in a surgical operation or the like, an agricultural chemical, a food, a cosmetic, and the like. Furthermore, in the present invention, unlike a polyion complex composed of a conventional natural product material, the carboxyl group and the amino group forming the polyion complex can be controlled, so that the structure is clear and highly safe, and the drug-carrying performance and release characteristics, Also, it becomes easy to control the physical properties and the like of the polysaccharide complex and it is possible to meet various required properties. Furthermore, according to the present invention, by using a COOH-type oxidized polysaccharide and water-soluble chitosan having a controlled acetylation rate, it is possible to form a complex that includes a drug component in the neutral region, and it is possible to form a complex with an acid or an alkali. It is possible to obtain a complex that does not require hydration treatment, can eliminate the influence of salt, and is completely water-soluble in both acidic and alkaline regions.

[0072]

[Brief description of drawings]

FIG. 1 is a chemical structural formula showing an example of the polysaccharide complex of the present invention.

FIG. 2 shows the amilouronate sodium salt used in the present invention.
Measured by dissolving in heavy water ¹³C-NMR spectrum and raw material
Of starch was dissolved in heavy water and measured¹³C-NMR spectrum
It's Koutor.

FIG. 3 is a ¹³ C-NMR spectrum measured by dissolving cellouronic acid sodium salt used in the present invention in heavy water.

FIG. 4 is a ¹³ C-NMR spectrum measured by dissolving chitouronate sodium salt used in the present invention in heavy water.

FIG. 5 ¹ H-NM measured by dissolving 30% N-acetylated chitosan used in the present invention in an aqueous deuterium chloride solution.
It is an R spectrum.

FIG. 6 ¹ H-NM measured by dissolving 50% N-acetylated chitosan used in the present invention in an aqueous deuterium chloride solution.
It is an R spectrum.

FIG. 7 is a ¹ H-NMR spectrum measured by dissolving 50% N-acetylated chitosan used in the present invention in heavy water.

FIG. 8 ¹ H-NM measured by dissolving 60% N-acetylated chitosan used in the present invention in an aqueous deuterium chloride solution.
It is an R spectrum.

FIG. 9 shows an oxidized polysaccharide used in the present invention and chitosan,
It is a graph which shows the biodegradability measured according to test example 1.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08B 37/08 A01N 53/00 504A F term (reference) 4C076 AA95 BB01 BB31 CC24 CC47 EE31 EE37 EE38 EE59 FF32 GG50 4C090 AA04 AA09 BA14 BA34 BA46 BC10 BC27 BD04 BD34 BD41 CA34 DA23 DA40 4H011 AA02 AC01 BA01 BB15 BB18 BC19 DA17 DC05 DH10

Claims (13)

[Claims] 1. A polysaccharide complex comprising an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at the 6-position of the pyranose ring of the polysaccharide by oxidation, chitosan, and at least one drug component. 2. The polysaccharide complex according to claim 1, wherein a polyion complex structure is formed by the oxidized polysaccharide and the chitosan. 3. The oxidized polysaccharide is obtained by a method of oxidizing a polysaccharide dissolved or dispersed in water in an aqueous system in the presence of a catalyst for an N-oxyl compound with an oxidizing agent, and The polysaccharide complex according to claim 1 or 2, wherein the primary hydroxyl group at the 6-position in the pyranose ring is selectively oxidized. 4. The chitosan has a ratio of glucosamine and N-acetylglucosamine as constituent monosaccharides of 4 to 4.
The polysaccharide complex according to any one of claims 1 to 3, which is in the range of 5:55 to 55:45. 5. The polysaccharide complex according to claim 1, wherein the drug component is a drug component. 6. The polysaccharide complex according to any one of claims 1 to 4, wherein the drug component is any of an agricultural chemical, an antibacterial agent, an antifungal agent, an insect repellent, and an aromatic agent. 7. A solution of 6 or more pyranose rings of a polysaccharide in an aqueous solution in which at least one drug component is dissolved or dispersed.
By adding an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at a position to chitosan, a polyion complex is formed to make it insoluble in water, and the polysaccharide component is characterized by including the drug component. Production method. 8. An aqueous solution in which an oxidized polysaccharide having a carboxyl group or a salt thereof introduced at the 6-position of the pyranose ring of the polysaccharide, chitosan, and at least one or more drug components are dissolved or dispersed together with an acid or an alkali. A method for producing a polysaccharide complex, characterized by forming a polyion complex of oxidized polysaccharide and chitosan to be insolubilized in water by a neutralization treatment, and including the drug component. 9. An aqueous solution in which an oxidized polysaccharide in which a carboxyl group or a salt thereof is introduced at the 6-position of the pyranose ring of a polysaccharide and chitosan are dissolved or dispersed is separately prepared in advance, and one or both or both of them are prepared. Separately from the aqueous solution, at least one or more drug components are dissolved or dispersed, and the respective aqueous solutions are mixed to form a polyion complex to insolubilize water, and at the same time, the drug component is contained. A method for producing a saccharide complex. 10. A natural polysaccharide, wherein the oxidized polysaccharide is obtained by a method of oxidizing a polysaccharide dissolved or dispersed in water in an aqueous system in the presence of a catalyst for an N-oxyl compound with an oxidizing agent. 10. The method for producing a polysaccharide complex according to claim 7, wherein the primary hydroxyl group at the 6-position in the pyranose ring is selectively oxidized. 11. The chitosan has a ratio of glucosamine and N-acetylglucosamine, which are its constituent monosaccharides,
It is in the range of 45:55 to 55:45, The manufacturing method of the polysaccharide complex in any one of Claim 7 to 10 characterized by the above-mentioned. 12. The method for producing a polysaccharide complex according to claim 7, wherein the drug component is a drug component. 13. The polysaccharide complex according to claim 7, wherein the drug component is any one of a pesticide, an antibacterial agent, an antifungal agent, an insect repellent, and an aromatic agent. Production method.