JPH108031A - Biodegradable sustained release pharmaceutical preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a biodegradable sustained release pharmaceutical preparation containing a mixture, etc., containing a modifier for controlling sustained release property of an active substance and an aliphatic polyester at a specific ratio, capable of gradually releasing an arbitrary release amount without making releasing surface area large and excellent in persistency of pharmacodynamic effects and resistance to environmental pollution. SOLUTION: This pharmaceutical preparation contains a mixture containing 99-10 pts.wt. aliphatic polyester such as polylactic acid and 1-90 pts.wt. at least one kind of compound selected from a group comprising poly-ε-caprolactone, polyvinyl acetate, ethylene-vinylacetate copolymer, ethylene-ethylacrylate copolymer, polyvinyl chloride, polymethacrylic acid ester and cellulose derivative or a mixture of two or more compounds thereof and an active substance retained by the mixture. Furthermore, equilibrium swelling ratio (at 40 deg.C) of a modifier for controlling sustained release property of the active substance to the active substance is preferably >=2wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable sustained-release preparation.

[0002]

2. Description of the Related Art In recent years, attention has been paid to the sustained release of active substances in various fields. For example, there are a fragrance for giving the indoor air a refreshing feeling, a communication disruptor using sex pheromone as a pest control means, and an attractant combined with an insecticide.

[0003] These require long-lasting effects, and require excellent sustained-release technology. Furthermore, recently, it is desired that it be biodegradable. For example, those used in the agricultural field, such as communication disruptors and sequestrants, are rarely recovered after use. Currently, it is left in fields such as fields. These drugs sprayed in large quantities
This is because collection after use requires a lot of manpower and is practically impossible. In addition, air fresheners and the like used indoors are disposed of as garbage, but plastic wastes are often landfilled because the heat of incineration is large and damages the incinerator. For this reason, a biodegradable sustained-release preparation that is decomposed by microorganisms when buried in soil and does not remain in soil is desired.

On the other hand, in recent years, various materials having biodegradability have been proposed, and some of them have been put to practical use. The materials constituting these materials are classified into several types, for example, cellulose-based materials, starch-added materials, aliphatic polyester-based materials, polyvinyl alcohol-based materials, and the like. These are used according to their respective characteristics such as use and price, but for sustained release of the active substance, aliphatic polyester-based ones are preferably used.

For example, in the field of agriculture which is often left in the field after use, Japanese Patent Application Laid-Open No. 6-116103 describes a pest control material comprising a biodegradable aliphatic polyester and an active substance. In addition, the present applicant has already developed a sustained release pheromone preparation using a polymer containing 3-hydroxybutyric acid as a main component as a release control layer, as a biodegradable sustained release pheromone preparation (Japanese Patent Application Laid-Open No. HEI 5 (1993) -107). -1631
No. 10).

As such a sustained-release preparation having biodegradability, an aliphatic polyester-based one is preferably used. In the aliphatic polyester, an ester bond in the structure of the aliphatic polyester firmly bonds molecular chains by an electrostatic bond. The active material has difficulty diffusing through the interstices of the polymer segments, resulting in low penetration of the active material through the aliphatic polyester. For this reason, there are problems that the release surface area must be increased in order to increase the amount of the active substance that evaporates, and that a large number of sustained-release preparations must be installed in order to maintain a constant concentration. Was.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for stabilizing an active substance for a long period of time during use without increasing the release surface area or using a large number of substances. An object of the present invention is to provide a degradable sustained-release preparation that can be degraded by microorganisms even when buried in soil after use and does not remain in soil after use.

[0008]

Means for Solving the Problems The present inventors have added a modifying agent for adjusting the sustained release of an incorporated active substance to 99 to 10 parts by weight of an aliphatic polyester having a low permeability of the active substance. It has been found that the mixing of 〜90 parts by weight makes it possible to easily control the release of the active substance and to solve all of the above problems, thus completing the present invention. That is, in order to achieve the above object, the invention of claim 1 is a biodegradable sustained release preparation, comprising 99 to 10 parts by weight of an aliphatic polyester and modified for adjusting the sustained release of an active substance. 1 to 90 parts by weight of the agent and the active substance retained by the mixture.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As a mixture for retaining the active substance of the sustained-release preparation of the present invention (hereinafter, this mixture is particularly referred to as a retention mixture), aliphatic polyesters 99 to 10 are used.
A mixture comprising 1 part by weight and 1 to 90 parts by weight of a modifier for adjusting the sustained release of the retained active substance (when there is no other ingredient, these parts can be replaced by% by weight) Used. Modifier is aliphatic polyester 99-10
When the amount is less than 1 part by weight, the effect of adding the modifying agent is not exhibited, and the aliphatic polyester is used in an amount of 1 to 90 parts by weight.
If the amount is less than 10 parts by weight, the effect of biodegradation cannot be expected. More preferably, the composition of the holding mixture has a modifier concentration in the range of 5 to 60% by weight.

The above-mentioned aliphatic polyester is not particularly limited as long as it has biodegradability, and specific examples thereof include malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, and anhydride. Adipic acid, sebacic acid, fumaric acid, maleic acid, dodecanedioic acid, malic acid, tartaric acid,
Polyvalent carboxylic acids having up to 20 carbon atoms exemplified by citric acid and the like and carbon exemplified by ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, etc. Number 20
Examples of polycondensation products with polyhydric alcohols, ring-opening polymers of cyclic esters such as lactide, which is a cyclic dimer of lactic acid, and condensation polymers of hydroxy acids such as lactic acid, hydroxybutyric acid and hydroxyvaleric acid. can do. These aliphatic polyesters may be used alone, or may be used as a mixture of two or more thereof.

As a modifier for adjusting the sustained release of the active substance, an equilibrium swelling ratio of the active substance at 40 ° C. is 2%.
Any substance can be used as long as it has at least% by weight. Here, the equilibrium swelling rate is Is the equilibrium swelling ratio at 40 ° C. represented by

[0012] Such modifiers include cellulose,
Examples include natural polymers such as chitin, chitosan, pullulan, and polyamino acids and derivatives thereof, and polyvinyl alcohol, and synthetic polymers such as polyethylene glycol, polyurethane, polyamide, polyolefins such as polyethylene and polypropylene, and polystyrene and derivatives thereof. However, in terms of the miscibility with the aliphatic polyester and the effect of improving the sustained release of the active substance, poly-ε-caprolactone, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, Desirable are polyvinyl chloride, polymethacrylate, cellulose derivatives such as cellulose triacetate and cellulose acetate butyrate, or mixtures thereof. As the ethylene-vinyl acetate copolymer, those having a vinyl acetate content of 4 to 90% are preferably used.

The active substance used in the present invention can be any substance having physiological activities such as attracting activity, repellent activity, aroma activity and the like, and all substances having pesticidal activity such as insecticidal activity without particular limitation. .

Specifically, for example, Z-7-dodecenyl acetate, Z-8-dodecenyl acetate, Z-9-dodecenyl acetate, E,
Z-7,9-dodecadienenyl acetate, Z, Z-7,
9-dodecadienyl acetate, E, E-8,10-dodecadienol, E-4-tridecenyl acetate, Z
-9-tetradecenyl acetate, Z-9-tetradecenal, Z-11-tetradecenyl acetate, Z-1
1-tetradecenal, Z-9-hexadecenal, Z
11-hexadecenal, Z, E-9,11-tetradecadienyl acetate, Z, E-9,12-tetradecadienyl acetate, Z-11-hexadecenyl acetate, Z, Z-7,11 -Hexadecadienyl acetate, Z, E-7,11-hexadecadienenyl acetate, E, E, Z-4,6,10-hexadecatrienyl acetate, E, E-10,12-hexadecadie Nal, Z, Z-3,13-octadecadienenyl acetate, E, Z-3,13-octadecadienenyl acetate, Z-7,8-epoxy-2-methyl-octadecene, Z-13-icosene- 10-on, E, E, Z-1
0,12,14-hexadecatrienyl acetate,
E, E, Z-10,12,14-hexadecatrienal, Z-10-tetradecenyl acetate, E, Z-
4,10-tetradecadienyl acetate, 14-methyl-1-octadecene, (R, Z) -5- (1-octenyl) oxacyclopentan-2-one, (R, Z)-
5- (1-decenyl) oxacyclopentan-2-one and the like can be exemplified. These are known as pheromones and consist of unsaturated aliphatic hydrocarbons having 10 to 20 carbon atoms, acetates, aldehydes, alcohols, ketones or epoxy compounds, and one or more of these compounds are used. Can be suitably used.

Examples of those having repellent activity include triethylene glycol monohexyl ether and N, N diethyl-m-triamide. Further, examples of compounds having aromatic activity include geraniol, limonene, benzyl alcohol and the like, and esters of hydrocarbons having 6 to 20 carbon atoms, ethers, aldehydes, alcohol compounds and the like. Further, examples of those having pesticidal activity include insecticides such as salicion, diadion, and chlorpyrifos, and fungicides such as thiophanate methyl and captan.

The form for retaining the active substance may be any form, and is not particularly limited. That is, various forms of holding the active substance by the holding mixture are included. Specifically, the active substance is kneaded into the microcapsules in which the surface of the active substance is coated with the holding mixture, or the active substance is kneaded into the holding mixture, or the solvent is removed after forming a homogeneous solution of the holding mixture and the active substance. Dispersing the active substance in the mixture for holding, and processing these into any shape such as spherical, plate, film, rod, pipe, thread, tape, chip, etc. it can. Furthermore, those obtained by coating the surface of these processed molded articles with a barrier layer for controlling the release of the active substance, and those coated with a pressure-sensitive adhesive for improving applicability can be exemplified. In addition, the active substance is filled into the holding mixture processed into a capillary, and both ends are heat-sealed, and the active substance is sealed, or a molded article of the holding mixture cut further at the center and one end is opened. Examples can be given.

However, in order to ensure uniform release over a long period of time, it is more desirable that the active substance is sealed as a liquid phase in a container made of a holding mixture. As such a form, a container having a tube shape, a bottle shape, or a bag shape is suitably used.

The active substance held in such a container as a liquid phase is released through the controlled release layer constituting the preparation. With the release control layer, the holding mixture is formed into a container,
When the active substance is encapsulated therein, it is the wall of the container itself. Here, in order to perform stable release control, in the case of a container shape, the thickness of the release control layer is preferably at least 0.02 mm or more.
If the thickness is less than 0.02 mm, it is not preferable because a pinhole is formed or an excessive release of an active substance such as a pheromone is caused. There is no particular problem if the thickness of the release control layer is 0.02 mm or more, but more preferably 0.05
mm to 5 mm. If it exceeds 5 mm, the release of pheromone tends to be too low.

Further, the release surface area of the sustained-release preparation comprising such a container is desirably 1 cm ² or more,
If it is less than 1 cm ² , it is difficult to secure a sufficient release amount, which is not suitable. There is no particular problem as long as the emission surface area is 1 cm ² or more, but it is more preferably 2 cm 2 to ² m ² . If it exceeds 2 m ² , it is not practical because the installation becomes difficult.

When the active substance is contained and held in a container made of a holding mixture of a sustained-release preparation, it may be divided and enclosed, but it is preferable to encapsulate the active substance in an amount of at least 1 mg or more. Preferably it is 5 mg or more. 1m
It is difficult to fill with a filling amount of less than g.

The container made of the holding mixture is preferably in the form of a tube, bottle, or bag. In the case of the tube, the inner diameter is preferably 0.4 mm to 10 mm. If it is smaller than 0.4 mm, it is difficult to fill the active substance, and if it is larger than 10 mm, it is difficult to seal. Bottle-shaped products are manufactured by blow molding or injection molding.
It is desirable that the volume is 00 ml and that the volume is less than 0.1 ml. On the other hand, if the volume is larger than 200 ml, the difference between the amount of the filled active substance and the internal volume is large, which is economically wasteful. In the case of bags, the amount of the filled active substance is 1 mg to 1 mg.
Desirably 00 g, less than 1 mg or 20
If it exceeds 0 g, it is difficult to fill it, which is not preferable in production.

Further, the biodegradable sustained-release preparation of the present invention is required to maintain its original performance during the period of use, and pigments and dyes for improving weather resistance, ultraviolet absorbers, antioxidants, etc. Various stabilizers, such as agents, may be added to the holding mixture, and such additives may be added to the active substance contained within the holding mixture container. Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

[0023]

【Example】

Example 1 A polycondensate (manufactured by Showa Kobunshi) consisting of 1,4-butanediol and a 4: 1 mixture of succinic acid and adipic acid was added to poly-ε-caprolactone (Union) at 100 ° C. using two rolls. 60% by weight). The obtained sample was heat-pressed at 130 ° C. for 5 minutes to produce a sheet having a thickness of 0.2 mm. The sheet was formed into a bag having a width of 20 mm and a length of 25 mm, and Z-11-hexadecenal, a sex pheromone of Konaga, was added to the bag.
0 mg was filled. Z-11 from the obtained sustained release preparation
When the release rate of hexadecenal was measured under the conditions of 30 ° C. and 1 m / s, the release rate was 2.1 mg / day, uniform release for about 40 days, and excellent long-term stable release. Furthermore, this sustained-release preparation is used from April to October,
When buried in the soil, it is quite tattered,
Decomposition was progressing until some disappeared. In addition, poly-ε-caprolactone (manufactured by Union Carbide) used as a modifier was used at 40 ° C. for Z-11-hexadecenal.
Was 8.3% by weight.

Comparative Example 1 1,4-butanediol and succinic acid and adipic acid:
Except for using a polycondensate (manufactured by Showa Kobunshi) consisting of the mixture of Example 1, a sustained-release preparation was prepared in the same manner as in Example 1 and the release rate was evaluated. Although a uniform release was obtained, a sustained-release preparation at least twice as much was required to ensure the same release rate as that of Example 1, and the release rate was too low to remain over the required period. The amount of active substance that would be lost was too high to be practical.

Example 2 A polycondensation product (manufactured by Showa Kobunshi) consisting of 1,4-butanediol and succinic acid was added to poly-ε at 120 ° C. using two rolls.
-30% by weight of caprolactone (manufactured by Union Carbide) was mixed. The obtained sample was heat-pressed at 150 ° C. for 5 minutes to produce a sheet having a thickness of 0.2 mm. This sheet was formed into a bag shape having a width of 25 mm and a length of 30 mm, in which the sex pheromone of codling moth, E, E-
100 mg of 8,10-dodecadienol was charged. The release rate of E, E-8,10-dodecadienol from the obtained sustained-release preparation was measured at 30 ° C. and 1 m / s, and a uniform release at 1.7 mg / day for about 50 days was performed. And had excellent long-term stable release properties. Furthermore, when this sustained-release preparation was buried in the soil from April to October, it partially disappeared, and decomposition was progressing so that it hardly retained its original form. In addition, the poly-
E, of ε-caprolactone (manufactured by Union Carbide)
The equilibrium swelling ratio at 40 ° C. with respect to E-8,10-dodecadienol was 8.9% by weight.

Comparative Example 2 Except for using a polycondensate comprising 1,4-butanediol and succinic acid (manufactured by Showa Polymer Co., Ltd.), a sustained-release preparation was prepared and the release rate was evaluated in the same manner as in Example 2. However, 0.6mg
Per day for about 150 days, a sustained-release formulation about 3 times as much as necessary to ensure the same release rate as in Example 2, and the required time due to the low release rate The amount of the active substance remaining after passing was too large to be practical.

Example 3 Poly-ε-caprolactone (manufactured by Union Carbide) was mixed with 40% by weight of polylactic acid (manufactured by Cargill) at 150 ° C. using two rolls. 160 samples obtained
0.3mm thick by heat pressing at 5 ℃ for 5 minutes
Was prepared. This sheet has a width of 20 mm and a length of 2
5 mm bag-shaped, into which Z-11-tetradecenyl acetate which is a sex pheromone of Coleoptera is 90 m
g. When the release rate of Z-11-tetradecenyl acetate from the obtained sustained release preparation was measured at 30 ° C. and 1 m / s, the release was uniform at 1.9 mg / day for about 40 days. And excellent long-term stable release. Furthermore, when this sustained-release preparation was buried in soil from April to October, the edges and the like disappeared, and the sustained-release preparation itself was decomposed to such an extent that it was brittle and easily broken. The equilibrium swelling ratio of poly-ε-caprolactone (manufactured by Union Carbide) at 40 ° C with respect to Z-11-tetradecenyl acetate, which was used as a modifier, was 7.
It was 1% by weight.

Comparative Example 3 A sustained-release preparation was prepared and the release rate was evaluated in the same manner as in Example 3 except that polylactic acid (manufactured by Cargill) was used.
It showed a release rate of only 0.01 mg / day and was not practical.

Comparative Example 4 A sustained-release preparation was prepared and the release rate was evaluated in the same manner as in Example 3, except that 0.5% by weight of poly-ε-caprolactone (manufactured by Union Carbide) was mixed. 01
Only a release rate of mg / day was shown and no modification effect was seen.

Comparative Example 5 To polylactic acid (manufactured by Cargill) was added 30% by weight of a polycondensate (manufactured by Showa Kobunshi) consisting of 1,4-butanediol and a 4: 1 mixture of succinic acid and adipic acid. A sample was prepared by mixing at 150 ° C. using two rolls. Using the obtained sample, a sustained-release preparation was prepared in the same manner as in Example 3 and the release rate was evaluated.
Only a release rate of mg / day was shown and no modification effect was seen. It should be noted that polycondensation comprising a mixture of 1,4-butanediol and succinic acid and adipic acid at a ratio of 4: 1 (manufactured by Showa Polymer)
For Z-11-tetradecenyl acetate
The equilibrium swelling at ° C. was 0.8% by weight.

Example 4 An ethylene-vinyl acetate copolymer was added to a polycondensate (manufactured by Showa Kobunshi) consisting of a mixture of 1,4-butanediol used in Example 1 and succinic acid and adipic acid at a ratio of 4: 1. (Vinyl acetate content 15 wt%: manufactured by Mitsubishi Chemical Corporation) was added at 40 wt%,
It mixed at 100 degreeC using two rolls. The obtained sample was heat-pressed at 130 ° C. to produce a sheet having a thickness of 0.2 mm. This sheet is 20mm wide and 20mm long
And filled with 90 mg of Z-11-tetradecenyl acetate in the same manner as in Example 3. When the release rate of Z-11-tetradecenyl acetate from the obtained sustained release preparation was measured at 30 ° C. and 1 m / s, the release rate was 2.0%.
The drug was uniformly released at a dose of mg / day for about 40 days, and was excellent in long-term stable release. Furthermore, when this sustained-release preparation was buried in the soil from April to October, it partially disappeared and was considerably ragged. The equilibrium swelling ratio of the ethylene-vinyl acetate copolymer (vinyl acetate content: 15 wt%: manufactured by Mitsubishi Yuka) at 40 ° C. with respect to Z-11-tetradecenyl acetate was 29. It was 1% by weight.

Comparative Example 6 Ethylene-vinyl acetate copolymer (vinyl acetate content 15
wt%: manufactured by Mitsubishi Chemical Corporation) was added in the same manner as in Example 4 except that 91% by weight was added, and the release rate was evaluated. As a result, a uniform release was obtained at 3.1 mg / day for about 20 days. However, inconveniences such as oozing of the pheromone on the surface of the sustained-release preparation and stickiness were observed. Further, when this sustained-release preparation was buried in the soil from April to October, no change was apparent in appearance, and no biodegradation was performed.

Comparative Example 7 Hamakikon (trade name: a communication disrupter for snake beetles)
(Shin-Etsu Chemical Co., Ltd.) was evaluated for release rate in the same manner as in Example 4, and after releasing uniformly at 1.9 mg / day for about 35 days, the release rate gradually decreased. In addition, this formulation from April
Until October, it was buried in the soil, but nothing changed.

Example 5 An ethylene-ethylene acrylate copolymer was added to a polycondensate (manufactured by Showa Kobunshi) consisting of a mixture of 1,4-butanediol used in Example 1 and succinic acid and adipic acid at a ratio of 4: 1. (Ethyl acrylate content 10%: manufactured by Nippon Unicar)
Was added and mixed at 100 ° C. using two rolls. After pelletizing the obtained sample with a sheet pelletizer, the inner diameter was 0.8 mm and the wall thickness was 0.5 with an extruder.
mm, and filled with Z, Z / E-7,11-hexadecadienyl acetate, which is a sex pheromone of cotton beetle, and heat-sealed every 20 cm to give a sustained-release preparation. Produced. When the release rate of the obtained sustained-release preparation was measured at 30 ° C. and 1 m / s, it was released at 0.8 mg / day for about 70 days, and was excellent in long-term stable release. When the obtained sustained-release preparation was buried in the soil from April to October, the biodegradation progressed, such as mold growth on the surface, although the shape was retained, and the surface was easily torn. Further, Z, Z of the ethylene-ethyl acrylate copolymer (ethyl acrylate content 10%: manufactured by Nippon Unicar) used as a modifier was used.
The equilibrium swelling ratio at 40 ° C. with respect to / E-7,11-hexadecadienyl acetate was 18.4% by weight.

Comparative Example 8 PB-Rope, a Communication Disrupting Agent for Cotton Beetles
When (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) was evaluated in the same manner as in Example 5, the release rate was 0.8 mg / day and the release was uniform for about 70 days, which was equivalent to that in Example 5. Furthermore, when this sustained-release preparation was buried in the soil from April to October, there was no change in the appearance, and it was not broken even when pulled by hand and biodegraded. Did not.

Example 6 To a polycondensation product of 3-hydroxyacetic acid and hydroxyvaleric acid (manufactured by Zeneca), 30% by weight of poly-ε-caprolactone (manufactured by Union Carbide) was added, and 140 wt.
Mix at ° C. After pelletizing the obtained sample with a sheet pelletizer, a thin tube having an inner diameter of 0.8 mm and a wall thickness of 0.5 mm was prepared with an extruder, and Z-8-dodecenyl acetate, which is a sex pheromone of Nasihime Sinui, was formed therein. , And heat-sealed and cut every 20 cm to prepare a sustained-release preparation. When the release rate of the obtained sustained-release preparation was measured under the conditions of 30 ° C. and 1 m / s,
It was uniformly released at 1.6 mg / day for about 40 days, and was excellent in long-term stable release. Furthermore, this sustained-release preparation was
During the months from October to October, when buried in the soil, it was barely retaining its shape, but was quite fragile and decomposed so that it could be easily made fine by hand. The equilibrium swelling ratio of poly-ε-caprolactone (manufactured by Union Carbide) at 40 ° C with respect to Z-8-dodecenyl acetate used as a modifier was 9.9% by weight.

Example 7 Poly (.epsilon.)-Caprolactone (manufactured by Union Carbide) was added with 10% by weight of polyvinyl acetate (manufactured by Aldrich).
Mixing was performed at 90 ° C. using this roll. After pelletizing the obtained sample with a sheet pelletizer, a bottle having a thickness of 2 mm, an inner volume of 5 ml, and an outer surface area of about 25 cm ² was produced by a blow molding machine. The bottle was filled with 1 g of rose-flavored geraniol, and the injection port was sealed to prepare a sustained-release preparation. When this sustained-release preparation was placed in a room, the fragrance of rose rose for about two months and was satisfactory.
Furthermore, when this sustained-release preparation was buried in the soil from April to October, although the shape was maintained, mold grew on the surface, the weight decreased by 9%, and biodegradation by microorganisms occurred. Was progressing. The equilibrium swelling ratio of polyvinyl acetate (manufactured by Aldrich) used as a modifier to geraniol at 40 ° C. was 12.9% by weight.

[0038]

As is apparent from the above description, by using the sustained-release preparation of the present invention, the active substance can be stably released over a long period of time, so that the effect can be maintained for a long period of time. In addition, since a large release rate of the active substance can be secured, the size and the number of the preparations can be reduced, and the cost can be reduced. Further, since it can be biodegraded, there is no need to collect it after use even when used for agricultural purposes, which is labor-saving. Furthermore, since the product is decomposed by microorganisms, the product does not remain in the soil as it is, which is also advantageous in terms of protecting the ring.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 1/00 LAP C08L 1/00 LAP 23/08 LCT 23/08 LCT 27/06 LFK 27/06 LFK 31/04 LHJ 31/04 LHJ 33/08 LJE 33/08 LJE 67/00 LNZ 67/00 LNZ 67/04 ZAB 67/04 ZAB

Claims (5)

[Claims] 1 to 99 parts by weight of an aliphatic polyester and 1 to 90 modifiers for adjusting the sustained release of an active substance.
And a biodegradable sustained-release preparation comprising the active substance retained by the mixture. 2. The biodegradable composition according to claim 1, wherein the equilibrium swelling ratio of the modifier for controlling the sustained release of the active substance to the active substance at 40 ° C. is 2% by weight or more. Sustained-release preparation. 3. The sustained-release biodegradable preparation according to claim 1, wherein the active substance is a pheromone. 4. The method according to claim 1, wherein the modifier is poly-ε-caprolactone,
Polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyvinyl chloride,
The biodegradable sustained-release preparation according to any one of claims 1 to 3, wherein the preparation is at least one selected from the group consisting of a polymethacrylate and a cellulose derivative or a mixture of two or more thereof. 5. A biodegradable sustained-release preparation, characterized in that the active substance is enclosed in a container comprising the mixture of claim 1, wherein the mixture controls the release of the active substance.