JP5936164B1 - Sustained release agent - Google Patents

Abstract

[Problem] To provide a sustained-release agent in which the content and release amount of a drug can be adjusted, and the remaining amount can be visually confirmed. A sustained-release agent comprising gypsum as a carrier for a water purification agent, a fragrance, a coloring agent, a herbicide, a pest control agent, a fungicide, or the like, and covering a central part 2 and a central part 2 The columnar sustained release agent (a) in which the outer edge part 3 has a different composition and the center part 2 is covered by the outer edge part 3, or the center part 2 is covered by the outer edge part 3, and the upper surface of the center part 2 And a columnar sustained-release agent (b) with exposed bottom and bottom. [Selection] Figure 1

Description

  The present invention relates to a sustained release agent that gradually releases a drug.

  Sustained release agents are used to prolong the effective action period of drugs and the like. For example, Patent Document 1 proposes an invention of an antibacterial material in which an essential oil component having antibacterial properties is adsorbed and held in porous calcium carbonate to give sustained release properties. Patent Document 2 proposes an invention of a resin molded product containing a sublimable drug component liquid or the like encapsulated therein.

JP 2010-150178 A JP 2014-42790 A

  The present invention provides a sustained-release agent that can adjust the content and release amount of a drug and can visually confirm whether or not the drug is released.

1. A sustained release agent characterized in that gypsum is used as a drug carrier.
2. A central portion and one or more outer edges covering the central portion;
The center portion and the outer edge portion have different compositions. The sustained release agent according to 1.
3. 1. The center portion and the outer edge portion are different colors. The sustained release agent according to 1.
4). 1. It has a floating body inside. ~ 3. The sustained release agent according to any one of the above.
5. 1. At least a part of the surface is covered with a waterproof material. ~ 4. The sustained release agent according to any one of the above.
6). The agent is one or more of a water purification agent, a fragrance, a coloring agent, a herbicide, a pest control agent, and a fungicide. ~ 5. The sustained release agent according to any one of the above.

The sustained-release agent of the present invention gradually releases the drug as the gypsum dissolves. The content of the drug can be adjusted by the amount of the drug added when the gypsum is hydrated and hardened, and the release rate of the drug can be adjusted by the amount of water added when the calcined gypsum is hydrated. The drug contained in the sustained-release agent does not ooze out from the surface and disappear before the dissolution of the sustained-release agent. As long as the gypsum as a carrier remains as a solid, the drug continues to be released, and whether the drug effect is maintained can be easily determined based on whether the sustained-release agent remains.
When any of water purification agents, fragrances, coloring agents, herbicides, pest control agents, and fungicides is included as a drug, these drugs are gradually dissolved over a long period of time until the sustained-release agent dissolves and disappears. Can be released. Moreover, Bacillus sp. Can also be included as a pest control agent and a fungicide. Since gypsum is neutral, microorganisms such as the genus Bacillus can be contained in the sustained release agent while alive. Furthermore, the Bacillus genus becomes a spore inside the sustained-release agent and can continue to survive for a long time in a dormant state.
By differentiating the composition of the central part and the outer edge part of the sustained-release agent, it is possible to control the amount of drug released over time. By making the concentration of the drug in the central part higher than that of the outer edge part, the amount of drug released can be kept substantially constant even when the sustained-release agent dissolves and the surface area becomes small. By making the concentration of the drug at the outer edge higher than that at the center, the amount of drug released immediately after injection can be increased, and the immediate effect can be enhanced while being a sustained-release agent. It can be compatible. For example, when a pest control agent is used as a drug and the concentration at the outer edge is higher than that at the center, pest control by releasing the drug at a high concentration immediately after injection, and sustained release of the drug accompanying dissolution of the sustained release drug Both long-term pest control can be performed. Moreover, the dissolution rate of gypsum can be adjusted by making the density of the gypsum which comprises the inside and outside of a sustained release agent differ.
If the central part of the sustained-release agent has a different color from the outer edge part, it is easy to visually recognize that the sustained-release agent introduced into the pond etc. is dissolved and becomes smaller and the center part is exposed. I can know. Further, when the sustained-release agent has a floating body inside, the floating body floats on the surface of the water, so that it is possible to know the timing at which a new sustained-release agent is added.
By covering at least a part of the surface of the sustained-release agent with a waterproofing material, the solubility can be reduced and the sustained-release property can be maintained over a long period of time.

The columnar sustained-release agent (a) whose center is covered by the outer edge and the columnar sustained-release agent (b) whose center is covered by the outer edge and whose top and bottom surfaces are exposed are shown. Figure. The figure which shows the rectangular parallelepiped sustained release agent with which the floating body was embedded inside. Top view (a) and front view (b) of specimen 1 The figure which shows the purified water shower head used in the Example. The side view (a) of the cartridge used in the Example, and the top view (b) of the lid | cover of a cartridge. FIG. 3 is a graph showing a change in weight of the specimen 1 in Example 1. Top view (a) and front view (b) of specimen 2 The figure which shows the weight change of the test body 2 in Example 2. FIG. FIG. 5 is a graph showing a change in weight of the specimen 3 in Example 3. The figure which shows the weight change of the test body in Examples 1, 3, and 4. FIG. The figure which shows the weight change of the test bodies 5a-5c in Example 5. FIG. The figure which shows the weight change of the test body 6 in Example 6. FIG. The figure which shows the weight change of the test body 7 in Example 7. FIG. The figure which shows the weight change of the test body 8 in Example 8. FIG.

The present invention relates to a sustained release agent that dissolves gradually in water to release a drug.
The sustained-release agent of the present invention uses gypsum as a drug carrier, and gradually releases the contained drug by dissolving the gypsum in water. When the sustained-release agent of the present invention is added in an appropriate amount with respect to the amount of water and a soluble sustained-release agent, the effect can be maintained for more than one year by adding it once.

When calcined gypsum obtained by partially dehydrating calcium sulfate dihydrate by heating or the like is added with water and kneaded, it hydrates and hardens. This cured product is mainly composed of calcium sulfate dihydrate and is generally called gypsum, and can be formed into a molded body of any shape by curing in a mold or the like. Is widely used. Calcium sulfate dihydrate, which is the main component of gypsum, is a poorly soluble compound having a small solubility of about 0.2 to 0.3% in water, depending on the water temperature.
When the water is added to the calcined gypsum and kneaded, the drug is added and cured by hydration, whereby the sustained-release agent of the present invention using gypsum as the drug carrier can be produced. The amount of the drug contained in the sustained release agent can be adjusted by the amount of the drug to be added. Further, the density of gypsum can be adjusted by the amount of water at the time of kneading, and the dissolution rate can be controlled by the density of gypsum. When there is a lot of water, the gypsum becomes sparse and dissolves quickly, and when there is little water, the gypsum becomes dense and dissolution becomes slow.
A slurry obtained by stirring calcined gypsum, a drug, and water is cured in a mold, so that it can be formed into a sustained-release agent having an arbitrary shape. In addition, a granular sustained-release agent can be obtained by a stirring granulation method in which the slurry is continuously stirred until it is cured. The shape of the sustained release agent of the present invention is not particularly limited, and examples thereof include a cubic shape, a rectangular parallelepiped shape, a spherical shape, a granular shape, a cylindrical shape, and a polygonal column shape.

  The sustained-release agent may have a uniform composition as a whole, but may have a central portion and one or more outer edge portions covering the central portion, and the central portion and the outer edge portion may have different compositions. . Having a different composition in the center and outer edge means that the composition of the drug, gypsum, or both is different, for example, the concentration, type, combination, gypsum composition, and density of the drug are different. Point to. The entire center portion may be covered with the outer edge portion, or a part thereof may be exposed on the surface of the sustained release agent. FIG. 1A shows a columnar sustained release agent 1 in which the central portion 2 is completely covered with the outer edge portion 3, and FIG. 1B shows that the central portion 2 is covered with the outer edge portion 3. The external view of the columnar sustained release agent 1 with which the bottom face was exposed is shown. The sustained-release agent 1 shown in FIG. 1 is cured in a state where the center portion 2 is first molded using a mold and the outer edge portion 3 is formed, and the center portion 2 is inserted into the uncured outer edge portion 3. It can shape | mold by doing. In addition, the shaping | molding method of the sustained release agent 1 which has the center part 2 and the outer edge part 3 is not limited to this, For example, after fixing the center part 2 previously shape | molded to the mold which shape | molds an outer edge part, a center part It can also be formed by pouring and curing a slurry having a composition different from the above. The number of layers of the outer edge portion 3 is not particularly limited, but since the manufacturing process becomes complicated when the number of layers is large, the outer edge portion 3 is preferably 1 to 3 layers.

  By differentiating the concentration of the drug between the central portion 2 and the outer edge portion 3, it is possible to adjust the release amount of the drug over time. The concentration of the drug in the central portion 2 and the outer edge portion 3 may be higher in the central portion 2 and may be higher in the outer edge portion 3. In a sustained-release agent having a uniform drug concentration, the amount of drug released is proportional to the surface area of the sustained-release agent. Therefore, when the sustained-release agent dissolves and becomes smaller, the drug elution amount decreases. On the other hand, by making the concentration of the drug in the center portion 2 higher than the concentration of the drug in the outer edge portion 3, the amount of the drug released over time can be kept substantially constant. Further, when the concentration of the drug at the outer edge 3 is higher than that at the center 2, the amount of drug released immediately after injection can be increased, and the immediate effect can be enhanced while being a sustained-release agent. And a sustained-release agent having properties. For example, if a pest control agent is used as a drug and the concentration at the outer edge is higher than that at the center, the pest that has already occurred can be controlled by releasing the drug at a high concentration immediately after the injection. Can be used for both pest control to prevent the generation of pests over a long period of time by the sustained release of the drug. As the number of layers of the outer edge part 3 is increased, the amount of drug released can be controlled more finely. However, as described above, the manufacturing process becomes complicated when the number of layers is large. A layer is preferred. Further, when the density of gypsum is made different between the composition of the central portion 2 and the composition of the outer edge portion 3, the amount of the drug released over time can be adjusted by the difference in dissolution rate.

  The sustained release agent of the present invention comprises gypsum having a specific gravity of about 2.3, water and a drug, and the specific gravity is about 1.3. Further, although it depends on the color and amount of the drug, it is usually white. Therefore, if the sustained release agent poured into water such as a concrete pond or drainage ditch, which is made of white or gray water, dissolves in water and becomes smaller, the sustained release agent remains or dissolves completely. It becomes difficult to see if it disappears. Therefore, it is preferable that the central part of the sustained release agent has a color different from that of the outer edge part. If the center is a color different from the color of the bottom of the water, by visually recognizing the dissolved color of the center, it can be known that the sustained-release agent is about to dissolve and disappear, and a new sustained-release It can be determined that it is time to add the agent. The color to be colored is not particularly limited, but orange, yellow, and green are easy to visually recognize.

  When molding the sustained-release agent, a floating body that is an object having a specific gravity of less than 1.0 is included in the sustained-release agent, and this floating body is used to indicate that the residual amount of the sustained-release agent has decreased. be able to. FIG. 2 shows a rectangular parallelepiped sustained release agent 1 having a spherical floating body 4. The shape of the floating body 4 is not particularly limited, and may be not only a geometric shape such as a spherical shape or a rectangular shape, but also a shape such as a flower, a ship, or a butterfly. The floating body 4 may be anything that floats on water, and foamed resin beads, plastic pieces, polystyrene foam, hollow spheres, and the like can be used without particular limitation. The sustained release agent 1 having the floating body 4 can be manufactured by pouring the slurry into the mold and molding the floating body 4 in a state where the floating body 4 is fixed in the mold with a wire or a thread. Furthermore, the outer edge part of a different composition and color can also be shape | molded centering on the sustained release agent which has the floating body 4. FIG. When the sustained release agent 1 having the floating body 4 is dissolved, the floating body 4 is exposed. When the dissolution further proceeds, the floating body 4 is separated from the sustained release agent 1 and floats on the water surface. When the floating body 4 floats on the surface of the water, it can be determined that it is time to administer a new sustained-release agent in water because the sustained-release agent 1 is about to dissolve and disappear.

The chemical | medical agent contained in the sustained release agent of this invention can be used without a restriction | limiting especially if it can disperse | distribute in the slurry which kneaded calcined gypsum and water. That is, the drug may be dispersible in a slurry of calcined gypsum and water, may be liquid or solid, may be soluble or insoluble in water, and may be hydrophilic or hydrophobic. For example, even if it is difficult to disperse in a mixed slurry of calcined gypsum and water as it is, the pretreatment such as emulsification with a surfactant or strong stirring, microencapsulation with a hydrophilic coating, etc. is performed. If it becomes dispersible in the slurry of calcined gypsum and water, it can be used as a medicine. In addition, even if the drug is a hydrophobic substance such as solid fat or resin, pretreatment such as improving the surface wettability of the target substance by surface treatment or improving dispersibility by pulverization If it becomes dispersible in the slurry of calcined gypsum and water, it can be used as a medicine. Even if the sustained-release agent of the present invention contains a water-soluble drug, the drug does not dissolve and disappear in water prior to the dissolution of gypsum.
Examples of the drug include water purification agents, fragrances, coloring agents, herbicides, pest control agents, fungicides, and the like, and one or a combination of two or more of them may be contained in the sustained release agent. Can do. As described above, the concentration, type, combination, and the like of the drug can be made different between the central part and the outer edge part, for example, the coloring agent and the drug can be contained in the central part, and only the drug can be contained in the outer edge part. .

Examples of the water purification agent include sodium thiosulfate, ascorbic acid, calcite neutralizers such as sulfites, and heavy metal precipitants. By shaping the sustained release agent containing a chlorinated neutralizing agent into an appropriate shape and loading it into a faucet, shower head or the like, the chlorinated water in tap water can be neutralized over a long period of time. When the shower head is loaded, if a transparent shower head is used, it can be easily recognized from the outside whether the sustained release agent remains.
By forming a sustained-release agent containing a fragrance into an appropriate shape and loading it into a faucet or a shower head, water having a fragrance can be supplied over a long period of time. As the fragrance, not only water-soluble fragrances but also lipophilic fragrances such as essential oils can be used. In addition, by adding a sustained release agent containing a fragrance and a colorant to a toilet tank, it is possible to determine whether or not the sustained release agent remains depending on the presence or absence of coloring at the same time as imparting a fragrance.

Examples of herbicides include aquatic plant removers, algae removers, moss removers, and the like, and examples of pest control agents include moth pesticides, boufraphores. As herbicides, pest control agents, and fungicides, not only synthetic compounds but also compounds derived from natural products such as essential oils can be used. Furthermore, microorganisms such as Bacillus sp. Can be contained in the sustained-release agent as an antifungal agent, an antifungal agent, and an antifungal agent. For example, Bacillus thuringiensis is known to have strong insecticidal properties and is used as a so-called BT agent. In addition to Bacillus thuringiensis, Bacillus subtilis, Bacillus sphaericus, Bacillus mojavensis, and Bacillus amyloliquesi are known. ing. In the sustained-release agent of the present invention, the base gypsum (calcium sulfate dihydrate) is neutral, so that microorganisms such as Bacillus can be survived by simply adding microorganisms to calcined gypsum and allowing them to hydrate and harden. It can be blended into the sustained-release agent as it is. The Bacillus genus forms spores when the environment deteriorates, and can continue to survive in a dormant state for several decades inside the sustained release agent. On the other hand, since general Portland cement is strongly alkaline, microorganisms such as Bacillus are reduced and killed during hydration and hardening.
As a herbicide, a sustained release agent containing at least one of a grass remover, algae remover, and moss remover suppresses the generation of aquatic plants, algae, and moss in reservoirs, fountains, garden ponds, ornamental aquariums, etc. Deterioration of water quality and appearance can be suppressed. As a pest control agent, a sustained-release agent containing either or both of a moth control agent and a boufra control agent is put into a water field where ponds and drainage are likely to occur, such as ponds and drains, for a long time. Insect repellent effect can be exhibited. When a sustained-release agent containing an antifungal agent is introduced into a drain outlet or the like, generation of mold can be suppressed, and odor and slime can be suppressed. Moreover, the generation | occurrence | production of the mold | fungi in a bathroom can be suppressed only by loading the shower head containing the mildewproofing agent in a shower head, and flushing a bathroom with the water which passed through this shower head after bath cleaning.
Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

"Example 1"
In a resin container, 4.0 g of fragrance (made by Miken Co., Ltd., trade name: water-soluble essential oil sweet orange) is weighed, tap water is added, and the standard mixed water amount of the test calcined gypsum (the amount of water used for the calcined gypsum) ) To 76.0 g. While stirring this water, it takes about 1 minute to mix 100.0 g of calcined gypsum (Yoshino Gypsum Sales Co., Ltd., trade name: gypsum for work), and then knead for 7 minutes. Poured into a mold and left in a room at room temperature. After about 24 hours, the cured molded body was taken out of the resin mold, and 13 cylindrical hemispherical cylindrical bodies having a diameter of about 10 mm, a length of about 70 mm, and a weight of about 7.0 g were obtained. FIG. 3 shows a top view (a) and a front view (b) of the specimen 1.

Eight of the obtained molded bodies were sealed and stored in a plastic bag with a chuck, and five were naturally dried for one week in an open state indoors. The average weight of the five air-dried compacts was 7.0 g immediately after demolding, but became 5.5 g by natural drying. The fragrance was maintained even after natural drying.
The molded body after natural drying was immersed in tap water until water bubbles disappeared and the weight was measured. The weight of the molded body after water absorption was 7.0 g. From this fact, it was confirmed that even if the molded body was dehydrated by natural drying, it returned to the water-containing state almost immediately after demolding when it was brought into contact with water and absorbed.

A molded body that had been sealed and stored for one week immediately after demolding after curing was designated as Specimen 1. Specimen 1 was placed in a water purification cartridge of a water purification shower head (manufactured by Sanei Watercock Co., Ltd., trade name: water purification chamoody) and set in the water purification shower head. FIG. 4 shows a clean water shower head 5, FIG. 5A shows a side view of the cartridge 6, and FIG. 5B shows a top view of the lid 61. The clean water shower head 5 is threaded so as to be separable at the center of the handle 51, and the cartridge 6 is loaded inside the handle. There is a gap through which water passes between the inner surface of the handle 51 and the outer surface of the cartridge 6, and the water that passes through the clean water shower head 5 is divided into water that passes through the inside and the outside of the cartridge 6. The cartridge 6 has a cylindrical shape, and a lid 61 is detachably fitted on the upper surface. The specimen 1 can be accommodated in the cartridge 6. The bottom surface of the cartridge 6 and the lid 61 have an opening so that water can pass therethrough.
While warm water adjusted to about 40 ° C. was passed through the clean water shower head 5, the specimen 1 was taken out every 10 minutes and weighed. The amount of water flow every 10 minutes is about 75L. Table 1 shows the weight of the specimen 1 measured for each passing time, and FIG. 6 shows the change in the weight of the specimen 1 with respect to the passing time. In addition, the measurement was performed with one specimen 1.
Specimen 1 dissolved 0.5 g every 10 minutes until 80 minutes, and thereafter, a decrease in dissolution rate due to a decrease in surface area was observed. Moreover, until 80 minutes, the fragrance of the fragrance | flavor which is a chemical | medical agent was able to be felt in the water discharge | released from a shower head. Even after 80 minutes, the sustained-release agent remains as a solid and the fragrance should have been released. However, the concentration of the fragrance decreases due to a decrease in the amount of release due to the decrease in the surface area of the specimen 1, and the human olfaction It is presumed that it was no longer felt.

"Example 2"
In a resin container, 5.0 g of sodium thiosulfate pentahydrate is weighed out as a neutralizing agent, and tap water is added to obtain a standard mixed water amount of the test calcined gypsum (amount of water used for calcined gypsum). Prepared to 0 g. While stirring this water for about 1 minute, 100.0 g of calcined gypsum (trade name: gypsum for work) was mixed and then kneaded. The effect of sodium thiosulfate added after about 3 minutes was considered. The resulting viscosity increase occurred. Therefore, the kneaded product was poured into a cylindrical resin mold with a kneading time of 4 minutes and allowed to stand in a room temperature room.
After about 24 hours, the cured molded body is taken out from the resin mold, and a long circle having a short side of 3 mm and a long side of 10 mm is connected to a long circle having a semicircle of 10 mm in diameter, a length of about 70 mm, and a weight. A cylindrical specimen 2 having a hemispherical shape on both ends, which is about 10.1 g, was obtained. FIG. 7 shows a top view (a) and a front view (b) of the specimen 2.

In the same manner as in Example 1, the weight of the specimen 2 loaded in the cartridge 6 of the clean water shower head 5 was measured. Table 2 shows the weight of the specimen 2 measured for each water passage time, and FIG. 8 shows the change in the weight of the specimen 2 with respect to the water passage time.
Specimen 2, which was 10.1 g at the start of measurement, was reduced to 2.5 g and a weight of about one quarter by passing water for 140 minutes.

Specimen 2 that passed through water to 2.5 g, and Specimen 2 that had been taken out of the resin mold and stored in a plastic bag with a chuck and were not permeable to water, had a povidone iodine solution (70 mg of povidone iodine in 1 mL, effective Iodine (7 mg) was added dropwise and allowed to stand at room temperature indoors. The drug sodium thiosulfate reduces iodine to produce colorless sodium iodide. Therefore, it can be confirmed whether the sodium thiosulfate which is a chemical | medical agent remains in a test body with the presence or absence of the decoloring effect | action of an iodine.
Specimen 2 was decolorized from the dropped iodine solution after about 1 hour both before and after water flow. From this, the sustained-release agent of the present invention has sodium thiosulfate inside even when the weight is reduced to a quarter by passing water, and the water-soluble sodium thiosulfate is present prior to the dissolution of gypsum. It was confirmed that no elution occurred. In addition, when the povidone-iodine solution was dropped in the same manner to the specimen 3 containing only gypsum and not containing sodium thiosulfate, the iodine solution was not decolored even after 1 hour, and the gypsum did not have a reducing ability. It was confirmed.

"Example 3"
In a resin container, weigh 80 g of tap water, which is 1.5 times the standard mixed water amount of the test calcined gypsum (the amount of water used for calcined gypsum), and stir it for about 1 minute. (Product name: gypsum for work) 70.0 g was mixed, and then kneaded for 7 minutes. The kneaded material was immediately poured into a cylindrical resin mold and left in a room temperature room. After about 24 hours, the cured molded body was taken out from the resin mold to obtain 13 hemispherical cylindrical specimens 3 having a diameter of about 10 mm, a length of about 70 mm, and a weight of about 6.6 g.

The obtained specimen 3 was naturally dried for one week in an open state indoors. The average value of the weight of the specimen 3 after natural drying was about 4.0 g.
When the specimen 3 after natural drying was immersed in a container containing water and water was added until no bubbles were generated, the weight of the specimen 3 was about 6.5 g. In addition, in the operation of adding water again after drying, the specimen 3 floats in the water immediately after being put into the water, but then sinks into the water and the average value of the time required to stop generating bubbles is about 5 minutes. Met. On the other hand, the weight after drying of the cylindrical molded body prepared in Example 1 prepared at the same time with the standard mixed water amount is about 5.5 g, and in the operation of adding water again after drying, no bubbles are generated. Took more than 15 minutes. From this, it was confirmed that the specimen 3 obtained by increasing the amount of mixed water by 1.5 times was low in density and rough.
The weight of the specimen 3 loaded in the cartridge 6 of the clean water shower head 5 was measured in the same manner as in Example 1. Table 3 shows the weight of the specimen 3 measured at each passing time, and FIG. 9 shows the change in the weight of the specimen 3 with respect to the passing time.
Specimen 3 showed a large dissolution amount as compared with Example 1 having the same shape of 0.9 g every 10 minutes in the initial stage of water flow. This is because the specimen 3 is coarser than the specimen 1. Further, the subsequent dissolution amount gradually decreased.

Example 4
The neck portion 52 of the clean water shower head 5 shown in FIG. 4 was loaded with a resin net that was cut into a 10 cm square and rounded to allow water to pass but not to pass solids. The sample 3 was loaded into the clean water shower head 5 without using a cartridge, and the weight of the sample 3 was measured in the same manner as in Example 1. In Example 4, since the warm water passing through the shower head does not flow into the inside and outside of the cartridge, the amount of water that can be contacted with the specimen is larger than that in Example 3. Table 4 shows the weight of the specimen 3 measured for each water passage time, and FIG. 10 shows a comparison of the weight changes of the specimens measured in Example 4 and Examples 1 and 3.
Example 4 showed a very high amount of dissolution compared with Example 3 particularly at the beginning of water flow, and the dissolution rate was 1.8 g in the first 10 minutes.
From the results of Example 3 and Example 1, the sustained release agent according to the present invention can adjust the density of the molded body after curing by adjusting the amount of water used for kneading at the time of production. It was confirmed that the dissolution rate, that is, the sustained release property of the sustained release agent of the present invention can be adjusted by the body density. Moreover, from the results of Example 4 and Example 3, it was confirmed that the dissolution rate of the sustained-release agent, that is, the sustained-release property of the contained drug can be adjusted by the amount of water in contact with the sustained-release agent.

"Example 5"
In a resin container, weigh out 76.0 g of tap water, which is the standard amount of water used for the test calcined gypsum (the amount of water used for calcined gypsum), and stir it for about 1 minute. ) 100.0 g was mixed, and then kneaded for 7 minutes. The kneaded product was immediately poured into a rectangular parallelepiped resin mold and left in a room temperature room. After about 24 hours, the cured molded body was taken out from the resin mold to obtain a rectangular parallelepiped shaped body having a length and width of about 72 mm and a height of about 22 mm.
The obtained rectangular parallelepiped shaped body was naturally dried for one week in an open state in a room. The dried rectangular parallelepiped shaped body is cut into approximately four equal parts, and the irregularities on the cut surface and the upper surface formed during molding are polished with sandpaper, and the length and width are about 32 mm to 34 mm, and the height is about 21 mm. A cuboid specimen 5 having a size of ˜22 mm was obtained.
An acrylic resin-based varnish (trade name: water-soluble glossy varnish, manufactured by Washin Paint Co., Ltd.) was applied to the surface of a part of the rectangular parallelepiped 6 surface of the obtained specimen 5 as a waterproof material. In the varnish application, the application and drying were repeated three times, the specimens 5a and 5b were subjected to natural drying at room temperature for 24 hours from the third varnish application, and the coating waterproof treatment with varnish was not performed. A specimen 5c was obtained. Table 5 shows the dimensions and waterproofing treatment of the specimens 5a, 5b, and 5c.

The specimens 5a to 5c were put in a resin net with a string attached, immersed in a water tank water of a flush toilet and taken out every 24 hours, and the specimen weight was measured. Table 6 shows the weight of the specimens 5a to 5c measured every 24 hours, and FIG. 11 shows the change in the weight of the specimens 5a to 5c with respect to the elapsed days.
The specimen 5c did not lose weight on the first day of immersion, which is presumed to be due to insufficient water absorption into the specimen before immersion. From the second day of immersion, almost constant weight loss was confirmed according to the area where each specimen was not waterproofed. It was confirmed that the dissolution rate of the sustained-release agent of the present invention, that is, the sustained-release property of the contained drug can be easily adjusted by subjecting the surface of the sustained-release agent to waterproofing.

"Example 6"
In a resin container, weigh 10.0 g of a maggot and puffer pesticide (Earth Pharmaceutical Co., Ltd., trade name: pesticide for maggot), add tap water, and mix the standard mixture of test gypsum. The amount was adjusted to 76.0 g, which is the amount of water (the amount of water used relative to calcined gypsum). While stirring this water, it takes about 1 minute to mix 100.0 g of calcined gypsum (trade name: gypsum for work), then knead for 7 minutes, and immediately pour the kneaded product into a rectangular parallelepiped resin mold. I left it indoors. After about 24 hours, the cured molded body was taken out from the resin mold, but was fixed to the resin container due to the influence of the contained chemical agent, so that the obtained molded body lacked the peripheral part.
The obtained molded body was naturally dried in the open state for one week in the room, and then the chipped peripheral part was cut and removed to obtain a rectangular parallelepiped specimen 6 having a length of about 35 mm, a width of about 71 mm, and a height of about 22 mm. .

The obtained specimen 6 was weighed in the same manner as in Example 5. Table 7 shows the weight of the specimen 6 measured every 24 hours, and FIG. 12 shows the change in the weight of the specimen 6 with respect to the elapsed days.
The maggot and puffer pesticide which is the drug used in Example 6 has a specific odor. Due to the sustained release of the drug from the sustained release agent, this unique odor was also felt from the flush water for flush toilets. The odor was confirmed even when 1 week had passed since the specimen 6 was immersed in the washing tank water, and it was confirmed that the sustained release agent of the present invention gradually released the drug.

"Example 7"
In a resin container, weigh out about 1.0 g of a commercially available acrylic paint (made by Delta Technical Coating. Inc., trade name: Serum Coat No. 2026 Orange) as a colorant, add tap water, and mix the standard mixture of the test baked gypsum. The amount was adjusted to 38.0 g, which is the amount of water (the amount of water used relative to calcined gypsum). The water was stirred for about 1 minute, 50.0 g of calcined gypsum (trade name: work gypsum) was mixed, and then kneaded for 12 minutes. The kneaded product was poured into a commercially available straw, allowed to stand for about 24 hours, and then the cured product was taken out of the straw, and the length was adjusted to obtain a cylindrical colored molded body having a diameter of about 6 mm and a length of about 60 mm.
Sprinkle 76.0 g of water, which is the standard water content of the test calcined gypsum (amount of water used for calcined gypsum), while stirring for about 1 minute, mix 100.0 g of calcined gypsum (trade name: work gypsum), and continue to 5 Kneading was performed for a minute, and the kneaded material was poured into a thick straw that had been pushed up against clay. The colored molded body obtained above is inserted into an uncured kneaded product inside a thick straw, and left to stand for about 24 hours. After that, the cured product is taken out, and a diameter of about 12 mm having a colored portion of about 6 mm in the center is obtained A specimen 7 having a length of about 80 mm was obtained.

A metal net was placed on the bottom of a water tank (vertical x horizontal x height = 25 cm x 40 cm x 28 cm, capacity of about 30 L), and the specimen 7 was allowed to stand on the net. Tap water was passed through the bottom of the water tank at about 100 ml / min, and the water was exchanged by allowing it to overflow from the top of the water tank. The specimen 7 was taken out every 24 hours and the specimen weight was measured. Table 8 shows the weight of the specimen 7 measured every 24 hours, and FIG. 13 shows the change in the weight of the specimen 7 with respect to the elapsed days.
The specimen 7 gradually decreased in weight loss as the surface area decreased. On the 8th day, the colored part started to appear partially, and on the 10th day, the colored part appeared on the entire surface, but it was too thin and broken when taken out from the water tank. .

"Example 8"
It took about 1 minute to 76.0 g of water which is a standard mixed water amount of the test calcined gypsum (amount of water used for calcined gypsum), and 100.0 g of calcined gypsum (trade name: work gypsum) was mixed. Subsequently, the mixture was kneaded for 5 minutes and poured into a casting mold.
A wire was stabbed into the center of a foamed resin bead having a diameter of 15 mm, which was a floating body, and the foamed resin bead was inserted from the upper part of the casting mold, and fixed with a wire so that the foamed resin bead became the center of the casting mold. After leaving still for about 24 hours, it was demolded, the wire was pulled out, and a specimen 8a having a bottom surface of about 41 mm × 58 mm, an upper surface of about 31 mm × 48 mm, and a height of about 30 mm was obtained.

  In the center of the casting mold, a wire body of a commercially available artificial flower (seller: Daiso Sangyo Co., Ltd., trade name: Decora Flower Garden), with two 6mm diameter foam resin beads stabbed to give buoyancy. Except for fixing, two specimens (samples 8b and 8c) containing artificial flowers at the center were obtained in the same manner as the sample 8a.

Specimens 8a and 8b were placed in a commercially available resin net, fixed so as to be in the middle of the water tank in the depth direction, and the specimen 8c was placed at the bottom of the water tank in the same manner as in Example 7. In the same manner as in Example 7, tap water was passed from the bottom of the water tank at about 100 ml / min, and specimens 8a to 8c were taken out every 24 hours and weighed. FIG. 14 shows the change in weight of the specimens 8a to 8c with respect to the number of days elapsed.
The weights of 8a and 8b fixed to the middle of the water tank decreased faster than 8c fixed to the bottom. This is because the liquid specific gravity of the water in which the gypsum is dissolved is larger than the liquid specific gravity of the water in which the gypsum is not dissolved, and therefore, the gypsum concentration is lower in the middle portion and the bottom portion of the water tank, and the specimens 8a and 8b It is presumed that was easier to dissolve.
In the specimen 8a, a part of the foamed resin beads was exposed on the 18th day, and completely exposed on the 29th day. In the specimen 8b, a part of the artificial flower was exposed on the 23rd day, and it was completely exposed on the 36th day. In the specimen 8c, a part of the artificial flower was exposed on the 32nd day, and it was completely exposed on the 38th day. The difference in the timing at which the floating body embedded in each specimen is exposed is derived from a deviation from the center of the embedded position.
The specimen 8a took less days to surface than the specimens 8b and 8c, because the buoyancy of the floating body (foamed resin beads having a diameter of 15 mm) used in the specimen 8a was large. Part of gypsum adheres to the surface of the floated floating body, and even if a small amount of gypsum adheres, it floats, so that dissolution of the sustained-release agent can be known at an early stage.
In specimens 8b and 8c, 8b installed at the middle part of the water tank floated faster than 8c installed at the bottom part of the water tank. This is because it was easy to dissolve. The floating body used in the specimens 8b and 8c has a small buoyancy, and has a complicated shape and a part of the floating body is embedded in the gypsum, so that the floating body does not float. Therefore, the floating body rises compared to the specimen 8a. It took a long time.

DESCRIPTION OF SYMBOLS 1 Sustained release agent 2 Center part 3 Outer edge part 4 Floating body 5 Clean water shower head 51 Handle part 52 Neck part 6 Cartridge 61 Cover

Claims (5)

Plaster is used as a drug carrier ,
A central portion and one or more outer edges covering the central portion;
The center portion and the outer edge portion have different compositions,
The sustained release agent , wherein the concentration of the drug in the outer edge portion is higher than the concentration of the drug in the central portion . The sustained release agent according to claim 1 , wherein the central portion and the outer edge portion have different colors. Sustained release agent according to claim 1 or 2, characterized in that it has a floating therein. The sustained release agent according to any one of claims 1 to 3 , wherein at least a part of the surface is coated with a waterproof material. The sustained-release agent according to any one of claims 1 to 4 , wherein the drug is at least one of a water purification agent, a fragrance, a colorant, a herbicide, a pesticide, and a fungicide.

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