JPH0219140A - Capsule for medical purpose - Google Patents

Abstract

PURPOSE:To eliminate the need for a large-scale driving means, etc., and to simplify and miniaturize the structure by driving a moving members by a mechanochemical material. CONSTITUTION:The capsule for medical purposes formed by previously packing a drug 3 into a drug housing chamber 4 of a capsule body 1 is orally dosed. The digestive liquid in the stomach infiltrates the inside of a working chamber 6 from an inlet/outlet hole 9 and comes into contact with the mechanochemical material 7 when the capsule for medical purposes arrives at the patient's stomach. The mechanochemical material expands by contact with the gastric juice. The expanded mechanochemical material 7 pushes a piston 2 to reduce the volume of the drug housing chamber 4. The drug 3 is then released from a release hole 5.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to medical capsules for administration into body cavities.

[Prior art] Until now, this type of medical capsule was developed in Japanese Patent Application Laid-open No. 57-16.
This method is known from Japanese Patent Publication No. 3309 and Japanese Patent Publication No. 19857/1985. The medical capsule disclosed in Japanese Patent Application Laid-Open No. 57-163309 incorporates a drive operation member made of a shape memory alloy into the capsule body, and the drive operation member moves the movable member to change the volume of the storage chamber, thereby controlling the volume of the drug solution. This is an attempt to spray or collect body fluids, etc. In addition, the method disclosed in Japanese Patent Publication No. 62-19857 also attempts to spray a medicinal solution or collect body fluids within a body cavity, but in particular detects the pH inside the body cavity and activates a timer, which is activated after a predetermined period of time. It controls the operation of the parts.

[Problems to be Solved by the Invention] However, in conventional medical capsules, the driving means for releasing the drug solution and collecting the sample is a driving member such as a shape memory alloy or a spring member, and a control circuit that controls the operation of the driving member. Furthermore, an energy source and the like were required, and these had to be housed within the capsule body.

Therefore, in order to meet this demand, the capsule itself has to be large, which increases the pain experienced by patients using the medical capsule. In addition, because of the need to incorporate many members, the volumes of the chemical liquid storage chamber and the sample collection storage chamber are limited, and the amount of medicine applied and the amount of sample collected, which are intended for use, are reduced.

Furthermore, if the device is made smaller in order to alleviate patient pain, the amount of medicine administered and the amount of sample collected will be reduced. Furthermore, the conventional structure described above is complex and expensive because it incorporates many members, and it is generally difficult to ensure that the complicated mechanism performs a predetermined operation.

The present invention has been made in view of the above-mentioned problems, and its purpose is to have a simple structure and miniaturization, and to
To provide a medical capsule in which the amount of medicine stored and the amount to be collected can be relatively large with respect to the external dimensions of the capsule.

[Means and Effects for Solving the Problems] In order to solve the above problems, the medical capsule of the present invention has a storage chamber that communicates with the outside through a communication path in the capsule body, and a volume of the storage chamber. A movable member that changes the volume is provided, a mechanochemical substance that moves the movable member by a change in volume, and an actuation means that changes the volume of the mechanochemical substance.

Since the movable member is driven by a mechanochemical substance in this way, there is no need for a large-scale driving means, the structure can be made simple and compact, and the predetermined operation can be performed reliably. Further, by making the capsule smaller, it is possible to alleviate the pain of the patient, and by simplifying the structure, it is possible to provide an inexpensive medical capsule. Furthermore, the amount of medicine stored in the capsule and the amount of sample collected can be made large relative to the external dimensions of the capsule.

[Embodiment] FIGS. 1 and 2 show a first embodiment of the present invention. In the figure, 1 is a capsule body made of a material that is harmless to living organisms. The capsule body 1 is formed into a cylindrical shape with both ends closed, and a piston 2 as a movable member that slides on the inner surface of the capsule body 1 and can move forward and backward is provided inside the capsule body 1. The internal space of this capsule body is separated into two chambers by the piston 2. One of these chambers is a drug storage chamber 4 that stores a liquid drug 3, and a wall of the capsule body 1 corresponding to this drug storage chamber 4 has a discharge passageway that communicates the drug storage chamber 4 with the outside. A hole 5 is formed.

The other chamber separated by the piston 2 forms a working chamber 6, and this working chamber 6 is provided with a mechanochemical substance 7 that expands and increases in volume when it comes into contact with an acidic liquid, as will be described later. ing. The mechanochemical substance 7 is formed into a cylindrical shape as a whole, and one end in the axial direction is attached to the back surface of the piston 2, and the other end is attached to the inner wall surface of the capsule body 1. Further, inside the capsule body 1, the side peripheral surface of the mechanochemical substance 7 is spaced apart from the inner wall surface of the capsule body 1 to form a void 8 around it. In addition, the capsule body 1 is connected to this cavity 8.
A plurality of holes 9 are formed in the wall for allowing digestive fluids, etc. to enter and exit. In other words, it constitutes means for operating the mechanochemical substance 7.

The mechanochemical substance 7 used is, for example, a material that expands and increases in volume when it comes into contact with an acidic liquid, such as an H-type ion exchange resin with a low degree of crosslinking made of polystyrene or divinylbinzene.

Next, the action of this medical capsule will be explained. A medical capsule filled with a medicine 3 in advance in the medicine storage chamber 4 of the capsule body 1 is orally administered. When this medical capsule reaches the patient's stomach, it passes through the entry/exit hole 9 into the working chamber 6.
Digestive fluid in the stomach enters the inside and comes into contact with the mechanochemical substance 7. Here, although the gastric juice is strongly acidic with a pH of about 1, the mechanochemical substance 7 expands and stretches as shown in FIG. Then, since the piston 2 is pushed, the volume of the drug storage chamber 4 is reduced, and the drug 3 is compressed and released from the release hole 5 into the stomach. Therefore, the drug 3 can be administered in a way that is suitable for the stomach.

In addition, when it is desired to administer drug 3 to the small intestine, since the small intestine is neutral or weakly acidic, the above mechanochemical substance 7 should be administered.
For example, polyacrylic acid (PA,
A) If it is made into a gel, the medical capsule can be constructed so that the drug 3 is not released in the stomach but is released in the small intestine.

According to the configuration of the medical capsule configured as described above, there is no need to incorporate a particularly large drive member or drive control mechanism. Therefore, the configuration can be significantly simplified and downsized, and the amount of medicine that can be accommodated can be increased. Further, by changing the characteristics of the mechanochemical substance 7, the release site of the drug 3 can be selected.

3 and 4 show a second embodiment of the invention. The medical capsule of this embodiment is an example of a capsule intended for collecting digestive juices. Similar to the first embodiment, a piston 2 is provided inside the capsule body 1 as a movable member that slides on the inner surface of the capsule body 1 and can move forward and backward. Separate into chambers.

One of the chambers is used as a storage chamber 4 in which digestive fluid is collected and stored. Further, in the wall portion of the capsule body 1 corresponding to the storage chamber 4, a collection hole 12 serving as a communication path and incorporating a check valve 11 is provided so as to communicate with the outside. The check valve 11 is made of an elastic material and is configured to allow only a flow from the outside of the capsule body 1 toward the inside of the storage chamber 4, and to prevent a reverse flow.

Further, the other chamber separated by the piston 2 forms a working chamber 6 similarly to the first embodiment, and this working chamber 6 contains a mechanochemical that contracts and reduces its volume when it comes into contact with an acidic liquid. A substance 7 is provided. The mechanochemical substance 7 is, for example, polyacrylic acid (FAA) gel crosslinked with polyvinyl alcohol (PVA).

In addition, inside the capsule body 1, the side peripheral surface of the mechanochemical substance 7 is separated from the inner wall surface of the capsule body 1 to form a void 8 around it, and communicates with this void 8 to form a wall of the capsule body 1. There are holes 9 for digestive juices etc.
The structure in which a plurality of are formed is similar to that of the first embodiment.

When this medical capsule is orally administered and reaches the patient's stomach, the digestive juices in the stomach enter the working chamber 6 through the entrance/exit hole 9 and come into contact with the mechanochemical substance 7. Here, since gastric juice is strongly acidic with a pH of about 1, the mechanochemical substance 7 contracts and becomes shorter as shown in FIG. Then, since piston 2 is pulled,
The volume of the storage chamber 4 increases, and the sampling hole 12 with the check valve 11 increases.
Digestive fluid is sucked out and taken into the storage chamber 4. Storage room 4
Once taken into the interior, the check valve 11 prevents the digestive fluid from leaking out again.

Note that if the mechanochemical substance 7 is one that contracts with neutral or alkaline liquid, the digestive fluid in the small intestine can be collected.

According to this embodiment, the digestive fluid in the body cavity can be collected, and the same effects as those of the first embodiment can be achieved.

5 and 6 show a third embodiment of the present invention. This embodiment relates to a medical capsule that is implanted in a living body, such as subcutaneous tissue, and releases a drug. The capsule body 21 is made of a material that is harmless to living organisms, such as 5US316L, titanium alloy, ceramics, polysulfone, etc. Inside the capsule body 21 is a piston 22 that is slidably disposed on the inner surface of the capsule body 21 in a fluid-tight manner.
It is divided into two rooms by.

A storage chamber 24 for storing the drug 23 is formed in the upper divided chamber, and a plurality of release holes 25 are formed in the inner wall of the capsule body 21 forming the storage chamber 24. Further, in the storage chamber 24, a mechanochemical substance 26 is installed which is long and cylindrical in the direction of movement of the piston 22.

One end of this mechanochemical substance 26 is attached to the piston 22, and the other end is attached and fixed to the inner wall of the capsule body 21. The mechanochemical material 26 in this embodiment is formed from a material whose volume contracts as the temperature increases, such as polyisopropylamide gel.

Further, a membrane 27 made of an open-cell porous material into which body fluids can freely enter is attached to the bottom opening of the capsule body 21. Further, a hole 2 is provided on the bottom side of the capsule body 21 for attaching the capsule body 21 to a living body by suturing.
8 is formed.

Therefore, when the capsule of this embodiment is used, the drug 23 is stored in the storage chamber 24 and the capsule body 2 is
1 is implanted in a predetermined site in the living body, and the above-mentioned installation is done through the hole 28.
It is sutured and fixed to the living body using.

Then, the temperature of the mechanochemical substance 26 is increased by inductively heating or dielectrically heating the position where the capsule is embedded using electromagnetic waves such as high frequency waves and microwaves.

As a result, the volume of the mechanochemical substance 26 contracts, and the piston 22 is pulled to release the drug 23 in the storage chamber 24 through the release hole 25 into the living tissue.

Further, the amount of release is determined depending on the degree of heating, and if heating is stopped, contraction of mechanochemical substance 26 is stopped and release of drug 23 is stopped.

This example has the same effects as those of the above example, but furthermore, in this example, the amount of release of the drug 23 and whether or not it is released can be controlled freely from the outside by dielectric heating or induction heating. can be controlled.

Furthermore, by storing an anticancer drug in this capsule, implanting it near the cancerous area, and heating the capsule, chemotherapy and thermotherapy can be performed at the same time, and a high therapeutic effect can be expected.

FIG. 7 shows a fourth embodiment of the present invention. The capsule of this embodiment is provided with a discharge mouthpiece 31 in place of the discharge hole 25 in the third embodiment, and a catheter 32 is connected to this discharge mouthpiece 31, and the extending tip of this catheter 32 is used for therapeutic purposes. It is inserted into a site, for example, the hepatic artery, and the drug 23 is administered thereto. Furthermore, magnetic powder 33 is mixed into the mechanochemical substance 26 .

Therefore, in the case of this capsule, by applying an alternating magnetic field from outside the body, the magnetic powder 33 generates heat, and the mechanochemical substance 26 can be contracted. Thereby, the drug 23 can be administered through the catheter 32 into a treatment target site, for example, into the hepatic artery.

Note that mechanochemical substance 26 is used instead of the magnetic powder described above.
Powder having an acoustic impedance significantly different from that of the material, such as metal powder or ceramic powder, may be mixed.

In this case, when ultrasound is applied from outside the body, the ultrasound is reflected by the powder due to the difference in acoustic impedance.
Attenuation generates heat and mechanochemical substances26
can be heated. In other words, the mechanochemical substance 26 is heated and can contract and release the drug 23 in the same manner as described above.

FIG. 8 shows a fifth embodiment of the present invention. The capsule of this example is intended to be administered orally and to release the drug 3 into the gastrointestinal tract. The basic configuration is the same as that of the first embodiment, except that a spring 35 is provided that biases the piston 2 in a direction to compress the drug 3 in the storage chamber 4. Since the piston 2 receives the biasing force of the spring 35, it can discharge the drug 3 while accurately following the degree of expansion and contraction of the mechanochemical substance 7 and being reliably positioned at a predetermined position. Other effects are similar to those of the first embodiment.

FIG. 9 shows a sixth embodiment of the present invention. 9th
In the figure, 1 is a capsule body made of a material that is harmless to living organisms. The capsule body 1 is formed into a cylindrical shape with both ends closed, and a piston 2 is provided inside the capsule body 1 so as to slide forward and backward in sliding contact with the inner surface thereof.

The internal space on one end side of the capsule body 1 partitioned off by the piston 2 is a medicine storage chamber 4 for storing the medicine 3, and the wall of the capsule body 1 corresponding to this medicine storage chamber 4 has the medicine storage chamber 4. A discharge hole 5 communicating with the outside is formed.

The other chamber separated by the piston 2 forms a working chamber 42 with a partition wall 41, which will be described later, and a circuit chamber 43 is formed within the other end on the working chamber 42 side.

The working chamber 42 is provided with a mechanochemical substance 7 that expands and increases in volume by applying a voltage, as will be described later. This mechanochemical substance 7 is formed into a cylindrical shape as a whole, and one end of the mechanochemical substance 7 in the axial direction is connected to the piston 2.
The other end of the mechanochemical substance 7 is attached to a partition wall 41 provided within the capsule body 1. Further, inside the capsule body 1, the side peripheral surface of the mechanochemical substance 7 is spaced apart from the inner wall surface of the capsule body 1 to form a void 8 around it. In and out holes 9 for digestive juices etc. are provided in the wall of the capsule body 1 in communication with this cavity 8.
are formed in multiple numbers.

Electrodes 44 are provided at both ends of the mechanochemical substance 7, respectively.
．． 45 is attached, through which a voltage is applied to the mechanochemical substance 7. Lead wires 46.47 are connected to the electrodes 44.45. Lead wires 46 and 47 are connected to a switching circuit 48 and a battery 49 installed in the circuit chamber 43.

Further, a receiving circuit 50 and an antenna 51 are installed in the circuit room 43.

When this is used, a medical capsule filled with the drug 3 in the drug storage chamber 4 is orally administered. Then, when radio waves are emitted from outside the body and received by the receiving circuit 5o through the antenna 51, the switching circuit 48 is turned on and the voltage of the battery 49 is applied to the mechanochemical substance 7.

The mechanochemical substance 7 is expanded and stretched by the trowel.

Then, since the piston 2 is pushed, the volume of the drug storage chamber 4 is reduced, and the drug 3 can be compressed and released from the release hole 5 into a body cavity such as the stomach, thereby allowing the drug 3 to be administered.

According to this embodiment, the release of the drug 3 can be controlled by radio waves from outside the body.

It should be noted that the present invention is not limited to the above-mentioned corner embodiments, and various modifications can be made in terms of the structure, application, etc.

〔Effect of the invention〕

As explained above, according to the medical capsule of the present invention,
Since the movable member is driven by a mechanochemical substance, there is no need for a large-scale driving means, the structure can be made simple and compact, and a predetermined operation can be performed reliably. Further, by making the capsule smaller, it is possible to alleviate the pain of the patient, and by simplifying the structure, it is possible to provide an inexpensive medical capsule. Furthermore, it provides various special effects such as the ability to store a large amount of medicine in the capsule and the amount of sample to be collected relative to the external dimensions of the capsule.

[Brief explanation of drawings]

1 and 2 are side sectional views of a first embodiment of the present invention, and FIGS. 3 and 4 are respectively side sectional views of a second embodiment of the present invention.
FIGS. 5 and 6 are side sectional views of the third embodiment of the present invention, and FIG. 7 is a side sectional view of the fourth embodiment of the present invention.
FIG. 8 is a side sectional view of the fifth embodiment of the present invention, and FIG. 9 is a side sectional view of the sixth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Capsule body, 2... Piston, 3... Drug, 5... Release hole, 7... Mechanochemical substance, 9
... Entrance/exit hole, 12... Collection hole, 21... Capsule body, 22... Piston, 23... Drug, 24...
... Storage chamber, 25... Release hole, 26... Mechanochemical substance, 31... Release cap, 32... Catheter, 33... Magnetic powder, 35... Spring. Applicant's representative Patent attorney Jun Tsuboi Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A capsule body, a storage chamber formed within the capsule body and communicating with the outside via a communication path, a movable member that changes the volume within the storage chamber, and a mechanochemical substance that moves the movable member by changing the volume. A medical capsule comprising actuating means for changing the volume of the mechanochemical substance.