DEVICE FOR ADMINISTERING A PHYSIOLOGICALLY ACTIVE SUBSTANCE TO THE GASTRO-INTESTINAL TRACT

Abstract: The invention relates to a device for introducing a physiologically active or diagnostic substance to the gastro-intestinal tract of a human subject in predetermined locations of said tract. The device comprises a capsule containing said substance. The capsule is intended to be swallowed by the subject. The capsule is connected to a line or wire to be swallowed by the subject together with the capsule apart from one end thereof which is to be kept and held outside the subject, by which means the capsule can be stopped and held at said predetermined locations.

Description: Device for administering a physiologically active substance to the gastro-intestinal tract. TECHNICAL FIELD OF THE INVENTION This invention relates to a device for introducing a physio ogically active or diagnostic substance to the gastro-inte tinal tract of a human subject in predetermined locations the tract. The device comprises a capsule containing sa substance, the capsule being intended to be swallowed by t subject. BACKGROUND TO THE INVENTION It may in some cases be desirable to administer a physiologi cally active substance to a specific part of, or location in the gastro-intestinal tract. One reason for this might fo instance be a local treatment of a local inflammation of th bowel, another the administering of a substance to th intestine in conjunction with a subsequent blood test fo testing the local permeability of the intestine. This would b especially important if it should prove to be desirable t minimize the systemic effects. A device for accomplishing such a local administering of drug or substance to the gastro-intestinal tract is disclose in DE-A-29 28 477. This prior art device discloses a capsul containing a substance which can be swallowed by the patien and which can be caused to open at a specific location in th gastro-intestinal tract. The trigger mechanism for opening th capsule may comprise a first wire which may be heated by mean of a high-frequency field applied from outside the patient The first wire is connected to a second wire made of plastic which melts when said first wire is heated. The second wire i connected to a spring which is released when said second wir melts. The compressive force of the spring is utilized to ope the capsule, thus releasing the substance. However, this prior art device suffers from some drawbacks One drawback is that the capsule may have to be tracked b means of ultrasound or X-rays until the desired location i reached each time this location is to be treated. Anothe drawback is that the capsule will not remain in the vicinit of the location to be treated when the substance is bein released since the capsule will continue to move along th gastro-intestinal tract in the normal manner together with th released substance. This means that this prior art device, i used for treatment, mainly would be suitable when fe treatments, each having a comparatively short duration, are t be performed. The short duration of the treatment would i some cases result in that relatively high doses might have t be used, with the concomitant undesirable systemic effects, i order to obtain the pharmacological effects. It further seem difficult to perform these treatments outside a hospital du to the necessity of hospital equipment such as X-ray equipme etc. BRIEF DESCRIPTION OF THE INVENTIVE CONCEPT The present invention aims to create a device of the ki described in the introductory clause of the attached ma claim which also easily can be used for repeated loc treatments of the gastro-intestinal tract which each may performed during a comparatively long period of time, th allowing the substance to act as long as necessary upon t desired location or part of the intestine. This is obtained in that said capsule is connected to a li or wire which is to be swallowed by the patient together wi the capsule apart from one end thereof which is to be kept a held outside the patient, by which means the capsule can stopped and held at said predetermined locations. The capsu is then held at the location as long as is necessary conclude the treatment. The wire then may be cut and wire a capsule then will leave the patient's body through the anus. In a preferred embodiment the capsule is closed initially a is provided with means for opening the capsule at sa predetermined location(s) when triggered by a signal tran mitted though said wire which preferably is electrical conductive. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT In the preferred embodiment the capsule is made of a relative ly stiff plastics material or metal. The material in t capsule preferably should be opaque to X-rays, at least t some extent. The capsule has the general shape of a typica oblong pharmaceutical gelatine capsule comprising two halves one being inserted into the other, the halves thus overlappin each other to a certain extent. A size suitable for swallowin has been found to be a length of 2 - 3 cm and a diameter o about 1 cm corresponding to a volume of about 2 ml. A number of holes are arranged equiangularly around th periphery of each half in their overlapping parts. Th distances between the holes is greater than the diameter o the holes, which means that the holes will be closed in on rotational position of the halves. The holes can be made t register or match when one half is rotated relative to th other, thus opening the capsule and exposing its contents. Th capsule further contains a spring which can be pretensioned t effect said relative rotation of the halves when triggered The spring can be triggered by any kind of a conventiona triggering mechanism which is responsive to an electrica signal and which can be miniatyrized. A thin, very flexible line or wire is attached to one end o the capsule. The line is sufficiently thin, flexible an smooth not to cause nausea when swallowed. The line furthe is made of an electrically conductive material and shoul preferably at least partly be made of a material which i opaque to X-rays. The line may be a thin wire of e.g. copper silver or stainless steel, preferably coated with teflon an may if necessary have two leads for the signal. This secon lead may for instance be necessary for the sake of safety i the triggering device is of a kind requiring a relative high voltage to react. The outside of the line may be provid with scale marks for each centimeter. In use the capsule is swallowed together with a certain amou of the wire, for instance a sufficient amount to allow t capsule to pass the pylorus. The normal peristaltic movemen of the intestine then will move the capsule along the inte tinal tract together with the wire. When the location to treated is reached, the wire is anchored iside or outside t patient, for instance in a tooth of the patient, which mea that the capsule will be stopped at this location. If there no great need for precision, this location may be determin by determining the length of wire the patient has swallowed means of the scale marks on the wire, otherwise an X-r device may have to be used in order to exactly place t capsule at the desired location. Once the capsule has be placed exactly, it is sufficient to note the location of scale mark in relation to some part of the patient's body, e the lips, in order to allow the placing of the capsule to repeated exactly if the treatment is to be repeated on t same patient. Then an electrical signal is sent to the capsule by way of t wire triggering the pretensioned spring which in turn wi rotate one of the two halves of the capsule relative to t other and expose the contents of the capsule to the interi of the intestine. If the capsule contains a contrast medium mixed with the substance in the capsule, it easily can checked if the substance is released correctly by means X-rays. When the capsule has been held at the desired location for period of time which is sufficient to conclude the treatme the wire is simply cut and the capsule will exit the natu way through the anus together with the wire. The advantages of this device are obvious. The treatment be carried out as long as necessary and the dosage per ti unit can be held low, thus minimizing the systemic effect The rate of release can be varied freely since the capsule c be made to remain indefinitely. Once the exact length of wire needed to reach the desir location has been determined, the treatment can be repeat by the patient as often as necessary without any need fo X-ray equipment, thus minimizing the exposure to X-rays. possible harmful influence from the triggering signal may b avoided since the signal can be sent through the insulate wire. POSSIBLE MODIFICATIONS OF THE INVENTION The invention of course can be modified in many ways withi the scope of the appended claims. The line could for instanc comprise optical fibers, thus allowing an optical signal to b sent through the line instead of the electrical signal. In the description of the preferred embodiment the capsul comprises two halves and is opened by means of a rotatio between the two halves, but the capsule of course can open i any other suitable way. The capsule could for instanc comprise two halves slideable longitudinally relative to eac other under the influence of the spring or include a ca lifted by means of a lever system. The capsule also can be made to open automatically indepen dently of any signal from the exterior of the patient. One wa of doing this may be to provide the capsule with a time-sett ing device which provides the signal for opening the capsul after a period of time which is sufficient to guarantee tha the capsule has reached the location to be treated. Anothe way may be to make parts of the shell of the capsule of material, e g gelatine, which dissolves in the gastro-intes tinal tract. The time elapsing until the capsule opens i dependent on the thickness and/or the material of these part of the shell, these factors being chosen such that the capsu has ample time to reach the location to be treated befo dissolving entirely and releasing the substance. The part the capsule to which the line is attached should howev preferably not be dissolvable since this part would facilita the movements of the line through the gastro-intestinal tra when the treatment has been concluded. The shell of t capsule could also be made of a material which dissolves at certain pH. In these latter cases it would also be easy to make the li or wire of a material which will be dissolved in the gastro intestinal tract since the line does not have to be designe for the transmission of a signal. In this case the paramete governing the dissolution of the line should be chosen su that no part of the line is dissolved until a sufficie period of time has elapsed to guarantee that the treatme safely has been concluded.

Claims: CLAIMS : 1. Device for introducing a physiologically active o diagnostic substance to the gastro-intestinal tract of human subject in predetermined locations of said tract, sai device comprising a capsule containing said substance, sai capsule being intended to be swallowed by the subject, c h a r a c t e r i z e d in that said capsule further i connected to a line or wire to be swallowed by the subjec together with the capsule apart from one end thereof which i to be kept and held inside or outside the subject, by whic means the capsule can be stopped and held at said predeter mined locations. 2. Device according to claim 1, c h a r a c t e r i z e d i that said capsule, being closed initially, is provided wit means for opening said capsule at said predetermined location when triggered by a signal. 3. Device according to any one of claims 1 or 2, c h a r a c t er i z e d in that said line or wire is electrically o optically conductive, it thus being possible to transmit sai signal for triggering the opening of said capsule electricall or optically from outside the subject through said line o wire. 4. Device according to any one of claims 1 - 3, c h a r a c t e r i z e d in that said capsule contains a receiver fo receiving signals for triggering the opening of said capsul transmitted magnetically, electromagnetically, ultrasonicall or in any other suitable way through the subjects body. 5. Device according to claim 1 , c h a r a c t e r i z e d i that said capsule has a shell, at least one part thereof bein slowly dissolved in the gastro-intestinal tract, thu releasing the substance after a certain time which i dependent on the dimensions and the material of the shell. 6. Device according to claim 2, c h a r a c t e r i z e d that said signal for opening said capsule is obtained after pre-determined period of time from a time-setting devi contained in said capsule. 7. Device according to any one of the preceding claim c h a r a c t e r i z e d in that said capsule or its conten at least to some degree is opaque to X-rays. 8. Device according to any one of the preceding claim c h a r a c t e r i z e d in that said wire or line at lea to some degree is opaque to X-rays. 9. Device according to anyone of the preceding claim c h a r a c t e r i z e d in that said line or wire provided with scale marks indicating the length of the li or wire.

Inventors: LINDSTROEM KJELL, MAANSSON WIKING, NYBERG LARS, LINDSTROEM, KJELL, MAANSSON, WIKING, NYBERG, LARS
Applicants: ASTRA AB, AKTIEBOLAGET ASTRA
Application year: 1991
Main classification: A61K9
IPC codes: A61M31, A61M37