WO2004047714A1

WO2004047714A1 - Multiple-chamber medical container and method for producing the same

Info

Publication number: WO2004047714A1
Application number: PCT/JP2003/014869
Authority: WO
Inventors: Katsuyoshi Nagao; Koichi Kume
Original assignee: Otsuka Pharmaceutical Factory, Inc.
Priority date: 2002-11-28
Filing date: 2003-11-21
Publication date: 2004-06-10
Also published as: JP4463205B2; JP2006507914A; TWI226234B; WO2004047714A8; TW200412926A; AU2003282391A1

Abstract

A multiple-chamber medical container accordingto the invention, wherein a weak discharge-control seal 21is provided separating a second storage chamber 11 from amedicament outlet 7 and being openable at the time of use,thereby a middle chamber 23 is formed between the weak discharge-control seal 21 and the medicament outlet 7, aliquid medicament is stored in the second storage chamber11, a pathway 25 allowing the second storage chamber 11 to communicate with the middle chamber 23 is formed in theweak discharge-control seal 21, and the pathway 25 allows a passage of gas and preventing a passage of liquid.

Description

DESCEIFT

MUL IPLE-CHAMBER MEDICAL CONTAINER AND METHOD FOR PRODUCING THE SAME

TECHNICAL FIELD

The present invention relates to a medical container and a method for producing the same, the container having multiple chambers for individually storing various unstable medicaments which will deteriorate with time if mixed together, wherein the medicaments stored in the chambers can be mixed together by opening a partition seal separating the chambers.

BACKGROUND OF THE INVENTION

Various multiple-chamber containers as described above have thus far been proposed. A typical example of these is a multiple-chamber container made of plastic film and formed in the shape of a bag. Making use of the plastic film, a weak partition seal to separate the chambers from each other is formed in such a container by heat-sealing the facing surfaces of the film.

While such a multiple-chamber container has the advantage of excelling in safety and hygiene as the mixing operation for the liquid medicaments can be aseptically carried out, there was the following problem. If a infusion tube is connected to a medicament outlet of the multiple-chamber container before opening the weak partition seal to mix the liquid medicaments, then one liquid medicament before mixture may be administered for a patient.

To solve this problem, for example Japanese Unexamined Patent Publication No.1997-327498 discloses a multiple-chamber medical container comprising an outlet of medicament and a weak discharge-control seal that partitions the outlet from an adjoining storage chamber. According to this multiple-chamber container, even in case a infusion tube is accidentally connected to the medicament outlet before opening the weak partition seal, the discharge of liquid medicament from the outlet can be prevented as long as the weak discharge-control seal is not opened.

It is necessary for such multiple-chamber medical container to undergo a heat-sterilization process in the end of production processes, and the process is often conducted either before or after the formation process of the weak discharge-control seal. That is, either of the following two production methods is generally adopted. In the first method, the weak discharge-control seal is formed after injecting a liquid medicament into each chamber, followed by heat- sterilization of the container. In the second method, the container is heat sterilized after filling of liquid medicaments, and subsequently the weak discharge-control seal is formed.

However, according to the first method, there exists so little liquid medicament in a middle chamber formed between the outlet and the weak discharge-control seal. Therefore, no sufficient vapor is generated by heating, and there is a problem in that the sterilization effect in the middle chamber is not fully achieved. In addition, as the weak discharge-control seal is formed after injecting the liquid medicaments, the first and the second method have a common problem in that a small amount of drug solution may adhere to the part where a middle chamber is to be formed. When the weak discharge-control seal is formed under such a circumstance, the product will be shipped while the liquid medicament is adhering to the middle chamber. If a product thus shipped is stored, the moisture of the adhering liquid medicament may transpire through the plastic film, and a crystal may precipitate. In case the crystal remains in the container without dissolving again, it may be administered to a patient together with the liquid medicament.

When opening the weak seal by pressing the container of the above multiple-chamber container, the pressure on the weak seal tends to act around the center of the seal. Accordingly, there may be a case where only the center part of the seal is opened while both ends remain unopened.

If such a situation arises in the weak discharge-control seal, the unopened parts in both ends will become barriers and the flow of the liquid medicament to the medicament outlet will be disturbed, resulting in a problem in that the liquid medicament cannot be smoothly administered. Especially when the weak discharge-control seal 51 is formed arcwise around the medicament outlet 53 and both ends thereof are connected to the circumference 55 of the container body as shown in FIG. 12, the unopened part 51a becomes a barrier so that the liquid medicament in both ends of the container fail to flow into the medicament outlet 53, therefore the all of the medicament may not be satisfactorily administered.

The present invention has been accomplished to solve the problems described above. An object of the present invention is first to provide a multiple-chamber medical container and a method for producing the same, in which a middle chamber between a weak discharge-control seal and a medicament outlet can be sufficiently sterilized and crystals formed from the liquid medicament is prevented from remaining in the middle chamber. Second, an object of the invention is to provide a multiple- chamber medical container wherein the discharge-control seal can be opened without leaving part of it unopened and the liquid medicament in the container can be reliably administered.

DISCLOSURE OF THE INVENTION The first multiple-chamber medical container according to the present invention has been accomplished to solve the above-described problems. The container is characterized in comprising: a container body having multiple storage chambers capable of storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers can communicate with each other at the time of use; wherein a liquid medicament is stored in at least one of the storage chambers, the container body comprises a discharge-control seal separating the storage chamber from the medicament outlet and being openable at the time of use, thereby forming a middle chamber between the discharge-control seal and the medicament outlet, a liquid medicament is stored in at least one of the multiple storage chambers adjoining the discharge-control seal, and a pathway to allow the storage chamber to communicate with the middle chamber is formed in at least one part of the discharge-control seal, the pathway allowing a passage of gas and preventing a passage of liquid.

According to this constitution, moisture that has transpired from the liquid medicament in the storage chamber flows into the middle chamber through the pathway. Therefore excessive dryness of the middle chamber can be prevented, and, for example, evaporation of moisture from the liquid medicament adhered to the middle chamber and the resulting precipitation of a crystal can be prevented. As a result, the crystal from the liquid medicament can be reliably prevented from being administered to a patient.

Such a multiple-chamber medical container is often subjected to heat sterilization in the course of production. As the middle chamber communicates with the storage chamber, the middle chamber is sufficiently sterilized by vapor flowing from the storage chamber even if the discharge-control seal is formed prior to the heat sterilization of the container body, so that all of the interior of the container body can be thoroughly sterilized.

In the above multiple-chamber medical container, the narrowest part of the pathway preferably has a width or diameter of 1 to 5 mm, thereby a free inflow of the liquid medicament from the storage compartment to the middle chamber can be reliably suppressed. Consequently, even if the pathway is formed, quick leakage of the medicament from the storage chamber to the medicament outlet before use can be reliably prevented.

The opening strength required for opening the discharge-control seal can be adjusted to be lower than that of the partition seal, thereby yielding the following effect. The multiple-chamber medical container is generally used in such a manner that the partition seal is opened to mix medicaments in storage chambers and then the discharge-control seal is opened to discharge the mixed medicaments from the outlet. To open the discharge- control seal, it is necessary to press all of the communicating storage chambers so that the pressure acts upon the discharge-control seal. When the opening strength of the discharge-control seal is adjusted to be lower than that of the partition seal, the discharge- control seal can be easily opened even in the case the area to be pressed is large, as pressing all of the storage chambers. "Opening strength" denotes the strength required for removing a part of each seal so that chambers partitioned with the seal can communicate with each other.

In addition, the discharge-control seal may be formed substantially arcwise around the medicament outlet in such a manner that both ends thereof are connected to the circumference of the container body in proximity to the medicament outlet. This enables a downsizing of the discharge-control seal so that the pressure for opening can work with efficiency. When the pathway is formed in proximity to the circumference of the container body here, the following advantage can be achieved. Since the pathway is not sealed, in many cases the discharge-control seal is opened firstly from the neighborhood of pathway when the internal pressure of storage chamber is raised. Therefore, the above-described constitution can prevent the formation of an unopened part to be a barrier of the flow of liquid in the neighborhood of pathway, i.e. the circumference of the container body. Consequently, even if the liquid medicament in the container body has decreased during use, the medicament flows along with the circumference toward the outlet, and then almost all of the liquid medicament can be discharged without waste.

The multiple-chamber medical container can be produced by the following two methods. That is, the multiple-chamber medical container may be produced by a method comprising the steps of: sealing the circumference of the container body except a medicament inlet part; forming the partition seal to provide multiple storage chambers; injecting a medicament into each of the storage chambers; sealing the medicament inlet part; forming the discharge-control seal having the pathway; and heat- sterilizing the container body after the formation of the discharge-control seal. The multiple-chamber medical container may also be produced by a method comprising the steps of: sealing the circumference of the container body except a medicament inlet part; forming the partition seal to provide multiple storage chambers; injecting a medicament into each of the storage chambers; sealing the medicament inlet part; heat-sterilizing the container body; and forming the discharge-control seal having the pathway after the heat-sterilization. The medicament outlet can be provided in the above medicament inlet part, and the medicament can also be injected into the storage compartment therefrom.

The second multiple-chamber medical container according to the present invention is a multiple-chamber medical container comprising: a container body having multiple storage chambers for storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers can communicate with each other at the time of use; wherein the container body comprises a discharge-control seal that connect to the circumference of the container body to separate the storage chamber from the medicament outlet and is openable at the time of use, and one end or both ends of the discharge-control seal have a narrower width than that of the center part thereof.

According to the above constitution, an end part of the discharge-control seal has a narrower width than that of the center part, so that it is easier to open the end part than the center part, for example when the same pressure is applied. When the pressure of pressing the container body acts greatly on the center part of the discharge-control seal while acting a little on the end part, an unopened part may remain sometimes. However, according to the above-described constitution, the end part can be opened even if the pressure is weak, so that the unopened part as a barrier of medicament outflow does not remain in the circumference of the container body. As a result, remaining of a part of the medicament due to the unopened part as a barrier is prevented and the medicament can be reliably discharged from the medicament outlet. In the above case, only one of both ends of the discharge- control seal may have a narrower width. However, in order to discharge the medicament smoothly without any unopened part, it is preferable to adjust both ends to have narrower widths. "Center part" of the discharge-control seal in the specification denotes a part in or near a center except both ends that tend to remain sealed without being broken at the time of opening. The third multiple-chamber medical container according to the present invention is a multiple-chamber medical container comprising: a container body having multiple storage chambers for storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers can communicate with each other at the time of use; wherein the container body comprises a discharge-control seal that connect to the circumference of the container body to separate the storage chamber from the medicament outlet and is openable at the time of use, and at least one end of the discharge- control seal has a sealing release strength per unit length in the longitudinal direction of the discharge- control seal that is lower than that of the center part.

According to the above constitution, an end of the discharge-control seal has lower sealing release strength than that of the center part, so that it is easier to open the end than the center part when the same pressure is applied. Accordingly, the similar effect as the second multiple-chamber medical container can be achieved. "Sealing release strength" used here denotes the strength required for removing a seal per unit length of the discharge-control seal. For example, in the case of forming the discharge-control seal by heat-sealing of film surfaces, the sealing release strength can be expressed as strength measured by a method based on JIS- Z0238.

In order to adjust the sealing release strength of one end of the discharge-control seal so as to make it lower than that of the center part in the above multiple- chamber medical container, for example, the following production process may be adopted. In the production of the container body from plastic films and the formation of the discharge-control seal by heat-sealing the facing films, two pairs of molds are used to sandwich the facing films. Specifically, a pair of first molds are used to heat-seal one or both end(s) of the discharge-control seal, and a pair of second molds are used to heat-seal the center part, and the discharge-control seal is formed by heat-sealing with the interval between the pair of first molds adjusted to be longer than that between the pair of second molds.

As the heat-sealing is carried out with the interval between the pair of first molds to form the end of the seal adjusted to be longer than that between the pair of second molds to form the center part, the pressure acting upon the end part during heat-sealing becomes lower than that of the center part. Consequently it is ensured that the sealing strength of the end part becomes lower than that acting upon the center part, and thus the sealing release strength of the end part can be reliably adjusted to be lower than that of the center part.

In addition, for example the following production process may be adopted to adjust the sealing release strength of an end of the discharge-control seal so as to make it lower than that of the center. In the production of the container body from plastic films and the formation of the discharge-control seal by heat- sealing the facing films, at least one heating is conducted as to an identical position for heat-sealing and the frequency of heating of one or both end(s) of the discharge-control seal is adjusted to be lower than that of the center part. Consequently, the less-heated end part has lower sealing release strength than that of the center part and can be opened with less power than that of center part.

Moreover, the following production process may be adopted. In the production of the container body from plastic films and the formation of the discharge-control seal by heat-sealing the facing films, the sealing temperature of one or both end(s) of the discharge-control seal is adjusted to be lower than that of the center part.

Thereby the end of the discharge-control seal has lower sealing release strength than that of the center part and can be opened with less power than that of the center part,

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view showing the first embodiment of the multiple-chamber medical container according to the present invention. FIG. 2 shows a method for producing the multiple-chamber medical container according to FIG. 1.

FIG. 3 is a plan view showing other example of the multiple-chamber medical container according to FIG. 1.

Fig. 4 is a plan view showing other example of the multiple-chamber medical container according to FIG. 1.

Fig. 5 is a plan view showing the second embodiment of the multiple-chamber medical container according to the present invention.

Fig. 6 is a plan view showing other example of the multiple-chamber medical container according to FIG. 5.

Fig. 7 is a plan view showing other example of the multiple-chamber medical container according to FIG. 5.

Fig. 8 is a plan view showing other example of the multiple-chamber medical container according to FIG. 5. Fig. 9 is a plan view showing other example of the multiple-chamber medical container according to FIG. 5.

Fig. 10 is a cross-sectional view showing an example of mold for forming the discharge-control seal in the multiple-chamber medical container according to FIG. 5.

FIG. 11 is a plan view showing a modified example of the multiple-chamber medical container according to the second embodiment.

Fig. 12 is a plan view showing a known multiple- chamber medical container.

BEST MODE FOR CARRYING OUT THE INVENTION

(First embodiment)

The first embodiment of the multiple-chamber medical container according to the present invention will be illustrated below with reference to the figures. FIG.

1 is a plan view showing the multiple-chamber medical container according to the present embodiment.

As shown in Fig. 1, a multiple-chamber medical container 1 comprises a container body 5 formed in the shape of rectangle by heat-sealing the circumferences 3 of two sheets of water-vapor-permeable plastic film and an outlet 7 of medicament that is connected to the container body 5 and has a rubber plug inside thereof. The container body 5 has a first chamber 9 and a second chamber 11 which are disposed in order in the longitudinal direction and store medicaments, and the two chambers 9 and 11 are separated from each other by a weak partition seal (partition seal) 13. The medicament outlet 7 is connected to the second chamber 11, and a suspension hole 17 for hanging the container 1 is located on the end of the container body 5 opposite to the medicament outlet 7.

The weak partition seal 13 is formed by heat- sealing the inner surfaces of two facing films of container body 5 and extends in a direction substantially vertical to the longitudinal direction of the container 5. The weak partition seal 13 separates two storage chambers 9 and 11 from each other before use, and is formed with such sealing strength that it can be opened by increasing the inner pressure of the storage chamber at the time of use.

A weak discharge-control seal (discharge-control seal) 21 is formed between the second storage chamber 11 and the medicament outlet 7 to interrupt the passage of medicament therebetween. The weak discharge-control .seal 21 is formed arcwise around the medicament outlet 7 and both ends thereof are connected to the circumference 3 of the container body 5 in proximity to the medicament outlet 7. Thereby a middle chamber 23 is formed in the shape of semi-circle between the weak partition seal 21 and the medicament outlet 7.

A pathway 25 having narrow width is arranged at the top part of the arc of weak discharge-control seal 21, and the second storage chamber 11 and the middle chamber 23 communicate with each other via the pathway 25. The width of the pathway 25 is preferably 1 to 5 mm so that the gas passage can be allowed between the storage chamber 11 and the middle chamber 23 and the inflow of liquid medicament from the second storage chamber 11 into the middle chamber 23 can be inhibited by the inner pressure of the middle chamber 23. The weak discharge-control seal 21 is formed in a similar way to the weak partition seal 13 by heat- sealing the inner surfaces of two facing films of container body 5. The weak discharge-control seal 21 is provided in such a manner as to be openable by increasing the inner pressures of the storage chambers 9 and 11, and the opening strength thereof is adjusted to be smaller than that of the weak partition seal 13.

Material of the films constituting the container body 5 may be selected from various resins, such as polyethylene, polypropylene, polystyrene, and like thermoplastic resins. In addition, not only a single- layered film but also a multi-layered film can be employed. For example, a film having three layers can be used, in which the inner and outer films are made of polyolefin such as polyethylene, polypropylene and the like, and the middle layer is made of cyclic olefin-based polymer. Each of the chambers 9 and 11 contains a medicament a or b respectively, which need to be separated because changes with time such as Maillard reaction occur when mixed or dissolved together in advance. Combination of medicaments to be stored in each chamber is not particularly limited, but at least it is necessary that the second storage chamber contain a liquid medicament. The reason will be described later in this specification. As an example of medicaments to be stored in storage chamber 9 or 11, the first storage chamber 9 may contain powders such as antibiotics and the second storage chamber 11 may contain a solution such as physiological saline. In addition, the first storage chamber 9 may contain an amino acid solution and the second storage chamber 11 may contain a mixture of sugar and an electrolytic solution. Alternatively, the first storage chamber 9 may contain a mixture of sugar and a fat emulsion and the second storage chamber 11 may contain a mixture of an amino acid solution and an electrolytic solution. Illustrated below is the use of the multiple- chamber medical container having above-mentioned constitution. In order to administer a medicament from the multi-chamber container 1 to a patient, firstly the pressure is applied on the first storage chamber 9 by pressing with a hand or the like to increase the internal pressure of the storage chamber. Thereby the weak partition seal 13 is opened so that the first storage chamber 9 and the second storage chamber 11 communicate with each other, and the medicaments in each chamber 9 and 11 are mixed together. After a needle with infusion tube is inserted into the rubber plug within the medicament outlet 7, the first and second chambers 9 and 11 are pressed overall to increase the internal pressure of the communicating chambers 9 and 11, and then the weak discharge-control seal 21 is opened. In this case, the needle may be inserted into the plug after opening the weak discharge-control seal 21. In this manner, the mixed medicaments in the container 1 are administered from the outlet 7 through the infusion tube to a patient.

Since the opening strength of the weak discharge-control seal 21 is adjusted to be lower than that of the weak partition seal 13, the following advantages can be achieved. As stated above, in the container 1 the weak partition seal 13 is opened to mix two medicaments and then the weak discharge-control seal 21 is opened. Here, only the first storage chamber 9 is need to be pressed to open the weak partition seal 13, while both of the first chamber 9 and second chamber 11 should be pressed to open the weak discharge-control seal 21. Accordingly, for example, it is harder to open the weak discharge-control seal 21 when the opening strengths of seals 13 and 21 are same, because the area to be pressed is large so that higher strength is necessary than that to open the weak partition seal 13. Therefore, when the opening strength of the weak discharge-control seal 21 is arranged to be lower as described above, easy open can be achieved even if the area to be pressed is large.

In the next place, a method for producing the multiple-chamber medical container will be described referring to FIG. 2. Here, a method for producing the second storage chamber 11 is described, omitting the first storage chamber 9. The multiple-chamber container of FIG. 1 is illustrated upside down in FIG. 2.

First, only fringes on both sides of the container body circumference 3 are heat-sealed, and then the weak partition seal 13 is formed with a lower sealing strength by heat-sealing (FIG. 2(a)). Second, the medicament outlet 7 is attached to the extremity of the container body 5 and the container body circumference 3 is sealed by heat-sealing (FIG. 2(b)). After injecting a liquid medicament from the medicament outlet 7, a rubber plug (not shown) is inserted into the medicament outlet 7 to stopper (FIG. 2(c)). Subsequently the weak discharge- control seal 21 is formed to surround the medicament outlet 7 by heat-sealing (FIG. 2(d)), and then the container body 5 is sterilized by heating. In the case of the first storage chamber 9, a hole for medicament injection is formed instead of arranging the medicament outlet 7 in FIG. 2(b), a medicament is injected into the hole and the hole is filled by heat-sealing, thereby providing the first storage chamber 9.

According to the embodiment described above, the narrow pathway 25 is arranged at the weak discharge- control seal 21 provided between the second storage chamber 11 and the medicament outlet 7. Since the pathway 25 allows a passage of gas but prevents a passage of liquid, the following hitherto known problem can be solved. In the production process, the container body 5 is heated to sterilize the interiors of storage chambers 9 and 11 by a vapor evaporated from a liquid medicament. However, in many cases there exists so little liquid medicament in the middle chamber 23 that even if the container body 5 is heated no vapor is generated in the middle chamber 23, and therefore the sufficient sterilization of the interior of middle chamber 23 is not ensured heretofore.

In contrast, according to the multiple-chamber medical container of the present embodiment, a liquid medicament is stored in the second storage chamber 11 adjoining the weak discharge-control seal 21 as well as the gas-permeable pathway 25 is provided at the weak discharge-control seal 21, and consequently a vapor generated in the second storage chamber 11 can be flew into the middle chamber 23. As a result, the interior of middle chamber 23 can be sufficiently sterilized. Since the liquid medicament does not pass through the pathway 25, the medicament within the second storage chamber 11 will not flow out toward the medicament outlet 7 until the weak discharge-control seal 21 is opened. Moreover, there has been another problem as follows. When a liquid medicament is injected as in FIG. 2 (c) , sometimes a slight amount of medicament may adhere to the proximity of the medicament outlet 7 and the medicament may remain within the middle chamber 23 after the weak discharge-control seal 21 is formed as shown in FIG. 2(d). In this case, the water content may evaporate from the medicament within the middle chamber 23 during storage of the container and a crystal may precipitate. If the crystal remains there, there is a possibility that the crystal may be administered to a patient together with the liquid medicament.

On the other hand, according to the multiple- chamber medical container of this embodiment, vapor within the second storage chamber 11 can flow into the middle chamber 23. Therefore, the water content is hardly evaporate even if a medicament adheres to the middle chamber 23, preventing the precipitation of crystal in the middle chamber 23. In addition, even if the medicament remains in the middle chamber 23, its amount is so slight that there arises no problem and the medicament may gradually transfers into the second storage chamber 11 when stored with the medicament outlet 7 turned upward.

Although the pathway 25 is located at the top part of the weak discharge-control seal 21 in the above embodiment, it can also be arranged in the proximity of the circumference 3 of the container body 5 as shown in FIG. 3(a) and 3(b). In this case, the following advantage can be achieved. As the pathway 25 is not heat-sealed, when increasing the inner pressures of the storage chambers 9 and 11, the weak discharge-control seal 21 is frequently opened from the proximity of the pathway 25. Therefore, the above constitution can prevent the formation of an unopened part in the proximity of the pathway 25, i.e. the container body circumference 3, which will become a barrier of the flow of liquid medicament. Consequently, even if an unopened part remains when the liquid medicament in the container body 5 has decreased during use, the medicament to stay in the container due to the unopened part can be minimized and almost all of the liquid medicament can be discharged out from the container via the outlet 7 without waste as shown in Fig. 3(c).

Although the weak discharge-control seal 23 is arranged arcwise in the above embodiment, the shape is not particularly limited. For example, the weak discharge- control seal may be shaped semi-ellipse, substantially arcwise having squared corners, or linear to link both sides of the container body 5 as shown in FIG. 4. The pathway 25 does not necessarily have a uniform width and has only to prevent a passage of liquid. Especially, when the width of the narrowest part is 1 to 5 mm, such effect can be fully achieved. The pathway 25 may be provided not only in one position but in two or more positions, as long as a passage of medicament is inhibited. (Second embodiment)

The second embodiment of the present invention will be illustrated below with reference to the figures. FIG. 5 is a plan view showing the multiple-chamber medical container according to the present embodiment. The present embodiment is different from the first embodiment in the constitution of the weak discharge-control seal. Since the other constitutions are same as that of the first embodiment, the same reference numerals are given thereto and the description thereof is omitted.

As shown in FIG. 5, the weak discharge-control seal 21 is formed to have a width differential in this embodiment so that both end parts 21a have narrower widths than that of the center part 21b. Accordingly, for example when the same pressure is applied, it is easier to open the both ends 21a than the center part 21b. As an example of such width differential, both end parts 21a preferably have a width that is 10 to 80 % of that of the center part 21b.

According to such constitution, the following advantage can be achieved. Generally the force to exert on the weak discharge-control seal 21 when pressing the container body 5 sometimes act on the center part 21b greatly while less on the end part 21a, thereby an unopened part remains. On the other hand, according to the above constitution, the widths of both end parts 21a of the weak discharge-control seal 21 are narrower than that of the center part 21b, and therefore the end parts 21b can be opened even if the force to exert thereon is small, ensuring that all of the weak discharge-control seal 21 is opened. Consequently an interruption of medicament flow due to an unopened part remaining in the container body circumference 3 is prevented, thereby precluding a part of medicament from remaining in the container body 5. As a result, a medicament can be reliably discharged from the medicament outlet 7, making sure that a suitable amount of medicament is administered to a patient.

Other than providing a width differential as described above, the following can be done to set both ends 21a of the weak discharge-control seal easier to be opened than the center part 21b. For example, the width of the seal may also be gradually turned narrow as it extends from the center part to both ends as shown in FIG. 6(a). The shape of the weak discharge-control seal 21 is not limited to an arc. For example, the seal may be shaped into a polygon, and both end parts 21a to connect to the container body circumference 3 may be arranged narrower as shown in FIG. 6(b).

In the above description, the both ends 21a of the weak discharge-control seal 21 are connected to a lower edge 3a of the circumference 3 where the medicament outlet 7 is located. However, the both ends 21a may also be connected to both of side edges 3b as shown in FIG. -7. It is also necessary in this case to set the both end parts 21a connected to the both of side edges 3b to have narrow widths . Both ends 21a may be narrowed by a width differential as shown in FIG. 7(a). The seal may also be narrowed gradually as it extends from the center part 21b to both ends 21a as in FIG. 7(b). Alternatively, as shown in FIG. 8, one of the ends 21a of the weak discharge- control seal 21 may be connected to the lower edge 3a where the medicament outlet 7 is provided, and the other end to the side edge 3b. Although both ends 21a of each weak discharge-control seal 21 have a narrower width in the above, only one of the two ends may also have a narrow width. However, in order to avoid an unopened part reliably, it is preferred to narrow the both ends.

In the above-described multiple-chamber medical container, the width of the weak discharge-control seal 21 is adjusted so that the both ends thereof are easily opened. However, easier opening of the both ends can also be achieved by changing the sealing conditions of the center part and both ends with their width kept same. For example as shown in FIG. 9(a), the heat sealing can be carried out with a mold to form the weak discharge-control seal 21, at the sealing temperature of both ends 21a lower than that of the center part 21b. Specifically, the center part 21b can be referred to as a high-temperature sealed part while the both end parts 21a as a low- temperature sealed part. The difference in the sealing temperature is preferably 0.3 to 10 °C, and thereby the sealing release strength of both ends 21a can be set smaller than that of the center part 21b.

"Sealing release strength" denotes the strength that can release the sealed state per unit length in the longitudinal direction of the weak discharge-control seal 21, i.e. the strength at the time the surfaces of two sealed films separate from each other. The sealing release strength can be expressed, for example as a peeling strength shown in JIS-Z0238. The peeling strength denotes the strength required for separating two film surfaces that are heat-sealed by a weak seal having a width of 15 mm. In this case, it is preferred that the peeling strength of the center part 21b of the weak discharge-control seal 21 is 1 to 7 N/15mm and the peeling strength of its both ends 21a is 25 to 90% of that of the center part. In addition, the sealing release strength of both ends 21a can be lowered also by decreasing the sealing frequency of both ends 21a than that of the center part 21b. In this case, for example as shown in FIG. 9(b), the whole weak discharge-control seal 21 can be formed by using an arc-shaped mold in the first heat-sealing, and only the center part can be sealed with a mold having plural dots in the second heat-sealing. The second mold may not be a dot type but may form a part of an arc. The sealing release strength of center part 21b can be heightened and the sealing release strength of both ends 21a can be lowered also by this method. Each position may be heat-sealed for more than two times.

As shown in FIG. 10, the sealing release strength can be adjusted by varying the thickness of the mold. That is, a pair of molds 41 for forming the weak discharge-control seal 21 is provided in such a manner as to consist of the first molds 41a for forming both end parts 21a and the second molds 41b for forming the center part 21b and the second mold 41b is provided thicker than the first mold 41a. Accordingly the distance between the molds is different between the end parts and the center part, and the sealing strength of both end parts 21a having a further distance between the molds becomes smaller when the heat-sealing is carried out. Therefore, the sealing release strength of the both ends 21a can be adjusted smaller than that of the center part 21b. The difference in thickness between the first mold 41a and the second mold 41b is preferably 20 to 80 μm.

The above-described constitution of the weak discharge-control seal 21 is applicable to the multiple- chamber container of the first embodiment. As shown in FIG. 11, a pathway is provided at the center part of the weak discharge-control seal and the both end parts 21a can be provided as to have a narrower width than that of the center part 21b. In addition, the pathway shown in the first embodiment can be formed at the weak discharge- control seal shown in FIGs. 6 to 9, where the both end parts 21a are opened more easily than the center part 21b. Although the present invention has been described above with reference to the above embodiments, the invention is not limited to these embodiments but can be modified variously without departing from the gist of the invention. For example, the weak partition seal 13 and the weak discharge-control seal 21 are prepared by heat-sealing of films in each of the above embodiment. However, the seal portions of the invention are not limited thereto and various modes can be employed as long as they are openable by the action of force from outside. The sealing portion may be provided, for example, by preparing a convex portion and a concave portion respectively on the surfaces of facing films of container body 5 and subjecting them to separable concavo-convex interdigitation. In other case, a membrane for partition having a part thinner than the other parts is provided, and the thin part is prepared in such a manner as to be broken by a pressure to allow the two storage chambers to communicate with each other. And the effect of the present invention can be obtained when a pathway allowing a gas passage and preventing a liquid passage is provided at such a seal. Especially, it is preferable when the narrowest part of the pathway has a width or diameter of 1 to 5 mm.

The number of the storage chambers is not limited to two as above, but may be three or more. In this case, the storage chambers should be just separated from each other by partition seals.

In the production method of the above embodiment, heat-sterilization of the container body 5 is carried out after forming the weak discharge-control seal (discharge- control seal) 21. However, the reverse can be done, i.e. the weak discharge-control seal 21 is formed after the heat-sterilization of the container body 5, in which the same effect as above can attained. Specifically, even if a liquid medicament is adhered to the interior of the middle chamber 23, as the second chamber 11 and the middle chamber 23 communicate with each other, the precipitation of a crystal due to dryness of middle chamber 23 can be prevented.

INDUSTRIAL APPLICABILITY The present invention provides a multiple- chamber medical container and a method for producing the same, wherein a middle chamber between a discharge-control seal and a medicament outlet can be sufficiently sterilized and a crystal from liquid medicament is reliably prevented from remaining in the middle chamber. The present invention also provides a multiple-chamber medical container and a method for producing the same, wherein the discharge-control seal can be opened without leaving an unopened part and the liquid medicament in the container can be administered reliably.

Claims

1. A multiple-chamber medical container comprising: a container body having multiple storage chambers capable of storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers may communicate with each other at the time of use; wherein the container body comprises a discharge-control seal separating the storage chamber from the medicament outlet and being openable at the time of use, thereby forming a middle chamber between the discharge-control seal and the medicament outlet, a liquid medicament is stored in at least one of the multiple storage chambers adjoining the discharge- control seal, and a pathway allowing the storage chamber to communicate with the middle chamber is formed in at least one part of the discharge-control seal, the pathway allowing a passage of gas and preventing a passage of liquid.

2. The multiple-chamber medical container according to claim 1, wherein the narrowest part of the pathway has a width or diameter of 1 to 5 mm.

3. The multiple-chamber medical container according to claim 1 or 2, wherein the discharge-control seal has a lower opening strength than that of the partition seal.

4. The multiple-chamber medical container according to claim 1, wherein the discharge-control seal is formed substantially arcwise around the medicament outlet and both ends thereof are connected to the circumference of the container body in proximity to the medicament outlet.

5. The multiple-chamber medical container according to claim 4, wherein the pathway is formed in proximity to the circumference of the container body.

6. The multiple-chamber medical container according to claim 4, wherein one end or both ends of the discharge-control seal have a narrower width than that of the center part thereof.

7. The multiple-chamber medical container according to claim 4, wherein at least one end of the discharge-control seal has a sealing release strength per unit length in the longitudinal direction of the discharge-control seal that is lower than that of the center part.

8. A method for producing the multiple-chamber medical container according to claim 1, comprising the steps of: sealing the circumference of the container body except a medicament inlet part; forming the partition seal to provide multiple storage chambers; injecting a medicament into each of the storage chambers; sealing the medicament inlet part; forming the discharge-control seal having the pathway; and heat-sterilizing the container body after the formation of the discharge-control seal.

9. A method for producing the multiple-chamber medical container according to claim 1, comprising the steps of: sealing the circumference of the container body except a medicament inlet part; forming the partition seal to provide multiple storage chambers; injecting a medicament into each of the storage chambers ; sealing the medicament inlet part; heat-sterilizing the container body; and forming the discharge-control seal having the pathway after the heat-sterilization.

10. A multiple-chamber medical container comprising: a container body having multiple storage chambers for storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers may communicate with each other at the time of use; wherein the container body comprises a discharge-control seal that connect to the circumference of the container body to separate the storage chamber from the medicament outlet and is openable at the time of use, and one end or both ends of the discharge-control seal have a narrower width than that of the center part thereof.

11. A multiple-chamber medical container comprising: a container body having multiple storage chambers for storing medicaments and a partition seal separating the storage chambers from each other; a medicament outlet attached to the container body for allowing the medicaments to be discharged from one of the storage chambers; and the partition seal being openable so that the storage chambers may communicate with each other at the time of use; wherein the container body comprises a discharge-control seal that connect to the circumference of the container body to separate the storage chamber from the medicament outlet and is openable at the time of use, and at least one end of the discharge-control seal has a sealing release strength per unit length in the longitudinal direction of the discharge-control seal that is lower than that of the center part.