JP2019188036A - Freeze-drying container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freeze-drying container which can be molded by a blow molding technique, has excellent cooling efficiency, and is not deformed during cooling. A container for freeze-drying has an inner layer containing at least a cyclic polyolefin resin and an intermediate layer containing an ethylene-vinyl alcohol copolymer. The height dimension A of the pinch-off portion formed on the bottom surface is 0.5 mm ≦ A ≦ 1.5 mm, the thickness B of the bottom portion at the pinch-off portion is 0.5 mm ≦ B ≦ 1.5 mm, and 1.0 mm ≦ A + B ≦ 2 It is 0.2 mm. The thickness G of the intermediate layer is 10 μm ≦ G ≦ 220 μm. When the length dimension of the pinch-off portion is D and the dimension (diameter) of the bottom recess is E, 0.5E <D <E. As the layer structure, for example, an outer layer containing a cyclic polyolefin-based resin is provided outside the intermediate layer, and an inner layer and an intermediate layer, and an outer layer and an intermediate layer are bonded by an adhesive layer, and the adhesive layer is maleic anhydride. A cyclic polyolefin resin obtained by graft polymerization of is included. [Selection diagram]

Description

  The present invention relates to a freeze-drying container capable of lyophilizing contents such as a chemical solution in the container.

  A freeze-dried medicine is filled in a container called a vial aseptically with a chemical solution for freeze-drying through a sterilization filter in a sterile room or clean room, and heat is conducted from the bottom of the container in the freeze-dryer. It is frozen by cooling. Thereafter, the vial is half-capped and dried under reduced pressure. After drying, the vial is completely capped to obtain a freeze-dried drug-containing vial.

  As a bottom flat container for freeze-drying a chemical using a freeze-drying line, for example, Patent Document 1 discloses an upper half formed with an opening to which a stopper can be semi-plugged, and the above chemical The container for freeze-drying is described in which the lower half to be stored and freeze-dried is separably provided.

  Conventionally, glass vial containers and ampoule containers have been used as containers for storing freeze-dried drugs such as antibiotics and protein preparations. However, in the freeze-drying container described in Patent Document 1, a stopper is used. By providing the upper half formed with an opening that can be half-plugged and the lower half that is stored and lyophilized by storing chemicals, it is possible to use materials other than glass, and The freeze-dried product can be easily and aseptically transferred into a medical container.

Japanese Patent Laid-Open No. 10-328270

  By the way, as medical containers filled with various chemical solutions, for example, blow molded bottles and blow molded bags made of plastic are blown, and in recent years, medical containers called the vials have been used. Containers are also being manufactured by blow molding techniques. According to blow molding, it is possible to efficiently produce a container, and it is expected that the manufacturing cost of the vial can be greatly reduced.

  However, in the medical container, the requirements regarding performance such as chemical resistance, chemical adsorption resistance, gas barrier property, and steam sterilization resistance are stricter than that of a general container. Strength is also required.

  In addition, especially in the case of the vial used for the freeze-drying, in addition to these requirements, it has excellent thermal conductivity with respect to the contents, the contents of the vial are cooled quickly, and the vial is not deformed upon cooling, Etc. are also required.

  Under such circumstances, it has been considered difficult to use blow-molded containers as freeze-drying containers. For example, blow molded bottles must have a pinch-off part that protrudes toward the outside of the container, so the shape of the bottom of the bottle must be recessed, and the grounding part of the bottom is only the outer peripheral part. This is because the ground contact area is small and the efficiency at the time of cooling in the freeze-drying line that cools from the bottom surface is poor.

  The present invention has been proposed in view of the above-described conventional situation, and provides a freeze-drying container that can be molded by blow molding technology, has excellent cooling efficiency and does not deform during cooling. The purpose is to do.

  In order to achieve the above object, the present inventors have made various studies over a long period of time. As a result, we came to the knowledge that it is possible to realize a freeze-drying container that is comparable to a glass vial by optimizing the materials used, layer structure, bottom shape, dimensions, etc. .

  The freeze-drying container of the present invention has been devised based on such knowledge, and has freeze-drying having an inner layer containing at least a cyclic polyolefin-based resin and an intermediate layer containing an ethylene-vinyl alcohol copolymer. The height A of the pinch-off part formed on the bottom surface is 0.5 mm ≦ A ≦ 1.5 mm, the thickness B of the bottom part of the pinch-off part is 0.5 mm ≦ B ≦ 1.5 mm, and 1 0.0 mm ≦ A + B ≦ 2.2 mm, and the thickness G of the intermediate layer is 10 μm ≦ G ≦ 220 μm.

  According to the present invention, it is possible to provide a freeze-drying container that can be blow-molded, has excellent cooling efficiency, and does not deform during cooling.

It is a figure which shows a freeze dryer typically. It is a schematic front view which shows the container for freeze-drying concerning embodiment of this invention. It is a schematic sectional drawing of the container for freeze-drying shown in FIG. It is a bottom view which shows the shape of the bottom face of the container for freeze-drying shown in FIG. It is an expanded sectional view of the bottom face vicinity of the freeze-drying container shown in FIG.

  Hereinafter, embodiments of a freeze-drying container (vial) to which the present invention is applied will be described in detail with reference to the drawings.

  First, lyophilization applied to the vial of this embodiment will be described. As shown in FIG. 1, the freeze dryer 50 includes a freeze dryer (vacuum chamber) 51, a cooling / heating device 52, an exhaust device 53, a cooling device 54, and a vacuum pump 55. The freeze-drying store | warehouse | chamber 51 is equipped with the cooling heating shelf 57 for mounting and cooling the freeze-drying container (vial) 1 to freeze-dry. The exhaust device 53 includes a cold trap 58 that adheres and solidifies sublimated water vapor.

  The lyophilization process of the drug using the lyophilizer 50 will be described. First, the freeze-drying container 1 containing the drug is set in the lyophilizer 50 at room temperature (20 ° C.), and the drug solution is thoroughly frozen by preliminary freezing. (For example, in the case of pharmaceuticals, cool to about -45 ° C. and keep it cool for about 3 hours). Next, sublimation drying is performed as primary drying. This is a process of drying a frozen chemical solution in a vacuum. Here, sublimation proceeds at a slow rate. Finally, the bound water is removed as secondary drying. This is a process of subliming water as ice and then removing the bound water as a finishing finish. Here, heating is performed up to the allowable temperature of the drug, and the vacuum is improved to increase the dryness of the drug. The above is the basic process of lyophilization, and the lyophilization container 1 is deprived of heat from the cooling and heating shelf 57 through the bottom contact surface with high thermal conductivity.

  The freeze-drying container 1 of the present invention is used for freeze-drying as described above, and has a form suitable for freeze-drying. Hereinafter, the configuration of the freeze-drying container 1 of the present embodiment will be described.

  As shown in FIGS. 2 and 3, the freeze-drying container 1 of the present embodiment has a form having a mouth 3 above the body 2, and an annular flange 4 around the mouth 3. Is formed. When the mouth 3 is used as a vial, for example, a lid such as a rubber stopper is attached. The freeze-drying container 1 is formed by, for example, blow molding, and the bottom portion 5 has a concave shape that is recessed inward, and the central portion thereof is cut by a mold at the time of molding. The linear pinch-off part 6 formed in this manner is formed so as to protrude from the bottom part 5.

  The freeze-drying container 1 has a multilayer structure, and in this example, three layers of an inner layer, a barrier layer (intermediate layer), and an outer layer are laminated, and an adhesive layer for adhesion is provided between each layer. It has a total of 5 layers. The layer configuration is not limited to this, and may be a configuration in which more layers are stacked, or a stacked configuration with a smaller number of layers.

  In the laminated structure, the inner layer is formed of a cyclic polyolefin resin. The cyclic polyolefin resin has a low drug adsorptivity, and by using the cyclic polyolefin resin for the inner layer, the adsorption of the drug contained in the chemical solution filled in the freeze-drying container 1 can be minimized. Moreover, since cyclic polyolefin-type resin is highly transparent, if this is used for an inner layer and an outer layer, the transparency of the freeze-drying container 1 as a whole can be ensured.

  The cyclic polyolefin resin used for the inner layer is a resin having at least a polymerizable cyclic olefin having an ethylenic double bond in the ring as a polymerization component, and the cyclic olefin as a polymerization component is a monocyclic olefin. It may be a polycyclic olefin.

  As the cyclic olefin, any known one can be used, but typical ones are norbornenes, cyclopentadiene, dicyclopentadiene, and further obtained by condensation of norbornene and cyclopentadiene. A polycyclic olefin etc. can be illustrated.

  The cyclic polyolefin-based resin may be a homopolymer of one type of cyclic olefin, or a copolymer of different types of cyclic polyolefin (for example, a copolymer of a monocyclic olefin and a polycyclic olefin). And the like. Alternatively, it may be a copolymer of a cyclic olefin and another copolymerizable monomer. In this case, examples of other copolymerizable monomers include chain olefins such as ethylene and propylene, (meth) acrylic monomers, unsaturated dicarboxylic acids or derivatives thereof, polymerizable nitrile compounds, and vinyl esters. And conjugated dienes.

  However, as for the cyclic polyolefin resin of the inner layer, from the viewpoint of low drug adsorption, a homopolymer consisting of only a cyclic polyolefin such as a homopolymer of one type of cyclic olefin or a copolymer of different types of cyclic polyolefins. A polymer is preferred. Cyclic polyolefin homopolymers have a lower drug adsorption than copolymers with other copolymerizable monomers. Moreover, it is preferable also in providing favorable impact resistance.

  As with the inner layer, the outer layer may be a cyclic polyolefin resin or another resin. By using the cyclic polyolefin resin for the outer layer, the transparency of the entire multilayer container 1 can be ensured. Examples of other resins used for the outer layer include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, and polyamide resins such as nylon under the trade name nylon.

  Meanwhile, the barrier layer is formed of a resin having a high gas barrier property. Examples of the gas barrier resin include an ethylene-vinyl alcohol copolymer resin, a polyamide resin, and a saturated polyester resin. Among them, it is preferable to use an ethylene-vinyl alcohol copolymer resin (EVOH). The ethylene-vinyl alcohol copolymer resin is a saponified ethylene-vinyl acetate copolymer, and any known one can be used. In the ethylene-vinyl alcohol copolymer resin, the ethylene content is preferably 20 to 70 mol% and the saponification degree of vinyl acetate is 95 mol% or more, more preferably the ethylene content is 25 to 50 mol%, and acetic acid. The saponification degree of vinyl is 98 mol% or more. If the degree of saponification is low, the gas barrier property may be lowered.

  The ethylene-vinyl acetate copolymer resin may include a third monomer component that can be copolymerized with the ethylene or the like. Examples of the third monomer component that can be copolymerized include α-olefins such as propylene, and unsaturated acids such as acrylic acid and methacrylic acid. The proportion of these copolymerization monomers is preferably 5 mol% or less.

  Next, an adhesive used for bonding the inner layer and the barrier layer, or the barrier layer and the outer layer (that is, an adhesive constituting the adhesive layer), a layer containing a cyclic polyolefin resin and an ethylene-vinyl alcohol copolymer A maleic anhydride-modified cyclic adhesive (for example, an adhesive layer between an inner layer 5 formed of a cyclic polyolefin resin and a barrier layer formed of an ethylene-vinyl alcohol copolymer) interposed between layers containing It is preferable to use an adhesive mainly composed of polyolefin. Maleic anhydride-modified cyclic polyolefin is obtained by graft polymerization of maleic anhydride to cyclic polyolefin, and since it is the same type of resin material, it has good affinity for the cyclic polyolefin resin in the inner layer and has sufficient adhesive strength. Demonstrate. Moreover, since maleic anhydride is introduced, the adhesive force to the ethylene-vinyl alcohol copolymer (EVOH) is also ensured by a chemical reaction.

  In the maleic anhydride-modified cyclic polyolefin, the cyclic polyolefin for graft polymerization of maleic anhydride can be the same as the cyclic polyolefin used for the inner layer, but its glass transition point (Tg) is 130 ° C. or higher. It is preferable. If the glass transition point is less than 130 ° C, the heat resistance may be insufficient. The maleic anhydride conversion rate in the maleic anhydride-modified cyclic polyolefin is preferably 0.5 to 1.5%.

  In addition to the maleic anhydride-modified cyclic polyolefin, an antioxidant is added to the adhesive layer. By adding an antioxidant, it is possible to effectively suppress a decrease in adhesive force caused by denaturation due to resin degradation. Moreover, generation | occurrence | production of the carbide | carbonized_material can also be suppressed.

  Examples of the antioxidant include phosphorus antioxidants and phenolic antioxidants, and these can be used alone or in combination. Any known phosphoric antioxidant or phenolic antioxidant may be used. For example, phosphorus antioxidants include high molecular weight phosphorus antioxidants and low molecular weight phosphorus antioxidants, any of which may be used.

  Specific examples of the high molecular weight phosphorus antioxidant include tris (2,4-branched C3-8 alkyl-butylphenyl) phosphite [tris (2,4-di-t-butylphenyl) phosphite]. Etc.] and tetrakis (2,4-di-branched C3-8 alkylphenyl) -4,4'-C2 such as tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene phosphite -4 alkylene phosphite. Examples of commercially available products include “Irgafos 168” manufactured by Ciba Japan.

  Examples of low molecular weight phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite; tri-2,4-dimethylphenylphosphine, tri-2,4, List phosphine compounds such as 6-trimethylphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri-o-anisylphosphine, tri-p-anisylphosphine, etc. Can do.

  As for the phenolic antioxidant, there are a high molecular weight phenolic antioxidant and a low molecular weight phenolic antioxidant, either of which may be used.

  Examples of the high molecular weight phenolic antioxidant include hindered phenolic compounds. Examples of the hindered phenol compound include tris (2-alkyl-4-hydroxy-5-branched C3) such as 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane. Tris (3,5-di-branched) such as -8 alkylphenyl) butane and 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene 1,3 such as C3-8 alkyl-4-hydroxybenzyl) benzene, 1,3,5-trimethyl-2,4,6, -tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene , 5-trialkyl-2,4,6-tris (3,5-di-branched C3-8alkyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3,5-di-t-butyl- 4-hi Roxyphenyl) propionate] tetrakis [alkylene-3- (3,5-di-branched C3-8 alkyl-4-hydroxyphenyl) propionate] C1-4 alkane, pentaerythrityltetrakis [3- (3,5 Pentaerythrityltetrakis [3- (3,5-di-branched C3-8 alkyl-4-hydroxyphenyl) propionate] such as -di-t-butyl-4-hydroxyphenyl) propionate]. Examples of commercially available products include “Irganox 1010” manufactured by Ciba Japan.

  Low molecular weight phenolic antioxidants include dibutylhydroxytoluene (BHT), butylated hydroxyanisole (BHA), 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4 -Ethylphenol, 2,6-di-t-butylphenol, 2,4-dimethyl-6-t-butylphenol, 2-methyl-4,6-di-nonylphenol, butylhydroxyanisole, styrenated phenol, 2,4, Monophenol compounds such as 6-tri-t-butylphenol and 4,4'-dihydroxydiphenyl, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl) -6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol) 4,4′-butylidenebis (2,6-di-t-butylphenol), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-dihydroxy-3,3′-di (α-methylcyclohexyl) ) Bisphenol compounds such as 5,5′-dimethyldiphenylmethane, hydroquinone compounds such as 2,5-di-t-butylhydroquinone, hydroquinone monomethyl ether, 2,5-di- (tertiary amyl) hydroquinone, n- Examples include hindered phenol compounds such as octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenol) propionate. Moreover, the low molecular weight phenolic antioxidant includes a hydrazine compound having a hindered phenol structure {N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine } And the like are also included.

  Although the addition amount of the antioxidant is arbitrary, it is preferably, for example, 300 ppm to 3000 ppm.

  As for the adhesive layer between the outer layer and the barrier layer, as in the case of the inner layer, when the outer layer contains a cyclic polyolefin, a maleic anhydride-modified cyclic polyolefin having an antioxidant added thereto is used as in the case of the adhesive layer. It is preferable.

  When the outer layer does not contain a cyclic polyolefin-based resin, the adhesive layer does not necessarily have to be obtained by adding an antioxidant to maleic anhydride-modified cyclic polyolefin. For example, maleic anhydride-modified polypropylene or maleic anhydride polyethylene can be used as an adhesive. In this case, the antioxidant may not be added. Moreover, you may add a styrene-type elastomer etc.

  For example, when a styrene-based elastomer is added to maleic anhydride-modified polypropylene, the melting point becomes high, and the adhesive layer does not become cloudy even if steam sterilization is performed. In addition, the styrene-based elastomer plays a role of absorbing shock, and even if a large impact is applied, the interface peeling does not occur.

  The styrene elastomer to be added is composed of a thermoplastic styrene end block and an elastic intermediate block, and is composed of a copolymer of a styrene monomer and an elastomer component. Here, examples of the styrene monomer include styrene and α-methylstyrene, and examples of the elastomer component include butadiene, isoprene, chloroprene, and 1,3-pentadiene. Specific examples of the styrene elastomer include styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isoprene-butadiene copolymer, and the like. Also. The styrenic elastomer used may be modified with maleic anhydride.

  The above is the layer structure of the freeze-drying container 1. In the freeze-drying container 1 having the above-mentioned multilayer structure, the inner layer is formed of a low-adsorbent cyclic polyolefin resin, so that the adsorption of the drug can be suppressed, and the inner layer and the outer layer are formed of a cyclic polyolefin-based resin. If formed of resin, a highly transparent medical container can be realized. Moreover, since it is set as the layer structure which laminated | stacked the barrier layer which consists of ethylene-vinyl alcohol copolymer resin etc. on these, it is possible to fully ensure gas-barrier property.

  In addition, since maleic anhydride-modified cyclic polyolefin is used for the adhesive layer interposed between the layer containing the cyclic polyolefin-based resin and the layer containing the ethylene-vinyl alcohol copolymer, and an antioxidant is added, Generation | occurrence | production can be suppressed and the fall of the adhesive force which arises by modification | denaturation by resin degradation, etc. can be suppressed effectively.

  The thickness of each layer in the freeze-drying container 1 is arbitrary. For example, the inner layer is preferably 200 μm to 500 μm, the outer layer is 200 μm to 500 μm, and the adhesive layer is preferably 5 μm to 50 μm. In particular, the thickness of the barrier layer (intermediate layer) is preferably 10 μm to 220 μm, whereby the freeze-drying container 1 exhibits characteristics suitable for freeze-drying.

  In the freeze-drying container 1, in addition to the layer configuration and thickness, the form of the bottom 5 is important for realizing freeze-drying suitability.

  FIG. 4 is a bottom view of the freeze-drying container 1 and FIG. 5 is an enlarged sectional view of the vicinity of the bottom of the freeze-drying container 1. The freeze-drying container 1 is formed by blow molding, and the bottom portion 5 has a concave shape that is recessed inward, and is formed by being cut by a die at the time of molding. A linear pinch-off portion 6 is formed so as to protrude from the bottom portion 5.

  Here, as shown in FIG. 5, the height dimension (projection amount) of the pinch-off part 6 is A, the thickness of the bottom part 5 at the part where the pinch-off part 6 is formed is B, and the inward direction formed on the bottom surface is directed to. Let C be the height from the installation surface of the recessed circular recess, D be the length of the pinch-off part 6, and E be the dimension (diameter) of the recess at the bottom.

  In the freeze-drying container 1 of the present invention, first, the height dimension A of the pinch-off portion formed on the bottom surface is 0.5 mm ≦ A ≦ 1.5 mm, and the bottom wall thickness B of the pinch-off portion is 0.5 mm ≦ B ≦. It is preferable that 1.5 mm and 1.0 mm ≦ A + B ≦ 2.2 mm. Moreover, it is preferable that A <C. If the height A of the pinch-off part or the thickness B of the bottom part of the pinch-off part is too small, the pinch-off strength is insufficient, and there is a risk of inconvenience in the shape of the bottom part, such as bottom pinch cracking or swelling of the bottom part. On the other hand, if the height dimension A of the pinch-off part or the thickness B of the bottom part of the pinch-off part is too large, heat conduction becomes insufficient and time for freeze-drying (cooling) becomes necessary. Is not preferable.

  Furthermore, the ratio (S2 / S1) of the projected area S1 on the installation surface of the circular recess recessed inward formed on the bottom surface and the actual surface area S2 of the recess is 1.02 or more and 1.10 or less. Is more preferable, and 1.04 or more and 1.08 or less are more preferable. The radius of curvature of the circular concave portion formed inward on the bottom surface is 10 mm or more and 100 mm or less, more preferably 15 mm or more and 50 mm or less, and further preferably 20 mm or more and 30 mm or less.

  Further, it is preferable that the length dimension D of the pinch-off portion 6 and the dimension (diameter) E of the concave portion on the bottom surface satisfy 0.5E <D <E. When D ≧ E, the pinch-off portion 6 protrudes from the bottom surface, and it is difficult to achieve a stable placement state. Conversely, if 0.5E ≧ D, the molding itself may be difficult.

  Although the embodiment to which the present invention is applied has been described above, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications or improvements are made without departing from the gist of the present invention. It is possible.

Hereinafter, specific examples of the present invention will be described based on experimental results.

Preparation of freeze-drying containers Freeze-drying containers (Examples 1 to 8 and Comparative Examples 1 to 6) having the forms shown in Table 1 were prepared. The produced freeze-drying container has a so-called vial shape, the inner volume is 5 mL, the pinch-off part width (length dimension D) is 11 mm, the inner diameter (E) of the recess formed in the bottom part is 17 mm, and the bottom part outer dimension. (F) is 23 mm. In addition, the materials used in the layer structure of the freeze-drying container are as follows.
-Inner layer: cyclic polyolefin Nippon Zeon, trade name ZEONEX690R (Tg 145 ° C)
-Outer layer: cyclic polyolefin Nippon Zeon, trade name ZEONEX1020R (Tg 102 ° C)
Barrier layer (intermediate layer): EVOH Nippon Gosei Co., Ltd., trade name DC3203B
・ Adhesive layer: Maleic anhydride-modified cyclic polyolefin

The prepared lyophilization container was set in the lyophilizer shown in FIG. 1 and lyophilized for evaluation. In the lyophilization, first, it was set in a lyophilizer at room temperature (20 ° C.) and cooled to −45 ° C. over 1 hour. Next, it was kept at −45 ° C. for 3 hours and completely frozen. Next, the pressure was reduced to 13.3 Pa, and the temperature was raised to 0 ° C. over 1 hour.

  During the lyophilization, the time for completing the lyophilization was compared with reference to a glass vial. Furthermore, the shape of the bottom of the freeze-dried container after freeze-drying was observed and evaluated. Regarding the bottom shape, when the temperature is raised from −45 ° C. during freeze-drying to 0 ° C., the volume of ice expands, and the bottom pinch cracks and the bottom expand. If there was at least one out of 100 pieces having such a bottom shape, it was marked as x. The results are shown in Table 1.

  As is clear from Table 1, in Comparative Examples 2 and 6 in which the height dimension A of the pinch-off part and the thickness B of the bottom part in the pinch-off part are large, freeze-drying takes a long time. The same applies to Comparative Example 3 in which the barrier layer (intermediate layer) is thick. On the other hand, in Comparative Examples 1, 4, and 5 in which the height dimension A of the pinch-off part and the bottom wall thickness B in the pinch-off part are small, the pinch-off strength is insufficient, and the bottom pinch crack and the bottom bulge are generated.

DESCRIPTION OF SYMBOLS 1 Container for freeze-drying 2 Trunk part 3 Mouth part 4 Gutter part 5 Bottom part 6 Pinch-off part

Claims (3)

A freeze-drying container having an inner layer containing at least a cyclic polyolefin-based resin and an intermediate layer containing an ethylene-vinyl alcohol copolymer,
The height dimension A of the pinch-off portion formed on the bottom surface is 0.5 mm ≦ A ≦ 1.5 mm, the thickness B of the bottom portion in the pinch-off portion is 0.5 mm ≦ B ≦ 1.5 mm, and 1.0 mm ≦ A + B ≦ 2. .2mm,
A freeze-drying container, wherein the thickness G of the intermediate layer is 10 μm ≦ G ≦ 220 μm.   2. The freeze-drying container according to claim 1, wherein 0.5E <D <E, where D is the length dimension of the pinch-off portion and E is the dimension (diameter) of the concave portion on the bottom surface. It has an outer layer containing a cyclic polyolefin resin on the outside of the intermediate layer, the inner layer and the intermediate layer, and between the outer layer and the intermediate layer are bonded by an adhesive layer,
The freeze-drying container, wherein the adhesive layer contains a cyclic polyolefin resin obtained by graft polymerization of maleic anhydride.

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