Patent Publication Number: US-6219997-B1

Title: Blister pack

Description:
This application is a divisional of application Ser. No. 08/930,778, filed on Oct. 8, 1997, pending, which is a 371 of PCT/SE97/01130, filed Jun. 24, 1997. 
    
    
     The present invention relates to a foldable blister pack, especially for drugs, an apparatus and a method for manufacturing such a blister pack, as well as the use of the same. 
     Blister packs for drugs in tablet form or in the form of powder or liquid enclosed in a capsule normally incorporate at least one blister part, which consists of a set of interconnected foils covering each other. One relatively rigid foil is in most cases referred to as the base and comprises cavities, so-called open “blisters”, for accommodating a tablet or capsule each, while the other foil, which is flat, is in most cases referred to as the lid and seals the opening of the cavities or blisters. 
     Examples of suitable materials for the lid are hard aluminium, soft aluminium, paper, polyester, polypropylene and PVC, and examples of suitable materials for the base are aluminium laminate, polypropylene, PVC, PVC/Aclar and PVC/PVDC. There also exist various laminates that may be used as basic material for these foils. 
     Blister packs can be accidentally damaged when they are being carried around in pockets, handbags etc. Such damage occurs frequently, especially if the lid foil is breakable. As a rule, blister packs are therefore stacked in a separate box or casing, which protects the blisters during transport. This package is normally bulky and voluminous owing to the construction of the blister packs. Further, the user might unintentionally lose the casing, or even throw it away. Thus, the presence of a casing does not in practical use guarantee that the drug is adequately protected. 
     To remedy this inconvenience, German Patent Application 44 29 503 discloses a compact blister pack comprising a foldable blister assembly. The blister assembly consists of two blister parts, each having a set of blisters, and an intermediate part free of blisters, which is located between the blister parts and is defined by two folding lines. The blister parts are foldable towards each other along said folding lines. The blisters of one blister part are so offset relative to the blisters of the other blister part that, after folding, the blisters of the two blister parts engage between each other. To protect the lid foil of the folded blister assembly, there is provided a protective unit which includes two closure panels that are interconnected by means of an intermediate panel, which is defined by two folding lines. This intermediate panel is joined to the intermediate part of the blister assembly such that a foldable blister pack is formed, in which the closure panels cover the lid foils after folding the blister pack. 
     One disadvantage of this compact blister pack is that the user has little space available for handling the blisters, in particular the blisters in the row adjacent to the intermediate part. A drug is removed by the user pressing one of the blisters with one of his fingers, thereby breaking the lid foil. Due to the lack of space, there is a risk that a blister part is torn away from the intermediate part, which is fixed to the protective casing. In such event, the blister part is no longer protected by the casing and is also separated from the user instructions that are printed on or attached to the protective casing. 
     Also, when a drug is being removed from the known blister pack, the blister parts have a tendency to bend and become dented. After some use, it might therefore be difficult, or even impossible, to fold the blister pack, since the uneven and dented blister parts no longer fit together. 
     Further, frequent use of the known blister pack might also lead to unintentional separation of a blister part from the casing, since the folding lines of the blister assembly are weakened each time the pack is folded or unfolded. This problem is more pronounced when the blister assembly is made of thin and/or flexible material. 
     Moreover, it is difficult to combine different drugs in the known blister pack. This blister pack requires the use of a foldable blister assembly, which is formed in one piece. Thus, in order to combine different drugs, these drugs must be combined when manufacturing the blister assembly. If different sets of drugs are to be used in the known blister pack, it is therefore necessary to keep a variety of blister assemblies in stock, each blister assembly containing a specific combination of drugs. 
     The prior art also comprises GB-B-1 133 947, GB-A-2 266 880, U.S. Pat. No. 3,743,084 and U.S. Pat. No. 4,340,141, disclosing other types of foldable packages containing blister parts. 
     The object of the invention is to solve or alleviate at least some of the problems described above. More specifically, the blister pack according to the invention should be compact and obviate the need for a separate, protective casing. Further, the blister pack should be durable and minimise the risk of the blister pack being accidentally damaged during use. Also, the blister pack should be capable of permanently carrying instructions for use, and preferably facilitate the provision of different drug combinations. Preferably, the blister pack should also provide for simple recycling of the materials used. 
     This object is achieved by the blister pack according to the appended claims. 
     The blister pack according to the invention has the advantage that the supporting unit will stabilise and protect the blister assembly. This is especially advantageous when the blister assembly is made of thin and/or flexible material. Further, separate blister parts, each carrying a different drug, can be combined to form a foldable unit by joining the blister parts to the supporting unit. In addition, the provision of a supporting unit will prevent accidental separation of a blister part from the blister assembly. 
     Further, since the supporting unit is joined to a tab on the protective unit, the blister pack has large continuous areas that can be printed with instructions for use or that can carry separate leaflets. Thus, the drugs always are accompanied by adequate instructions for use. 
    
    
     The invention will now be described in more detail with reference to the accompanying drawings, in which: 
     FIG. 1 illustrates a first preferred embodiment and shows in FIG. 1 a  the blister assembly, in FIG. 1 b  the supporting unit, in FIG. 1 c  the protective unit, in FIG. 1 d  the unfolded blister pack, and in FIG. 1 e  an end view of the folded blister pack; 
     FIG. 2 illustrates a second preferred embodiment and shows in FIG. 2 a  the blister assembly, in FIG. 2 b  the supporting and protective units, in FIG. 2 c  the unfolded blister pack, and in FIG. 2 d  an end view the folded blister pack; and 
     FIG. 3 illustrates a third preferred embodiment, wherein FIG. 3 a  is a perspective view of the blister pack in unfolded condition, and FIG. 3 b  is an opposite perspective view of the blister pack in FIG. 3 a.   
    
    
     The blister pack in FIGS. 1 a-e  has a blister assembly  10 , which consists of a first and a second blister part  11 ,  12 . Between the blister parts  11 ,  12 , there is formed an intermediate part  13  defined by two parallel, longitudinal folding lines  14 ,  15 . Consequently, the blister parts  11 ,  12  can be folded towards each other along said folding lines  14 ,  15 . The blister assembly  10  is composed of a base foil, in which blisters  16  are formed, and a flat lid foil, which is attached to said base foil. Thus, the lid foil seals the openings of the blisters  16 , each blister  16  containing one piece of medicine, e.g. a tablet or a capsule. 
     Each blister part  11 ,  12  has two parallel rows of blisters  16 , the blisters  16  of one part  11  being so offset relative to the blisters  16  of the other part  12  that, when the blister parts  11 ,  12  are mated in face-to-face relationship, the blisters  16  engage between each other to form a single blister layer. To this end, the height of the blisters  16  essentially corresponds to the distance between the folding lines  14 ,  15 . 
     The protective unit  20  consists of first and second closure panels  21 ,  22  and an intermediate panel  23  therebetween. The intermediate panel  23  is defined by two parallel, longitudinal folding lines  24 ,  25 , and the protective unit  20  is foldable along these folding lines  24 ,  25 . Further, the protective unit  20  has a tab  26 , which is connected to one longitudinal edge of the first closure panel  21  via a folding line  27 . 
     Further, a separate supporting unit  30  is provided, which includes first and second base panels  31 ,  32 , each having two parallel rows of holes  33 . Between the base panels  31 ,  32 , there is formed a linking panel  34  defined by two parallel, longitudinal folding lines  35 ,  36 , along which the base panels  31 , 32  can be folded towards each other. 
     The blister assembly  10  is attached to the supporting unit  30  in such a manner that the blisters  16  are aligned with the holes  33  and the lid foil of the blister assembly  10  is facing the supporting unit  30 . 
     The protective and supporting units  20 ,  30  are so interconnected that the folding line  36  between the second base panel  32  and the lining panel  34  coincides with one edge of the first closure panel  21 . To this end, the linking panel  34  of the supporting unit  30  is fixedly joined to the tab  26  on the protective unit  20 . Consequently, the folding lines  24 ,  25 ,  27  of the protective unit  20  are parallel to the folding lines  14 ,  15  of the blister assembly  10  and folding lines  35 ,  36  of the supporting unit  30 . 
     The folding of the blister pack is simple, since only two folding operations are necessary to close the pack, namely folding the first base panel  31  onto the second base panel  32  and, finally, folding the second closure panel  22  onto the first base panel  31 . In the folded condition shown in FIG. 1 e,  the blister pack is protected by the closure panels  21 ,  22  abutting against the base panels  31 ,  32  and thereby covering the holes  33 . 
     Preferably, the width of the intermediate panel  23  essentially corresponds to the thickness of the folded supporting unit  30 , and the first closure panel  21  has essentially the same dimensions as the second closure panel  22 , thereby creating a folded package in the form of a rectangular parallelepiped. The blister pack is maintained in its folded condition by fastening means  28 , e.g. a piece of reclosable adhesive tape. Obviously, the folded blister pack is very stable and protected on all longitudinal sides. 
     One longitudinal side of the folded blister pack is formed by the tab  26 , which is further stabilised by the supporting unit  30  and the blister assembly  10  being joined thereto. This improves the stability of the blister pack, in particular with respect to shear forces. 
     It should also be noted that the supporting unit  30  will stabilise and protect the blister assembly  10 . There is no risk of a blister part  11 ,  12  being accidentally torn away from the blister assembly  10 . 
     In the blister pack according to the invention, instructions can be printed on the closure panels  21 ,  22  and/or on a separate leaflet that is fixed to one closure panel side facing the blister assembly  10 . Thus, it is ensured that the drugs always are accompanied by adequate instructions for use. 
     In FIGS. 2 a-d,  a second preferred embodiment is shown, which differs from the first embodiment in that the supporting unit  30  is formed integral with the protective unit  20 . All embodiments employ a similar blister assembly  10 , which therefore need not be described in more detail here. The units  20 ,  30 , having already been described with reference to FIG. 1, need no further description either. 
     One edge of the second base panel  32  is connected to a tab  26 ′ of the first closure panel  21  via a folding line  28 ′. The tab  26 ′ is connected to the first closure panel  21  via a folding line  27 ′. Evidently, all folding lines  24 ,  25 ,  27 ′,  28 ′,  35 ,  36  of the protective and supporting units  20 ,  30  are parallel to each other. 
     As is apparent from FIG. 2 c,  the blister assembly  10  is joined to the supporting unit  30  in such a manner that the blisters  16  are aligned with the holes  33  and the lid foil of the blister assembly  10  is facing the supporting unit  30 . 
     The blister pack is folded from left to right, as seen in FIG. 2 c,  the first base panel  31  being first folded onto the second base panel  32 . These parallel panels  31 ,  32  are then folded onto the first closure panel  21  and, finally, folded onto the second closure panel  22 . In the folded condition of the blister pack, the first closure panel  21  will cover the first base panel  31 , and the second closure panel  22  will cover the second base panel  32 , thereby protecting that part of the lid foil which is accessible through the holes  33 . 
     The second embodiment, apart from having the same advantages, is also easier to manufacture than the first embodiment, since it contains only two separate parts. However, the second embodiment requires a more complicated folding operation and might also be more difficult to handle for the patient because of the greater length of the blister pack in unfolded condition. 
     FIGS. 3 a-b  show a third embodiment, which differs from the second embodiment in that the supporting unit has only one base panel  31 , which is formed integral with the protective unit  20 . The base panel  31  is connected to a tab  26 ′ of the first closure panel  21  via a folding line  28 ′. The tab  26 ′ is connected to the first closure panel  21  via a folding line  27 ′. 
     One and only one blister part  11  of the blister assembly  10  is joined to the base panel  31  in such a manner that the blisters  16  are aligned with the holes  33  and the lid foil faces the base panel  31 . 
     Folding the blister pack is easy, and only two folding operations are required to close the pack, namely folding the base panel  31  onto the second blister part  12  and, finally, folding the second closure panel  22  onto the base panel  31 . In folded condition, the blister pack is protected by the closure panels  21 ,  22  covering the holes  33  and is thereby protected on all its longitudinal sides. 
     The folded blister pack is very stable and shear resistant. One reason for this is that one longitudinal side of the folded blister pack is formed by the tab  26 ′, which is stabilised by the base panel  31  being joined thereto. Since the base panel  31  is placed inside the folded pack, between the blister assembly  10  and the closure panel  22 , the blister pack is locked in a stable configuration when folded. This stability is achieved with minimum use of raw material in the protective and supporting units  20 ,  30 . 
     Further, since the base panel  31  is joined to the tab  26 ′ on the protective unit  20 , the blister pack has large continuous areas that can be printed with instructions for use. Thus, the drugs always are accompanied by adequate instructions for use. 
     This third embodiment enables the user to remove the second blister part  12 , when emptied, from the blister pack by simply tearing along the folding line  15 , which might be perforated to facilitate separation. 
     In another conceivable embodiment; the intermediate part  13  is also joined to the intermediate panel  26 ′. In the preferred third embodiment, the intermediate part  13  is, however, not joined to the intermediate panel  26 ′, thereby providing the additional advantage of facilitating the removal of the drugs from the blisters, since the user has more space available for handling the blisters  16  on the second blister part  12 , in particular the blisters  16  in the row adjacent to the intermediate part  13 . A drug could be removed from the blister pack by the user pressing one of the blisters  16  with one of his fingers, thereby breaking the lid foil, and this preferred embodiment allows the user more liberty of action when applying pressure on the blisters. Thus, the risk of accidentally separating the blister part  12  from the blister pack is less than in a conventional blister pack. 
     This embodiment also has a cutout  36 ′, which is formed at one of the corners of the base panel  31  and which uncovers part of the blister assembly  10 . This feature facilitates the separation of the blister assembly  10  from the supporting and protective units  20 ,  30 , since the blister assembly  10  can readily be gripped at the cutout  36 ′ and be torn away from said units  20 ,  30 . In view of the recycling of the materials used, this is an attractive feature, which can be incorporated in any of the embodiments of the invention. 
     In all embodiments shown, the folding lines are arranged in parallel to each other. This parallelism is preferred, since it facilitates the folding of the blister pack. 
     Evidently, the blister assembly of the first and second embodiments of the inventive blister pack could consist of two separate blister parts, which are joined in any suitable manner, e.g. by being glued to a supporting unit. 
     Further, it is appreciated that the blister assembly could consist of several blister parts, which are interconnected by intermediate parts free of blisters, said blister parts being folded in pairs in a meandering manner. Also, the blister pack can include more than one blister assembly, for example by one blister part of each blister assembly being joined to a respective supporting unit on the protective unit. 
     Further, it should be noted that a combined blister pack could be formed from two blister packs according to the invention, preferably by joining a closure panel of one blister pack with a closure panel of the other blister pack. Referring to the embodiment of FIG. 3, the first closure panel  21  of one blister pack could, on the side facing away from the blister assembly  10 , be joined to a corresponding closure panel  21  on another blister pack. This combined blister pack has the same advantages as the included, individual blister packs. 
     According to the invention, the blister assembly can be fixedly joined to the protective unit by any suitable means, e.g. an adhesive. This also applies to the attachment of the blister assembly to the supporting unit as well as the attachment of the supporting unit to the protective unit. 
     Further, the shape of the holes in the supporting unit must not necessarily correspond to the shape of the blisters and could have any form uncovering the lid foil in front of the blisters. 
     In a preferred embodiment, the blister pack according to the invention is used for a pharmaceutically active drug, such as a proton pump inhibitor, e.g. omeprazole. The blister pack could have at least two differently shaped sets of blisters, each set containing a different drug. This type of blister pack is especially useful for packing, in one blister pack, two drugs e.g. a proton pump inhibitor and at least one antibiotic that should be administered in combination, such as omeprazole and an antibiotic. Another embodiment of the invention is to use the blister pack for packing tablets which contain a combination of drugs. 
     A wide variety of antibiotics may be used in combination with a suitable proton pump inhibitor. Such antibiotics include for example nitroimidazole antibiotics, tetracyclines, penicillins, cephalosporins, carbopenems, aminoglycosides, macrolide antibiotics, lincosamide antibiotics, 4-quinolones, rifamycins and nitrofurantoin. In the following examples of such antibiotics are listed: ampicillin, amoxicillin, benzylpenicillin, phenoxymethylpenicillin, bacampicillin, pivampicillin, carbenicillin, cloxacillin, cyclacillin, dicloxacillin, methicillin, oxacillin, piperacillin, ticarcillin, flucloxacillin, cefuroxime, cefetamet, cefetrame, cefixine, cefoxitin, ceftazidime, ceftizoxime, latamoxef, cefoperazone, ceftriaxone, cefsulodin, cefotaxime, cephalexin, cefaclor, cefadroxil, cefalothin, cefazolin, cefpodoxime, ceftibuten, aztreonam, tigemonam, erythromycin, dirithromycin, roxithromycin, azithromycin, clarithromycin, clindamycin, paldimycin, lincomycirl, vancomycin, spectinomycin, tobramycin, paromomycin, metronidazole, tinidazole, ornidazole, amifloxacin, cinoxacin, ciprofloxacin, difloxacin, enoxacin, fleroxacin, norfloxacin, ofloxacin, temafloxacin, doxycycline, minocycline, tetracycline, chlortetracycline, oxytetracycline, methacycline, rolitetracyclin, nitrofurantoin, nalidixic acid, gentamicin, rifampicin, amikacin, netilmicin, imipenem, cilastatin, chloramphenicol, furazolidone, nifuroxazide, sulfadiazin, sulfametoxazol, bismuth subsalicylate, colloidal bismuth subcitrate, gramicidin, mecillinam, cloxiquine, chlorhexidine, dichlorobenzylalcohol, methyl-2-pentylphenol. The active antibiotics could be in standard forms or used as salts, hydrates, esters etc. A combination of two or more of the above listed drugs may be used. Preferable antibiotics are clarithromycin, erythromycin, roxithromycin, azithromycin, amoxicillin, metronidazole, tinidazole and tetracycline. Clarithromycin and metronidazole alone or in combination are especially suitable. 
     An apparatus (not shown) for manufacturing any of the embodiments having a supporting unit, comprises a device, such as a punching machine, for producing a protective unit and a supporting unit from one or two blanks and for providing folding lines therein, a device for applying an adhesive to the supporting unit, a device for aligning and combining a blister assembly with the supporting unit, and a device for folding the blister pack along the folding lines. In the case of a blister pack with separate supporting and protective units, the apparatus could comprise a device for combining these units before folding the blister pack.