Patent Publication Number: US-2021186807-A1

Title: Blister pack for medicinal products and tool for producing the blister pack

Description:
RELATED APPLICATIONS 
     This application is a divisional application from U.S. Ser. No. 16/521,888, filed Jul. 25, 2019, which claims priority to European Patent Application No. 18 185 814.3, filed on Jul. 26, 2018, entitled “Blister Pack for Medicinal Products and Tool for Producing the Blister Pack”, the the contents of which are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The disclosure relates to a blister pack for medicinal products, in particular tablets, capsules, or sugar-coated pills, and to a tool for producing the blister pack. 
     BACKGROUND 
     Blister packs for medicinal products usually consist of a bottom film, into which a plurality of blister pockets are formed, which are then filled with medicinal products, and of a lidding film. The lidding film is sealed to the bottom film and thus closes the blister pockets, so that the medicinal products in the pockets can be protected during storage. 
     For certain medicinal products, it can also be necessary to provide an insert of active material in the area of the blister pocket. This material can serve, for example, to dry the air present in the sealed pocket and thus to ensure the integrity of the medicinal products. Inserts of active material are usually placed in a chamber connected to the blister pocket before the pocket is sealed with the lidding film. 
     The additional inserts of active material, however, increase the amount of space which blister packs of this type occupy. In addition, the inserts of active material must be introduced into chambers of relatively complex shape in the blister pockets, so that they will not fall out of the blister pocket when the blister pocket is squeezed by the user, who might then unintentionally ingest the insert. This complicates the production process. 
     BRIEF SUMMARY 
     It is an object of the present disclosure to provide a blister pack of the simplest possible configuration for medicinal products with an active material in the area of the pocket of the blister pack and to provide a blister pack which takes up only a small amount of space and can be handled safely, and to provide a corresponding tool for producing a blister pack of this type. 
     According to an aspect of the disclosure, the blister pack for medicinal products, in particular tablets, capsules, or sugar-coated pills, comprises a bottom film, in which at least one blister pocket is formed, the blister pocket being surrounded by webs of the bottom film. The at least one blister pocket comprises an at least two-level shape with a first recess, which defines a first level of the blister pocket, and a second recess, which is arranged in a subsection of the two-dimensional area over which the first recess extends and is situated lower down than the first recess. A lidding film covers the at least one blister pocket and is sealed to webs of the bottom film. A strip of active material is arranged in the at least one blister pocket and is sealed to the lidding film. The medicinal product is accommodated in the second recess, and the strip of active material is accommodated in the first recess. In a bottom area, the first recess comprises a peripheral rib, which extends around the second recess, or at least two projecting knobs, which are arranged next to the second recess, wherein the strip of active material rests on the rib or on the knobs. 
     With this configuration, the blister pack is easy to manufacture. It also offers the advantage that there is a secure bond between the strip of active material and the lidding film in the area of the sealing points and guarantees that the user will be able to use the blister pack without making a mistake. 
     The rib is, or the knobs are, preferably an integral part of the bottom film. Thus the structure of the blister pack is as simple as possible. Another advantage is that the rib or the knobs can be formed in the bottom film at the same time as the blister pockets during the production process. 
     In preferred embodiments, the rib is rounded at the top or the knobs have a flat plateau surface. As a result, an effective support surface for the strip of active material is obtained, which, during the sealing operation, exerts a force, counter to that of the upper sealing tool, on the strip of active material and the lidding film. The support surface for the strip of active material preferably has relatively small dimensions, so that the counterpressure produced by the rib or by the knobs is exerted over a relatively small area, as a result of which the bond between the lidding film and the strip of active material is especially strong in the area of the sealing point. 
     In an especially preferred embodiment, the strip is a section of a film and comprises a thickness of 0.2-2 mm, and more preferably of 0.3-1.2 mm. Such a thin film is advantageous in reducing the space requirement but at the same time is thick enough to ensure the reliable handling of the strip during the production process. 
     The rib has, or the knobs have, advantageously a height in the range of 0.5-5 mm, preferably of 1-3 mm. This produces a gap of sufficient size between the medicinal product and the strip of active material. 
     It is preferred that the active material, as a result of its material properties, has an absorption function for absorbing at least one substance or a release function for releasing at least one substance. Thus, depending on the requirements of the medicinal product, the integrity of the product can be ensured over a long period of time. 
     In a preferred embodiment, precisely two knobs are provided, which are arranged on opposite sides of the second recess. In this case, the connection between the strip of active material and the lidding film is limited to the minimum of precisely two sealing points. These two sealing points are accordingly especially long-lasting. 
     In one possible embodiment, the strip of active material is arranged transversely to the medicinal product. 
     In one embodiment, the strip of active material comprises an opening, which is arranged above the medicinal product. As a result, the medicinal product can be pressed through the recess and out of the blister pocket. 
     According to an aspect of the disclosure, the tool for producing a blister pack for medicinal products, in particular tablets, capsules, or sugar-coated pills, comprises at least one trough for forming or receiving at least one blister pocket of the blister pack. The at least one trough comprises an at least two-level shape with a first recess, which defines a first level of the trough, and a second recess, which is arranged in a subsection of the two-dimensional area over which the first recess extends and is situated lower down than the first recess. In a bottom area, the first recess can comprise an upright peripheral projection, which extends around the second recess; at least two upright projections a certain distance apart, which are arranged next to the second recess; at least one upright, movable support element, which extends around the second recess; or at least two upright movable pins a certain distance apart, which are arranged next to the second recess. 
     With a tool configured in this way, the shape of a blister pack described above can be produced easily and reliably. This embodiment pertains, first, to a forming tool for forming a corresponding contour of the blister pockets, and, second, to a sealing tool, in which the lidding film and the strip of active material can be sealed together at predefined sealing points in an especially reliable manner. 
     In preferred embodiments, the projection or projections or the support element or the pins comprise a rounding or a flat plateau area at the apex or at the tip. 
     In a preferred embodiment, precisely two projections or pins are provided. 
     It is also preferred that several projections be present and that the projections be of equal height, preferably in the range of 0.5-5 mm, more preferably of 1-3 mm. Alternatively, several pins can be present, and the pins can be extended in such a way that they project equally far beyond the bottom area of the first recess, preferably by 0.5-5 mm, more preferably by 1-3 mm. 
     In one embodiment, a support element or several pins are present, and the support element or the pins are spring-loaded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of part of one embodiment of a blister pack according to the disclosure, in which the lidding film has been omitted for the sake of clarity; 
         FIG. 2  is a top view of a blister pocket of the blister pack of  FIG. 1 , where the lidding film has been omitted for the sake of clarity; 
         FIG. 3  is a cross-sectional view of a blister pocket of the blister pack of  FIG. 1 ; 
         FIG. 4  is a perspective view of a part of another embodiment of a blister pack according to the disclosure, in which the lidding film has been omitted for the sake of clarity; 
         FIG. 5  is a top view of a blister pocket of the blister pack of  FIG. 4 , wherein the lidding film has been omitted for the sake of clarity; 
         FIG. 6  is a cross-sectional view of a blister pocket of the blister pack of  FIG. 4  with a sealed-on lidding film; 
         FIG. 7  is a perspective view of a part of another embodiment of a blister pack according to the disclosure, in which the lidding film has been omitted for the sake of clarity; 
         FIG. 8  is a top view of a blister pocket of the blister pack of  FIG. 7 , wherein the lidding film has been omitted for the sake of clarity; 
         FIG. 9  is a cross-sectional view of a blister pocket of the blister pack of  FIG. 7  with a sealed-on lidding film; 
         FIG. 10  is a schematic diagram of a unit for producing blister packs according to the disclosure; 
         FIG. 11  is a schematic, cross-sectional view of a forming device with a tool according to the disclosure, which can be used to produce the blister packs; 
         FIG. 12  is a top view of the recess in the lower forming tool of  FIG. 11 ; 
         FIG. 13  is a schematic, cross-sectional view of a sealing device with a tool according to the disclosure, which can be used to produce the blister packs, in an opened position; 
         FIG. 14  is a schematic, cross-sectional view of the sealing device of  FIG. 13  in a closed sealing position; 
         FIG. 15  is a schematic cross-sectional view of another sealing device with a tool according to the disclosure, which can be used to produce the blister packs, in an opened position; 
         FIG. 16  is a schematic, cross-sectional view of the sealing device of  FIG. 15  in a closed sealing position; 
         FIG. 17  is a cross-sectional view of a blister pocket of another embodiment of the blister pack according to the disclosure with a sealed-on lidding film; 
         FIG. 18  is a schematic, cross-sectional view of another forming device with a tool according to the disclosure, which can be used to produce the blister packs; 
         FIG. 19  is a schematic, cross-sectional view of another sealing device with a tool according to the disclosure, which can be used to produce the blister packs, in an opened position; and 
         FIG. 20  is a schematic, cross-sectional view of another sealing device with a tool according to the disclosure, which can be used to produce the blister packs, in an opened position. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1-3  show a first embodiment of a blister pack  2  according to the disclosure for medicinal products  4 , in particular tablets, capsules, or sugar-coated pills. The blister pack  2  comprises a bottom film  6 , in which at least one blister pocket  8  is formed, which is surrounded by webs  10  of the bottom film  6 . The part of the blister pack  2  shown in  FIG. 1  has only one blister pocket  8 . Blister packs  2  usually comprise a plurality of blister pockets  8 , which are usually distributed in a regular pattern across the blister pack  2 . A frequently used arrangement of the blister pockets  8  in the blister pack  2  is a matrix of rows and columns. 
     A lidding film  12 , which covers the at least one blister pocket  8 , is sealed to the webs  10  of the bottom film  6  and closes off the at least one blister pocket  8 . The lidding film  12  is shown only in  FIG. 3 , whereas it has been omitted in  FIGS. 1 and 2  for the sake of clarity. 
     Materials which can be used for the bottom film include in particular PVC, PVDC, Aclar, aluminum, PETG, and laminated films. The material for the lidding film can be in particular aluminum, polyethylene, polypropylene, and paper-laminated films or composite films. 
     A strip  14  of active material is arranged in the at least one blister pocket  8  and is sealed to the lidding film  12 . The seal to the lidding film  12  can extend across the entire surface area of the strip  14 , over only certain parts of the surface of the strip, or along lines; or it can be present only at certain points. 
     As a result of its material properties, the active material generally comprises an absorption function for absorbing at least one substance or a release function for releasing at least one substance. The most widespread purpose for which the strip is used is to absorb moisture. In the case of strips  14  with an absorption function, however, the strips  14  of active material can also absorb oxygen, CO 2 , reactive impurities, or odors, for example. In the case of strips  14  with a release function, the strips  14  of active material can release nitrogen or carbon dioxide, for example. 
     A strip  14  of active material preferably comprises a thickness in the range of 0.2-2 mm, and more preferably of 0.3-1.2 mm. The material of the strip  14  preferably has at least some stiffness, so that it can be easily handled. The material of the strip  14  is preferably a film, more preferably a polymer, and especially preferably a three-phase polymer. The film can be produced by extrusion, for example, wherein the active particles are added to the polymer. Channels within the polymer allow the movement of gases. The active particles are preferably present as spheres in the strip  14  of active material. 
     In the embodiment according to  FIGS. 1-3 , the product  4  is configured as an oblong shape, and the strip  14  of active material has a substantially rectangular base surface. The strip  14  is arranged transversely to the product  4 , preferably at an angle of approximately 45°. Standard dimensions of the strip  14  in the longitudinal and transverse directions are in the range of approximately 5-50 mm. 
     As can be seen in  FIG. 3 , each blister pocket  8  comprises a two-level shape, in which a first recess  16  defines a first level of the blister pocket  8 . A second recess  18  is arranged in a subsection of the two-dimensional area over which the first recess  16  extends and is situated lower down than the first recess  16 . The medicinal product  4  is accommodated in the second recess  18 , whereas the strip  14  of active material is accommodated in the first recess  16 . The strip  14  of active material rests on support surfaces  20  of the first recess  16 , which are arranged next to the second recess  18 . The strip  14  and the product  4  are therefore preferably a certain distance apart in the vertical direction. 
     The two support surfaces  20  for the strip  14  of active material are located diametrically opposite each other on two sides of the second recess  18 . The strip  14  of active material therefore covers a large part of the second recess  18 , and two of its opposite corner areas rest on the support surfaces  20 . 
     The support surfaces  20  for the strip  14  of active material are formed by two knobs  50  projecting upward from the bottom film  6  in the area of the first recess  16 . The two knobs  50  can be seen only in the cross-sectional view according to  FIG. 3 , because they are covered by the strip  14  in the other two views. 
     The embodiment of the blister pack  2  according to the disclosure shown in  FIGS. 4-6  has a structure similar to that of the embodiment shown in  FIGS. 1-3  and as previously described. Elements which are the same have been provided with the same reference numbers. In contrast to the embodiment of  FIGS. 1-3 , the medicinal product  4  has here a circular base surface. The strip  14  of active material again has a substantially rectangular base surface and rests by its two narrower edge areas on the support surfaces  20  of the knobs  50 , which are arranged on opposite sides of the second recess  18 . The strip  14  of active material therefore covers a large part of the product  4 . 
     The embodiment of the blister pack  2  according to the disclosure shown in  FIGS. 7-9  is again substantially the same as the embodiment according to  FIGS. 1-3 . Elements which are the same have been provided with the same reference numbers. The medical product  4  is in the form of a sphere. In contrast to the previously described embodiments, the strip  14  of active material has an opening  22 , which is arranged above the medicinal product  4 . The medicinal product  4  can therefore pass through the opening  22  of the strip  14  of active material when the blister pack is squeezed. The area of the lidding film  12  sealed to the strip  14  of active material is therefore not broken when the product  4  is squeezed out, but only the area of the lidding film  12  above the opening  22  is broken. 
     The shape of the blister pockets  8  can differ from the embodiments described so far. Any geometric configuration is conceivable as long as the blister pocket  8  has a shape with at least two levels. The shape of the second recess  18  depends preferably on the shape of the product  4  to be packaged, which can have any imaginable geometric shape. In addition to the previously mentioned oblong shape, pill shape, or spherical shape, it is also possible for a triangular or polygonal shape to be present. 
     Finally, the shape of the strip  14  of active material can also depart from the exemplary embodiments described above. The strips  14  can have, for example, a round, oval, or triangular base surface instead of the rectangular base surface illustrated above. In each of these embodiments, it is possible to provide an opening  22  in the strip. The strips  14  are usually cut-to-size blanks. 
     A knob  50  can be arranged on each of two opposite sides of the second recess  18 , as shown in the previous exemplary embodiments. It is also possible, however, for more than two knobs  50  to be arranged around the second recess  18 . 
     A method for producing blister packs  2  according to the disclosure will now be described with reference to  FIG. 10 . First, a bottom film  6  is provided in the form of a roll and unwound. Blister pockets  8  are formed in the unwound bottom film  6  in a forming station  24 , wherein each blister pocket  8  has the previously described shape with at least two levels. Then the second recesses  18  of the blister pockets  8  are filled with the medicinal products  4  in a filling station  26 . 
     Strips  14  of active material are provided in a feed station  28 , and a strip  14  of active material is placed in the first recess  16  of each blister pocket  8  on the support surfaces  20  of the knobs  50 , above the medicinal product  4 . The strip  14  of active material is thus preferably arranged above the medicinal product  4 , preferably a short distance away from it. The strips  14  of active material are preferably provided by starting with a web of active material wound up into a roll and by stamping out the strips  14  of active material from the unwound web. The strips  14  of active material are preferably put in position by means of a pick-and-place machine. It is also possible, however, to use other means of transferring the strips  14  of active material. 
     In a following sealing station  30 , the lidding film  12  is provided and sealed to the webs  10  of the bottom film  6 . Simultaneously, the lidding film  12  is also sealed to the strips  14  of active material. All of these steps taken together, therefore, result in the formation of a sealed blister web. Finally, in a downstream stamping station  32 , the individual blister packs  2  are stamped out of the blister web. The individual blister packs  2  are then sent on for additional processing steps. 
       FIG. 11  shows a first forming tool  34  according to the disclosure and a second forming tool  36 , which cooperate in the forming station  24  to form the blister pockets  8  in the bottom film  6 . The two forming tools  34 ,  36  are movable relative to each other between an opened position and a closed or forming position. For this purpose, at least one of the two forming tools  34 ,  36  must be movable, preferably both of them. In the closed or forming position, the two forming tools  34 ,  36  clamp the bottom film  6  between them for the forming process. A compressed-air source  38  is connected to the second forming tool  36  to bring about the formation of the blister pockets  8  in the tightly clamped bottom film  6 . 
     The first forming tool  34  comprises at least one, preferably a plurality, of troughs  40  for forming at least one blister pocket  8  in the bottom film  6 . The at least one trough  40  comprises an at least two-level shape. A first recess  42  of the trough  40  defines a first level of the trough  40 . A second recess  44  of the trough  40  is arranged in a subsection of the two-dimensional area over which the first recess  42  extends and is situated lower down than the first recess  42 . 
     In the area of the first recess  42  of the trough  40 , the first forming tool  34  comprises two upright projections  46 , which are arranged next to the second recess  44 . As a result, during the forming of the blister pockets  8  in the bottom film  6 , the two upward-projecting knobs  50  are formed in the bottom film  6  and serve as support surfaces  20  for the strips  14  of active material. The two projections  46  can be seen again in the top view of  FIG. 12 . The shape of the trough  40  thus corresponds to the shape of the blister pockets  8  to be formed. The shape of the trough  40  shown in  FIG. 12 , for example, corresponds to the shape of the blister pockets  8  of the blister pack  2  of  FIGS. 1-3 . 
     In  FIGS. 13 and 14 , a first sealing tool  54  according to the disclosure and a second sealing tool  56  are sketched, which cooperate in the sealing station  30  to seal the lidding film  12  to the webs  10  of the bottom film  6  and to the strips  14  of active material. The two sealing tools  54 ,  56  are movable relative to each other between an opened position ( FIG. 13 ) and a closed position ( FIG. 14 ). For this purpose, at least one of the two sealing tools  54 ,  56 , preferably both of them, must be movable. In the closed sealing position, the two sealing tools  54 ,  56  press the lidding film  12  against the webs  10  of the bottom film  6  and against the strips  14  of active material. The second sealing tool  56  comprises at least one heating means  58 . The first sealing tool  54  can comprise a cooling means (not shown). 
     The first sealing tool  54  comprises at least one, preferably a plurality, of troughs  60  for accommodating at least one blister pocket  8  of the bottom film  6 . The at least one trough  60  comprises an at least two-level shape. A first recess  62  of the trough  60  defines a first level of the trough  60 . A second recess  64  of the trough  60  is arranged in a subsection of the two-dimensional area over which the first recess  62  extends and is situated lower down than the first recess  62 . The shape of the trough  60  corresponds substantially to the shape of the blister pockets  8  previously formed in the forming station  24 . In this concrete example, the shape of the trough  60  corresponds to the blister pack of  FIGS. 1-3 . 
     The first sealing tool  54  comprises two upright projections  66 , which correspond to the shape of the knobs  50  formed in the bottom film  6  and are arranged so that the knobs  50  come to rest on the projections  66  during the sealing process. The projections  66  serve to support the knobs  50  of the bottom film  6  during the sealing process. 
     When the strip  14  of active material is placed on the at least one support surface  20  of the first recess  16 , it is advantageous for the strips  14  of active material to project above the webs  10  of the bottom film by an amount of 0.05-0.5 mm, more preferably of 0.08-0.2 mm. The geometry of the blister pockets  8  and of the knobs  50  in the first sealing tool  54  is accordingly to be adapted to the thickness of the strip  14  of active material, so that this excess projection is present before the sealing process in the sealing station  30 . The excess projection of the strips  14  ensures that the lidding film  12  is sealed not only to the webs  10  of the bottom film  6  but also to the strips  14  of active material. 
     The sealing tools  54 ,  56  shown in  FIGS. 15 and 16  correspond substantially to the sealing tools  54 ,  56  shown in  FIGS. 13 and 14 . Elements which are the same have been provided with the same reference numbers. As a modification of the embodiment of  FIGS. 13 and 14 , the projections  66  in the first sealing tool  54  according to the disclosure are replaced by pins  68 , which project upward beyond the bottom area of the first recess  62  of the trough  60 . The pins  68  serve to support the knobs  50  of the bottom film  6  during the sealing step. The pins  68  can be spring-loaded, as shown. The pins  68  can be mounted in the first sealing tool  54  so that they can be extended. 
     The knobs  50  in the bottom film  6  preferably have a height in the range of 0.5-5 mm, more preferably of 1-3 mm. Accordingly, the projections  46  in the first forming tool  34  and possibly the projections  66  in the first sealing tool  54  also comprise a height in the range of 0.5-5 mm, preferably in the range of 1-3 mm. If pins  68  are being used, the pins  68  preferably project above the bottom area of the first recess  62  of the trough  60  by a distance in the range of 0.5-5 mm, preferably of 1-3 mm, or they are extended by this amount. 
     In the embodiments shown, the knobs  50  are illustrated as rounded elevations. Knobs  50  of other shapes are also conceivable, such as knobs  50  with a triangular cross-sectional form with a rounded tip or with a flat plateau surface at the top, on which the strips  14  of active material can rest. The knobs  50  can also be in the form of elongated objects extending along a line (straight or curved). The shape of the projections  46 ,  66  and/or of the tips of the pins  68  preferably corresponds in each case to the shape of the knobs  50  in the bottom film  6 . 
     It is also possible to provide a peripheral rib instead of several knobs  50 . This is conceivable especially in the case of the embodiment according to  FIGS. 7-9 .  FIG. 17  shows a cross-sectional view of this modification. The peripheral rib  70 , when viewed from above, can have any desired ring-like shape. For example, it can be a circular ring, an oval ring, a polygonal ring, etc. 
     For the production of blister packs like those shown in  FIG. 17 , the only measure required is to create a peripheral projection  76  in the first forming tool  34  of the same shape as that of the rib  70 .  FIG. 18  shows a cross-sectional view of a configuration of this type. 
     A peripheral projection  86  of similar shape is preferably also formed in the first sealing tool  54 , as can be seen in the cross-sectional view of  FIG. 19 . 
     Alternatively, it would also be possible to use a peripheral, extendable support element  78  in the first sealing tool  54 , the apex of which corresponds to the shape of the rib  70 .  FIG. 20  shows a cross-sectional view of a configuration of this type. The support element  78  is preferably spring-loaded. 
     With respect to the cross-sectional shape of the rib  70 , of the projection  76 , of the projection  86 , or of the apex of the support element  78 , what was said about the cross-sectional shape of the knobs  50  also applies here correspondingly.