Abstract:
A protective case for a blister pack containing medicines, includes a semi-rigid horizontal upper panel having cells delimiting housings open at the bottom and which are obturated by covers with each housing containing medicine. The case includes:
       perforated horizontal bottom upon which the lower face of the blister pack lays; and   a perforated upper panel which covers the upper face of the blister pack; wherein
 
the blister pack is trapped between the bottom and the upper panel each of which includes holes coinciding with the location of the cells, the case having elements for fixing the upper panel with respect to the bottom, and the bottom and the upper panel of the case are made of rigid plastic.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a protective case for a blister pack containing medicines. 
   The invention relates more particularly to a protective case for a blister pack containing medicines intended for clinical trials, of the type comprising a semi-rigid horizontal upper panel comprising blister-shaped cells delimiting housings open at the bottom and which are obturated by covers and each of which contains a medicine able to be expelled by the flat lower face of the blister pack by tearing the cover of the blister. 
   The case is of the type comprising:
         a perforated horizontal bottom upon which the lower face of the blister pack lays; and   a perforated upper panel which covers the upper face of the blister pack;
 
and of the type in which the blister pack is trapped between the bottom and the upper panel each of which comprise holes coinciding with the location of the cells, the case comprising means of fixing the upper panel with respect to the bottom, the bottom and the upper panel of the case being made of rigid plastic.
       

   A medicine is subjected to clinical tests before being marketed. For example, the effectiveness of the medicine is tested by administering the active constituent to a first group of sick people and by administering a placebo to a second control group of sick-people. 
   It is known to deliver the medicine sealed in a blister pack in a case in the form of a wallet with which is integrated an information notice relating to the medicine that it contains. The blister pack is trapped in the case, or wallet, in such a way that the medicine is always accompanied by the corresponding notice. 
   In the context of clinical studies, referred to as double-blind, the cases must be indiscernible from each other whatever their contents may be: placebo or active constituents. 
   According to a known example, the case consists of a folded sheet of flexible cardboard comprising a central panel flanked by two lateral flaps that can be folded down over the central panel. 
   The blister pack is trapped between the central panel and a first lateral flap. The central panel and the first flap are each perforated with holes coinciding with the location of the cells. The perforated flap is then folded down and then sealed on the central panel, for example by pasting. The holes in the central panel allow the ejection of the medicine by pressure on the cell and tearing of the cover, the medicine then being retrieved under the lower face of the case. 
   The second lateral flap forms a protective lid for the cells of the blister pack. The information notice corresponding to the medicines is located on one or both of the faces of the lid. 
   Such a case in particular makes it possible to use the contents of the blister pack without ever separating the notice. The switching of medicines or a placebo is thus prevented. 
   Furthermore, any attempt at tampering with the case generally results in visible damage. 
   However, such a case made of cardboard is flexible and deforms in use. Furthermore, the cardboard is more likely to become deformed if it is exposed to a damp atmosphere. 
   Furthermore, it can be envisaged that when a case is tampered with, the damage may be camouflaged by pasting the perforated lateral flap back onto the central panel. 
   Finally, the packaging of the blister pack in such a case necessitates a first operation of positioning of the blister pack in the pre-pasted case and then an operation of pasting the perforated flap onto the central panel, which can take up to 7 seconds. 
   The document U.S. Pat. No. 3,587,517 describes a case which comprises a rigid bottom upon which a rigid flap is mounted such that it rotates about a lateral hinge. A blister pack of medicine is intended to be inserted flat between the bottom and the flap. The bottom and the flap comprise holes coinciding with the locations of the cells of the blister pack. The case also comprises a rigid lid which is mounted such that it rotates with respect to the bottom between a position folded down over the flap in such a way as to protect the cells from shocks and an open position in which the cells are accessible. 
   However, this case is not suitable for use in the context of clinical trials. The case is in fact reusable, since the flap comprises reversible means of closure with respect to the bottom. It is therefore possible to substitute the original blister pack with a similar one but containing substances of different nature without the appearance of the case revealing such a substitution. In order for the results of the clinical trials to be reliable, it is therefore essential that the case should be tamper-proof once the blister pack is trapped between the bottom and the flap. 
   SUMMARY OF THE INVENTION 
   In order to improve the packaging time and to solve the other problems mentioned above, the invention proposes a case of the type described previously, characterized in that the fixing means are elastic interlocking means that cannot be dismantled. 
   According to other features of the invention:
         the case comprises at least one pin forming a stop for the horizontal positioning the blister pack with respect to the ejection holes in the bottom of the case;   the pin constitutes a male element of the elastic interlocking fixing means, the female element being carried by the upper panel;   the male element and the female element are formed in one piece with the bottom and with the top panel respectively;   the bottom comprises a rim that extends vertically upwards and which surrounds the upper panel;   the upper panel is a flap that is mounted such that it articulates about a transverse axis by means of a first hinge on one side of the bottom which has no vertical rim;   the first hinge is formed by a plastic film which is formed in one piece with the bottom and with the upper panel;   the first hinge forms a stop for positioning the blister pack with respect to the holes in the bottom;   the case comprises an upper lid for protecting the cells which is made of rigid plastic and which is mounted such that it pivots with respect to the bottom about a second hinge between a closed position in which it envelopes the cells of the blister pack by cooperation of its shape with that of the bottom, and an open position in which the cells are accessible to a user;       

   the second hinge is a plastic film which is formed in one piece with the bottom and the lid;
         the lid is held in the closed position by means working by cooperation of complementary shapes between the lid and the upper panel and/or the bottom;   the elastic interlocking is produced by elastic deformation of the female element.       

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the invention will appear on reading the following detailed description given with reference to the appended drawings among which: 
       FIG. 1  is an exploded perspective view of a case produced according to the invention, the case being open and unfolded, ready to receive a blister pack of medicines; 
       FIG. 2  shows the case of  FIG. 1  with its lid in the open position which shows the blister pack of medicines trapped in the case; 
       FIG. 3  is a plan view which shows the bottom of the case upon which the blister pack of medicine is positioned; 
       FIG. 4  is a perspective view in partial cross-section through the cross-sectional plane  4 - 4  of  FIG. 2  showing in detail the elastic interlocking fixing means of the intermediate flap on the bottom of the case before the interlocking has taken place; 
       FIG. 5  is a view showing the fixing means of  FIG. 4  after the interlocking has taken place; 
       FIG. 6  shows the case of  FIG. 1  with its lid in the closed position and which comprises an information notice; 
       FIG. 7  is a large scale view in longitudinal cross-section through the cross-sectional plane  7 - 7  of  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In the rest of the description, and in a non-restrictive way, a longitudinal, vertical and transverse orientation will be used as indicated by the coordinate system L, V, T shown in  FIG. 1 . 
     FIG. 1  shows a case  10  for protecting a blister pack  12  of medicines. The case  10  is empty in this case and it is in an original unfolded state in which it is ready to receive the blister pack of medicines  12 . 
   In a known way, the blister pack  12  comprises a semi-rigid horizontal upper panel  14  which comprises blister-shaped cells  16  delimiting housings open in the downward direction which are obturated by covers  17  as shown in  FIG. 7 . Each of the housings can house a medicine  19  that can be expelled through the flat lower face  18  of the blister pack  12  by deformation of the cell  16  and by tearing of the cover  17  as illustrated by the central cell  16  in  FIG. 7 . The medicines  19  are for example in the form of tablets, capsules or suppositories suitable for protection by a blister pack. 
   The case  10  comprises in particular a central bottom  20  which is principally formed by a horizontal panel of overall rectangular shape whose short front  22  and rear  24  sides are oriented in the transverse direction and whose long sides  26  and  28  are oriented in the longitudinal direction according to  FIG. 1 . 
   The bottom  20  is in particular intended to support the flat lower face  18  of the blister pack  12  which is placed in position in the direction of the arrow F shown in  FIG. 1 . 
   The bottom panel  20  comprises a lateral rim  30  which extends vertically upwards from the two long sides  26  and  28  and from the short rear edge  24 . 
   A flat rectangular flap  32 , whose dimensions are substantially complementary to those of the bottom  20 , is mounted such that it articulates about a front transverse hinge  34 , on the short front side  22  of the bottom  20 , between an unfolded position and a folded down position. 
   In the unfolded position, as shown in  FIG. 1 , the flap  32  totally uncovers the bottom  20  of the case  10 . 
   In the folded down position, as shown in  FIGS. 2 and 7 , the flap  32  totally covers the bottom  20  in such a way as to trap the blister pack  12  between the lower face  36  of the flap  32  and the upper face  38  of the bottom  20 . The flap  32  is then surrounded by the rim  30  of the bottom  20 . 
   The flap  32  and the bottom  20  comprise holes  40  and  42  respectively which are formed such that they coincide with the locations of the cells  16  of the blister pack  12  when the flap  32  is in the folded down position. The cells  16  and the holes  40  and  42  are in this case produced in the form of four longitudinal rows of nine units. 
   As shown in  FIG. 2 , the holes  40  of the flap  32  provide the user with access to the cells  16  such that the user can thus select a medicine  19  and eject it by pressing vertically on the chosen cell  16 , the medicine  19  then being ejected through the cover  17  and through the corresponding hole  42  in the bottom  20  as illustrated by the arrow F′ shown in  FIG. 7 . 
   The case  10  comprises non-detachable or tamper-proof means of fixing the flap  32  in the position in which it is folded down on the bottom  20 . The flap  32  is more precisely fixed by the vertical elastic interlocking of a series of pairs of elements each comprising a male element  44  and a female element  46 . The fixing means are shown in greater detail in  FIGS. 4 and 5 . 
   The male element  44  consists of a pin  48  that extends vertically upwards from the upper face  38  of the bottom  20 . The free end of the pin  48  comprises a hemispherical head  50  whose horizontal flat faces downwards. 
   The pin  48  is intended to cooperate with the corresponding female element  46  which is carried by the flap  32 . According to this embodiment, the female element  46  is a pit  54  with a pierced bottom which extends vertically from the upper surface  56  of the flap  32 . The pit  54  comprises a lower opening  52  intended to receive the hemispherical head  50  of the pin  48 . 
   The pit  54  also comprises vertical slits which divide the pit  54  into two symmetrical halves in order to facilitate its elastic deformation and consequently the interlocking with the male element  44 . 
   Thus, when the pin  48  is interlocked in the female element  46 , as shown in  FIG. 5 , the upper end of the pit  54  is butted against the downward-facing flat of the pin  48  in order to prevent any vertical movement of the flap  32  with respect to the bottom  20 . The flap  32  is thus firmly attached to the bottom  20  and the blister pack  12  is trapped in the case  10 . 
   Furthermore, the pit  54  has the shape of a truncated cone whose lower end is located in the opening  52  and which is intended to increase the resistance to unlocking by pinching effect. 
   As can be seen in  FIG. 1 , the interlock orifices  52  of the flap  32  are encircled by a skirt  58  for protecting the pairs on fixing elements  44 ,  46  and which extends vertically from the upper surface  56  of the flap  32  and which prevents any attempt at dismantling by separating the two halves of each pit  54 . 
   As seen in  FIG. 3 , the pairs of elastic interlocking fixing elements  44 ,  46  are six in number in this case. The pins  48  carried by the bottom  20  are distributed around the periphery of the bottom  20  at the rate of two lateral pins  48 L on each of the long sides  26  and  28  of the bottom  20  and two frontal pins  48 F on the rear short side  24 . The pins  48  determine precisely the horizontal position of the blister pack  12  with respect to the ejection holes  42  when the latter is placed in the bottom  20  and before folding down the flap  32 . The short front side  22  of the blister pack  12  is adjacent to the front hinge  34 . 
   The pins  48  and the front hinge  34  thus advantageously form positioning stops for the blister pack  12  with respect to the bottom  20 . 
   The case  10  also comprises a lid  60  which is particularly visible in  FIGS. 2 and 6 . The lid  60  is a panel whose overall dimensions are similar to those of the bottom  20 . The lid  60  is mounted such that it articulates on the upper edge of the rim  30  of the short rear side  24 , about a transverse rear hinge  62 , between an open position and a closed position. 
   In the open position, as shown in  FIG. 2 , the lid  60  uncovers the upper part of the blister pack  12  in such a way as to provide the user with access to the medicines  19 . The lid can be opened through 180° providing totally free access to the blister pack. 
   In the closed position, as shown in  FIG. 6 , the lid  60  is globally horizontal and its lower reverse side  64  is pressed against the upper edge of the rim  30  of the bottom  20 . The lid  60  comprises at its free end, that is to say the side opposite to that of the rear hinge  62 , a flange  66  which extends perpendicularly from its reverse side  64  in such a way as to close the short front side  22  of the case  10  which does not have a vertical rim  30 . 
   The lid  60  therefore encloses and protects the upper face  14  of the blister pack  12  and, in particular, the cells  16 . In the closed position, only the obverse side  68  of the lid  60  is visible. 
   The obverse side  68  of the lid  60  can in particular serve as a support for a notice  70  giving information on the medicines  19  contained in the case  10 . The notice  70  is for example pasted on the obverse side  68  or on the reverse side  64 . The notice can also be printed or inscribed on the lid in sunken or in raised form. 
   The flap  32  comprises two tabs  72  which make it protrude beyond the front hinge  34 . In the folded down position of the flap  32 , these two tabs  72  extend horizontally from the short front side  22  of the case  10 . 
   The tabs  72  are designed to hook the lid  60  in the closed position by elastic interlocking with grooves (not shown) formed in the flange  66  of the lid  60 . 
   In the centre of the flange  66  of the lid  60  there is a protrusion  74  forming a grip to allow the user to disengage the lid  60  from the engagement of the tabs  72  in order to open the case  10  by raising it. 
   The case  10  is in this case made entirely of rigid plastic. The case  10  is thus resistant to shocks and its mechanical properties are not harmed by exposure to a damp atmosphere. 
   According to this embodiment, the case  10  is made in one piece by molding. The front  34  and rear  62  hinges are therefore each formed by a plastic film which is continuous with the bottom  20 . The case  10  is advantageously made from a material of the polypropylene type such that repeated openings and closings of the lid  60  do not cause any fracturing by fatigue of the rear hinge  62  during the use of the case  10 . 
   The pins  48  are also made in one piece with the bottom  20  and the female elements are made in one piece with the flap  32 . The manufacture of this case  10  does not therefore necessitate any assembly operation since it consists of a single part. 
   During the operation of packaging the blister pack  12  in the case  10 , an operator places the blister pack  12 , with the cells  16  uppermost, on the bottom  20  between the pins  48  as illustrated by the arrow F in  FIG. 1 , the case  10  being unfolded, with its three sections  20 ,  32  and  60  horizontal such as they are on removal from the mould. 
   Then, the flap  32  is folded down on top of the blister pack  12  against the bottom  20 . The blister pack  12  is therefore automatically positioned since the folding formed at the level of the front hinge  34  by the flap  32  and the bottom  20  pushes the blister pack  12  which is guided laterally into position by the lateral pins  48 L and is stopped when butted against the frontal pins  48 F. 
   The pits  54  of the flap  32  are then brought vertically into contact with the pins  48  which penetrate through the lower openings  52 . The convex head  50  of the pin  48  elastically separates the two halves of the pit  54 . The pit  54  then returns elastically to its original shape against the pin  48 , under the head  50 . The pairs of fixing elements  44  and  46  are then in an interlocked position and the flap  32  thus traps the blister pack  12  against the bottom  20  in such a way that it cannot be dismantled. 
   Because of this case  10 , it is not necessary to position the blister pack  12  exactly in the case  10  since the exact positioning is obtained when the flap  32  is folded down and then fixed. This method of fixing is advantageously fast and does not call upon any external means. 
   During the use of the case  10 , the user grasps the closed case  10  by supporting the lower face of the bottom  20  in the palm of his hand and by squeezing the two long lateral sides  26  and  28  between his fingers. Then he uses his other hand to open the lid  60  of the case  10  by raising the protrusion  74 . Finally, with a finger, he presses the cell  16  containing the desired medicine  19  in order to eject it through the hole  42  in the bottom  20 , into the palm of his hand which is supporting the case  10 . 
   Such a case  10  makes any attempt at tampering with it in order to remove the blister pack  12  difficult. 
   In fact, as the flap  32  is surrounded very closely by the rim  30  of the bottom  20 , it is difficult to obtain purchase for inserting a lever into the interstice between the flap  32  and the bottom  20  for the purpose of raising the flap  32 . 
   It is also difficult to attempt to separate the blades  54  which edge the interlock orifice  52  of the flap  32  in order to release the head  50  of the corresponding pin  48  since the periphery of the orifice  52  is protected by the skirt  58 . Furthermore, it would be necessary to carry out this operation simultaneously on the six fixing means because of the rigidity of the flap  32 . 
   Therefore, the only method of reaching the blister pack  12  is to cut off the heads  50  of each pin  48 , which leaves traces that cannot be eradicated. That is to say that, in the case of tampering, the case  10  bears traces that are impossible to camouflage. 
   In a variant of the invention, which is not shown, the flap  32  and the bottom  20  are two separate parts.