WO2004041675A1

WO2004041675A1 - Child resistant blister pack

Info

Publication number: WO2004041675A1
Application number: PCT/GB2003/004757
Authority: WO
Inventors: Ian Jobling; Balbir Raj; Andrew Ernest Parker
Original assignee: Ian Jobling; Balbir Raj; Andrew Ernest Parker
Priority date: 2002-11-04
Filing date: 2003-11-04
Publication date: 2004-05-21
Also published as: AU2003285486A1; GB0225643D0

Abstract

A blister pack unit comprises a flexible first sheet (4) having at least one blister pocket formed therein for the location of a unit dose, a frangible second sheet (8) located across the first sheet to close the or each pocket, and a flexible cover sheet (10), characterised in that the cover sheet is fixed to one side, or to two opposing sides, of the first and/or second sheets so as to extend across the or each pocket and be generally adjacent to the second sheet. The unit improves the child-resistant nature of blister packs, in particular pharmaceutical blister packs, by requiring the simultaneous application of pressure along the fixed sides during the actual release of a unit dose. This combination of actions should reduce the possibility of accidental release of unit doses by inquisitive fingers when not desired. Meanwhile, the actions are easy to understand and carry out by adults, and the return of the blister pack after release of a unit dose is to a `closed' configuration without requiring positive action by the user.

Description

CHILD RESISTANT BLISTER PACK

The present invention relates to child resistant closures primarily but not exclusively for blister packs of medicaments, such as pharmaceuticals.

Many medicaments are packaged in blister packs comprising a plurality of deformable pockets formed in a flexible sheet. Unit doses of medicament such as tablets, ampoules or vials, are located in the pockets, which are then closed, preferably sealed, by an overlying frangible film, generally being a metallic foil. To remove a unit dose, a pocket is pushed to force the unit dose through the frangible film. This arrangement is very convenient and widely used.

Unfortunately, it is also easy for children to access the unit doses, and possibly ingest them. Legislation is now requiring improvements in the child safety aspects of blister packs. Some manufacturers are trying to meet this by using thicker foils that need a greater force to push the unit dose through. Whilst this may work, the downside is that individuals who are elderly or have reduced manual dexterity can find it difficult to remove the tablets.

GB2352231 discloses a child resistant unit dose holder being a sheet having a number of ears' which can be located around a blister pack, and which prevent a unit dose from being released until the blister pack is removed from the holder. The blister pack can only be removed from the holder by flexing the holder, which extra action is a further deterrent to a child. However, this still requires the blister pack to be replaced into the holder once the required unit dose is released, and the number of extra actions required may not be conducive to being followed by all users.

It is an object of the present invention to provide an improved child resistant closure.

Thus, according to one aspect of the present invention, there is provided a blister pack unit, said unit comprising a flexible first sheet having at least one blister pocket formed therein for the location of a unit dose, a frangible second sheet located across the first sheet to close the or each pocket, and a flexible cover sheet, characterised in that the cover sheet is fixed to one side, or to two opposing sides, of the first and/or second sheets so as to extend across the or each pocket and be generally adjacent to the second sheet.

By having the cover sheet adjacent to the second- sheet, accidental release of a unit dose is prevented without separation of the third sheet from its adjacent arrangement with the first and/or second sheet.

Preferably, the cover sheet is spaced from the first and/or second sheet by a distance less than the dimensions of a unit dose.

Where the third sheet is fixed to the first and/or second at one side only, the cover sheet is preferably biased towards the first and/or second sheet.

Preferably, the cover sheet is fixed to the first and/or second sheet on opposing sides, preferably partly, substantially or wholly along each side. In this way, the cover sheet and the face of the first sheet are adapted to flex oppositely upon pressure on the fixed sides, so as to form an enlarged space thereinbetween. The enlarged space allows for the deblistering of a unit dose from a pocket into the enlarged space formed.

The present invention is particularly adapted to suit pharmaceutical blister packs, as are widely used. In this regard, the first and second sheets of the unit of the present invention equate to the form of well-known pharmaceutical blister packs. However, the present invention is equally applicable to blister packs providing products or substances other than the pharmaceuticals.

The first sheet of the present invention generally has more than one pocket, commonly two rows of pockets. The first sheet is generally formed of a flexible plastic material, optionally with further layers, as is well known in the art.

The second sheet is preferably formed from a material able to at least close each pocket, more generally seal each pocket. Preferably, the second sheet is also adapted to provide a tamper-evident indication if a pocket has been opened. Generally, the second sheet can be formed of a foil, e.g. a metallic foil. The second layer could optionally be formed of a number of layers of material, as is known in the art.

The flexible cover sheet could be formed of any suitable flexible material, preferably one or more plastic materials. The material should be of sufficient strength to prevent the passage of unit doses therethrough, whilst being resiliently deformable or pliable to bend without breaking.

The cover sheet could be adapted to be biased to preferentially flex in or against one direction, so as to either assist flexing away from the second sheet for the release of unit doses, or to increase the difficulty to flex the cover sheet away from the second sheet, and so increase the child proof nature of the unit, and so as to help return the unit to its ^λsafe' or ^Λclosed' position once used.

The cover sheet could be biased against or for flexing in one direction 'by including biasing means, such as designing folds or grooves into the cover sheet, or by including additional means such as strips of more resilient material or ridges on or within the cover sheet. The flexibility can be controlled by the number, type, material or positioning of the biasing means. The biasing means could be to keep the third sheet generally adjacent to the first and/or second sheet. The unit could be adapted such that the first sheet and cover sheet are biased to flexing in one direction, i.e. co- planarly, which requires particular attention to bias the cover sheet away from the first sheet.

The cover sheet may be secured to the first and/or second sheet using any suitable fixing method or design, including, but not limited to, the use of adhesives, welding, gripping, hooking, poppers, or other conjunction or male and female locking means, in a manner to effectively secure the two parts so that they cannot reasonably be detached or disunited. Alternatively, at least one side of the cover sheet to be fixed to the first and/or second sheet is formed integrally therewith. Where two opposing sides are to be fixed, the other side of the cover sheet could then be subsequently fixed in a manner as described above once the pockets are filled with unit doses.

The cover sheet could be fixed to the first and/or second. sheets at any suitable distance from the location of the pockets. In one embodiment, the cover sheet is fixed to at least the first sheet along the edges of the sheets.

In ^"another embodiment, the cover sheet extends over at least one edge of the first sheet, and further optionally, is at least partially fixed to the first sheet on the pocket side of the first sheet. The cover sheet may extend partly, substantially or wholly over the pocket side of the first sheet.

According to a further embodiment of the present invention, the unit includes one or more further sheets being integrally formed or fixed with the first, second and/or cover sheets. Preferably, at least one such further sheet is wholly or substantially co-planer with the first, second and third sheets. In one embodiment, the further sheet (s) could form at least a cover over the pockets, more preferably a general enclosure or box- like form around the blister pack.

The cover sheet, and/or any additional sheet as described above, could include written or diagrammatic information concerning the unit doses or other products therein, such as details about the unit doses, the dosing rate, the user's name, and/or contraindications or antidotes to the unit dose. Thus, such information could be located with the unit for more immediate reading and availability, than for instance on separate packaging or leaflets as is common in the art.

In particular, current pharmaceutical legislation requires the product name, batch no, manufacturer & the expiry date to be present on the foil of a pharmaceutical blister pack. This information must be readable even when there is only one unit dose remaining in the pack. The present invention allows this information to be put on the cover sheet, as the blister pack and the cover sheet cannot be separated.

The present invention could also include a transparent or other cover over the pockets. Such a cover could be held in position by hinges, slides, catches or other similarly effective means, and may employ a locking means to further improve childproof properties. The cover could be unlocked, slid off or folded back on a hinge or otherwise cleared from the pockets to enable access for the release of unit doses. The cover could then be replaced and held in position by similar means.

The present invention therefore extends in a second aspect to a container or carton including a blister pack unit as hereinbefore defined. In another embodiment of the present invention, the cover sheet comprises or includes one or more bars or strips, each strip or bar adapted to be adjacent to one or more blister pockets, for instance a number of blister pockets in a row. The bars or strips may be individually fixed to the first and/or second sheet, or be conjoined with one or more conjoining members at the or both ends thereof, which conjoining members are then fixed to the first and/or second sheet. The bars or strips are preferably independent from each other, and provide the ability for access to be limited to a number- of pockets only. Thus, each separate strip would be required to be flexed away from the first sheet to create an open space thereinbetween for the release of the unit dose or doses thereunder. Separation of each strip could be further controlled by the opening of a seal such as a tear-off strip or other means, before flexing.

The use of individual strips or bars increases the child-resistance, by limiting the number of- unit doses which could be released in any one instance. The use of individual strips or bars could also assist in the application of sequential dosing, and the realisation thereof to be user.

Where the cover sheet is fixed to the first and/or second sheet along two opposing sides, the unit requires to be squeezed on such sides in order to bring the sides closer, to create the space and allow release of a unit dose. This creates an open ^Λtube' structure having two opposing ^''open ends' . Upon release of the unit dose, it can be removed or made available through one of the open ends by the use of fingers, or by tipping the unit dose into the palm of the hand.

In a further benefit of the present invention, mishandling of a unit dose during its release is also reduced in at least two ways. Firstly, should a unit dose have been released from its pocket, but not exited the open space, then accidental release of the unit, e.g. by it being dropped such as by individuals who are elderly or have reduced manual dexterity, will generally result in the released unit dose still being within the unit, and not yet separate from the sheets, and contaminated by being for instance dropped on the floor or indeed lost in the surrounding area. Secondly, present blister packs usually involve the forceful release of the unit dose through the foil into free air, but hopefully towards a hand or other receptacle into which it . can be successfully held or captured. Commonly however, the unit dose is not successfully captured, and again is dropped onto a floor or similar, and so contaminated. Again, the present invention avoids this as the unit dose on release is travelling towards the cover sheet, which at least absorbs the first impact of the ejected unit dose from the pocket.

The or each open end could be additionally sealed to provide a tamper-evident feature. Such seals could be broken by tearing of a strip or strips to create the open sides, only following which can the first and third sheets be flexed.

The open ends could also be initially held open to create a greater three dimensional structure for the unit, wherein the opening or breaking or physical flattening or snapping of any seals causes the cover sheet to then flatten and be adjacent against the ^'first and/or second sheets. In order to aid the transport and storage of the unit of the present invention, with the ends held open, the unit could have a box formed therearound or be placed in a box. Rails or similar guides based inside the container or box so formed could aid location and/or alignment of the unit. The ends of the container or box could be sufficient to prevent the unit from falling out whilst adopting this open form.

The unit of the present invention could include one or more further tamper-evident seals along one or more sides or across one or more sheets, preferably the cover sheet, either longitudinally or laterally. One or more of the seals could be adapted to be resealed, such as by the use of Velcro, a zip, magnetic strips or a zip lock or similar means, as an additional child-barrier.

One end could also be fixed in the manner hereinbefore described for one or sides of the cover sheet, so as to create a pocket-like enclosure. The unit of the present invention will commonly be square or rectangular in shape. Preferably the opposing sides of the first and third sheets to be pressured equate to the two opposing edges of the square or rectangular form.

According to another aspect of the invention, there is provided a blister pack sleeve comprising a flexible planar member and a pair of flanges extending inwardly from opposite sides of the member to define a slot for receiving a blister pack having a flat face and a pocket face, the planar member of the sleeve being able to cover the flat face of the pack and thereby prevent removal of a unit dose from a pocket, wherein said sleeve includes an engagement means adapted to wholly or substantially fix one or more parts of the pack with the sleeve such that release of a unit dose from a pocket of the blister pack is only possible by an opposite flexing of the pack and the planar member of the sleeve.

In this aspect, the sleeve may be a disposible item, possibly useable on a 'one-off basis. Alternatively, the engagement means could be adapted to disengage a blister pack once empty, either by particular agility or the parts or by breakage of the pack such as cutting with scissors. The engagement means could include any uniting arrangement, such as friction areas, Velcro or the like, or the engagement of opposing male and female parts on the pack and sleeve. Embodiments of the present invention will now be described by way of example only, and with reference to the following diagrammatic drawings in which:

Figure 1 is a side view of a unit dose pack unit in a closed position;

Figure 2 is a side view of the unit in Figure 1 in an open position for release of a unit dose;

Figure 3 is a perspective view of the unit in Figure 2;

Figure 4 is a perspective view of a second unit of the present invention;

Figure 5 is a perspective view of a third unit according to the present invention;

Figure 6 is a perspective view a of a unit dose holder according to a fifth embodiment of the present invention along with a pharmaceutical blister pack;

Figure 7 is a variation of the holder shown in Figure 6; and

Figure 8 is a side view of a fifth unit according to the present invention.

Referring to the drawings, Figure 1 shows a blister pack unit 2 in a rest or 'closed' position. The 1 unit 2 has a flexible first sheet 4 showing two

2 blister pockets 6 within which could be located

3 pharmaceutical tablets and the like, as unit doses. 4

5 Fixed to the first sheet 4 is metallic frangible

6 second sheet 8. Its distance from the first sheet 4

7 is exaggerated for illustrative purposes only. in

8 practice, the second sheet 8 is generally welded to

9 the first sheet so as to close the pockets 6, and 10 often to hermetically seal the pockets 6.

11

12 Fixed to the first and second sheets 4, 8 is a cover

13 sheet 10 formed of a resilient plastic material such

14 as polyurethane. The cover sheet 10 is fixed along

15 its two opposing sides 12 so as to extend across all

16 the pockets 6 and be^' generally adjacent to the

17 second sheet 8. Again, the spacing of the cover

18 sheet 10 from the other sheets 4, 8 in Figure 1 is

19 for illustrative purposes only, and in practice, the

20 three sheets 4, 8, 10 would be wholly or

21 substantially very close and co-planar. Certainly,

22 • the distance of the cover sheet 10 from the second

23 sheet 8 is less than the dimensions of a unit dose

24 in the pocket 6. 25

2.6 Figures 2 and 3 show the blister pack unit 2 in use.

27 As shown in Figure 2, pressure applied along arrows

28 A, generally by fingers and/or palms of a hand(s),

29 cause the first and second sheets 4, 8, and the

30 cover sheet 10, to flex oppositely, so as to create

31 an enlarged space 14 thereinbetween. The

32 introduction of a utensil or finger between the sheets 4, 10 may assist in their separation and opposite flexing.

This enlarged space 14 is intended to be greater than the dimensions of a unit dose in the pocket 6. Thus, pressure put on the pocket 6, -generally by one or more fingers, forces the unit dose therein to go though the second sheet 8, and be released from the unit 2 into the open space 14. The unit dose can then be retrieved by tilting the unit 2, or using further fingers to extract it from within the unit 2. Release of the pressure along arrows A returns the sheets 4, 8 and 10 to their original positions shown in Figure 1, preventing further release of unit doses from the unit 2 purely by pressure on the pocket 6.

Thus, the present invention improves the child- resistant nature of blister packs, in particular pharmaceutical blister packs, by requiring the simultaneous application of pressure along arrows A during the actual release of a unit dose. This combination of actions should reduce the possibility of accidental release of unit doses by inquisitive fingers when not desired. Meanwhile, the actions are ,,easy to understand and carry out by adults,,., and the return of the blister pack after release of a unit dose to the 'closed' configuration shown in Figure 1 without requiring positive action by the user, further assists in ensuring that the blister pack unit 2 will inherently be in its safe configuration when not in use. The default configuration of the blister pack unit 2 is therefore in the improved safety position.

Moreover, the blister pack unit 2 involves no complete separation or disengaging of parts to allow access to the unit doses. This avoids the need for reassembley by the user to return the blister pack to a safe configuration. For instance if a blister pack is separated from the holder of GB2352231, the blister pack is still partially child safe, (i.e. a blister pack as on the market today) . However, in the present invention, the blister pack cannot be totally separated from the cover sheet, and as such it remains child safe at all times.

Further, the shape of the blister, pack units 2 in Figure 1 adds little, if any, further space to the overall size and configuration of a blister pack without the cover sheet, thereby ensuring that existing manufacturing packaging and transport arrangements need not be altered, i.e. resized or rehoused, so avoiding increased packaging, transport and storage costs.

The present invention also reduces the possibility of accidental access to the content of the pockets 6 caused by twisting the blister pack such as to rupture the frangible second sheet 8. The invention reduces this likelihood as the cover sheet 10 adds rigidity to the whole structure. Furthermore, if there is rupture of the frangible second sheet 8 whilst the unit 2 is in its closed position, as shown for example in Figure 1, the contents of the pockets 6 can still not be released.

Figure 3 shows a perspective view of Figure 2, illustrating an open end created by the 'tube' like structure of the blister pack unit 2 in its open- configuration.

The cover sheet 10 is preferably heat welded to the other sheets 4, 8, generally in a production process following the filing of the pockets 6 and location of the second sheet 8 thereover.

Figure 4 shows a second blister pack unit 20 of the present invention. In this arrangement, generally having the same blister pack arrangement 22 of Figures 1-3, the cover sheet 24 has flanges 26 extending over the edges of the blister pack 22, which flanges 26 are conjoined by strips 28 so as to envelop the blister pack 22. In this arrangement, the cover sheet 24 is fixed to the first sheet of the blister pack 22 on its pocket side, preferably along each flange 26, and/or each strip 28. This can increase the area of fixation between the cover sheet 24 and the blister pack 22.

Figure 5 shows a third unit 30 wherein the cover sheet includes a number of strips 34, each strip 34 covering for example two pockets in a row (as shown in the blister packs in Figures 3 and 4) . Each strip 34 is independent, thereby requiring separate flexibility of each strip 34 for access to the pockets thereunder, thereby avoiding the availability of unit doses from other pockets at one time.

Figure 6 shows a blister pack 38 and a blister pack holder 40. The holder 40 comprises a flexible planar member 42 and a pair of flanges 44 extending inwardly from opposite sides of the member to define a slot 46 for receiving the blister pack 38. The planar member 42 covers the flat face 48 of the pack 38 and thereby prevent removal of a unit dose from a pocket 50. The inside of the planar member 42 and flanges 44 are partly, substantially or fully coated with a gripping surface adapted to engage and retain the blister pack 38 in the sleeve 40 by friction.

Figure 7 shows a cover sheet 60 having a fold line 62 that runs parallel to the sheet sides. This fold line biases the bending action of the cover sheet 60 'inwardly', i.e. generally in the same direction as the flexing of a blister pack and in a direction opposite to the one required for access to the blister pockets. This improves the child resistant property. Only by inducing the bend in the cover sheet 60 away from its desired direction, would the enlarged open space be made available for the release of a dose unit. The use of fold lines and similar is applicable to all variations of the cover sheet shown and described herein.

Figure 8 shows a further blister pack unit 70, wherein the cover sheet 72, in exaggerated form for illustrative purposes only, is shown being extended to create side and top walls 74, 76 around^" the blister pack 78, so as to create a container, carton or box like structure around the blister pack 78. The cover sheet 72, side walls 74 and top wall 76 are preferably integrally formed, and folded during the manufacturing process. The fixing of the cover sheet 72 to the blister pack 78 and itself is shown diagrammatically in Figure 8.

The present invention provides a simple but effective improvement to the resistance to accidental opening and access to the contents of blister packs. This is particularly important for pharmaceuticals, and to increase their 'child- resistance' . The present invention provides a single blister pack unit which can easily be formed during the manufacturing process, whilst not affecting the size and nature of existing blister packs and their packaging. The present invention also enables the use of the already existing thinner •■ foils which are easier for the elderly to. break and in combination with the cover sheet offer much improved child safe dispensing units.

Claims

1. A blister pack unit, said unit comprising a flexible first sheet having at least one blister pocket formed therein for the location of a unit dose, a frangible second sheet located across the first sheet to close the or each pocket, and a flexible cover sheet, characterised in that the cover sheet is fixed to one side, or to two opposing sides, of the first and/or second sheets so as to extend across the or each pocket and be generally adjacent to the second sheet.

2. A blister pack unit as claimed in Claim 1 wherein the cover sheet is spaced from the first and/or second sheet by a distance less than the dimensions of a unit dose.

3. A blister pack unit as claimed in Claim 1 or Claim 2 wherein the cover sheet is fixed to the first sheet and/or second sheet on opposing sides.

4. A blister pack unit as claimed in Claim 3 wherein the cover sheet is fixed to the first sheet partly, substantially or wholly along its sides.

5. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet and the first sheet are adapted to flex oppositely upon 19

pressure on the fixed sides, so as to form an enlarged space thereinbetween.

6. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet is biased to preferentially flex in or against one direction.

7. A blister pack unit as claimed in Claim 6 wherein cover sheet includes biasing means.

8. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet is fixed to the first and/or second sheet by heat welding.

9. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet is fixed to at least the first sheet along the edges of the first and cover sheets.

10. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet extends at least partially over the pocket side of the first sheet.

11. A blister pack unit as claimed in any one of the preceding Claims wherein the cover sheet comprises or includes one or more bars or strips, each strip or bar adapted to be adjacent to one or more blister pockets. 20

12. A blister pack unit as claimed in any one of the preceding Claims wherein the unit includes one or more tamper-evident seals.

13. A blister pack unit as claimed in any one of the preceding Claims wherein the unit is square or rectangular.

14. A blister pack unit as claimed in any one of the preceding Claims wherein the unit is a pharmaceutical blister pack unit.

15. A container including a blister pack unit as claimed in any one of the Claims 1 to 14.

16. A blister pack sleeve comprising a flexible planar member and a pair of flanges extending inwardly from opposite sides of the planar member to define a slot for receiving a blister pack having a flat face and a pocket face, the planar member of the sleeve being able to cover the flat face of the pack and thereby prevent removal of a unit dose from a pocket, wherein said sleeve includes an engagement means adapted to wholly or substantially fix one or more parts of the pack with the sleeve such that release of a unit dose from a pocket of the blister pack is only possible by an opposite flexing of the pack and the planar member of the sleeve.