Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a tamper-evident,
child resistant package of the type openable by means of
a tear strip. The invention especially relates to blister
packs provided with tear strips to access the blisters.
More especially the invention relates to blister packs
adapted to contain unit dose capsules, tablets or like
products.
It is desirable to provide for tamper evident
packaging which will give a clear indication when the package
has been subject to tampering. However, at the same time
the package must be sufficiently easy for the average consumer
to open while, preferably, being child-resistant.
A conventional package often comprises a laminate
of a blister layer having article receiving pockets with
a foil backing layer. The foil material i5 rupturable
to release the article. While such a package is tamper-
evident unless the whole foil layer is replaced, it is
not very child resistant. US Patent No 4,537,312 to
Intini shows one improvement over the conventional blister
packages described. That patent describes and claims a
package in which such a conventional package is enclosed
between an outer front layer and an outer back layer sized
larger than the conventional package and sealed to one
another around their periphery and through apertures in
the laminate. Tabs are provided at the edges of the sealed
front and back layers connected to tear strips in the back
layer each of which overlies foil covering a blister pocket.
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At least the tear strips of the back layer are made of
a material which, on tearing, will leave a stratum still
overlying the foil to thereby reinforce it.
Such a package is, due to the provision of both
front and back layers, considerably more expensive in materials
and manufacturing steps than the simple blister pockets
with unprotected foil backing. Moreover, in some cases
where the contents of the pockets are very light, increase
the weight and thus shipping costs by a very substantial
amount. Moreover, the manufacturing steps involved are
dependent on the number of layers in the package.
It is an object of the present invention to provide
an improved tamper-evident, child resistant, blister package.
It is a further object of the invention to provide
a tamper-evident, child resistant, blister package having
a reinforcement against tampering in which the weight and
hence material, manufacturing and shipping costs are reduced.
Another object of the invention is to provide
a simple method of making a tamper-evident, child resistant,
blister package.
According to the invention is provided a blister
package to contain a number of articles, such as medicaments
in the form of capsules, tablets or the like or non-
medicaments such as batteries, nuts, bolts, hooks or other
small hardware, comprising an outer front blister layer
including a number of article receiving pockets, a rupturable
film sealed to the blister layer and overlying the pockets,
and a reinforcing back layer formed of material which,
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on tearing, separates into strata, the back layer comprising
a matrix adhered to the rupturable film sealed to the
blister layer, a number of tear strips adhered to the
rupturable film overlying the pockets and a manually grippable
tab for each tear strip, the tabs being free of the rupturable
film.
Preferably the blister layer is provided with
a number of indentations, each indentation being in the
vicinity of at least one of the pockets, and at least one
tab overlying an indentation whereby finger access to the
tab is aided.
More preferably, ~hen indentations are provided,
the rupturable film extends into the indentations and is
sealed onto a surface of the indentation.
According to another aspect of the invention
is provided a method of forming a blister package comprising
forming a blister sheet with a front surface and a rear
surface and havlng a number of pockets open at the rear
surface, delivering an article such as a capsule, tablet
or the like into each pocket, sealing a rupturable film
to the blister sheet rear surface to close the pockets,
selectively adhering the rupturable ilm to a reinforcing
layer whereby portions of Eilm and layer in the vicinity
of each pocket are free from each other, the reinforcing
layer being formed of material which, on tearing, separates
into strata and comprislng a matrix having a number of
tear strips located to overlie the pockets and a manually
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grippable tab for each tear strip, each tab comprising
a free portion of the rupturable film.
Preferably the rupturable film may be selectively
adhered to the reinforcing layer by applying a heat sealable
coating to the bottom of the rupturable film and/or a
compatible heat sealable coating to the top surface of
the reinforcing layer and applying heat and pressure to
seal the film to the layer except to said portions whereby
said portions of layer and fi]m are unsealed.
Preferably the blister layer is provided with
a number of indentations, each indentation being in the
vicinity of at least one of the pockets, and the portions
of the rupturable film and reinforcing layer overlie the
indentations.
More preferably, when indentations are provided,
the rupturable film extends into the indentations and is
sealed onto a surface of the indentation by means of a
heat sealable coating compatible with the blister layer.
Conveniently the indentations are formed after sealing
of the rupturable film to the blister sheet, for example
by pressing. As is known in the art the blister sheet
may include plurality of article receiving pockets for
unit doses of pharmaceutical products. The sheet may comprise
a normally rectangular continuous blister sheet of a
flexible clear film which cannot be easily ruptured. Such
a film may be, for example, a vinyl thermoplastic film
about 12mls thick. Examples of rupturable film are also
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well known in the art. It may be co-extensive with the
blister sheet and may be formed of aluminum foil approximately
lml thick and may be joined to the blister sheet by convent-
ional heat sealable coatings under heat and pressure,
The reinforcing layer is suitably a paper product,
for example card. The tear strip may be defined by parallel
lines of perforations or slots in the reinforcing layer
forming longitudinal tear lines of the strip. One end
of the strip may end at the edge of the reinforcing layer
and at the other end it may be provided with its tab. The
tab may be rectangular and integral with the strip at one tab
edge while the other three edges may be defined by cuts through
the reinforcing layer. To facilitate bending the tab outwardly
from the tear strip and matrix without disturbing the tear
strip, a score line may be provided between tab and tear strip.
An embodiment of the invention will now be
described by way of example with reference to the drawings,
in which:
Fig. 1 is an isometric exploded view of a package
embodying the invention,
Fig. 2 is a top elevational of the package o~ Fig. l,
Fig. 3 is a side elevation of the package of
Figs. l and 2,
Fig. 4 is a bottom plan view of the blister sheet
of the illustrated package,
Fig. 5 is a bottom plan view of the blister sheet
with rupturable film in place,
Fig. 6 is a bottom plan view of the complete package,
Fig. 7 is a section along the line 7 - 7 of Fig. 2,
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Fig. 8 is a section along line 8 - 8 of Fig.
2 showing the package bent -to expose the leading edge of
a tab to facilitate opening,
Fig. 9 is a partial isometric view of a tablet
containing package illustrating removal of the tab and
tear strip.
Referring to the drawings, a package for unit
doses of pharmaceutical tablets comprises a front blister
sheet 10, rupturable film 12 and a reinforcing layér 14.
The blister sheet 10 may be clear, vinyl plastic about
12ml thick, the rupturable film is usually foil about
lml thick and will, hereinafter be referred to as foil,
and the reinforcing layer may be card and may be of any
convenient thickness as will separate into strata on tearing.
The blister sheet 10 comprises a number of bubbles
or pockets 16 projecting from its front surface to contain
tablets 28 and also is provided with indentations 18 each
of which is located between two pockets 16. Foil 12 is
sealed onto the rear surface of blister sheet 10 in any
convenient manner for example, by the use of a conventional
sealant to close the pockets 16.
In manufacture, the indentations 18 may be formed
in the blister sheet before or after the foil is applied.
It is however, convenient to apply the foil to the flat
surface and thereafter form the indentations, stretching
the foil slightly in the process.
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The reinforcing layer 14 may be adhered to the foil
12 using a suitable heat sealable coating which is applied all
over the surface of the foil, for example hy means of a flexo-
graphic printing press. Alternatively, the coating may be
applied to the reinforcing layer.
The reinforcing layer comprises a matrix 22 and tear
strips 24 having tabs 26~ the layer being proportioned and
located so that the tear strips 24 lie over the closed pockets
16 and the tabs lie over the indentations 18. The matrix 22 and
the tear strips are firmly attached to the foil 12 by the
adhesive such that any attempt to pull the matrix and/or the tear
strips 24 away will result in the reinforcing layer 1 separating
into strata 28 (see Fig. 9) rather than total removal from the
foil 12.
The tear strips 24 are formed by parallel cuts from
edge to edge of the reinforcing layer. The cuts are located so
that the strip between each pair of cuts covers two pockets 16
and an indentation 18 thus forming two tear strips 24 and their
tabs 26 so that the reinforcing layer will remain of unitary
structure before it is applied to the foil 14, it is convenient
that at least over part of the length of each cut there are
interruptions of the cut. Thus suitably, the cuts have slotted
or perforated portions 32 over the length of the tear strip 24.
That portion 31 of the cuts defining the tabs 26 should be made
as clean cuts so that the tab is more easily grasped in the fingers.
The tabs 26 are delineated from their respective tear strips by
a score line 30 whereby the tabs 26 are more easily bent away
from the package to be grasped in the fingers.
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While a package of particular configuration of
reinforcing layer has been described, it is to be appreciated
that the configuration of the reinforcing layer is only of
importance in that the tear strips 24 should overlay the
pockets and that the grippable tabs 26 should not adhere
to the foil. In particular, an embodiment is described
in which two tabs from different tear strips are located
to share the unsealed area of single indentation. Clearly,
an indentation may be provided for each tab if desired.
In operation, the user wishing to obtain a tablet
from a pocket bends the package thereby exposing the leading
edge of one of the tabs 26. He can then grip the tab 26
- in his fingers. Alternatively, as the finger approaches
the tab, it will automatically push the adjacent tab 26
into the underlying indentation 18 facilitating access
to the desired tab 26. Having taken hold of the tab, the
userpulls it outwardly and toward the edge of the package
generally parallel to the cuts 32 defining the long edges
of the tear strip 24. The tear strip 24 will separate
into strata 28 and the top stratum attached to the tab
26 will pull back revealing the bottom stratum and indicating
that the package is partially open or that an attempt has
been made to open it. The tablet may thereafter be accessed
through the bottom strata and the foil by conventional
means such as by pushing the tablet and pocket towards
it while at the same time deforming the pocket to stretch
the foil and reinforcing layer to a point which facilitates
breaking them with the aid of the product to be dispensed.
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