SUBSTRATE SECTIONS WITH IMPROVED STORAGE STABILITY DURING THEIR STORAGE IN BAGS, AND A METHOD FOR PRODUCING THE SAME

SECTIONS DE SUBSTRAT A STABILITE AU STOCKAGE AMELIOREE LORS DE LEUR STOCKAGE DANS DES SACS ET LEUR PROCEDE DE FABRICATION

English Abstract

Substrate sections which have been rendered pressure--sensitive
adhesive and sealed in bags so as to be protected
against loss of active substance, the pressure-sensitive
adhesive surface of which is covered by a carrier layer
which projects at least partially beyond said substrate
sections and is divided by an incision, thus forming a
detachment aid, through which incision adhesive may leak
out in cold flow during storage and may cause the substrate
section to stick to the bag, characterized in that in order
to increase storage stability by avoiding leakage of
pressure-sensitive adhesive, the carrier layer is configured
with two carrier layer sections (2, 3) which over-lap
each other in the region (4) where they are joined.
(Fig. 1)

French Abstract

La présente invention concerne des sections de substrat auto-adhésives, protégées contre les pertes de matière active par scellement en sacs. La surface auto-adhésive desdites sections est couverte par une couche porteuse qui fait au moins partiellement saillie sur ladite surface. Ladite couche porteuse est séparée par une encoche, formant une aide au détachement. Pendant un stockage, l'adhésif peut sortir par cette encoche en flux froid et engendrer un collage avec le sac. Cette section de substrat se caractérise en ce que la couche porteuse comporte deux sections de couche porteuse (2, 3) qui se chevauchent dans la zone de leur assemblage (4), afin d'améliorer la stabilité au stockage en évitant la sortie d'adhésif de la couche porteuse.

Claims

Claims:

1. A substrate section which is sealed in a bag, comprising a backing layer
and a matrix which is
connected with said backing layer and is comprised entirely of a pressure-
sensitive adhesive
material or has been rendered pressure-sensitive adhesive on its application
surface by
providing said surface with a pressure-sensitive adhesive layer, the pressure-
sensitive adhesive
surface of said matrix being covered by a carrier layer which projects at
least partially beyond
said substrate sections and is divided by an Incision, wherein to increase
storage stability by
avoiding leakage of pressure-sensitive adhesive, the carrier layer is
configured with two carrier
layer sections which overlap each other In the region where they are joined.


2. The substrate section according to Claim 1, wherein one of the carrier
layer sections Is wider
than the other section by the amount of the overlap.


3. The substrate section according to Claim 1, wherein both carrier layer
sections are, by the
amount of half the overlap, wider than half the width dimension of an
undivided carrier layer.


4. The substrate section according to any one of Claims 1 to 3, wherein the
region of overlap is
positioned centrally or eccentrically on the substrate section.

Description

CA 02373276 2001-12-03

The invention relates to substrate sections which have been
rendered pressure-sensitive adhesive and are sealed in bags
so as to be protected against loss of active substance, the
pressure-sensitive adhesive surface of which is covered by
a carrier layer which at least partially projects beyond
the said substrate sections and is divided by an incision,
thus forming a release aid, through which incision pres-
sure-sensitive adhesive may leak out in cold flow during
storage and may cause agglutination with the bag.

it is known how to manufacture and use flat-shaped pres-
sure-sensitive adhesive substrate sections. These may be,
for example, active substance-containing transdermal
therapeutic systems. if such systems contain volatile
components, for example as active agents, there results the
necessity of protecting the substrate sections which have
been provided with these components against evaporation of
the volatile components during the time span between
manufacture and use, that is, during their storage up to
their application.
This is achieved, for example, by providing the pressure-
sensitive adhesive substrate sections with a detachable
carrier layer so as to protect their pressure-sensitive
adhesive surface and subsequently sealing the sections in a
bag surrounding the same on all sides. Here it is con-
venient for the carrier layer to project beyond the pres-
sure-sensitive adhesive surface of a substrate section so
as to, on the one hand, facilitate the peeling of the
carrier layer off the substrate layer prior to use, and, on
the other hand, prevent the substrate sections from
sticking to the package surfaces as a result of pressure-


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sensitive adhaolva material leaking in co].d flow. when the
packags is open only at one side, such sticking would make
removixig the laminate more dif f icult or evon render it
impossible.
To olimf.nate this problem, it has already been proposed to
provide an incision in the detachable carrier layer, which
results in easier detachment of the carrier layer and
enablas application of the pressure-sensitive adhesive
substrate sections to the site of application in a patient.
A disadvantage of this measure raxuits from the fact that
during storage of the packaged substrate sections it is
still possible for the pressure-senaitive adhesive to leak
out at the cutting edge of the detachable carrier layer by
way of cold flow, it may thus cause extremely dieadvatstiage-
ous sticking of the sections to the aurfaces of the
package, so that e,vitbdrawing the laminate from a package
which is open at one side is made even more difficult or
impossible.

It i.a the object of the presant invention to provide, =in a
substrate section of the kind mentioned as defined herein,
an embcdimer-t of the carrier layer
provided with a releasing aid, by means of which embodiment
the leaking-out of pressure-aensitive adhesive in cold flow
caa be prevented easiZy,and with simple means, thus facili-
tating easy withdxawzll of substrate aeations from a package
which is open oaly at one side.

'1'his object is achieved by the invention in a substrate
section of the kind mentioried at the beginning hereof by
the fact that to incraaae the storage stability the carrier
layer is configured with two carrier layer sections which
overlap each other*ia the area where they are joined
together, prevent3.ng the leaking-out of adhesive.
.
=


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To great advantage, by means of this surprisingly simple
embodiment of the carrier layer, the leakage of adhesive
and thus any sticking to the packaging material is pre-
vented, and the removal of the laminate when the package is
open only at one side is facilitated without difficulty,
while the detachability of the carrier layer from the
substrate section remains undiminished.

A process for forming substrate sections comprising carrier
layer sections, which carrier layer sections project beyond
the said substrate sections and form a region of overlap,
is characterized in that the said carrier layer sections
are supplied with the pressure-sensitive adhesive substrate
sections via a dispensing process, for example, according
to WO 92/17237, after the carrier layer sections have been
overlapped.

Further details, features and advantages of the invention
will become apparent from the following explanation of an
embodiment example represented schematically in the
drawing.
Fig. 1 shows the substrate layer 1 in cross-section,
comprising a backing layer 5 and a matrix 6 connected
thereto. Said matrix may either be comprised entirely of a
pressure-sensitive adhesive material or be rendered
pressure-sensitive adhesive on its application surface by
providing it with a pressure-sensitive adhesive layer (not
shown). The pressure-sensitive adhesive surface or the
pressure sensitive adhesive-rendered matrix 6, respective-
ly, is covered by a carrier layer which projects beyond
said matrix 6 at least partially and which according to the
invention is configured with two carrier layer sections 2,3
which overlap each other in the region where they are
joined.
Due to the fact that the carrier layer sections 2, 3
project beyond the matrix 6 at the side edges 7, 8 in a


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manner known per se, in the possible case of adhesive
leaking out, any sticking to the package bag is reliably
prevented.
On account of the fact that the carrier layer 2,3, which is
assembled in two parts for reasons of better detachability,
is configured with a region of overlap 4, the said carrier
layer prevents, also in this region, the leaking-out of
pressure-sensitive adhesive in cold flow during a prolonged
storage.

One embodiment provides for one of the carrier layer
sections 2 to be wider than the other section 3 by the
amount of the overlap 4.

However, one may also take the measure of configuring both
carrier layer sections 2, 3 to be wider, by an amount of
half of the overlap, than half the width dimension of an
undivided carrier layer 1.

Furthermore the region of overlap 4 may be placed either
centrally or eccentrically on the substrate section 1,
without diminishing its function as a detachment aid. This
measure facilitates manufacture and its control.

A process for forming substrate sections 1 comprising
carrier layer sections 2, 3 which project beyond the said
substrate sections and form a region of overlap 4 is
characterized in that the carrier layer sections 2, 3 are
supplied with the pressure-sensitive adhesive substrate
sections 1 after the said carrier layer sections 2, 3 have
been overlapped.

The solution according to the present invention is
surprisingly simple and optimally solves the task posed at
the beginning hereof.

Representative Drawing