Note: Descriptions are shown in the official language in which they were submitted.
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DRESSINGS
The present invention relates to adhesive dressings
for use on skin and to the application of such dressings
to the human body. In particular, this invention relates
to self-adhesive conformable dressings in a presentation
which allows easy and sterile application of the dressing.
Certain favoured self~adhesive conformàble dressings
known in the art usually comprise a polymeric film having
an adhesive on at least part of its surface. Such
dressings are sold for various uses which include
attaching catheters to the body. Several presentations of
such dressings are known and include the following:
A first dressing is known as Bioclusive Transparent
Dressing (trade mark of Johnson and Johnson Products
Inc.), which is a self-adhesive conformable film presented
so that it is adhesive over the major part of one of its
surfaces, leaving a non-adhesive tab at one side-edge/ the
total area of the film being co-terminous with a backing
sheet to which the self-adhesive part of the film is
adhered, the non-adhesive tab and the corresponding part
...., ~,
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of the backing sheet being perforated to allow removal of
the tab.
I
A second dressing is known as Ensure (trade mark of
Parke Davis and Co.) which is a self-adhesive conformable
film, presented with the adhesive surface of the film
adhered to a removable backing sheet, the film having
attached thereto, along one side-edge, a first
non-adhesive tab, the non-adhesive surface of the film
being covered with a removable protective layer which has,
along one side-edge, a second non-adhesive tab attached by
the side-edge of the tab remote from the centre of the
protective layer.
A third dressing is known which is a self-adhesive
conformable film, presented as described in~European
Patent Application No. 51,935. In one of these
presentations, available as Tegaderm (trade mark of and
available from Minnesota Mining and Manufacturing Co.) the
adhesive surface of the film is adhered to a backing sheet
or release liner, the backing sHeet being wider than the
film, thus forming a tab at one side-edge to allow removal
of the backing sheet, the non-adhesive surface of the film
being covered with a removable protective layer or
releasable layer having a centre cut-out which, when
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removed, forms a window, the remaining frame being
removable by means of a tab alony its side-edge or by
means of a split in the frame.
In each of the preceeding known presentations,
therefore, the means for releasing the backing sheet from
the film is situated at a side-edge of the film. It has
been found that this can result in difficulties in
centring the dressing about a catheter (or part of the
body), since one side of the dressing adheres to the
catheter before the other side can be positioned. This in
itself also leads to the possibility of 'rucking' of the
dressing, leaving gaps around the catheter and surrounding
skin which defeats the aim of sterility.
In a fourth known presentation which is described in
European Patent Application No~ 81990, published after the
priority date of the application for the present invention
a dressing, is known in which a backing layer is secured
to the non-adhesive side of the film to improve
handleability of the dressing. The backing layer is an
opaque, fibrous material. This means that it is not
possible to see through the dressing to accurately
position it on the skin, particularly important when the
dressing is to be used to surround a catheter. The
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dressings of the present invention overcome this
disadvantage by providing a backing layer or support layer
on the non-adhesive side of the film in the form of a
transparent polymeric layer.
Other difficulties arising with the above-described
hitherto-known presentations include major problems in
applying the dressing without touching the adhesive,
thereby defeating the aim of sterility.
The ~irst dressing described above also suffers from
the disadvantage of having to remove a tab from the
dressing once it is in place: this can cause movement and
rucking of the dressing.
The present invention helps overcome these problems
by providing a dressing comprising a self-adhesive
conformable film adhered to a removable protector, which
protector has means in the form of handles for releasing
it ~rom the film, ¢haracterised in that the release means
is situated away from the side-edges of the protector~
It is clear from the above ~herefore that the present
invention provides an adhesive dressing suitable for use
on the skin which comprises (a) a bacteria proof~
transparent film coated with adhesive on one ~ace, ~b) a
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protector over the whole of the adhesive which protector
consists of a first part and a second part, the first part
disposed over one side of the dressing and the second part
-disposed over the remainder of the dressing said first and
second parts being adapted to provide handles whereby said
first and second parts can be grasped and peeled away from
the adhesive and (c) a removable transparent polymeric
film support layer over the non-adhesive face of the film.
The first and second parts of the protector together
cover the whole of the adhesive face of the film. The two
parts meet or overlap at a point away from the edge of the
dressing. The two parts may be of unequal area but
preferably will have an approximately equal area in
contact with the adhesive face in which case they will
meet or overlap about a line approximately at the centre
of the dressing. Such a dressing in which the areas are
equal is within the scope of the present invention.
Thus in a favoured aspect the present invention
provides a dressing which comprises (a) a bacteria-proof
transparent film adhesive film coated with adhesive on one
face and (b) a protector over thè whole of the adhesive
which protector comprises a first and second part, the
first part disposed to one side of the dressing and the
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second part disposed over the remainder of the dressing,
said first and second parts abutting and each of said
first and second parts possessing a portion bent back away
from the plane of the dressing whereby said first and
second parts can be grasped and peeled away from the
adhesive and (c) a removable transparent polymeric film
support layer over the non-adhesive surface of the film.
Most aptly the first and second parts abut along an
approximately central line across the face of the
dressing.
This invention therefore includes the advantage of
being able to position the dressing over a catheter (or
part of the body) so that a middle part of the dressing
first adheres to the catheter. By 'a middle part' is
meant a part of the dressing which is not a side-edge.
The protector can then be gradually released from the
middle in a direction towards each side-edge, thereby
greatly reducing the possibility of rucking the dressing
an~ increasing the chances of maintaining sterility.
The two parts of the protector may abut each other
where they meet or more preferably the second part may
overlie a portion of the first part of protector without
having a bent back portion or may overlie a portion of the
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first part of the protector and then have a bent back
portion.
I
Thus in a preferred aspect the present invention
provides an adhesive dressing suitable for use on the skin
which comprises (a) a bacteria proof, transparent film
coated with adhesive on one face, (b) a protector layer
over the whole of the adhesive which protector comprises a
first part and a second part, the first part disposed to
one side of the dressing and the second part disposed over
the remainder of the dressing, said first part possessing
a portion which is bent back away from the plane of the
dressing, said second part overlapping onto the first part
over the bent back portion whereby said first and second
parts can be grasped and peeled away from the adhesive and
(c) a removable transparent polymeric film support layer
over the non-adhesive face of the film.
In a further preferred aspect the present invention
provides an adhesive dressing suitable for use on the skin
which comprises ~a) a bacteria proof, transparent film
coated with adhesive on one face, (b) a protector layer
over the whole of the adhesive which protector comprises a
first part and a second part, the first part disposed to
one side of the dressing and the second part disposed over
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the remainder of the dressing, each of said first and
second parts possessing a portion bent back away from the
plane of the dressing, the second part being adapted to
overlap the first part at least over a part of the bent
over portion of the first part whereby said first and
second parts can be grasped and peeled away from the
adhesive and (c) a removable transparent polymeric film
support layer.
Preferably, in the dressing o~ this invention the
removable support layer covering the non-adhesive surface
of the film is such that the support layer is attached
less tenaciously to the film than is the protector to the
adhesive.
More preferably, the area of the removable support
layer is co-terminous with the area of the film and has
attached thereto, at one side-edge, and extending from the
support layer, a tab to allow its removal. This overcomes
the disadvantage of rigidity exhibited by the frame of the
third known presentation described above, allawiny the
dressing to be more easily applied to curved surfaces.
This also overcomes the disadvantage of the tab
arrangement of the second known presentation described
above, where~ in use, the angle at which the tab has to be
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pulled is such as to increase the likelihood of rucking of the
dcessing once in position.
The con~oemable bacteria pcoof film for use in the present
invention is a tcansparent polymeric film 80 as to allow
observation of the surface to which the dressing i~ to be adhered.
Examples of suitable films, and adhasives the~efor, are described
in Bcitish Patent Specification No. 1,2~0~631, European Patent
Speciication No. 51-935 (especially the polyurethanes) and f ilm6
prepared from the hydrophilic polyurethanes di~losed in European
Patent Specification No. 50035. Films, and adhesives, described
in these specifications are ~prefeeeed~ are al80 to be taken to be
preferred for use in the dressing of thi6 invention.
The adhesive coated film most suitably transmits moisture vapour
at a rate of at least 300gm/m2/Z4 h~s/37C/100-10~ RH, more
favourably at least 900g~m2, desirably at lea8t SoOg/m2 and
peefeeably at least 700g/m2 (when measured by the Payne Cup
Method).
The film is de~ieably formed a synthetic polymer
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including polyurethane and i8 9 to 35 microns thick, more 6uitably
lO to 30 microns thick and prefecably rom 20 to 25 micron6 thick.
The adhesive may be an all over spread, pattern ~pread, a
microporous layer or a porous layer or the like. The adhesive may
be pattern spread using the method described in British Patent No.
~19,635. The adhe6ive may be formed as a porous layer by the
method de~cribed in British Pa~ent No. l,563,695. However, it is
preferred ~hat the adhe ive is in the focm of an all over spread,
that i8 as a continuous layer containing no pore~ or micropores.
Sultable adhe~ives which are moisture vapour transmitting
as an all over spread or continuou6 layer include various acrylate
ester copolymel: and polyvinyl ether pres6ure sensitive adhesive6
for example as disclosed in Briti~h Patent No. 1,230,631.
Favoured pre~ure sensitive adhesives comprise copolymers of
acrylic ester with acrylic acid for example as disclosed in United
Kingdom Application No. 2,070,6~1.
A prQ~Qrred pressure sensitive adhesive comprise6 a blend
of high and low viscosity polyvinyl ethyl ether
-- 10 --
disclosed in British Patent No. 1,280,631. A second
preferred pressure sensitive adhesive is disclosed in
United Kingdom Application No. 2,070,631 as a copolymer of
47 parts by weight 2-ethyl-hexylacrylate, 47 parts by
weight butyl acrylate and 6 parts by weight of acrylic
acid polymerised in acetone.
The adhesive is suitably employed at weights per unit
area of 10 to 75gm 2, more usually 15 to 65gm~2,
preferably at 25 to 40gm~2 for example 29gm~2,
10 329m-2.
The protector may be any convenient material used for
such purposes such as a polymer or paper film and
especially those treated for easy release properties, for
example by siliconisation.
The protector sheet for use in this invention may
comprise any material known to those skilled in the art or
; described in the above-listed specifications. Preferably,
- the protector is of transparent or translucent material
which includes poly(vinyl chloride) or siliconised paper,
such as siliconised glassite paper, or other siliconised
polymers such as high or low density polyethylene which
have been surface treated.
The support layer is most suitably formed from a
transparent polymer such as polyethylene, polypropylene,
polyamide, polyester or the like. Most aptly the support
layer is adapted for easy release from the film, for
example by including a blocking compound or silicone
coating. Generally the layer is 12 to 35 microns thick,
more aptly 15 to 30 microns, for example 20 to 25 microns
thick.
The removable support layer present in this invention
may be made of any suitable transparent polymeric film
material which allows the dressing to be positioned over
curved surfaces. Such materials include low or high
density polyethylene, polypropylene, polystyrene,
cellophane, nylon, polyester or the like.
In another aspect, the present invention therefore
; pr~vides a method of applying a dressing as hereinbefore
described which method comprises positioning the dressing
over the surface to which it is to be applied, such that
the protector is adjacent the surface, and removing the
protector from the film, characterised in that the first
part of the dressing to adhere to the surface is away from
the side-edges of the protector and then remov-i-ng a
support layer from the non-adhesive surface af the film.
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Especially preferred is a method wherein release
means, situated away from the side-edges of the protector,
are used to release the protector.
In a further aspect, the present invention provides a
method of preparing such a dressing as hereinbefore
described -comprising applying-adhesive to at least a part
of a conformable transparent polymeric film, affixing to
said part of the film a protector layer having means for
removing the protector from the film which means is
situated away from the side-edges of the film, and
sterilising the re~ul-ting dressing. The method further
includes the step of less tenaciously affixing a
removable, support layer to the non-adhesive surface of
the film. ~ -
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More preferably, the method still further includes
the step of attaching a non-adhesive tab to the support
layer.
The dressings of this invention may be made by ~a)
extruding the polymer which is to form the film layer
through a die of the appropriate size on to the material
which is to form the support layer which is typically in
film form. An adhesive layer may be cast from solution
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onto a siliconised release paper and then transfer coated
onto the film face of the laminate formed above to form an
adhesive strip. The protector is then applied to adhesive
face of the strip and the resulting strip cut to form
dressings of the desired size; (b) the polymer which is
to form the film and the material which is to form the
support layer may be coextruded to form a laminate strip
of the required thicknesses. The adhesive and protector
are then transferred to the strip in a conventional
manner; (c) the polymer which is to orm the film may be
cast onto the support layer from a solution or syrup, the
solvent of which will not effect the support layer. After
removal of the solvent, a preformed adhesive layer may be
transfer coated onto the film face and finally the
protector added.
~ further step which may be included in the
preparation is to attach a non-adhesive tab to the one
edge of the support layer by means of a thin strip of
adhesive tape.
~nce the dressings have been cut to size they may be
individually placed in bacteria proof packages and the -
package sealed and sterilized in the normal way.
In a still further aspect, the present invention
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provides a sterile dressing according to the invention
contained in a bacteria-proof package.
Such packages include those made from paper, plastic
or aluminium foil.
Preferably, the package contains or incorporates
instructions on how to use the dressing-according to the
invention.
One favoured form of this invention comprises a
dressing 10cm x 10cm which is a 25 micron thick
polyurethane film (such as an Estane 5701F, trade mark of
B.F. Goodrichj coated over one face with a 25 micron thick
layer of acrylic adhesive (such as the preferred adhesive
of European Patent Application No. 51935) in which
dressing a 20 micron thick film of low density
polyethylene which has been siliconised acts as support
layer~and a protector comprises two lQcm x 6cm pieces of
siliconised glassite paper placed so that each has a
10cm x 5cm portion which overlays the adhesive and a
10cm x lcm strip folded back to provide a handle.
Such devices overcome the disadvantages of the
devices of European Patent Application No. 51935 such as
the inflexibility introduced by using a "frame".
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The present invention will now be illustrated by way
of example only, with reference to the accompanying
drawings in which:
Figure 1 shows a cross-sectional view of a dressing
according to this invention; and
Figure 2 shows a plan view of a dressing according to
this invention.
Figure 3 shows a cross-section view of a dressing
according to another aspect of this invention;
Figure 4 shows a cross-section view of a dressing
according to another aspect of this invention.
Referring first to Figure 1, the dressing 1 comprises
a conformable film 2 of polyurethane on one surface of
whic~ is spread an acrylic adhesive 3 to which surface is
adhered a protector 4 of poly(vinyl chloride) or
siliconised paper.
The protector 4 just overlaps the film 2 and is in
two parts 5 and 6. Each of the two parts 5 and 6 terminate
towards the middle (but not necessarily in the centre) of
the sheet 4 in tabs 7 and 8 which overlap so that the
total surface of the adhesive 3 is covered.
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Figure 2 shows the extent of the overlapping 9
between tabs 7 and 8; and also the overlapping 10 between
protector 4 and film 2.
Referrinq back to Figure 1, in this embodiment of
this invention, there is a support layer 11 over the
non-adhesive surface of film 2 made of polyethylene. A
tab 12 is provided at one edge of the layer 11, extending
therefrom and attached thereto by tape 13. Both tab 12
and tape 13 are transparent, tab 12 being a blue colour to
allow easy identification during use.
In use, the device 1 is positioned so that overlap 9
(Figure 2) is over that part of the catheter (or other
surface) which centralises the dressing about the
c~theter. Tabs 7 and 8 are grasped and gradually pulled
toward the corresponding edges of the dressing exposing
adhesive 3, and gentle pressure is applied so that the
dressing adheres to the catheter. The two parts 5 and 6
of the protector 4 are thus removed entirely and disposed
of. Next, blue tab 12 on support layer 11 is grasped and
pulled towards the middle of the device so that support
layer 11 is gradually removed and then disposed of. Thus,
film 2 remains adhered to the catheter by adhesive 3.
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Figure 3 shows a similar dressing to that described
in Figure 1 except that the second part of the protector 6
instead of having a bent back portion 8, overlaps onto the
; first portion of the protector 5.
Figure 4 shows a similar dressing to that described
in Figure 1 except that the first and second part~ of the
protector abut each other and do not overlap.
The adhesive films employed in this invention may be
rëpresented by a membrane coated over one surface with an
adhesive layer. Most suitably the membrane is 10 to 40
microns---thick and-preferably-from--20 to 35 microns thick,
for example 25 microns thick. Most suitable the adhesive
layer is 15 to 65 microns thick and preferably from 20 to
~" microns thick, for-example 25 to 35 microns thick.
Desirably both membrane and adhesive are formed from
moi~ure vapour permeable materials.
Preferably the protector is in two parts which are
approximately equal in size so that the two parts come
together at approximately the middle of the sheet.
Pre~erably each of the two parts of the protector is
adapted-to provide handles for example in the form of tabs
projecting away from the middle of the sheet (that is part
of each of the two parts of the backing sheet is folded
r ~ ~;~;~671
19
back upon itself providing handles).
This invention is particularly effective for
materials having an extension of at least 300~ at
300kg/sq. cm.
EXAMPLE 1 _
Preparation of an Adhesive Dressing
A syrup of a polyurethane (Estane 5701F, trade mark
of B.F. Goodrich) in tetrahydrofuran/acetonè, (solids
content 15~) is cast onto a film of a polyester (Melinex,
trade mark of I.C.I.) to form a film of polyurethane which
is 25 microns in thickness.
A solution of an acrylic ester copolymer, formed from
the copolymerisation of 47 parts 2-ethyl-hexylacrylate, 47
parts butylacrylate and 6 parts of acrylic acid is spread
onto silicone release paper and the solvent removed to
give an adhesive layer at a weight of 29 gm2~
The adhesive layer is then transfer coated onto the
polyurethane face of the laminate formed above.
The two part protector layer is then transferred to
the adhesive coated laminate so as to cover the whole of
the adhesive surface.
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A non-adhesive tab is then adhered to the one edge of
the polyester film by means of an adhesive tape.
The dressing strip so formed is then cut to the
appropriate size.
The individual dressings may be placed and sealed in
a bacteria proof pack and the package sterilised by
conventional means.
In use, the sterile dressing is removed from the
pack, the two parts of the protector peeled a little back
so as to expose a small area of adhesive which is then
accurately placed on the body. The remaining adhesive
surface is exposed by peeling back the protector and the
dressing smoothly applied to the skin. The tab is then
used to remove the support layer from the non-adhesive
face of the dressing.
EXAMPLE 2 _
Preparation of an Adhesive Dressin~
A polyurethane (Estane 58201, trade mark of
B.F. Goodrich) is extruded onto a 20 micron thick film of
low density polyethylene the sur~ace of which has been
siliconised, to form a film of polyurethane 25 microns
thick.
An adhesive layer is formed on a siliconised release
paper as described in Example 1. The adhesive layer is
transfer coated onto the polyurethane face of the
; 5 polyurethane-polyethylene laminate.
The two part protector is then placed on the adhesive
surface and finally a non-adhesive tab is adhered to one
edge of the polyethylene support layer using a thin strip
of adhesive tape.
The dressing may be packaged and used as described in
Example 1.
