Note: Descriptions are shown in the official language in which they were submitted.
APPLICATION OF SURGICAL DRESSINGS
The present invention relates to conformable,
bacteria proof adhesive dressings for use on the 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 dresslngs.
Certain favoured self-adhesive conformable dressings
known in the art 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, known as Bioclusive Transparent
Dressing (trade mark of Johnson and Johnson Products
Inc.), 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
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adhered, the non-adhesive tab and the corresponding part
of the backing sheet being perforated to allow removal of
the tab.
A second dressing, known as Ensure (trade mark of
5 Parke Davis and Co.), 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-adhe~ive
~ ~b~ ,~ ed
~ conformable film, presented as described i~ European
Patent Application No. 51-935. In one of these
p~s~ntations, available as Tegaderm Transparent Dressing
(trade mark of 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
removed, forms a window, the remaining frame being
removable by means of a tab along its side-edge or by
means of a split in the frame.
In each of the 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.
Other difficulties arising with the above-described
hith~rto known presentations include major problems in
apply~ing the dressing without touching the adhesive,
thereby defeating the aim of sterility.
The first 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
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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 from the film, characterised in that the release means
is situated away from the side-edges of the protector.
It is clear from the above therefore that the present
invention provides an adhesive dressing suitable for use
on the skin which consists essentially of (a) a bacteria
proof, transparent film, coated with adhesive on one face,
(b) a 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 o~ 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.
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 areas but
preferably they will have an approximately equal area in
contact with the adhesive face in which case the two parts
will meet or overlap about a line approximately at the
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centre of the dressing. Such a dressing is within the
scope of the present invention~
Thus in a favoured aspect the present invention
provides a dressing which consists essentially of (a) a
bacteria proof transparent film coated with
adhesive on one face and (b) a protector over the whole of
the adhesive characterised in ~hat the protector comprises
a first and second part, the first part disposed to one
side Gf the dressing and the 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~
Most aptly the first and second parts abut along an
a~p~ximately 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 la middle part' is
meant a part of the dressing which is not a side-edge.
The protector can then be gradually released from the
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middle in a direction towards each side-edge, thereby
greatly reducing the possibility of rucking the dressing
and increasing the chances of maintaining sterility.
The two parts of the protector may abut each other
where they meet as described above or more preferbly the
second part may overlie a portion of the first part of the
protector without having a bent back portion or may
overlie a portion of the first part of the protector and
then have a bent back portion.
Thus in a preferred aspect the present invention
provides an adhesive dressing suitable for use on skin
which consists essentially of (a) a bacteria proof,
transparent film coated with adhesive on one face and (b)
a protector layer over the whole of the adhesive which
protector comprises a first part and a second part, the
f-r~t 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 on to the first part over the bent back
portion whereby said first and second parts can be grasped
~nd peeled away from the adhesive.
In a f~rther preferred aspect the present invention
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provides an adhesive dressing suitable for ~ISe on the skin
which consists essentially of (a) a bacteria proof,
transparent film coated with adhesive on one face and (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 disposed over 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 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.
The conformable film for use in the present invention
is preferably a transparent polymeric film so as to allow
observation of the surface to which the dressing is to be
adhered.
The film may itself be multi-layer and may include
more than one continuous and/or interrupted polymeric
layer.
Examples of suitable films, and adhesives therefor,
are described in British Ratent Specification No. -
1,280,631, European Patent Specification No. 51-935
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~especially the polyurethanes) and suitable films prepared from
the hydrophilic polyurethanes are disclosed in EuLopean Patent
Specification No. 50035. Films, and adhesives, described in the~e
specifications as 'preferred' are al60 to be taken to be preferred
for use in the device of thi6 invention.
The adhesive coated film most suitably transmits moisture
vapour at a rate o~ at least 300g~m2t24 hrfi/37C/100-10% RH,
de6irably at least 400g/m2 and more favourably at least
SoOg/m2 and preferably at least 700 g/m2.
The film i5 desirably formed from polyurethane which i8 9
to 35 microns thick, more suitable 10 to 30 microns thick and
pcefeLably fcom 20 to 25 microns thick.
The adhesive may be an all over spread, pattern spread, a
microporous layer or a porous layec or the like. The adhe6ive may
be pattern spread using the method de~cribed in Bcitish Patent No.
819635. The adhesive may be focmed as a porous layer by the
method described in British Patent No. 1,563,695. ~owever, it is
preferred that the adhesive is in the form of an all over seread,
that i~ a6 continuous layer containing no pores or
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micropore~.
Suitable adhe6ive~ which are moistuee vapour tran~mitting
as an all over spread or continuous layer include various acrylate
ester copolymer and polyvinyl ether peessure sen6itive adhesives
for example as disclosed in British Patent No. 1,2~0~631.
Favouced pressure 6ensitiYe adhesives comprise copolymers of
acrylic ester with acrylic acid for example as disclosed in United
Kingdom Application No. 2,070,631.
A preferred pressure ~ensitive adhesiY0 compri~es a blend
of high and low viscosity polyvinyl e~hyl ether disclosed ln
British Patent No. 1,280,631. A second preferred pressure
sensitive adhesive is disclosed in United Kingdom Application No,
2,070,631 a6 a copolymer of 47 parts by weight
2-ethyl-hexylacrylate, 47 part6 by weight butyl acrylate and 6
parts by weight acrylic acid polymeri~ed in acetone.
The adhesive i8 suitable employed at weights per unit
area of 10 to 75gm~2, more usually 15 to 65 gm 2, preferably
at 25 to 40gm 2 for example 29gm 2, 32gm 2.
The protector may be any convenient material used for
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such purposes such as a polymer or paper film and
especially those treated for easy release properties, for
example by siliconisation.
The protector 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 backing sheet is of transparent or translucent
material such as 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.
In another aspect, the present invention therefore
provides 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
~he-~rotector 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 way from
the side-edges of the backing sheet.
Especially preferred is a method wherein release
means, situated away from the side-edges of the protector
are used to release the protector.
7~
In a further aspect, the present invention provides a
method of preparing such a dressing comprising applying
adhesive to at least a part oE a conformable transparent
polymeric ~ilm, affixing to said-part of the film a
protector having means for removing the protector from the
film which means is situated away from the side-edges of
the protector, and sterilising the resulting dressing.
In a still further aspect, the present invention
provides a dressing according to the invention contained
in a bacteria proof package.
Preferably, the package contains or incorporates
instructions on how to use the device according to the
invention.
One favoured dressing of this invention comprises a
dr~ sing 10cm x lOcm which is a 25 micron thick
polyurethane film ~(such as an Estane 5701F, trade mark o-
B.E. Goodrich) 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 protector comprises two 10cm 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.
A second favoured dressing of this invention
comprises a dressing lOcm x lOcm which is a 25 micron
thick polyurethane film (such as an Estane 5701F, trade
mark of BDF. Goodrich) coated over one ace with a 25
micron thick layer of acrylic adhesive (such as that whose
preparation is described in Example 1 of United Kingdom
Patent Application No. 2070631) in which dressing a
protector comprises two lOcm x 6cm pieces oE siliconised
high density polyethylene so that for the first part a
lOcm x 5cm portion overlays the adhesive and a lOcm x lcm
strip is folded back and for the second part a lOcm x 5cm
portion overlaps the adhesive and the remaining lOcm x lcm
strip is unfolded and overlays the first part.
Alternatively the second part may be a piece which is
lOcm-x 7cm, a lOcm x 5cm portion overlays the adhesive
whilst a strip lOcm x 0.5cm overlays the first part of the
protector, the remaining lOcm x 1.5cm strip being fQlded
back to provide a handle.
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-secti-onal view of a dressing
according to this invention; and
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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 a further aspect of this invention.
Referring first to Figure 1, the dressing 1 comprises
a conformable film 2 of polyurethane on one surface of
which is spread an acrylic adhesive 3 to which surface is
adhered a protector 4 of poly(vinyl chloride) or
siliconised paper or siliconised polyethylene.
The protector 4 just overlaps the film 2 and is in
two-pa~s 5 and 6. Each of the two parts 5 and 6
termina~e towards the middle (but not necessarily in the
centre) of the sheet 4 in tabs 7 and B ~hich overlap so
that the total surface o~ the adhesive 3 is covered.
Figure 2 shows the extent of the overlapping 9
between tabs 7 and 8; and also the overlapping 10 between
backing sheet 4 and film 2.
In use, the dressing 1 is positioned so that overlap
9 (Figure 2) is over that part of the catheter (or other
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14
surface) which centralises the dressing about the
catheter. Tabs 7 and 8 are grasped and gradually pulled
toward the corresponding edges of the device, 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. Thus, film 2 remains adhered to the catheter by
adhesive 3.
Figure 3 shows a similar dressing to that described
in Figure 1 except that the second part of the protector
instead of having a bent back portion 8, overlaps onto the
first portion of the protector 5.
~ igure 4 shows a similar dressing that described in
Figure 1 except that the first and second parts of the
prot~ctor abut each other and do not overlap.
The adhesive films employed-in this invention may be
represented 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
40 microns thick, for example 25 to 35 microns thick.
Desirably both membrane and adhesive are formed from
22~
moisture 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.
Preferably 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 protector is fvlded
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 Dressin~
A syrup of a polyurethane (Estane---5701F, trade-mark
of B.F. Goodri~h) in tetrahydrofuran/acetone (solids
content 15~) is cast onto a siliconised release paper and
the solvent removed to give a film 30 microns thick.
,...
A solution in acetone of an acrylic ester copolymer
~ormed from the copolymerisation of 47 parts by weight
2-ethyl hexylacrylate, 47 parts by weight butylacrylate
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16
and 6 parts by weight acrylic acid is cast onto a
siliconised release paper to give a film at a weight of 32
g/m2 after removal of the solvent.
The adhesive layer is then transfer coated by
conventiona~ means onto the polyurethane film.
The folded protector in two parts is then placed on
the adhesive layer by conventional means so as to cover
the whole of the adhesive surface.
The strip thus produced is cut to give individual
dressings of the desired size.
The individual dressings may be placed and sealed in
a baeteria proof pack-and sterilised in a conventional
manr.~r.
In use, the sterile dressing is removed from the
pack,--the two parts of the protector pulled back a little
way to expose a small area of adhesive which may be
accurately and smoothly placed where required. The
remainder of the adhesive surface is then exposed and
positioned by removal of the protector.
