SKIN CONTACT MATERIAL
The present invention relates to a skin contact material for positioning against a human or
animal skin and in particular, although not exclusively, to a material suitable for ostomy
use, wound care and as a medical dressing and adhesive.
Self-adhering skin contact materials find widespread use in the medical field and in
particular with ostomy appliances. Initially, medical grade pressure-sensitive adhesives,
typically formed from an acrylic, were used to adhere appliances to the peristomal skin of a
patient. More recently, moisture absorbing, and in particular hydrocolloid containing, skin
barrier materials have emerged as more suitable skin contact materials. These materials
absorb moisture from the skin and allow the skin to breathe whilst being sufficiently tacky
for good skin adhesion but being easily peeled away without irritating or damaging the
skin.
Skin friendly adhesive barrier materials are disclosed in US 3,339,546; US 4,477,325; US
4,738,257 and US 4,867,748.
However, hydrocolloid based substrates may not possess the required adhesive
characteristics for certain skin contact applications and an additional adhesive may be
required. The problem with medical grade adhesives is that they tend to be skin irritant
following extended use. In particular, and as a generalisation, they do not allow the same
level of moisture transfer with the skin.
What is required therefore is a medical grade skin contact material for use as a barrier layer
and/or a means of attaching appliances to the skin that comprise the required adhesive
properties whilst allowing moisture transfer with the skin.
Accordingly, the inventors provide a substrate based skin contact material preferably
formed from a hydrocolloid having a silicone based adhesive component extending over
regions of the substrate surface. The adhesive is formed non-continuously over the
hydrocolloid so as to provide areas of the hydrocolloid that are devoid of the silicone
adhesive. Accordingly, with the material in contact with the skin, adhesion is provided via
the silicone adhesive whilst the areas of exposed hydrocolloid are capable of moisture
transfer so as to significantly improve the skin friendliness of the material during use and
allow the material to be readily removed from the skin without causing irritation.
According to a first aspect of the present invention there is provided a skin contact material
for positioning against human or animal skin, the material comprising: a hydrocolloid
substrate having a first surface intended to be positioned against the skin and a second
surface intended to be facing away from the skin; a silicone adhesive layer provided on the
first surface and intended to be positioned in contact with the skin to adhere the material to
the skin, the silicone adhesive layer being non-continuous over the first surface such that
areas of the first surface are not concealed by the silicone adhesive layer, the areas capable
of positioning directly adjacent and/or in contact with the skin.
The hydrocolloid substrate may comprise a synthetic or natural hydrocolloid, such as a
hydrocolloid derived from natural sources. The hydrocolloid may comprise anyone or a
combination of a gum, a cellulose or cellulose derivative, an alginate or a starch.
Optionally, the hydrocolloid comprises gelatine or pectin. Optionally, the hydrocolloid
comprises a carboxymethylcellulose in a polyisobutylene matrix. Alternatively, the
substrate may be non-hydrocolloid based and may comprise low density polyethylene, high
density polyethylene, polypropylene, polyester or a silicone based material. Alternatively
the substrate could be a composite of two or more different materials including polymers
and hydrocolloids.
Preferably, the silicone adhesive comprises a two part catalysed, low temperature curing
silicone elastomer. As will be appreciated, the silicone adhesive may be formed as a
composite of a plurality of different silicones and/or silicone based materials.
Optionally, the skin contact material may be provided as a sheet or roll from which a user
or medical practitioner may cut the desired shape and size. Moreover, the hydrocolloid
substrate may comprise a thickness in the range 0.5 to 5.0 mm.
As indicated, the enhanced skin friendliness of the present material is provided by layering
the silicone adhesive upon the substrate at discrete regions so as to provide areas of
exposed substrate for positioning in contact with the skin. Accordingly, the silicone
adhesive may be formed as lines or dots on the skin contact surface of the substrate.
Where the adhesive layer is formed as individual dots, flecks or marks, the pattern created
by these dots may be uniform across the surface of the substrate. Alternatively, the pattern
may change over the substrate surface and the material may comprise different patterns at
different regions over the substrate. Where the adhesive layer comprises lines or ridges
extending over the substrate, these lines may extend in different directions where the
spacing between the lines or ridges is the same or variable across the substrate surface.
Optionally, the lines may create a square, rectangular or circular grid pattern. Preferably,
for ostomy applications, the silicone adhesive is bonded to the substrate and takes the form
of concentric circles extending around a central aperture extending through the substrate.
According to a second aspect of the present invention there is provided a medical dressing
comprising a skin contact material as described herein. According to a third aspect of the
present invention there is provided a stoma gasket comprising a skin contact material as
described herein. According to a fourth aspect of the present invention there is provided a
medical adhesive pad, tape or sheet comprising a skin contact material as described herein.
According to a fifth aspect of the present invention there is provided a skin barrier pad for
positioning about a stoma comprising a skin contact material as described herein.
According to a sixth aspect of the present invention there is provided an ostomy bag
comprising a skin contact material as described herein.
According to a seventh aspect of the present invention there is provided a skin contact
material for positioning against human or animal skin, the material comprising: a substrate
having a first surface intended to be positioned against the skin and a second surface
intended to be facing away from the skin, the substrate comprising any one or a
combination of a hydrocolloid, a low density polyethylene, a high density polyethylene, a
polypropylene, a polyester or a silicone based material; a silicone adhesive layer provided
on the first surface and intended to be positioned in contact with the skin to adhere the
material to the skin, the silicone adhesive layer being non-continuous over the first surface
such that areas of the first surface are not concealed by the silicone adhesive layer, the
areas capable of positioning directly adjacent and/or in contact with the skin.
A specific implementation of the present invention will now be described, by way of
example only, and with reference to the accompanying drawings in which:
Figure 1 is perspective view of a skin contact material having a substrate and an
adhesive component bonded to one face of the substrate according to the specific
implementation;
Figure 2 is a cross section to A-A of Figure 1;
Figure 3 is a perspective view of a further specific implementation of the skin
contact material of Figure 1;
Figure 4 is a cross section through B-B to Figure 3;
Figure 5 is a perspective view of a stoma gasket formed from the skin contact
material according to a specific implementation;
Figure 6 is a cross sectional side view of the stoma gasket of Figure 5 secured in
position against a patient's skin and in contact with a flange of an ostomy bag;
Figure 7 is a cross sectional side view of the skin contact material used as a
wound dressing adhesive to maintain a dressing in position over a wound at the skin; and
Figure 8 is a side view of an ostomy bag having a flange comprising the skin
contact material according a specific implementation.
Referring to Figures 1 and 2, the skin contact material 100 comprises a substrate 101
having a first surface 102 intended to be facing the skin and an apposed second surface 103
intended to be facing away from the skin. An adhesive layer 104 is provided on the
surface 102 and according to the specific implementation, layer 104 comprises a
rectangular grid pattern formed by perpendicular aligned ridges 105, 106.
Adhesive layer 104, formed from the narrow ridges 105, 106 is regarded as 'discontinuous'
over surface 102 such that the adhesive 104 does not coat completely surface 102 and there
is provided regions 107 that are devoid of adhesive 104 with regions 107 being exposed
substrate 102.
The rectangular grid pattern formed by ridges 105, 106 is uniform across surface 102 such
that the space between ridges 105, 106 is equal in the respective directions across substrate
surface 102. According to the specific implementation, the thickness of substrate 101 is in
range 0.5 to 5.0 mm. The distance by which ridges 105, 106 extend from surface 102 is a
small percentage of this thickness and may be of the order of 0.01 mm.
Figures 3 and 4 illustrate a further embodiment of the skin contact material of Figures 1
and 2. According to the further embodiment, the adhesive layer is formed as a regular
repeating array of nodes or bumps 300. The bumps 300 are separated from one another by
a regular or uniform discreet separation distance such that the skin contact surface 102 of
substrate 101 is exposed at spacings 301 between the bumps 300.
The material of the embodiment of Figures 1 to 4 is suitable for use as a medical grade skin
contact material and in particular a material for adherence to the skin of colostomy,
ileostomy and urostomy appliances. The material is also suitable for adherence to the skin
of patient monitoring appliances, prosthetics and wound dressings.
Specifically with regard to ostomy applications, Figure 5 illustrates a specific embodiment
of the skin contact material 500 formed as an annular disc suitable for use as a skin contact
stoma gasket. The pad 500 comprises a central aperture or bore 504 extending through pad
500. Pad 500 comprises a substrate 506 having a skin contact surface 501 and opposed
surface 502 intended to be facing away from the skin. An adhesive layer 503 is provided
on the surface 501 and is formed as a series of concentric circles extending between central
bore 504 and parameter edge 507. The concentric circles 503 are spaced apart from one
another and therefore formed as discreet ridges separated by regions 505 of exposed
substrate surface 501.
Figure 6 illustrates the pad 500 of Figure 5 secured in position at the peristomal skin 604.
The adhesive ridges 503 are positioned in contact with the peristomal skin 604 such that
regions 505 are in a position very close to or in direct contact with skin 604 so as to
provide moisture transfer between pad 500 and skin 604. That is, moisture is actively
transferred from skin 604 and into material 500 via regions 505. This would otherwise not
be possible if adhesive layer 503 extended continuously over skin facing surface 501.
An ostomy bag 600 comprises a flange 601 formed from a solid support 602 that supports
an attachment flange 603. Bag 600 is secured to the skin 604 indirectly by mating
attachment 603 with the external facing surface 502 of gasket pad 500. Central bore 504
of gasket 500 is appropriately sized to fit around stoma 601 and allow the free passage of
excreted matter into bag 600. The ostomy bag 600 and the gasket 500 may be readily
removed from the peristomal skin 604 by simply pilling-away the gasket 500.
Figure 7 illustrates a further use of the present skin contact material as a wound dressing.
The wound dressing 700 comprises a substrate 701 and an adhesive layer 702 incompletely
formed across the skin contact surface of substrate 701 . According to the further
embodiment, adhesive layer 702 may be formed at an outer perimeter region of the
substrate so as to provide a central region 705 that is devoid of adhesive 702.
Alternatively, adhesive layer 702 may extend across the entire skin facing surface of
substrate 701 but importantly comprising regular repeating regions that are devoid of the
adhesive layer. The adhesive patch 700 is configured to retain a second wound dressing
material 704 in contact with the skin 706 surrounding the region of a wound 703. Due to
the moisture transfer capability of substrate 701 , the skin 706 at the region in contact with
the pad 700, is allowed to breathe and does not become irritated by this contact.
According to further embodiments, the silicon adhesive layer 104, 300, 503, 702 may also
be provided on the second surface of the substrate 103, 502 intended to be facing away
from the skin. This second opposed adhesive layer may have the same or a different
configuration to the skin contact adhesive layer on the first surface. Also, this second and
opposed adhesive layer may have a uniform configuration across the second surface 103,
502 or the configuration may be different at different regions on surface 103, 502 as
described with references to the first adhesive layer detailed in figures 1 to 7.
Figure 8 illustrates an ostomy bag 800 having an internal chamber 801 to receive excreted
matter. An attachment flange 802 provides an interface between the chamber 801 and a
stoma whilst providing a means of attachment of the bag 800 to the peristomal skin. The
present skin contact material is formed as a permanent or releasable part of flange 802 and
extends around a central aperture 805 for positioning around the stoma. Flange 800
comprises a substrate 803 with moisture transfer characteristics as described with reference
to Figures 1 to 7. A silicone adhesive layer 804, as described herein, is formed as discrete
concentric circles on the skin facing side of flange 802 and extends around the central
aperture 805 as described with reference to Figure 5.
According to further specific implementations the substrate may be non-hydrocolloid
based and may comprise medical grade polymers such as polyalkylenes, polyesters and/or
silicone based materials.
According to a first example the substrate may comprise a low density polyethylene.
Suitable low density polyethylene materials include those available from Dow Corning,
MI, USA under the product range Dow™ LDPE.
According to a second example the substrate may comprise a high density polyethylene.
Suitable materials include those available from Dow Corning, MI, USA under the product
range Dow™ HDPE or materials under the product range Eraclene™ HDPE available
from Polimeri Europa, ENI Rome, Italy.
According to a third example the substrate may comprise a polypropylene material.
Suitable materials include those available from Westlake Plastics Company, PA, USA
under the product range Propylux™ HS.
According to a fourth example the substrate may comprise a polyester material. Suitable
materials include polyesters available from Bayer MaterialScience LLC, PN, USA under
the product range Texin™ RxHM125.
According to a fifth example, the substrate may comprise a silicone based material.
Suitable materials include those available from Dow Corning, MI, USA under the product
range Silastic™ and the Class VI Elastomers under the product range C-6.
As will be appreciated, the different types of substrate according to the further examples
are bondable to the adhesive layer according to conventional bonding techniques and
processes as described with reference to the previous embodiments.

Claims:
1. A skin contact material for positioning against human or animal skin, the material
comprising:
a hydrocolloid substrate having a first surface intended to be positioned against
the skin and a second surface intended to be facing away from the skin;
a silicone adhesive layer provided on the first surface and intended to be
positioned in contact with the skin to adhere the material to the skin, the silicone adhesive
layer being non-continuous over the first surface such that areas of the first surface are not
concealed by the silicone adhesive layer, the areas capable of positioning directly adjacent
and/or in contact with the skin.
2. The material as claimed in claim 1 wherein the hydrocolloid substrate comprises a
synthetic material.
3. The material as claimed in claim 1 wherein the hydrocolloid substrate comprises a
natural hydrocolloid.
4. The material as claimed in claim 3 wherein the hydrocolloid comprises any one or
a combination of the following set of:
a gum;
a cellulose;
cellulose derivative
an alginate;
a starch.
5. The material as claimed in any preceding claim further comprising gelatine or
pectin.
6. The material as claimed in any preceding claim wherein the hydrocolloid further
comprises a carboxymethyl cellulose in a polyisobutylene matrix.
7. The material as claimed any preceding claim wherein the silicone adhesive is a
composite and comprises a plurality of different silicones and/or silicone based materials.
8. The material as claimed in any proceeding claim wherein the hydrocolloid
substrate comprises a thickness in the range 0.5 to 5.0 mm.
9. The material as claimed in any proceeding claim wherein the silicone adhesive is
formed as lines, dots, flecks or marks on the first surface.
10. The material as claimed in claim 9 wherein the lines, dots, flecks or marks create
a pattern on the first surface that is substantially uniform across the first surface.
11. The material as claimed in claim 9 wherein the lines, dots, flecks or marks create
a pattern at the first surface that is substantially non-uniform over the first surface such that
the silicone adhesive comprises a plurality of different patterns at different regions of the
hydrocolloid substrate.
12. The material as claimed in any preceding claim wherein the silicone adhesive is
formed as lines or ridges extending over the first surface.
13. The material as claimed in claim 12 wherein the lines or ridges are distributed at
the first surface to create geometric shapes.
14. The material as claimed in claim 12 wherein the lines or ridges are distributed at
the first surface to define concentric circles extending around a central aperture extending
through the substrate.
15. A medical dressing comprising a skin contact material according to any preceding
claim.
16. A stoma gasket comprising a skin contact material according to any one of claims
1 to 14.
17. A medical adhesive pad, tape or sheet comprising a skin contact material
according to any one of claims 1 to 14.
18. A stoma skin barrier pad for positioning around a stoma comprising a skin contact
material according to any one of claims 1 to 14.
19. An ostomy bag comprising a skin contact material according to any one of claims
1 to 14.
20. A skin contact material for positioning against human or animal skin, the material
comprising:
a substrate having a first surface intended to be positioned against the skin and a
second surface intended to be facing away from the skin, the substrate comprising any one
or a combination of a hydrocolloid, a low density polyethylene, a high density
polyethylene, a polypropylene, a polyester or a silicone based material;
a silicone adhesive layer provided on the first surface and intended to be
positioned in contact with the skin to adhere the material to the skin, the silicone adhesive
layer being non-continuous over the first surface such that areas of the first surface are not
concealed by the silicone adhesive layer, the areas capable of positioning directly adjacent
and/or in contact with the skin.