[0001] The present disclosure relates to an absorbent pad, and more
particularly to the absorbent pad which is a non-medicated, non-adherent super absorbent
polymer pad that is pre-sterilized by gamma radiation to serve as a primary as well as
secondary dressing for burn wound or the like.
BACKGROUND
[0002] The skin of the human body serves as a protective barrier against the
environment. The skin serves as a barrier to infection and prevents the loss of water and
electrolytes from the body. Thus, the loss of the integrity of large portions of the skin as a
result of illness or injury or burn can lead to major disability or even death. The skin burn
healing is a dynamic, interactive process involving soluble mediators, blood cells,
extracellular matrix, and parenchymal cells. From the metabolic perspective, the skin burn
healing requires deposition of new proteins to repair tissue defects and formation of new
epidermis to cover the surface. These metabolic events in the skin wound are regulated by
nutrients, hormones and growth factors.
[0003] The burn statistics for India has an estimated annual burn incidence of
6-7 million which has been derived from the data from major burn centers of our country
and management thereof leaves much to be desired. A more than 50% Total Burn Surface
Area (TBSA) patient has little chance of survival in our country. The challenge is the
management of body fluid regulation on discharge of large amounts of exudate as a natural
process from the burn wounds, requiring a dressing change as per clinical assessment, yet
be retained in the dressing to keep the affected area cool and wet for optimal healing
environment and prevent spread of infection in the peri-wound area. Healing a burn wound
is a time-consuming laborious task with unpleasant experience to the patient (including a
frequent dressing change) and for the healthcare providers from surgeons down to clinical
and support staff of the hospital unit.
3
[0004] Gamgee pad most commonly used, as a primary dressing is a
combined dressing prepared from Cotton Gauze and cotton wool which due to its adherent
property may result in rawness of wound and damage to granulating tissue on change The
Gamgee dressing absorb up fluid by convection i.e. it is "sucked" up, wetting the dry cotton
fibers and creates dryness around the wound. Moreover, these dressings require frequent
replacement as per clinical assessment. It is prepared by Hospital staff in house under
inadequate sanitary conditions and are presumed sterile. Though Autoclave sterilization is
a Gold Standard and such sterilizers are mandatory in all hospitals, but maintaining product
sterility is a challenge because of its storage conditions. This is because every time the lid
of the drum is opened to pick up the product, the sterility of the product is affected and also
due to short shelf life of 36 to 42 hours. Other issues affecting sterility standards of the
product is proper functioning / maintenance of the autoclave apparatus and rusted drums
etc.
[0005] Other dressing / pad applications available in current scenario range
from synthetic skin substitutes and biological materials to Collagen, Hydrocolloids.
Hydrogel, foam based and silver-based dressing materials. These dressings respectively
have limited efficacy for burn wounds for many reasons such as sticking (“adherence”) to
the open wound surface when removed during change leads to rawness of wound and / or
is not Lint free i.e. small fibers of the dressing pads are left on the surface of the wound
and inherent bio-burden, etc. Also post procedure infections are a major cause of concern
wherein the secondary dressing plays a very important role in healing the wound. Most of
the commercially available sterile dressings are usually sterilized by an unregulated
Ethylene Oxide process known to leave a toxic residue.
[0006] Therefore, there is a need of a dressing pad that can be used as primary
as well as a secondary dressing which overcomes above mentioned problems associated
with currently available dressings for burn wounds.
4
OBJECT OF THE INVENTION
[0007] An object of the present invention is to provide an absorbent pad as a
non-limiting embodiment of the present disclosure, for a burn wound which comprises of
a plurality of layer capable of absorbing fluids within a very short span of time. The
dressing pad includes a super absorbent polymer capable of absorbing fluids within a very
short span of time.
[0008] Another object of the present invention is to provide an absorbent pad
with a first layer or an inner most layer made of a non-adherent polypropylene mesh layer
that covers the wound.
[0009] Another object of the present invention is to provide a fourth layer or
the outermost layer to prevent a strike through in order to prevent spreading of peri-wound
infections.
[0010] Another object of the present invention is to provide an absorbent pad
with negligible bio-burden.
SUMMARY
[0011] This summary is provided to introduce aspects related to an absorbent
pad and the aspects are further described below in the detailed description. This summary
is not intended to identify essential features of the claimed subject matter nor is it intended
for use in determining or limiting the scope of the claimed subject matter.
[0012] An embodiment of the present invention discloses an absorbent pad
comprising a first layer forming a contact with a wound, said first layer includes a nonadhesive layer with perforations therein to allow the fluid from said wound to pass through;
a hydrophilic second layer next to said first layer structured to allow the fluid to pass
through therein and preventing back flow of the fluid to sad first layer; a third layer next to
5
said second layer includes an absorbent polymer granule for absorbing the fluid released
from said wound; and a hydrophobic fourth layer, wherein the fluid from said wound is
absorbed by said third layer and retained in semi liquid form or a gel like structure within
the absorbent pad to simultaneously provide wetness to the wound and provide a cool
feeling.
[0013] An embodiment of the present invention discloses that the nonadhesive layer of said first layer is in range of 20-40 GSM.
[0014] An embodiment of the present invention discloses that the hydrophilic
second layer is a hydrophilic spun bond layer in the range of 20 to 40 GSM, and preferably
30 GSM.
[0015] An embodiment of the present invention discloses that the hydrophilic
second layer is one or more layers of non-woven polyester spun bond.
[0016] An embodiment of the present invention discloses that the third layer
includes the absorbent polymer granules sandwiched between a plurality of fluff pulp
layers, and the absorbent polymer granules are evenly or unevenly spread between the fluff
pulp layers of the third layer to absorb the fluid and retain it within itself
[0017] An embodiment of the present invention discloses that the third layer
is 200-600 GSM, and preferably 500 GSM.
[0018] An embodiment of the present invention discloses that the
hydrophobic fourth layer is a polyester material layer of 40-70, and preferably 50 GSM.
[0019] An embodiment of the present invention discloses that the non-woven
polyester material is at least one of a spun-bond by melt-blown by spun-bond construction
process or SMS and/or any other derivate of polyester spun-bond by melt-blown material
of 3 or more layers.
6
[0020] An embodiment of the present invention discloses that the nonadhesive layer of the first layer is a polypropylene layer.
[0021] An embodiment of the present invention discloses that the pad is presterilized by gamma radiation.
BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 discloses an embodiment of the present invention, depicting
a dressing pad with four layers.
[0023] Figure 2 discloses an embodiment of the present invention, depicting
third layer of the dressing pad.
REFERENCE
NUMERAL
DESCRIPTION OF
ELEMENT
100 Absorbent pad
110 First layer
120 Second layer
130 Third layer
132 Superabsorbent polymer
granules
134 Fluff pulp layer
7
140 Fourth layer
DETAILED DESCRIPTION
[0024] Some embodiments of this disclosure, illustrating all its features, will
now be discussed in detail. The words "comprising", “having”, and "including," and other
forms thereof, are intended to be equivalent in meaning and be open ended in that an item
or items following any one of these words is not meant to be an exhaustive listing of such
item or items, or meant to be limited to only the listed item or items. It must also be noted
that as used herein and in the appended claims, the singular forms "a," "an," and "the"
include plural references unless the context clearly dictates otherwise. Although any
devices and methods similar or equivalent to those described herein can be used in the
practice or testing of embodiments of the present disclosure, the exemplary devices and
methods are now described. The disclosed embodiments are merely exemplary of the
disclosure, which may be embodied in various forms.
[0025] The embodiments herein and the various features and advantageous
details thereof are explained with reference to the non-limiting embodiments in the
following description. Descriptions of well-known components and processing techniques
are omitted so as to not unnecessarily obscure the embodiments herein. The examples used
herein are intended merely to facilitate an understanding of ways in which the embodiments
herein may be practiced and to further enable those of skill in the art to practice the
embodiments herein. Accordingly, the examples should not be construed as limiting the
scope of the embodiments herein.
[0026] Figure 1 discloses an embodiment of the present invention, which
discloses an absorbent pad for example may be for burn wounds. The absorbent pad 100
8
comprises of a plurality of layers. In one of the embodiments, the absorbent pad 100 may
include four layers which may further includes innermost i.e., a first layer 110 forming a
contact with the wound, a second layer 120, a third layer 130 and a fourth layer 140. In
another exemplary embodiment of the present invention, the absorbent pad 100 may be
non-medicated and sterile with a shelf life of may be around 3 years.
[0027] In one of the exemplary embodiments, the first layer may be a
polypropylene layer or mesh. In another exemplary embodiment, the first layer may be 10
to 30 GSM and, preferably 20 GSM or the like. The GSM value for example may vary as
per the need or case. In yet another exemplary embodiment, the first layer may be a
nonwoven poly propylene mesh. The nonwoven poly propylene mesh may be with nonadherent properties. The nonwoven poly propylene mesh may include or constructed with
perforations to form a pathway or a channel. In yet another exemplary embodiment, the
channel or pathway may allow the fluid from the wound to pass through into the third layer
i.e., an absorbent layer through a second layer.
[0028] In yet another exemplary embodiment, the mesh of the first layer may
be selected from the group consisting of polypropylene fibers, polyester fibers, nylon
(Polyamide) fibers, polyethylene fibers, hydrophobic chitosan fibers, PP/PE bi-component
fibers, PA/PE bi-component fibers, PET/PA bi-component fibers. In an exemplary
embodiment, the mesh of the first layer may be a polypropylene mesh.
[0029] In yet another exemplary embodiment, the second layer may be
adjacent to the first layer. The second layer may be a hydrophilic spun bond layer. In yet
another exemplary embodiment, the hydrophilic spun bond layer may be a non-woven
polyester spun bond. In yet another exemplary embodiment, the second layer may be either
single or double layered, which may allow the fluid from the first layer to pass through. In
another exemplary embodiment the one or more layers of the second layer may prevent a
back flow of fluid from the second layer towards first layer by rapid action soaking and
passing on the fluid to the nest layer for immediate absorption. The absorption rate is
9
defined as sinking time matching to Test Method BP 2007/ISO 9073-6, water holding
capacity standard BP 2007, Tensile Strength EDANA 20.2 – 89, Thickness EDANA 120.6
05 (OPTION A), Elongation EDNA 20.2 – 89 etc.
[0030] In yet another exemplary embodiment, the second layer may be in the
range of 20 to 50 GSM, and preferably 30 to 40 GSM based on the Test standard ASTM D
3776-96, which may provide soaking strength. In an exemplary embodiment, the second
layer with hydrophilic spun bond of 30 GSM was used, and the following details were
observed in table 1:
Table 1
Basis weight 30 GSM
Tensile Strength MD N 37
Elongation MD% above 40
Elongation CD% above 40
Strike through rate Less than 5 sec
Run off % Less than 10
[0031] In yet another exemplary embodiment, and as seen from above table
1, the strike through rate i.e., time take for the fluid to reach from the wound to the third
layer or the superabsorbent layer is less than 5 second which is superior ability of the
10
dressing pad over the prior art. MD = Mean Direction i.e., horizontal axis and CD = Cross
Direction = Vertical axis
[0032] In yet another exemplary embodiment, the spun bond layer may be
made of spun bond fibers, which may mean fibers that have an average cross section
diameter of greater than 10 μm. The spun bond fibers may be webs that are formed by
laying spun bond fibers randomly on a collecting surface, and subsequently bonding the
fibers, such as by thermal bonding, hydroentanglement etc. In yet another exemplary
embodiment, the spun bond non-woven fabric may be formed from continuous fibers,
which are more or less smooth, with a diameter, for example, in the order of 17-20 microns,
which may cohere to one another by calendering. The spun bond non-woven fabric
therefore may generate close soldering points joined by portions of straight, and
comparatively very hard, fibers, giving a certain rigidity to the fabric. In yet another
exemplary embodiment, the spun bond fiber may be made by blending or otherwise
uniformly mixing at least one C8 to C16 fatty acid monoglyceride and the solid
polypropylene. The spun bond fiber, for example, may be made by intimately mixing the
monoglyceride with pelletized or powdered polymer, and melt extruding the mixture into
a fibrous web using any of the commonly known processes for producing nonwoven webs.
[0033] Figure 2 discloses an embodiment of the present invention. The third
layer 130 next to the second layer of the dressing pad 100 may be made of, for example,
evenly or unevenly spread superabsorbent polymer granules sandwiched between a
plurality of the fluff pulp layers. In yet another exemplary embodiment, the evenly or
unevenly spread superabsorbent polymer granules 132 over the fluff pulp layer 134 may
be in required density so as to constitute, for example, 500 GSM i.e. grams per meter square
over all or the like. The third layer may therefore absorb the exudate or fluid by diffusion
at the molecular level by converting into a semi-liquid form or gel form and yet allowing
the wound surface experiencing a wetness and a cool feeling necessary for expeditious
healing.
11
[0034] In yet another exemplary embodiment, the super absorbent polymers
are cross linked networks of flexible polymer molecular-sized chains that make up the body
mass which is remarkably similar looking to the mass of cotton fibers. The fluid absorption
/ diffusion occurs through osmotic pressure caused by the concentration gradient of
electrolytes inside and outside the polymer particles layer i.e. by the superabsorbent
polymer granules. During this process, the absorbent polymer also takes up and retains
proteins, cell debris and even micro-organisms. This allows the absorbent pad to swell and
absorb large amounts of liquid. The fluid thus diffused forms gel like structure and is
retained within the dressing pad.
[0035] In yet another exemplary embodiment, the third layer may include the
superabsorbent polymer with cellulose / wood pulp or fluff pulp in the ratio of 40:60
percentage by weight.
[0036] In yet another exemplary embodiment, the fluff pulp may be made of
the fluff pulp fibers. One or more than one, or any combination thereof, of fluff pulp and/or
fluff pulp fibers may be used in the present invention. The fluff pulp and fluff pulp fibers
may be treated or untreated, and they may optionally contain one or more than one
additives, or combination thereof. In another exemplary embodiment, the fluff pulp may
include cellulosic fiber. In another exemplary embodiment, the fluff pulp, for example, may
be made from pulp fibers derived from hardwood trees, softwood trees, or a combination
of hardwood and softwood trees and / or bark thereof. In yet another exemplary
embodiment, the fluff pulp fibers may be prepared by one or more known or suitable
digestion, refining, and/or bleaching operations such as, for example, known mechanical,
thermomechanical, chemical and/or semichemical pulping and/or other well-known
pulping processes. In yet another exemplary embodiment, the hardwood pulps or cellulose
as may be used herein to include fibrous pulp derived from the woody substance of
deciduous trees such as birch, oak, beech, maple, and eucalyptus. In yet another exemplary
embodiment, the softwood pulps as may be used herein may include fibrous pulps derived
12
from the woody substance of coniferous trees gymnosperms such as varieties of fir, spruce,
and pine, as for example loblolly pine, slash pine, Colorado spruce, balsam fir and Douglas
fir. In yet another exemplary embodiment, at least a portion of the pulp fibers may be
provided from non-woody herbaceous plants including, but not limited to, kenaf, hemp,
jute, flax, sisal, or abaca. In yet another exemplary embodiment, the fluff pulp fiber may
be either bleached or unbleached. In yet another exemplary embodiment, the fluff pulp may
be a recycled fluff pulp fiber.
[0037] In yet another exemplary embodiment, the third layer may include
superabsorbent polymer granules. The superabsorbent polymer granules may be made from
superabsorbent polymer (SAP). The superabsorbent particles may be irregularly shaped
and varied in size, and may have a diameter of up to 1 mm, or approximately 1 mm. The
superabsorbent granules may comprise a sodium acrylate type material.
[0038] In another exemplary embodiment of the present invention, the fourth
layer may be adjacent to the third layer. In yet another exemplary embodiment, the fourth
layer may be a hydrophobic layer, for example, of 50 GSM or the like. In another exemplary
embodiment, the fourth layer may be a non-woven fabric that may be consisting of 3 layers
of polyester material. In yet another exemplary embodiment, the polyester material may be
spun-bond by melt-blown by spun-bond also termed as SMS. The polyester material may
be, for example, with bacterial barrier properties, preventing strike through, preventing
environment contamination to the secondary dressing that may lead to infection prevention.
[0039] In yet another exemplary embodiment, the polyester material may be
a non-woven material of mixture or compound, for example, the combinations may include
Spun bond-melt blown-spun bond method (SMS), spun bond- (SC), spun bond-air-flow
(SA), melt blown-air laid (MA) are combed, and is typically in the their combination of
layer form. In yet another exemplary embodiment, in the examples described above, one
or more single layers can produce by each method. For example, such as, SMS can refer to
one four layers of “SMMS” or, five layers of "SSMMS" web, or three layers of "sms" web,
13
or its any reasonable variation, wherein small letter matrix shows independent each layer,
and capitalization indicates similar, adjacent layer establishment. The SMS layer matches
standards of Tensile Strength Dry (MD) – EN 29073 – 1992, Tensile Strength Dry (CD) –
EN 29073 – 1992, Hydro head AATCC -127, Resistance to Liquid EN 20811-1992, etc. In
yet another exemplary embodiment, the non-woven material includes fiber being selected
from material including but not limited to polyolefin, polyester, cellulose, artificial silk,
polyamide, polyesteramide, polyvinyl alcohol and their combination thereof. The fiber may
be made via any suitable method, such as, but not limited to spun lacing method, and
preferably have between 45 GSM and 75 GSM, the dry basis that is more preferably
between 45 GSM and 65 GSM. In yet another exemplary embodiment of the present
invention, the non-woven material may include but not limited to wood-fibers or woodfibers with combination of material including but not limited to polyolefin, polyester,
cellulose, artificial silk, polyamide, polyesteramide, polyvinyl alcohol or the like. The
suitability is to prevent a strike through, preventing spread of infectious fluid in case of an
over flow.
[0040] In another exemplary embodiment, the dressing pad may be presterilized by GAMMA irradiation or the like.
[0041] The super absorbent pad with the layers as detailed below has
following advantages based on clinical assessment:
1. Non-adherent, non-sticky – easy to remove (least painful removal)
2. Faster rate of absorbency by diffusion on molecular level, since the
"fibers" are actually long chained molecules.
3. Greater absorption capacity and retention properties
4. Prevents a compression leak
14
5. Wetness of wound surface providing for optimal environment of
healing
6. Maximising patient comfort
7. Longer replacement time as per clinical assessment
8. Negligible Bio burden.
9. Lint free
10. Pre-Sterilized, prevents infection
11. Packed in medical grade heat sealed peal able paper pouch
12. Easy to transport in sterile condition
13. Longer Shelf life in packaged form
14. Applied to all types of exudating wounds.
[0042] Ideal wound dressing Characteristics:
1. Provides hydration if dry or desiccated
2. Removes excessive exudate from the wound without allowing the wound
to dry out thereby maintaining a moist environment and cool feel
3. Allows gaseous exchange so that oxygen, water vapour and CO2 may pass
in and out of the dressing
4. Is thermally insulating so as to maintain the wound core temperature at
approximately 37 degrees centigrade
15
5. Is impermeable to micro-organisms in order to minimise contamination of
the wound from outside and the wound itself
6. Is free from either particulate or toxic contamination
7. Is non-traumatic and does not adhere to the wound, so that at dressing
change it will not damage granulating tissue.
8. Provides protection to periwound area
9. Does not release particles or fibers
10. Can conform to wound shape
11. Minimal pain during application and removal
12. Easy to use.
13. Cost-effective

WE CLAIM

1. An absorbent pad 100 comprising:
a first layer 110 forming a contact with a wound, said first layer includes
a non-adhesive layer with perforations therein to allow the fluid from
said wound to pass through;
a hydrophilic second layer 120 next to said first layer structured to allow
the fluid to pass through therein and preventing back flow of the fluid to
said first layer 110;
a third layer 130 next to said second layer 120 includes an absorbent
polymer granule for absorbing the fluid released from said wound; and
a hydrophobic fourth layer 140,
wherein the fluid from said wound is absorbed by said third layer 130
and retained in semi liquid form within the absorbent pad 100 and
simultaneously provides wetness to the wound.
2. The pad 100 as claimed in claim 1, wherein the non-adhesive layer of said
first layer 110 is in range of 20-40 GSM.
3. The pad 100 as claimed in claim 1, wherein the hydrophilic second layer is
a hydrophilic spun bond layer in the range of 20 to 40 GSM, and preferably
30 GSM.
17
4. The pad 100 as claimed in claim 3, wherein the hydrophilic second layer
120 is one or more layers of non-woven polyester spun bond.
5. The pad 100 as claimed in claim 1, wherein the third layer 130 includes the
absorbent polymer granules sandwiched between a plurality of fluff pulp
layers, and
wherein the absorbent polymer granules are evenly or unevenly
spread between the fluff pulp layers of the third layer to absorb the
fluid.
6. The pad 100 as claimed in claim 5, wherein the third layer 130 is 200-600
GSM, and preferably 500 GSM.
7. The pad 100 as claimed in claim 1, wherein the hydrophobic fourth layer
140 is a polyester material layer of 40-70, and preferably 50 GSM.
8. The pad 100 as claimed in claim 7, wherein the polyester material is at least
one of a spun-bond by melt-blown by spun-bond or SMS and/or any other
derivate of polyester spun-bond by melt-blown material of 3 or more layers.
9. The pad 100 as claimed in claim 1, wherein the non-adhesive layer of the
first layer 110 is a polypropylene layer.
10. The pad 100 as claimed in claim of the preceding claims, wherein the pad
100 is pre-sterilized by gamma radiation.