U.S. patent application number 13/797864 was filed with the patent office on 2013-07-25 for medical devices, wound dressings, and methods for dressing wounds.
The applicant listed for this patent is David J. Vachon. Invention is credited to David J. Vachon.
Application Number | 20130189339 13/797864 |
Document ID | / |
Family ID | 42784516 |
Filed Date | 2013-07-25 |
United States Patent
Application |
20130189339 |
Kind Code |
A1 |
Vachon; David J. |
July 25, 2013 |
Medical Devices, Wound Dressings, and Methods for Dressing
Wounds
Abstract
Medical devices, wound dressings, and methods of dressing wounds
are described. Devices and methods using silicone and
pharmaceutically active agents are described. Devices including
covers and bases are described.
Inventors: |
Vachon; David J.; (Spokane,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vachon; David J. |
Spokane |
WA |
US |
|
|
Family ID: |
42784516 |
Appl. No.: |
13/797864 |
Filed: |
March 12, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13299117 |
Nov 17, 2011 |
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13797864 |
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12690081 |
Jan 19, 2010 |
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13299117 |
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12162990 |
Jul 31, 2008 |
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PCT/US07/02780 |
Jan 31, 2007 |
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12690081 |
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61414598 |
Nov 17, 2010 |
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61449038 |
Mar 3, 2011 |
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60764033 |
Jan 31, 2006 |
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Current U.S.
Class: |
424/404 ;
424/445; 424/78.18; 424/78.35; 514/57; 602/48 |
Current CPC
Class: |
A61K 33/38 20130101;
A61P 43/00 20180101; A61K 31/198 20130101; A61K 31/795 20130101;
A61K 31/65 20130101; A61L 2300/80 20130101; A61P 31/04 20180101;
A61L 2300/434 20130101; A61K 38/00 20130101; A61L 26/0052 20130101;
A61P 17/02 20180101; A61P 3/02 20180101; A61L 26/0066 20130101;
A61P 31/00 20180101; A61P 7/04 20180101; A61P 23/00 20180101; A61K
45/06 20130101; A61K 31/167 20130101; A61K 31/18 20130101; A61K
31/444 20130101; A61K 31/713 20130101; A61P 7/02 20180101; A61P
29/00 20180101; A61P 35/00 20180101; A61K 31/167 20130101; A61K
2300/00 20130101; A61K 31/18 20130101; A61K 2300/00 20130101; A61K
31/198 20130101; A61K 2300/00 20130101; A61K 31/444 20130101; A61K
2300/00 20130101; A61K 31/65 20130101; A61K 2300/00 20130101; A61K
31/713 20130101; A61K 2300/00 20130101; A61K 33/38 20130101; A61K
2300/00 20130101 |
Class at
Publication: |
424/404 ;
424/445; 424/78.35; 424/78.18; 514/57; 602/48 |
International
Class: |
A61L 26/00 20060101
A61L026/00 |
Claims
1. A medical device comprising: a component configured to be
coupled to a recipient, the component having at least one surface
configured to abut at least one surface of the recipient; and a
tacky silicone layer residing on at least a portion of the one
surface of the component, the tacky silicone layer comprising
polystyrene sulfonate material distributed therein.
2. The medical device of claim 1 wherein the polystyrene sulfonate
material comprises silver polystyrene sulfonate (cross-linked" and
non-cross-linked).
3. The medical device of claim 1 wherein the polystyrene sulfonate
material comprises salts of polystyrene sulfonate.
4. The medical device of claim 1 wherein the component comprises
wound dressing fabric.
5. The medical device of claim 4 wherein the wound dressing is
substantially planar.
6. The medical device of claim 1 wherein the component is
configured as a frame having at least one opening within the frame,
the tacky silicone layer residing along a perimeter of the
frame.
7. The medical device of claim 1 wherein the component is
configured to engage at a portion of an epidermis of a patient, the
patient being the recipient.
8. The medical device of claim 1 wherein the tacky silicone layer
further comprises additional pharmaceutically active agents.
9. The medical device of claim 8 wherein the pharmaceutically
active agents include one or more of antimicrobial,
anti-inflammatory, and/or antiproteolytic agents.
10. A medical device comprising: a component configured to be
coupled to a recipient, the component having at least one surface
configured to abut at least one surface of the recipient; and a
tacky silicone layer residing on at least a portion of the one
surface of the component, the tacky silicone layer comprising
silver-organo complex material distributed therein.
11. The medical device of claim 10 the silver-organo complex
comprise one or more of silver polystyrene sulfonate, crosslinked
silver polystyrene sulfonate (IRP69-silver), silver
carboxymethylcellulose, and silver polysaccharides.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/299,117 which was filed Nov. 17, 2011,
which claims priority to: U.S. Provisional Patent Application No.
61/414,598 which was filed on Nov. 17, 2010; U.S. Provisional
Patent Application No. 61/449,038 which was filed on Mar. 3, 2011;
U.S. patent application Ser. No. 12/690,081 which was filed on Jan.
19, 2010, which is a continuation in part of, and claims priority
to, U.S. patent application Ser. No. 12/162,990 filed Jul. 31,
2008, claiming priority to International Patent Application No.
PCT/US07/02780 filed Jan. 31, 2007, both of which claim priority to
U.S. Provisional Patent Application Ser. No. 60/764,033 entitled
"Method For The Reduction of Protease Levels and Delivering
Cationic Therapeutic Agents Using Water-Soluble Polyanionic
Oligomers & Polymers & Their Salts" filed Jan. 31, 2006.
The present patent application hereby incorporates each of these
listed patent applications by reference in their entirety.
TECHNICAL FIELD
[0002] The disclosure relates generally to medical devices, barrier
wound dressings, and methods for dressing wounds. More
specifically, embodiments of the disclosure relate to surgical
wound barrier dressings, including transcutaneous medical device,
barrier dressings, antimicrobial adhesive barriers for surgical
drapes, and antimicrobial adhesive barriers with absorbent
surfaces, and processes for their production and use, for
controlling infections and/or preventing and/or minimizing protein
drug degradation, for a drug such as insulin, at the site of the
delivery from an infusion set.
BACKGROUND
[0003] There are various types of surgical procedures that create
surgical wounds including investigative or corrective, minor or
major, open (traditional) or minimal access surgery, elective or
emergency, and/or incisions (simple cuts) or excision (removal of
tissue). In each case surgery exposes sub-cutaneous tissue; the
resulting wound requires management to promote satisfactory healing
and to avoid complications such as infection. In the majority of
cases this will require the use of some form of wound dressing.
With ideal healing conditions, a surgical wound, whether an
incision or excision, will follow the normal wound healing pathway
associated with acute wounds. There are three accepted modes of
healing. These include: Primary, Secondary, and tertiary intention
healing. Primary intention healing involves bringing the edges of
the wound together (in apposition) and securing them with sutures,
clips or skin closure strips. These wounds usually seal within 24
to 48 hours and generally heal within 8 to 10 days. Healing takes
place throughout the depth of the wound simultaneously and little
new tissue has to be formed. There may be a little leakage from the
wound for the first 2 days; the presence of bloody exudate or odor
beyond this is a warning sign of a potential complication. Managing
the risks associated with the open phase of healing is a prime
consideration. Secondary intention healing requires that a wound is
left open to allow healing by contraction and replacement of
missing tissue with granulation and epithelial tissue. It is common
for surgical excisions or traumatic wounds with tissue loss to be
healed this way. The healing duration will depend on the amount of
tissue that must be replaced and the resulting scar may be quite
extensive. In tertiary intention healing, or delayed closure the
wound is kept open to allow for drainage of exudate, control of
contamination or for further surgical procedures to be completed.
At a later date (usually within 7 days as bacterial contamination
rises markedly from the 8th day onwards), the patient returns to
the operating room for the wound to be surgically closed. If the
wound has to be kept open for longer periods of time and there is
significant bacterial contamination; this has to be reduced before
the wound is closed.
[0004] Infection is of major concern to most clinicians,
institutions and patients. Prior to the development of antiseptics
(Lister .about.1860) and aseptic technique, infection rates
following surgery were between 70% and 90% and 30% to 50% of these
patients died as a consequence of these wound infections.
Fortunately this situation has improved, with typical infection
rates of -10% being quoted in clinical literature. However, even
surgical units applying the most advanced and thorough aseptic
protocols rarely produce infection rates below a 5% average.
Surgical site infection (SSI) occurs in an estimated 15% of clean
surgeries and 30% of contaminated surgeries. Plastic adhesive
drapes with and without antimicrobial agents is a popular method of
protecting the wound from SSI, but conflicting results place their
efficacy in question. The embodiments disclosed herein can be used
to improve the performance of surgical drapes.
[0005] The risk of infection is significantly higher in hospitals
than in the home environment because the patient may be in a state
of reduced immunity and may be exposed to micro-organisms against
which an immune response has not been prepared. The development of
an infection adds a substantial cost to treatment. A two-year,
retrospective control study undertaken at the Alfred Hospital
determined that the incremental cost attributable to surgical site
infection after undergoing Coronary Artery Bypass Graft Surgery
(CABG) was $12,419. The magnitude of the incremental cost was
driven by an increase in the length of hospital stay and the
required drug therapy. Thus, infection is potentially a
considerable financial drain on valuable patient care
resources.
[0006] The risk of surgical incision complication is increased in
certain categories of patients including: the elderly or very
young, immuno-compromised or immuno-suppressed, those with
underlying debilitating disease, the nutritionally deprived, and
those taking drugs and therapeutic treatments that reduce their
ability to withstand infection.
[0007] The literature recognizes the criteria for an effective
post-operative dressing as possessing high moisture vapor
permeability (MVP), low adherence to the wound surface, absorbency,
waterproof, or wash-proof for minor surgery, bacterial barrier,
conformable, non-sensitizing, good adhesion to skin, sterile, low
cost, non-flammable and non-toxic.
[0008] Transcutaneous medical devices are catheters, pins, implants
and the like which pass through the skin, are indwelling for some
considerable time, and reside inside and outside of the body during
the course of function. Transcutaneous medical devices include but
are not limited to central venous catheters, peripheral venous
catheters, Swan-Gaus pulmonary catheters, central nervous system
implants (ex. external ventricular drainage and ventricular
reservoirs), peritoneal dialysis catheters, such as for continuous
ambulatory peritoneal dialysis and continuous cyclic peritoneal
dialysis, hemodialysis catheters, transvenous pacemaker leads and
temporary orthopedic pins. Transcutaneous medical devices, when in
place, have a portion of the device which is external, that is
which is left protruding from the skin, and which can be the cause
of infection. The risk of acquiring infections from transcutaneous
devices is high. For instance, the risk of acquiring
catheter-related bloodstream infection ranges from 0.9 to 8%. These
nosocomial bloodstream infections cause a case fatality of more
than 20%, and account for an increase of thousands of dollars in
hospital costs per infection, or tens of thousands of dollars per
survivor in ICU needing an extra week of hospital stay. As for
peritoneal dialysis, a very experienced center today still has a
peritonitis rate of one episode per 15 to 25 patient months. The
major sources of bacteria in these device-related infections are
from surrounding skin.
[0009] Long-term transcutaneous devices such as catheters, certain
biosensors, and infusion devices require patients to endure
extended skin breaches (wounds) that can be difficult to manage
clinically, i.e. infection and inflammation. These complications
not only shorten device lifespan, but also compromise patient
health. In the case of short-term, transcutaneous glucose sensors,
FDA has approved their usage for 3-7 days for patients with
diabetes. Infection can be an issue with these short-term sensors,
although generally the sensors are removed prior to the development
of a full-blown infection. The ability to extend the in vivo
lifespan of these sensors from days to weeks can lower the cost of
such a therapy; however the longer these devices remain implanted,
the risk of infection and hence adverse effects will increase.
Adverse effects seen at sites of transcutaneous device
implantation, including glucose sensors include infection,
irritation, redness, itching and inflammation. Such adverse effects
lead to shortened device lifespan in vivo and in addition they can
discourage patient involvement in implantable sensors. Clearly,
decreasing the risk of infections and inflammation at sensor
implantation sites would likely not only increase sensor lifespan,
but also decrease associated complications and adverse events.
[0010] To prevent infections associated with transcutaneous medical
devices and surgical wounds, antiseptic preparation of
insertion/incision sites, the initial application of topical
anti-microbial solutions such as alcohol or iodine to the insertion
sites is known. For transcutaneous devices, a further topical
ointment after insertion of the device, such as an ointment
containing neomycin, polymyxin and bacitracin, has been shown to
prevent catheter/device colonization/infection, but it may increase
the risk of fungal infections. For surgical incision sites,
dressing the wound with an antimicrobial wound dressing such as a
silver-based wound dressing is known. Ointments may be inconvenient
depending upon the type of wound as a consequence of having to
continually apply a dosing and the difficulty associated with being
able to view the wound for assessment, i.e. requiring multiple
replacements or having to clean the wound prior to evaluation.
There have also been attempts to prevent infection at the site by
the addition of an antimicrobial cuff to the catheters at or below
the entry point, i.e. with an anti-microbial agent impregnated in
the cuff. Efforts to coat the catheters with anti-microbial agents
are known. However, these efforts have failed in clinical trials.
Presently, the most common catheter dressing used in hospitals
comprises sterile gauze or polyurethane film, both which have
limited infection control properties. Efforts to replace gauze with
a transparent film dressing to allow a visual check on the
insertion site are known, see for instance U.S. Pat. No. 5,372,589,
issued Dec. 13, 1994 to Davis. No anti-microbial control is taught
with such a dressing. Johnson & Johnson Medical Inc. markets a
product under the trademark BIOPATCH.RTM., a chlorhexidine
gluconate-impregnated polyurethane sponge catheter patch. An
iodophor transparent dressing has also been suggested. However, to
date, no completely effective anti-microbial device for use with
transcutaneous medical devices is known. A layered antimicrobial
device for securing transcutaneous devices is described by Burrell
et al. in U.S. Pat. No. 7,137,968.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the disclosure are described below with
reference to the following accompanying drawings.
[0012] FIG. 1 is a medical device according to an embodiment of the
disclosure.
[0013] FIG. 2 is a medical device applied to a patient according to
an embodiment of the disclosure.
[0014] FIG. 3 is a schematic sectional of a medical device such as
a conformal surgical wound device barrier (island) dressing where
the wound contact layer is fabricated from an absorbent material
and the surrounding silicone gel barrier is formulated to include
an antimicrobial agent, according to an embodiment of the
disclosure.
[0015] FIGS. 4A and 4B are schematic sectionals of a medical device
such as an antimicrobial adhesive "frame" barrier for placement
around a surgical site. The barrier can be a three-layer construct
comprising a top absorbent layer, a tacky silicone gel barrier
formulated to include an antimicrobial agent, and a release liner
that can be removed just prior to application, according to an
embodiment of the disclosure.
[0016] FIG. 5 is a representation of a medical device such as a
surgical barrier border placed on a patient's abdomen prior to a
surgical procedure, according to an embodiment of the
disclosure.
[0017] FIGS. 6A, 6B, and 6C are schematic sectionals of a medical
device such as an island dressing including a flexible impervious
layer and high surface area fabric composite beneath a tacky
silicone gel layer with an absorbent "island" pad and release liner
upper layer, according to an embodiment of the disclosure.
[0018] FIG. 7 is a schematic of a representative process flow that
will allow for high volume production of a medical device in
accordance with embodiments of the present disclosure.
[0019] FIG. 8 is a schematic sectional figure of a medical device
such as a two-layer transcutaneous device dressing in accordance
with embodiments of the present disclosure.
[0020] FIG. 9 is a schematic perspective view of a medical device
such as a three-layer transcutaneous device composed of a cover and
base mounted on opposite sides of a common substrate to form a top
securing layer and a bottom dressing showing the opening for
placement around the transcutaneous medical device, according to an
embodiment of the disclosure.
[0021] FIG. 10 is a schematic perspective view of the device of
FIG. 9 in another configuration, according to an embodiment of the
disclosure.
[0022] FIG. 11 is a schematic cross sectional figure of a two-layer
transcutaneous device dressing in place with a catheter penetrating
the skin of a patient, according to an embodiment of the
disclosure.
[0023] FIG. 12 is a schematic sectional of a two-component, two
layer transcutaneous device dressing where the inner component is
fabricated from a silicone gel formulated to contain a water
absorbing material according to an embodiment of the
disclosure.
[0024] FIG. 13 is a plan view of the transcutaneous device barrier
dressing slid in place with a biosensor surrounded by a single
dressing, such that the dressing is in contact with a portion of
the sensor protruding from the skin according to an embodiment of
the disclosure.
[0025] FIG. 14 is a plan view of the transcutaneous device
dressing, according to an embodiment of the disclosure, showing the
slit in the lower dressing.
[0026] FIG. 15 is a schematic perspective view of a three-layer
transcutaneous device composed of a cover and base, with the lower
skin contacting base including an inner insert of a water absorbing
material and portions mounted on opposite sides of a common
substrate to form a top securing layer and a bottom dressing
showing the opening for placement around the transcutaneous medical
device, according to an embodiment of the disclosure.
[0027] FIG. 16 is a chlorhexidine diacetate release profile (10%
loading in silicone gel), according to an embodiment of the
disclosure.
[0028] FIG. 17 is a polyhexanide hydrochloride release profile (10%
loaded in silicone gel), according to an embodiment of the
disclosure.
[0029] FIG. 18 is a polyhexanide hydrochloride release profile (10%
loading in silicone gel with 10% polyvinylpyrrolidone blended into
the silicone), according to an embodiment of the disclosure.
[0030] FIG. 19 is a chlorhexidine diacetate release profile (10%
loading in silicone gel with 10% carboxymethylcellulose blended
into the silicone), according to an embodiment of the
disclosure.
[0031] FIG. 20 is a representation of the zones of clearance for
10, 15, & 20% chlorhexidine diacetate loaded Momentive
Performance Materials UV-cured silicone gel, according to an
embodiment of the disclosure.
[0032] FIG. 21 is a representation of the zones of clearance for
15% and 10% octenidine dihydrochloride loaded Nusil MED 6345 with A
and B part ratios of 50:50, 45:55 respectively, and 10% octenidine
loading in a 50:50 formulation and 0.5% and 10% polyhexanide
hydrochloride with A and B part ratios of 50:50 each. FIG. 19 is a
representation of the zones of clearance against Staphylococcus
epidermidis (ATCC 12228) for 1.15% octenidine dihydrochloride (1:1,
A:B), 2.10% octenidine dihydrochloride in Med 6345 (0.9:1.1, A:B),
3.10% octenidine dihydrochloride (1:1, A:B), 4. 0.5% PHMB (1:1,
A:B), and 5.10% PHMB (1:1, A:B) all formulated in Nusil Med 6345.
FIG. 20 is a representation of the zones of clearance against
Staphylococcus aureus (clinical isolate) for 1.15% octenidine
dihydrochloride (1:1, A:B), 2. 10% octenidine dihydrochloride in
Med 6345 (0.9:1.1, A:B), 3.10% octenidine dihydrochloride (1:1,
A:B), 4. 0.5% PHMB (1:1, A:B), and 5.10% PHMB (1:1, A:B) all
formulated in Nusil Med 6345. FIG. 22 is a representation of the
zones of clearance for 15% and 10% octenidine dihydrochloride
loaded Nusil MED 6345 with A and B part ratios of 50:50, 45:55
respectively, and 10% octenidine loading in a 50:50 formulation and
0.5% and 10% polyhexanide hydrochloride with A and B part ratios of
50:50 each. FIG. 19 is a representation of the zones of clearance
against Staphylococcus aureus (ATCC 12228) for 1.15% octenidine
dihydrochloride (1:1, A:B), 2.10% octenidine dihydrochloride in Med
6345 (0.9:1.1, A:B), 3.10% octenidine dihydrochloride (1:1, A:B),
4. 0.5% PHMB (1:1, A:B), and 5.10% PHMB (1:1, A:B) all formulated
in Nusil Med 6345. FIG. 20 is a representation of the zones of
clearance against Staphylococcus aureus (clinical isolate) for
1.15% octenidine dihydrochloride (1:1, A:B), 2.10% octenidine
dihydrochloride in Med 6345 (0.9:1.1, A:B), 3.10% octenidine
dihydrochloride (1:1, A:B), 4. 0.5% PHMB (1:1, A:B), and 5.10% PHMB
(1:1, A:B) all formulated in Nusil Med 6345.
DESCRIPTION
[0033] This disclosure is submitted in furtherance of the
constitutional purposes of the U.S. Patent Laws "to promote the
progress of science and useful arts" (Article 1, Section 8).
[0034] Applicant has recognized numerous shortcomings of current
securing devices. For example, a securing device is taught for
affixing an intravenous device to the body in U.S. Pat. No.
3,918,446, issued Nov. 11, 1975 to Buttaravoli. The device has an
upper and a lower pad, between which the intravenous device is
fixed. Since the function of the device is to secure the device to
the body, there is a teaching to provide an adhesive material to
the bottom of lower pad, and to the bottom of the top pad. There is
a mention of providing the adhesive with an antibacterial
agent.
[0035] This device has the disadvantage of using adhesives with the
antibacterial agent, which generally limits the effectiveness and
long lasting ability of the antibacterial agent. Furthermore, the
adhesive can be irritating next to the skin, cause skin damage and
patient discomfort on removal, and inhibits the removal or changing
of the device. Furthermore, many adhesives that are placed onto the
surface of a matrix aimed at the delivery of an active
pharmaceutical ingredient (API) can act as a moisture barrier,
which can limit the effectiveness of the API because moisture
generally facilitates the delivery of the API by first dissolving
the API and subsequently aiding the release of the API from the
material which has been placed at the site of interest, i.e. the
site of transcutaneous device implantation. The term agent and
ingredient may be used interchangeably herein.
[0036] The disclosed dressing is a waterproof, conformable dressing
formulated with or without any variety of active pharmaceutical
ingredients (such as an antimicrobial agent, antiproteolytic agent,
or oligodynamic metal, and/or mixtures of thereof), the bulk
dressing material possessing appreciable tack (and as such does not
require the use of a secondary adhesive layer, although one can be
used if desired) that will not damage epithelium upon removal, is
easily constructed with or without an absorbent pad to collect
wound exudate, and creates a seal (barrier) around the entire wound
to limit any infiltration of invading pathogens to the incision
site.
[0037] Embodiments of the device of the present disclosure can
provide a skin friendly, conformal, tacky & self adhesive
silicone gel construct compounded with an antimicrobial agent. The
device can also include a protective top layer that acts as an
adhesion layer in some embodiments, a peel away release liner, and
a slit through the dressing exposing access to a central cutout
that allows placement of the barrier dressing on the skin and below
the transcutaneous device when in place thus allowing the
transcutaneous device to remain in contact with the skin to provide
a conformal antimicrobial barrier surrounding the device and
therefore limiting the likelihood of infection of the device or the
tissue surrounding the device. In one embodiment, the
transcutaneous device dressing barrier is secured around the device
and a second similar barrier device mounted on the opposite side of
the protective barrier is secured over the top of the protruding
transcutaneous device (such as a catheter) and to the top
(protective) layer. In the case of a surgical wound dressing
barrier device, a skin friendly, conformal, tacky & self
adhesive silicone gel construct compounded with an antimicrobial
agent. The dressing also includes a protective top layer that acts
as an adhesion layer in some embodiments, a peel away release
liner, and an absorbent pad in the center of the dressing (island)
allows placement of the barrier dressing on the skin surrounding
the surgical wound in order to provide a conformal antimicrobial
barrier surrounding the wound and therefore limiting the likelihood
of infection of the wound. In one embodiment, the surgical wound
dressing barrier is secured around the wound and the absorbent
material is in direct contact with the closed or open surgical
wound, abrasion, or penetrating injury. In the case of a dry wound,
a tacky silicone wound dressing barrier without an absorbent
"island" can be utilized in order to protect the wound from
external insult and invading pathogens.
[0038] Barrier wound dressings of the disclosure can include a
first tacky silicone gel polymer interfacial adhesion layer
formulated to include at least one active pharmaceutical agent are
provided.
[0039] Barrier wound dressings and antimicrobial barrier adhesives
including a first tacky silicone gel polymer interfacial adhesion
layer to include an active pharmaceutical agent wherein said active
pharmaceutical agent can include an antibacterial agent,
anti-inflammatory agent, nutrient, antibiotic agent, healing agent,
antiproteolytic agent, anesthetic agent, oligodynamic metal, are
provided.
[0040] Tacky silicone gel polymer interfacial adhesion layers
incorporating an active pharmaceutical agent of organic,
organometallic, or metallic nature comprising one or more of an
antimicrobial agent, antibiotic agent, anti-inflammatory agent,
antiproteolytic agent, anesthetic agent, nutritional agent, healing
agent, coagulation agent, anticoagulation agent, oligodynamic
metal, moisturizing agent, or an angiogenesis stimulating agent are
provided.
[0041] Barrier wound dressings including tacky silicone gel polymer
interfacial adhesion layers formulated to include at least one
active pharmaceutical agent are provided.
[0042] Barrier wound dressings including a first tacky silicone gel
polymer interfacial adhesion layer including an active
pharmaceutical agent wherein said active pharmaceutical agent can
include one or more of an antibacterial agent, anti-inflammatory
agent, nutrient, antibiotic agent, healing agent, or anesthetic
agent are provided.
[0043] Single dressing barrier wound dressings including a single
tacky silicone gel polymer interfacial adhesion layer adapted for
application upon a tissue surface and surrounding the medical
device at the location where the device breaches the body surface
modified to include a central inner absorbent material component
formulated to include at least one active pharmaceutical agent are
provided.
[0044] Also provided are barrier wound dressings including a single
tacky silicone gel polymer interfacial adhesion layer adapted for
application upon a tissue surface and encompassing a surgically
created incision site whereby a non-adherent, fluid-absorbing layer
is in contact with the closed, or open, incision, and the conformal
"tacky" silicone interfacial adhesion layer is adhered to skin
surrounding the surgical wound. The silicone interfacial adhesion
layer may be formulated to include at least one active
pharmaceutical agent or one of many non-active compounds that may
aid in the healing of the surgical wound. It is understood that
dressings created for the purposes of dressing surgical wounds can
be used to dress wounds resulting from injury or trauma.
[0045] Surgical site barriers including a single tacky silicone gel
polymer interfacial layer comprising a top (upper) layer of high
surface area material for the absorbance of fluids are provided in
roll format and the conformal "tacky" silicone layer can be adhered
to the skin surrounding the site where the surgery may be
conducted. The silicone interfacial adhesion layer may be
formulated to include at least one active pharmaceutical agent or
one of many non-active compounds that may aid in preventing
bacterial infiltration of the surgical wound.
[0046] The devices and methods of the present disclosure are
described with references to FIGS. 1-22. Referring first to FIG. 1,
a medical device 10 is shown that includes a substrate 12 having
one surface 16 and another opposing surface 18. On the one surface
16 is a composition 14 comprising a silicone material and at least
one pharmaceutically active agent.
[0047] In accordance with example implementations, the silicone
material can be a tacky silicone material. Silicone is a polymer
comprising siloxane units such as the dimethylsiloxane variety. The
silicone material can be a gel having "tack" consistent with the
amount of cross linking units present in the material. Generally,
medical grade silicones are cured by one of three mechanisms. These
include: 1. Room temperature vulcanization (RTV) which is either a
single component silicone rubber precursor that can utilized
condensation-type chemistry involving the loss of acetic acid
during cure or as platinum catalyst-based addition chemistry; 2.
Peroxide catalyzed vulcanization whereby two components are
combined (one containing the catalyst) where the catalyst is a
peroxide, such as benzoyl peroxide, which initiates a free radical
reaction for vulcanization/crosslinking of the two components with
the addition of heat; and 3. Platinum complex-mediated (addition
cure) rubber that requires compounding of two components and
heating or irradiating the rubber mixture to drive the reaction to
completion.
[0048] The pharmaceutically active agent can be one or more of an
antibacterial agent, anti-inflammatory agent, nutrient, antibiotic
agent, healing agent, antiproteolytic agent, anesthetic agent,
oligodynamic metal agent, coagulation agent, anticoagulation agent,
moisturizing agent, and/or angiogenesis stimulating agent.
[0049] Antimicrobial agent can be a term for drugs, chemicals, or
other substances that either kill or slow the growth of microbes.
Among the antimicrobial agents are antibacterial drugs, including
antibiotics, antiviral agents, antifungal agents, organometallic
compounds such as silver carbenes, anti parasitic drugs, and
oligodynamic metals to include silver and the like. Antibiotics are
commonly classified based on their mechanism of action, chemical
structure, or spectrum of activity. Most antibiotics target
bacterial functions or growth processes. Antibiotics that target
the bacterial cell wall (penicillins, cephalosporins), or cell
membrane (polymoxins), or interfere with essential bacterial
enzymes (quinolones, sulfonamides) are usually bactericidal in
nature. Those that target protein synthesis, such as the
aminoglycosides, macrolides, and tetracyclines, are usually
bacteriostatic. Further categorization is based on their target
specificity: "Narrow-spectrum" antibiotics target particular types
of bacteria, such as Gram-negative or Gram-positive bacteria,
whereas broad-spectrum antibiotics affect a wide range of bacteria.
In the last few years, three new classes of antibiotics have been
brought into clinical use. This follows a 40-year hiatus in
discovering new classes of antibiotic compounds. These new
antibiotics are of the following three classes: cyclic lipopeptides
(daptomycin), glycyclines (tigecycline), and oxazolidinones
(linezolid). Tigecycline is a broad-spectrum antibiotic, whereas
the two others are used for Gram-positive infections. These
developments show promise as a means to counteract the bacterial
resistance to existing antibiotics.
[0050] The antimicrobial agent can include an "Anti-microbial
metal" which can be metals whose ions have an anti-microbial
effect. "Metal" or "metals" includes one or more metals whether in
the form of substantially pure metals, alloys or compounds
including oxides, and salts such as nitrides, borides, sulphides,
halides, carboxylates, or hydrides. The metal may also be
biocompatible. Anti-microbial metals include Ag, Au, Pt, Pd, Ir, Ga
(i.e. the noble metals), Sn, Cu, Sb, Bi, Ce, and Zn. Atoms, ions,
molecules or clusters of the anti-microbial metal (herein after
"species" of the anti-microbial metal) can have "Anti-microbial
effect" when they are released.
[0051] The antimicrobial agent can be one or more of chloroxylenol
(parachlorometaxylenol), acedapsone; acetosulfone sodium; alamecin;
alexidine; amdinocillin; amdinocillin; pivoxil; amicycline;
amifloxacin; amifloxacinmesylate; amikacin; amikacin sulfate;
aminosalicylic acid; aminosalicylate sodium; amoxicillin;
amphomycin; ampicillin; ampicillin sodium; apalcillin sodium;
apramycin; aspartocin; astromicin sulfate; avilamycin; avoparcin;
azithromycin; azlocillin; azlocillin sodium; bacampicillin
hydrochloride; bacitracin; bacitracin, methylenedisalicylate;
bacitracin zinc; bambermycins; benzoylpas calcium; berythromycin;
betamicin sulfate; biapenem; biniramycin; biphenamine
hydrochloride; bispyrithionemagsulfex; butikacin; butirosin
sulfate; capreomycin sulfate; carbadox; carbenicillin disodium;
carbenicillin, indanyl sodium; carbenicillin phenyl sodium;
carbenicillin potassium; carumonam sodium; cefaclor; cefadroxil;
cefamandole; cefamandolenafate; cefamandole sodium; cefaparole;
cefatrizine; cefazaflur sodium; cefazolin; cefazolin sodium;
cefbuperazone; cefdinir; cefepime; cefepime hydrochloride;
cefetecol; cefixime; cefmenoxime hydrochloride; cefmetazole;
cefmetazole sodium; cefonicid monosodium; cefonicid sodium;
cefoperazone sodium; ceforanide; cefotaxime sodium; cefotetan;
cefotetan disodium; cefotiam hydrochloride; cefoxitin; cefoxitin
sodium; cefpimizole; cefpimizole sodium; cefpiramide; cefpiramide
sodium; cefpirome sulfate; cefpodoxime; proxetil; cefprozil;
cefroxadine; cefsulodin sodium; ceftazidime; ceftibuten;
ceftizoxime sodium; ceftriaxone sodium; cefuroxime;
cefuroximeaxetil; cefuroximepivoxetil; cefuroxime sodium;
cephacetrile sodium; cephalexin; cephalexin hydrochloride;
cephaloglycin; cephaloridine; cephalothin sodium; cephapirin
sodium; cephradine; cetocycline hydrochloride; cetophenicol;
chloramphenicol; chloramphenicolpalmitate;
chloramphenicolpantothenate complex; chloramphenicol sodium
succinate; chlorhexidinephosphanilate; chlorhexidinediacetate,
chlorhexidinedihydrochloride, chlorhexidinedigluconate,
chlortetracycline bisulfate; chlortetracycline hydrochloride;
cinoxacin; ciprofloxacin; ciprofloxacin hydrochloride; cirolemycin;
clarithromycin; clinafloxacin hydrochloride; clindamycin;
clindamycin hydrochloride; clindamycinpalmitate hydrochloride;
clindamycin phosphate; clofazimine; cloxacillinbenzathine;
cloxacillin sodium; cloxyquin; colistimethate sodium; colistin
sulfate; coumermycin; coumermycin sodium; cyclacillin; cycloserine;
dalfopristin; dapsone; daptomycin; demeclocycline; demeclocycline
hydrochloride; demecycline; denofungin; diaveridine; dicloxacillin;
dicloxacillin sodium; dihydrostreptomycin sulfate; dipyrithione;
dirithromycin; doxycycline; doxycycline calcium;
doxycyclinefosfatex; doxycyclinehyclate; droxacin sodium; enoxacin;
epicillin; epitetracycline hydrochloride; erythromycin;
erythromycin acistrate; erythromycin estolate; erythromycin
ethylsuccinate; erythromycin gluceptate; erythromycin lactobionate;
erythromycin propionate; erythromycin stearate; ethambutol
hydrochloride; ethionamide; fleroxacin; floxacillin; fludalanine;
flumequine; fosfomycin; fosfomycintromethamine; fumoxicillin;
furazolium chloride; furazoliumtartrate; fusidate sodium; fusidic
acid; ganciclovir and ganciclovir sodium; gentamicin sulfate;
gloximonam; gramicidin; haloprogin; hetacillin; hetacillin
potassium; hexedine; ibafloxacin; imipenem; isoconazole;
isepamicin; isoniazid; josamycin; kanamycin sulfate; kitasamycin;
levofuraltadone; levopropylcillin potassium; lexithromycin;
lincomycin; lincomycin hydrochloride; lomefloxacin; lomefloxacin
hydrochloride; lomefloxacin mesylate; loracarbef; mafenide;
meclocycline; meclocyclinesulfosalicylate; megalomicin potassium
phosphate; mequidox; meropenem; methacycline; methacycline
hydrochloride; methenamine; methenamine hippurate; methenamine
mandelate; methicillin sodium; metioprim; metronidazole
hydrochloride; metronidazole phosphate; mezlocillin; mezlocillin
sodium; minocycline; minocycline hydrochloride; mirincamycin
hydrochloride; monensin; monensinsodiumr; monovalent silver salts,
nafcillin sodium; nalidixate sodium; nalidixic acid; natainycin;
nebramycin; neomycin palmitate; neomycin sulfate; neomycin
undecylenate; netilmicin sulfate; neutramycin; nifuiradene;
nifuraldezone; nifuratel; nifuratrone; nifurdazil; nifurimide;
nifiupirinol; nifurquinazol; nifurthiazole; nitrocycline;
nitrofurantoin; nitromide; norfloxacin; novobiocin sodium;
octenidinedihydrochloride, octenidinediacetate,
octenidinedigluconate, ofloxacin; onnetoprim; oxacillin and
oxacillin sodium; oximonam; oximonam sodium; oxolinic acid;
oxytetracycline; oxytetracycline calcium; oxytetracycline
hydrochloride; paldimycin; parachlorophenol; paulomycin;
pefloxacin; pefloxacinmesylate; penamecillin; penicillins such as
penicillin g benzathine, penicillin g potassium, penicillin g
procaine, penicillin g sodium, penicillin v, penicillin v
benzathine, penicillin v hydrabamine, and penicillin v potassium;
pentizidone sodium; phenyl aminosalicylate; piperacillin sodium;
pirbenicillin sodium; piridicillin sodium; pirlimycin
hydrochloride; pivampicillin hydrochloride; pivampicillinpamoate;
pivampicillinprobenate; polyhexamethylenebiguanide (polyhexanide
hydrochloride, PHMB); polymyxin b sulfate; porfiromycin;
propikacin; pyrazinamide; pyrithione zinc; quindecamine acetate;
quinupristin; racephenicol; ramoplanin; ranimycin; relomycin;
repromicin; rifabutin; rifametane; rifamexil; rifamide; rifampin;
rifapentine; rifaximin; rolitetracycline; rolitetracycline nitrate;
rosaramicin; rosaramicin butyrate; rosaramicin propionate;
rosaramicin sodium phosphate; rosaramicinstearate; rosoxacin;
roxarsone; roxithromycin; sancycline; sanfetrinem sodium;
sarmoxicillin; sarpicillin; scopafungin; silver acetate; silver
nitrate, nanocrystalline silver, silver polystyrene sulfonate
("cross-linked" and non-cross-linked); silver carboxymethyl
cellulose, silver polysaccharides (such as silver chondroitin
sulfate and the like), silver carbene compounds, sisomicin;
sisomicin sulfate; sparfloxacin; spectinomycin hydrochloride;
spiramycin; stallimycin hydrochloride; steffimycin; streptomycin
sulfate; streptonicozid; sulfabenz; sulfabenzamide; sulfacetamide;
sulfacetamide sodium; sulfacytine; sulfadiazine; sulfadiazine
sodium; sulfadiazine silver; sulfadoxine; sulfalene; sulfamerazine;
sulfameter; sulfamethazine; sulfamethizole; sulfamethoxazole;
sulfamonomethoxine; sulfamoxole; sulfanilate zinc; sulfanitran;
sulfasalazine; sulfasomizole; sulfathiazole; sulfazamet;
sulfisoxazole; sulfisoxazole acetyl; sulfisboxazolediolamine;
sulfomyxin; sulopenem; sultamricillin; suncillin sodium;
talampicillin hydrochloride; teicoplanin; temafloxacin
hydrochloride; temocillin; tetracycline; tetracycline
hydrochloride; tetracycline phosphate complex; tetroxoprim;
thiamphenicol; thiphencillin potassium; ticarcillincresyl sodium;
ticarcillin disodium; ticarcillin monosodium; ticlatone; tiodonium
chloride; tobramycin; tobramycin sulfate; tosufloxacin;
trimethoprim; trimethoprim sulfate; trisulfapyrimidines;
troleandomycin; trospectomycin sulfate; tyrothricin; vancomycin;
vancomycin hydrochloride; virginiamycin and/or zorbamycin.
[0052] Antimicrobials can be biocompatible when the toxicity that
is demonstrated is tolerable for the intended utility. Thus, for
human utility, biocompatible can be acceptably toxic or non-toxic
to humans or human tissues.
[0053] One of the most common methods of measuring anti-microbial
effect is by the Kirby-Bauer method. The Kirby-Bauer method
measures the zone of inhibition (ZOI) created when the material is
placed on a bacterial lawn grown onto agar. A relatively small or
no ZOI (ex. less than 1 mm) indicates either a non useful
anti-microbial effect or low solubility of the active agent in the
media of study, while a larger ZOI (ex. greater than 5 mm)
indicates a highly useful anti-microbial effect. One procedure for
a ZOI test is set out in the Examples which follow.
[0054] "Sustained release" or "sustainable basis" are used to
define release of atoms, molecules, ions or clusters of an
anti-microbial metal that continues over time measured in hours or
days, and thus distinguishes release of such metal species from the
bulk metal, which release such species at a rate and concentration
which is too low to achieve an anti-microbial effect, and from
highly soluble salts of anti-microbial salts such as silver
nitrate, or less soluble silver salts such as silver acetate, or
highly soluble antimicrobial (organic species) such as
polyhexamethylene biguanide dihydrochloride (PHMB or polyhexanide),
or organic species with lower solubility that include chlorhexidine
diacetate, octenidine dihydrochloride, or more complex salts such
as octenidine polystyrene sulfonate, polyhexamethylene biguanide
polystyrene sulfonate, polyhexamethylene biguanide carboxymethyl
cellulose, or octenidine carboxymethyl cellulose.
[0055] The pharmaceutical agent can be an anti-inflammatory agent.
The anti-inflammatory agent can be one or more of hydrocortisone,
hydroxyltriamcinolone, alphamethyldexamethasone,
dexamethasone-sodium phosphate, dexamethasone; beclomethasone
dipropionate, clobetasolvalerate, desonide, desoxymethasone,
desoxycorticosterone acetate, dexamethasone, dichlorisone,
diflorasonediacetate, diflucortolonevalerate, fluadrenolone,
fluclaroloneacetonide, fludrocortisone, flu methasonepivalate,
fluosinoloneacetonide, fluocinonide, flucortinebutylester,
fluocortolone, fluprednidene (fluprednylidene)acetate,
flurandrenolone, halcinonide, hydrocortisone acetate,
hydrocortisone butyrate, methylprednisolone,
triamcinoloneacetonide, cortisone, cortodoxone, flucetonide,
fludrocortisone, difluorosonediacetate, fluradrenaloneacetonide,
medrysone, amc, amcinafide, betamethasone and the balance of its
esters, chlorprednisone, chlorprednisone acetate, clocortelone,
clescinolone, dichlorisone, difluprednate, flucloronide,
flunisolide, fluoromethalone, fluperolone, fluprednisolone,
hydrocortisone valerate, hydrocortisone cyclopentylproprionate,
hydrocortamate, meprednisone, paramethasone, prednisolone,
prednisone, beclomethasonedipropionate, betamethasonedipropionate,
triamcinolone prostaglandin H synthetase inhibitors (Cox I or Cox
II), flurbiprofen, ketorolac, suprofen, nepafenac, amfenac,
indomethacin, naproxen, ibuprofen, bromfenac, ketoprofen,
meclofenamate, piroxicam, sulindac, mefanamic acid, diflusinal,
oxaprozin, tolmetin, fenoprofen, benoxaprofen, nabumetome,
etodolac, phenylbutazone, aspirin, oxyphenbutazone, NCX-4016,
HCT-1026, NCX-284, NCX-456, tenoxicam, carprofen, cyclooxygenase
type II selective inhibitors, vioxx, celecoxib, P54, etodolac,
L-804600, S-33516; PAF antagonists, A-137491, ABT-299, apafant,
bepafant, minopafant, E-6123, BN-50727, nupafant, modipafant, PDE
IV inhibitors, ariflo, torbafylline, rolipram, filaminast,
piclamilast, cipamfylline, CG-1088, V-11294A, CT-2820, PD-168787,
CP-293121, DWP-205297, CP-220629, SH-636, BAY-19-8004, and/or
roflumilast.
[0056] The active pharmaceutical agent can be an antiproteolytic
agent. The antiproteolytic agent can be one or more of amprenavir
(Agenerase), fosamprenavir (Lexiva), indinavir (Crixivan),
lopinavir/ritonavir (Kaletra), ritonavir (Norvir), saquinavir
(Fortovase), and nelfinavir (Viracept), salts of ethylene diamine
tetracetic acid, salts of polystyrene sulfonate, and sulfated oligo
& polysaccharides.
[0057] Composition 14 can comprise from about 60 to about 99 (wt/wt
%) silicone material; from about 1 to about 40 (wt/wt %)
pharmaceutical agent. Composition 14 can be prepared before partial
or complete curing of the silicone material. Composition 14 can be
prepared as part of the curing of the silicone material.
Composition 14 can be prepared upon partial or completion of the
curing of the silicone material.
[0058] Medical device 10 may be configured as a wound dressing.
Composition 14 may be an adhesive mixture bound to substrate 12.
The adhesive mixture can be a tacky silicone material and at least
one active pharmaceutical agent. The adhesive mixture can be
conformal and/or pressure sensitive.
[0059] Substrate 12 can be substantially planar. Substrate 12 can
be a flexible fabric such as one or both of knitted and non-woven
fabric. Substrate 12 can be cellulosic such as one or both of
cotton or wool. Substrate 12 can be a polymeric material. The
polymeric material can be one or both of woven or a film. Substrate
12 can be one or more of a polyurethane, polyalkylene,
polysiloxane, polyester, and/or polyamide. Substrate 12 can be a
fenestrated film material.
[0060] In accordance with example embodiments, composition 14,
configured as an adhesive mixture, for example, can extend around
the perimeter of the substrate. Substrate 12 can define an opening
extending between the periphery of the plane of the substrate. The
substrate can define an opening extending from an edge of the plane
inwardly to a point away from the edge. The adhesive mixture may
extend around the perimeter of the opening.
[0061] Alternate compositions and/or configurations of the devices
of the present disclosure, including various anti-microbial
formulations of composition 14 used in the devices are set out in
further detail below.
[0062] As an example, composition 14 can be formed of an tacky
silicone gel such as Nusil Technologies MED 6345 (platinum curing
silicone elastomer) and substrate 12 may be formed of a high
surface area, porous, non-adherent material such as a woven,
non-woven, or fenestrated film material, fabric such as cotton,
gauze, a polymeric netting or mesh such as polyethylene, nylon,
polypropylene or polyester, an elastomer such as polyurethane or
block copolymer elastomers such as Kraton, or a foam such as open
cell polyurethane foam. Example woven meshes may be formed from
polyester, acetate, or cotton gauze. One example, hydrophilic
polyurethane foam is HYPOL.TM., available from W. R. Grace &
Co., New York, N.Y., USA.
[0063] An absorbent material for use in the devices of the
disclosure such as part of composition 14 or as a separate a wound
contact layer or as substrate 12 such as an upper surface of a
surgical site antimicrobial frame, or around transcutaneous devices
such as a super-pubic catheter where leaking urine may be absorbed
and held away from the skin where otherwise it can cause irritation
and maceration, is a non-woven rayon/polyester core such as
SONTARA.TM. 8411, a 70/30 rayon/polyester blend commercially
available from Dupont Canada, Mississauga, Ontario, Canada. This
product is sold by National Patent Medical as an American White
Cross sterile gauze pad. However, other suitable absorbent
materials include woven or non-woven materials, non-woven such as
Evolon.RTM. spun bond polyester being preferred given the ability
to absorb up to 400% of its own weight in liquid as a consequence
of the high surface area. The material may be made from fibers such
as rayon, polyester, rayon/polyester, polyester/cotton, cotton and
cellulosic fibers. Creped cellulose wadding, an air felt of air
laid pulp fibers, cotton, gauze, and other well known absorbent
materials suitable for medical dressings can be utilized. Other
absorbent materials which may be used for the inner portions of the
barrier dressing device include foamed materials (synthetic and
biopolymers), hydrogels, absorbent polymers such as hydrocolloids
to include any variety known in the wound healing art including
carboxymethylcellulose (CMC), alginates, collagen, hydrophilic
polyurethanes, crosslinked acrylic polymers, crosslinked
polyethylene glycol, silicone gel blends that incorporate absorbent
polymers such as poly(vinylpyrrolidone) (PVP), polyethylene glycol
(PEG), carboxymethylcellulose (CMC), alginates, or a commercially
available hydrocolloid wound dressing such as Carra Colloid
(Carrington Laboratories). These absorbent materials may also be
formulated to include an active pharmaceutical ingredient such as
an antimicrobial agent (e.g. chlorhexidine) or a healing aid such
as vitamin E and the absorbent material may be connected to the
bulk dressing (silicone gel) material in at least two ways that
include as an island situated upon the silicone gel or recessed
into the silicone gel.
[0064] Referring to FIG. 2, device 10 can be applied to epidermal
layer 22 of patient 20 for example. Layer 22 may or may not include
a laceration, ulcer, or other epidermal breach. Device 10 can be
applied to layer 22 contacting composition 14 with layer 22 as part
of a method for dressing wound for example. Of course device 10 may
be applied to layer 22 for other reasons, including but not limited
to post or pre surgical, or prophylatically for example. In
accordance with one method, substrate 12 can be adhered to layer 22
using composition 14.
[0065] Referring to FIG. 3, a device 32 is shown configured as a
surgical wound barrier dressing. Device 32 can include composition
14 configured as a silicone gel component 34 having a release liner
36 attached thereto. Device 32 can include a fluid absorbing
portion bound to the substrate such as an absorbent layer 38 on the
surface of component 34 opposing the surface having release liner
36 attached thereto. Absorbent layer 38 may take the form of an
island above component 34 and/or may be attached to component 34
with an interfacial layer 40. The absorbent layer can be a
hydrocolloid for example and may be part of composition 14 for
example.
[0066] Referring to FIGS. 4A and 4B, in accordance with an
alternative embodiment, devices 50 and 60 are shown than can be
configured as an insert and frame. Devices 50 and 60 can be
configured as an antimicrobial surgical barrier that may be
implemented as part of a surgical drape or may be used alone. FIG.
5 is a representation of the surgical barrier placed on the abdomen
prior to a surgical procedure. Device 70 is represented as a
pictorial representation of the barrier is applied to the abdomen,
for example. In accordance with example implementations, devices 50
and 60 can be constructed of composition 14 configured as a tacky
silicone gel layer 54 and 64, respectively. These layers 54 and 64
may have release liners 56 and 66 on one side and substrate 52 and
62 on the opposing side. Device 50 may be used as a surgical tape
to confine dressings for example, and device 60 may be used to
define a barrier for a surgical procedure.
[0067] Referring to FIGS. 6-7, another embodiment of a medical
device is shown as well as a process flow for producing same.
Referring to FIGS. 6A-6C, device 80 is configured as a disk or
puck. Device 80 can include a composition 14 configured as a
silicone gel component 86 having a release liner 90 on one surface
and substrate 12 configured as a fabric material 84 on the opposing
surface. Device 80 can further include and an impervious flexible
layer 82 on the opposing surface of fabric material 84. Device 80
can define a base 92 having an island 94 extending therefrom. Base
92 can include at least silicone gel component 86 and fabric
material 84. Island 94 can extend from silicone gel component 86
and/or include an absorbent material 88. Island 94 can include
release liner 90, and release liner 90 may be continuous from the
one surface of silicone gel component 86 to an opposing surface of
absorbent material 88. Alternatively, silicone gel component 86 can
be cured as a sheet in a mold where release is facilitated easily
and fabric layer 84 added to the surface. The fabric silicone
composite can be turned 180 degrees and absorbent material layer 88
added. Shapes of the device can be die cut from the sheet as
desired.
[0068] Referring to FIG. 7 a process flow for preparing device 80
is shown with the materials being consistent with those described
in FIGS. 6A-6C. In the fabrication of such devices it can be
beneficial to dispense the uncured silicone gel mixture 91 over a
composite substrate that includes a bottom layer impervious to a
silicone liquid composition ready for cure and comprising a thin
flexible material such as a polymer such as polyurethane and a
second layer in contact with the first impervious layer comprising
a high surface area material such as a polyester fabric (woven or
non-woven). When cured this composition can remain flexible and the
gel can be further modified to include an absorbent component and
covered with a release liner, for example. The following method can
also be applied to scaling up to produce island dressings or
similar 5-layer configurations.
[0069] In accordance with a specific example, a platinum catalyzed
2-component system can be utilized such as Med 6345 (Nusil, of
Carpenteria Calif.), comprising parts A and B which are generally
combined in equal proportions (50:50 w/w) and a known quantity of
the finely divided antimicrobial agent is added and the mixture
combined with the aid of a spatula or by using an automated mixing
apparatus such as a SpeedMixer. In practice, the antimicrobial
agent may be combined with one of the constituents (part A or B)
and mixed to a fine consistency before adding the second part or as
a kit for storage and use at a later time. The material is cast
onto a release liner, such as a polyethylene or a fluoropolymer for
example and into a mold and the silicone mixture gently leveled by
the use of a spatula. The barrier dressing formulation is cast onto
a release liner within a curing "tool" (mold) and the tool is
placed in a convection oven set at 80.degree. C. and the
formulation cured for a period of 2-3 hours to yield a tacky gel
substrate with a release liner affixed to one side. The protective
layer is subsequently pressed onto the available silicone gel
surface and the protective layer is retained by contact adhesion.
By using a slight excess of part B, such as a 55:45 w/w of part B
to part A, the gel may be formulated to have increased
firmness.
[0070] In yet another example of a silicone material that can be
used, a proprietary UV-curing silicone gel (Momentive Performance
Materials, Albany, N.Y. 12211). Part A and part B (catalyst) are
mixed thoroughly with the desired quantity of antimicrobial agent
and the formulation cast onto a release liner contained by a curing
"tool" (mold) and the tool placed onto a Dymax conveyer system with
a Fusion UV system employing an Iron D bulb. The silicone was
readily cured following 2 passes at a 2 ft/minute exposure
rate.
[0071] The devices may be sterilized using gamma or electron beam
radiation is preferred for sterilizing such barrier dressings, as
discussed in U.S. Pat. No. 5,454,886, the entirety of which is
incorporated by reference herein. The sterilized dressings should
be sealed in packaging which excludes light penetration to avoid
oxidation of any of the anti-microbial additives. Polyester, or
metalized polymer and heat sealable pouches are preferred. The
shelf life of anti-microbial dressings sealed in such a fashion is
at least one year.
[0072] Referring to FIGS. 8-15 other embodiments of medical devices
are depicted. The medical devices may be single or multi-component
medical devices and they may be utilized as dressings for
transcutaneous devices. Referring to FIG. 8, device 100 can include
at least two layers of medical dressing materials laminated
together by contact adhesion. Device 100 includes a two-layer
silicone gel construct dressing in accordance with the disclosure
can include a first layer 102, which will be skin facing in use, a
second layer 104 which preferably forms an protective layer. The
layers 102 and 104 are shown to be laminated together by contact
adhesion onto one surface of 100. In accordance with the
disclosure, layer 102 can be considered composition 14 and layer
104 can be considered substrate 12. Layer 104 can include an
opening 106 extending from a perimeter 108 of layer 104 to a
portion 110 of layer 104. This opening can be configured in various
shapes such as a circular opening to receive a transcutaneous
device, for example.
[0073] Referring to FIGS. 9-11, medical device 120 is shown that
includes a base 124 having an opening 106 configured to receive a
transcutaneous medical device. Base 124 can include composition 14
configured as a tacky substance such as a tacky silicone gel and
composition 14 can be associated with one surface configured to
engage a portion of epidermis of a patient. Device 120 can also
include a cover 122 associated with base 124 and configured to mate
with another surface 130 opposing the one surface 128 of base
124.
[0074] Cover 122 and base 124 can be associated via a common
substrate 12 such as fabric 126. As shown, cover 122 and base 124
can be situated 180 degrees apart on opposite sides of the fabric
126. In accordance with example configurations, In FIG. 2, cover
and base can be mated by folding pliable substrate 126 at hinge
125. As an example this can provide an adhesion boundary between
the cover and base and the common central piece of fabric 126.
[0075] Referring to FIG. 10, cover 122 and base 124 are shown at
90.degree. from each other and intimating how the adhesion of cover
122 to substrate 126 can be accomplished. Referring to FIG. 11
depicts device 120 securing transcutaneous device 132 with the
cover 122 adhering to substrate 126 and securing device 132 through
epidermal layer 22. Base 124 of device 120 can further define a
trough 134 extending from the perimeter of the base to the opening
with the trough configured to receive at least a portion of the
transcutaneous device. FIG. 12 details device 120 from a top down
perspective detailing slit 106 and inner absorbent material 422,
for example.
[0076] Referring to FIG. 13 an embodiment of a medical device 320
is shown securing a subcutaneous glucose sensor 327 piercing the
dermis 22 with its electronic connector 328 sitting external to
body 20.
[0077] FIGS. 14 and 15 detail alternative cover/base device 222 as
a three-layer device 220, to include a inner absorbent material 527
surrounding tacky silicone barrier 224 and protective top layer
material 524.
[0078] In accordance with this disclosure, the cover and base may
be may be formulated separately to include different additives. For
example, the base may include an antimicrobial agent and the cover
may be free of any additive. In another embodiment, the base and
cover can both be formulated to include an antimicrobial agent. In
yet another embodiment, the base may include an organic-based
antimicrobial agent and the cover can include an antimicrobial
metal salt such as silver acetate thus alleviating contact of the
skin by a silver salt containing polymer, which could lead to skin
discoloration. The cover and base may be of equivalent thicknesses
or different thicknesses and may range from approximately 3 mm to
approximately 15 mm, for example.
[0079] Also in accordance with this disclosure, the substrate may
be a polymer material that includes polyurethanes, polyalkylenes,
polysiloxanes, for example in sheet or film or foam form or it may
be a polymer material in fabric form such as a woven, non-woven, or
knitted fabric that includes polyesters, polyamides, and
cellulosics that include natural fibers such as cotton, wool or the
like. Additionally, the substrate may be coated with the previous
or other materials alone or in combination, such polyurethane, for
example. Furthermore, the substrate may be designed to wick fluid
from the center of the device by controlling the thickness and
surface area of the material; for example, using a non-woven
material such as a polyester. Substrate thicknesses may span a
range of approximately 0.6 mm to approximately 5 mm, for
example.
[0080] The medical devices as dressings can be sized to cover a
significant portion of the device 132 that protrudes from the skin
22, and not just the immediate skin area surrounding the
penetration site. This may aid in limiting infection, since
bacterial migration along the skin to the device 132 are minimized.
A minimum dressing size will preferably provide at least 5 cm of
protruding device 132 coverage, and more preferably 15 cm coverage.
Depending on the size of the transcutaneous medical device, the
termination point of the slit 106, may include additional cuts,
preferably a cross-cut, or a penetrating hole (not shown), to allow
the dressing barrier to fit around the device while still
maintaining close contact with both the skin and protruding section
of the medical device.
[0081] FIG. 12 shows device 420 from a top-down view with
protective substrate 124 and slit 106. Device 420 further includes
absorbent material 422 above a portion of substrate 124.
[0082] FIG. 13 demonstrates placement of device 320 over epidermis
22 of patient 20. Substrate 322 can be supported by composition
324, for example, a protective layer over tacky silicone gel, with
or without a pharmaceutical agent. Device 320 can secure a
biosensor with connector 328 above substrate 322 and transcutaneous
lead 327 below epidermis 22. Composition 324 can adhere to dermis
22 securing the biosensor in place. The biosensor can be an
enzymatic sensor based upon glucose oxidase for example. Generally,
these glucose sensors evaluate glucose by electrochemically
measuring hydrogen peroxide resulting from the enzymatic digestion
of glucose by glucose oxidase.
[0083] FIGS. 14 and 15 represent alternative embodiments of
cover/base medical device configurations. Referring first to FIG.
14, medical device 220 can include base 224 with opening 106. Base
224 can be associated with cover 222 via a hinge portion 226, for
example. Base 224 can include a substrate 223 which may form part
of hinge portion 226. FIG. 15 represents another device embodiment,
device 520, that can include base 524 and cover 522 associated
therewith. Base 524 can include substrate 523 thereover, which may
extend and attach to cover 522 via hinge 526. Above substrate can
be absorbent material 527 which may also extend into opening
106.
[0084] As described herein, the disclosure provides devices and
methods for its use with a transcutaneous medical device, such as
an intravascular catheter, which punctures the skin of a patient
and which has a portion of the medical device protruding from the
skin or to dress a wound that may be surgically created or created
by trauma. These transcutaneous devices are prone to infection as a
consequence of easy access of bacteria to the open wound. As
described, the devices of the present disclosure can be formed from
a flexible, adherent silicone gel having upper and lower surfaces,
with the lower surface being the skin facing surface in use and the
top adherent surface protected by a substrate such as a flexible
woven, knitted, or non-woven fabric. The device may have an opening
formed therein extending from one edge inwardly to a termination
point within the confines of the device. Current dressings for
protection against infection of transcutaneous devices generally
utilize a secondary transparent film (adhesive) dressing, such as
with BIOPATCH.RTM., in order to secure the device around the
transcutaneous device. It has been recognized that these secondary
dressings can irritate skin (allergic response) and damage
epithelium when removed thus leading to further tissue irritation.
The compositions of the devices of the present disclosure can be
more gentle to skin upon removal and less likely to lead to an
allergic response.
[0085] Specific embodiments of these devices may or may not include
one or more of a pharmaceutical agent or other functional agents
such as a protease inhibitor incorporated into the silicone gel for
placement adhered above the wound, without the use of additional
adhesives at the upper and lower surfaces of the device. As an
example use, the device can be placed next to the skin, the opening
allowing the base to surround the puncture site and at least a
portion of the transcutaneous device protruding from the skin such
that the lower surface of the base of the device is in contact with
the skin while the upper surface of the base of the device is also
in contact with a portion of the transcutaneous device protruding
from the skin. A cover may be utilized and joined to the base and
folded onto the top portion of the base such that the lower surface
of the cover is in contact with the upper surface of the base and
at least a portion of the transcutaneous device so as to secure the
transcutaneous device and provide another layer of antimicrobial
protection. In accordance with aspects of the disclosure, the
portion of the transcutaneous device protruding from the skin can
be exposed to composition 14 such as antimicrobial (silicone)
material of the base. When affixing the cover to the base, a
greater surface area of the transcutaneous device may also be
exposed to composition 14 as part of the silicone gel of the cover
secures the transcutaneous device to the substrate of the base.
[0086] The embodiments herein describe devices and/or methods for
preventing infection, protein drug degradation, prolonging the use
of transcutaneous devices, and/or protecting wounds, including
surgical wounds from external or bacterial insult is disclosed.
Embodiments of the disclosed medical device are conformal, and can
include an adhesive silicone barrier dressing surrounding a device
that breaches the skin of a patient undergoing diagnostic, drug, or
nutritional therapy, or encompassing a surgically created wound or
placing just prior to the creation of a surgical wound. The
conformal pressure sensitive barrier may be compounded to include
one or more of a tissue preserving agent, a drug preserving agent,
an antibiotic agent, an antibacterial agent, a pain suppressing
agent, or a tissue healing agent and/or the device may be
constructed to include an absorbent layer. Devices that may benefit
from the conformal barrier device include, but are not limited to,
biosensors, infusion devices, venous access devices, feeding tubes,
wound drainage tubes, orthopedic pins, stomas, surgical drapes,
catheters, and the like. Surgical wounds that may benefit from a
conformal antimicrobial barrier device that has the ability to
absorb some wound exudate include those surgical incisions created
in any variety of locations on the human body. The conformable
barrier device can be flexible and adhesive thus allowing the
device to follow difficult contours such as from the top of the
foot onto the shin (90 degree angle) or under the arm/armpit where
a dressing may actually be required to fold back on itself (180
degree angle). The soft-and-supple nature of the device can allow
these kinds of wound cover to be worn in comfort and to act as a
barrier to the ingress of pathogenic microorganisms.
[0087] Embodiments of the disclosure a device such as a dressing
barrier device that can include a tacky silicone gel construct
formulated with an active pharmaceutical agent that has been finely
divided and put through a sieve in order to ensure that the size of
the particles is below a certain size. The device can be placed to
overlie and surround an open wound supporting a transcutaneous
device in order to minimize bacterial infiltration, prevent tissue
loss, and provide stability and protection to active pharmaceutical
agents susceptible to degradation resulting from inflammation. In
addition, the device may be placed to overlie and surround a
(closed) surgical wound in order to minimize bacterial
infiltration, prevent external insult, provide a moist and
antibacterial environment to the healing wound, and/or provide a
healing aid (e.g. skin moisturizer) at the site of incision
(staples or sutures).
[0088] In a another embodiment, composition 14 of the device can
include the active pharmaceutical agent, the silicone gel, and in
the form of a concentric part, a hydrocolloid or other water
absorbing material in order to aid with fluid absorption around the
wound site. In another embodiment, the device includes both a base
and cover; the cover can be extended to form two distinct tacky
silicone gel constructs, one of the cover and one of the base,
bound to opposite sides of substrate 12 such as a protective layer
and preferably with a non-overlapping boundary between the two
constructs. In this arrangement, the base can be adhered to the
skin surface surrounding the transcutaneous implant; the
transcutaneous device is surrounded by the base with the
transcutaneous device resting perpendicular to an opening in the
base. The cover can then be folded onto the base to envelop the
transcutaneous device and fix it in place while adhering to the
upper protective layer of the base. The upper protective layer can
be a high surface area material such as a woven polyester fabric,
for example.
[0089] Embodiments of the disclosed devices have application to
transcutaneous medical devices such as those listed above, made
from a wide variety of materials, for example metals, including
steel, titanium and aluminum and their alloys, latex, nylon,
silicone, polyester, polyurethane, and other plastics and rubbers.
Such transcutaneous devices are generally made of bioinert or
biocompatible materials. The transcutaneous device may take a
variety of shapes including rod or tube shapes, hollow or solid,
and may be rigid or flexible, factors dictated by its intended
utility. One example transcutaneous device includes an infusion set
used with an infusion pump as part of intensive drug therapy. The
purpose of an infusion set is to deliver a drug under the skin or
into a central venous access point. It is a complete tubing system
to connect an infusion pump to the infusion system generally
including a catheter, subcutaneous cannula, adhesive mount,
quick-disconnect, and a pump cartridge connector.
[0090] Devices of the disclosure may have application to surgically
created wounds that may be sutured closed or remain open with the
device creating a barrier that surrounds the wound site and the
devices of the disclosure may, or may not provide an absorbent
material that sits over the open or closed wound. In addition, the
absorbent material may be formulated to include an antimicrobial
agent or any other number of agents that may aid the healing of the
wound.
[0091] Use of the devices of the disclosure as barrier dressings
such as with transcutaneous devices such as flexible catheters, for
example, can include a release liner fitted onto the contact layer
of the barrier dressing which is subsequently removed prior to the
device being placed on the skin and around the transcutaneous
device (e.g. catheter) by passing or placing the catheter through
the opening in the base contact layer. In an alternative procedure,
the barrier dressing is first placed around the transcutaneous
device and the release liner (which has been slit in a separate
operation) is removed one-half at a time. Prior to removal of the
release liner, the dressing can be rotated, oriented, and situated,
if needed, to ensure that the opening is roughly perpendicular to
the long axis of the catheter, thus ensuring that the portion of
the catheter protruding from the skin is contacted by the upper
surface of the base. Once the base is secure, the release liner of
the cover is removed and the cover folded over the base such that
the lower surface of the cover is in contact with the portion of
the catheter protruding from the skin.
[0092] If the transcutaneous device is rigid, such as a temporary
orthopedic pin, the base can be put in place as set out above, and
the cover can then be folded and secured around the portion of the
pin protruding from the skin, in a tent-like manner or in another
embodiment the cover is slit and each portion is placed
independently in an overlapping fashion, since the pin generally
protrudes at an angle normal to the skin surface. One or more
slits, holes, or openings may be provided in the cover in order to
accommodate any type of transcutaneous device. Furthermore, the
cover may be configured to include a secondary adhesive layer, such
as a clear adhesive medical tape such as a clear acrylic. The clear
adhesive layer may be provided in place of the silicone gel cover
or in addition to the silicone gel cover. The clear adhesive can be
affixed to the fabric layer and provided with a release liner for
rapid placement over the transcutaneous device.
[0093] In vitro experiments involving embodiments of the present
disclosure, formulated to include antimicrobial active
pharmaceutical agents manufactured as described above and as
described in greater detail in the examples have been shown to
control bacterial growth.
EXAMPLES OF FORMULATIONS FORMED INTO BARRIER DRESSING
CONFIGURATIONS
Example 1
Nusil Med 6345 Formulated with Chlorhexidine Diacetate (CHXDA)
[0094] 10% CHXDA [0095] 13.995 g Part A, 13.996 g Part B, 3.11 g
CHXDA combined and stirred by hand to homogeneity. [0096] The
release profile for chlorhexidine is shown in the following
graphical representation in FIG. 16.
Example 2
Nusil Med 6345 Formulated with Polyhexanide Hydrochloride
(PHMB)
[0096] [0097] 10% PHMB [0098] 14.04 g Part A, 14.02 g Part B, 3.12
g PHMB [0099] The release profile for polyhexanide is shown in the
following graphical representation in FIG. 17.
Example 3
Nusil Med 6345 Formulated with Octenidine Dihydrochloride
[0099] [0100] 15% Oct. [0101] 14.03 g Part A, 13.99 g Part B, 4.94
g octenidine
Example 4
Nusil Med 6345 Formulated with Silver Acetate
[0101] [0102] 1% Ag acetate [0103] 13.47 g Part A, 16.47 g Part B,
3.04 g silver acetate [0104] 45:55 A:B
Example 5
Nusil Med 6345 Formulated with Polyvinylpyrrolidone (PVP) and
Polyhexanide Hydrochloride (PHMB)
[0104] [0105] 10% total solids (1:1 PHMB:PVP) [0106] 14.02 g Part
A, 14.02 g Part B, 3.12 g PHMB/PVP [0107] The release profile for
polyhexanide is shown in the following graphical representation in
FIG. 18.
Example 6
Nusil Med 6345 Formulated with Carboxymethylcellulose and
Chlorhexidine Diacetate
[0107] [0108] 15% CHX-DA [0109] 14.00 g part A, 14.02 g part B,
7.15 g CHX-DA, 1.75 g CMC [0110] The release profile for
polyhexanide is shown in the following graphical representation in
FIG. 19.
Example 7
Nus Med 6345 Formulated with Sodium Polystyrene Sulfonate
(Crosslinked, Amberlite IRP69)
[0110] [0111] 20% IRP69 (available from Rohman and Haas) [0112]
13.2 g part A, 13.2 g part B, 6.6 g IRP69
Example 8
NusilMed 6345 Formulated with Silver Polystyrene Sulfonate
(Crosslinked, Amberlite IRP69, Silver Modified)
[0112] [0113] 20% IRP69 [0114] 13.2 g part A, 13.2 g part B, 6.6 g
IRP69
[0115] In compliance with the statute, embodiments of the invention
have been described in language more or less specific as to
structural and methodical features. It is to be understood,
however, that the entire invention is not limited to the specific
features and/or embodiments shown and/or described, since the
disclosed embodiments comprise forms of putting the invention into
effect.
* * * * *