U.S. patent application number 12/490235 was filed with the patent office on 2010-06-03 for systems and methods for applying an antimicrobial coating to a medical device.
This patent application is currently assigned to BECTON, DICKINSON AND COMPANY. Invention is credited to Ken Cluff, Azhar Khan, David T. Ou-Yang.
Application Number | 20100136209 12/490235 |
Document ID | / |
Family ID | 42223012 |
Filed Date | 2010-06-03 |
United States Patent
Application |
20100136209 |
Kind Code |
A1 |
Ou-Yang; David T. ; et
al. |
June 3, 2010 |
SYSTEMS AND METHODS FOR APPLYING AN ANTIMICROBIAL COATING TO A
MEDICAL DEVICE
Abstract
Methods for applying an antimicrobial coating to a medical
device is disclosed. Generally, the methods comprise providing a
medical device, dispensing an antimicrobial coating onto the
device, flushing excess coating from the device, and curing the
coating onto the device. In one aspect, the coating includes a
UV-curable, antimicrobial composition. In this aspect, the medical
device can be coated and the coating can be cured with UV light in
a manner of seconds. In another aspect, the coating includes an
antimicrobial solution that contains an acrylate-type polymer or
copolymer. In this aspect, the medical device can be coated and the
coating can be heat-cured in a manner of minutes. Both the
UV-curable composition and the antimicrobial solution can also
include rheological modifiers, as necessary. Additionally, the
compositions include one or more antimicrobial agents, which may be
selected from a wide array of agents.
Inventors: |
Ou-Yang; David T.;
(Woodbury, MN) ; Khan; Azhar; (Salt Lake City,
UT) ; Cluff; Ken; (Saratoga Springs, UT) |
Correspondence
Address: |
David W. Highet, VP & Chief IP Counsel;Becton, Dickinson and Company
(Kirton & McConkie), 1 Becton Drive, MC 110
Franklin Lakes
NJ
07417-1880
US
|
Assignee: |
BECTON, DICKINSON AND
COMPANY
Franklin Lakes
NJ
|
Family ID: |
42223012 |
Appl. No.: |
12/490235 |
Filed: |
June 23, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61118988 |
Dec 1, 2008 |
|
|
|
Current U.S.
Class: |
427/2.1 |
Current CPC
Class: |
A61L 2300/206 20130101;
A61L 29/085 20130101; B05D 3/0254 20130101; C09D 4/06 20130101;
C10M 2205/14 20130101; A61L 2300/404 20130101; C10M 169/04
20130101; C10M 2215/06 20130101; C10M 2201/105 20130101; C09D 5/14
20130101; C09D 5/1668 20130101; B05D 3/067 20130101; C10N 2030/16
20130101; C08F 220/18 20130101; A61L 29/16 20130101; C08F 222/1006
20130101; C10N 2040/50 20200501; C10M 2229/0515 20130101; C10N
2020/06 20130101; A61L 2300/208 20130101; C10M 2215/04
20130101 |
Class at
Publication: |
427/2.1 |
International
Class: |
B05D 3/00 20060101
B05D003/00 |
Claims
1. A method for applying an antimicrobial coating to a medical
device, the method comprising: providing a first medical device;
dispensing an antimicrobial coating onto the first device, wherein
the coating is selected from: a) a UV-curable, antimicrobial
composition, and b) an antimicrobial solution comprising an
acrylate polymer or copolymer; flushing an excess amount of the
coating from the first device; and curing the coating.
2. The method of claim 1, wherein the UV-curable composition
comprises: a photoinitiator; an oligomer; a monomer; a Theological
modifier; and an antimicrobial agent.
3. The method of claim 2, wherein the photoinitiator is selected
from the group consisting of benzoin ether, acetophenone, benzoyl
oxime, acyl phosphine oxide, Michler's ketone, thioxanthone,
anthroguionone, benzophenone, methyl diethanol amine,
2-N-butoxyethyl-4-(dimethylamino) benzoate, and combinations
thereof.
4. The method of claim 2, wherein the oligomer is selected from an
acrylated aliphatic urethane, an acrylated aromatic urethane, an
acrylated polyester, an unsaturated polyester, an acrylated
polyether, an acrylated acrylic, and combinations thereof.
5. The method of claim 2, wherein the monomer is selected from the
group consisting of 2-ethyl hexyl acrylate, isooctyl acrylate,
isobomylacrylate, 1,6-hexanediol diacrylate, diethylene glycol
diacrylate, triethylene glycol diacrylate, pentaerythritol tetra
acrylate, penta erythritol tri acrylate, dimethoxy phenyl
acetophenone hexyl methyl acrylate, 1,6 hexanidiol methacrylate,
and combinations thereof.
6. The method of claim 1, wherein the antimicrobial solution
further comprises: a solvent selected from an alcohol having from 1
to 6 carbons, an alkane having from 1 to 6 carbons, acetone, and
combinations thereof; a rheological modifier; and an antimicrobial
agent.
7. The method of claim 6, wherein the acrylate polymer or copolymer
is selected from the group consisting of an alkyl acrylate, an
alkyl methacrylate, an alkyl hydroxyl (meth) acrylate, an alkyl
methoxycinnamate, and combinations thereof.
8. The method of claim, 1 wherein the flushing of the excess
coating comprises blowing the excess coating from the device with a
pressurized, inert gas.
9. The method of claim 8, wherein the excess coating is recycled
and dispensed onto a second medical device.
10. The method of claim 1, wherein the curing of the coating
comprises exposing the first device having the UV-curable
composition disposed thereon to UV light.
11. The method of claim 1, wherein the curing comprises exposing
the first device having the antimicrobial solution to heat.
12. A method for applying an antimicrobial coating to a medical
device, the method comprising: providing a medical device;
dispensing a UV-curable, antimicrobial composition onto the medical
device, wherein the coating comprises an oligomer, a monomer, a
photoinitiator, a Theological modifier, and an antimicrobial agent;
flushing an excess amount of the composition from the device; and
curing the composition by exposing the composition to UV light.
13. The method of claim 12, wherein the dispensing, flushing, and
curing of the composition is completed in less than about 30
seconds.
14. The method of claim 12, wherein the dispensing, the flushing,
and the curing of the composition is completed in less than about
10 seconds.
15. A method for applying an antimicrobial coating to a medical
device, the method comprising: providing a medical device;
dispensing an antimicrobial solution onto the medical device;
flushing an excess amount of the composition from the device; and
curing the composition with a heat source, wherein the
antimicrobial solution comprises an acrylate polymer or acrylate
copolymer.
16. The method of claim 15, wherein the antimicrobial solution
further comprises a solvent selected from an alcohol having from 1
to 6 carbons, an alkane having from 1 to 6 carbons, acetone, and
combinations thereof.
17. The method of claim 15, wherein the antimicrobial solution
further comprises a Theological modifier and an antimicrobial
agent.
18. The method of claim 15, wherein the dispensing, flushing, and
curing of the composition are completed in less than about 10
minutes.
19. The method of claim 15, wherein the dispensing, flushing, and
curing of the composition are completed in less than about 5
minutes.
20. The method of claim 17, wherein the antimicrobial agent is
selected from cetyl pyridium chloride, cetrimide, benzalkonium
chloride, alexidine, chlorhexidine diacetate, phthalaldehyde, and
combinations thereof.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/118,988, filed Dec. 1, 2008, entitled
"Antimicrobial Compositions and Methods for Medical Product Use;"
the entire disclosure of which is incorporated herein by this
reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to systems and methods for
using antimicrobial coatings in various medical applications. One
of the major challenges of modern medical treatment is control of
infection and the spread of microbial organisms.
[0003] One area where this challenge is constantly presented is in
infusion therapies of various types. Infusion therapy is one of the
most common healthcare procedures. Hospitalized, home care, and
other patients receive fluids, pharmaceuticals, and blood products
via a vascular access device inserted into the patient's vascular
system. Infusion therapy may be used to treat an infection, provide
anesthesia or analgesia, provide nutritional support, treat
cancerous growths, maintain blood pressure and heart rhythm, or for
many other clinically significant uses.
[0004] Infusion therapy is facilitated by a vascular access device.
The vascular access device may access a patient's peripheral or
central vasculature. Additionally, the vascular access device may
be indwelling for a short term (e.g., days), a moderate term (e.g.,
weeks), or a long term (e.g., months to years). The vascular access
device may also be used for continuous infusion therapy or for
intermittent therapy.
[0005] A common vascular access device is a plastic catheter that
is inserted into a patient's vein. Generally, the length of such a
catheter may vary from a few centimeters, for peripheral access, to
many centimeters, for central access. The catheter may be inserted
transcutaneously or may be surgically implanted beneath the
patient's skin. The catheter, or any other vascular access device
attached thereto, may have a single lumen or multiple lumens for
infusion of many fluids simultaneously.
[0006] The vascular access device commonly includes an adapter
(e.g., a Luer adapter) to which other medical devices may be
attached. For example, an administration set may be attached to a
vascular access device at one end while an intravenous (IV) bag is
attached at the other. The administration set is a fluid conduit
for the continuous infusion of fluids and pharmaceuticals.
Commonly, an IV access device is a vascular access device that
attaches to another vascular access device, closes the vascular
access device, and allows for intermittent infusion or injection of
fluids and pharmaceuticals. An IV access device may include a
housing and a septum for closing the system. The septum may be
opened with a blunt cannula or a male Luer of a medical device.
[0007] When the septum of a vascular access device fails to operate
properly or has inadequate design features, certain complications
may occur. Complications associated with infusion therapy may cause
significant morbidity and even mortality. One significant
complication is catheter related blood stream infection (CRBSI). An
estimate of 250,000-400,000 cases of central venous catheter (CVC)
associated blood stream infections (BSIs) occur annually in US
hospitals.
[0008] Current vascular access devices prevent complications, such
as infection resulting in CRBSIs, by providing a septum that
functions properly during attachment and/or access of the vascular
access device by other medical devices. Septa that function
properly will act, in part, as infection barriers between the
internal and external environments of the vascular access device
during attachment and/or access by other medical devices. By
functioning properly as infection barriers, septa minimize CRBSIs
and other complications.
[0009] In some cases, a vascular access device may serve as a nidus
of infection, resulting in a disseminated BSI. This may be caused
by failure to regularly flush the device, a non-sterile insertion
technique, or by pathogens that enter the fluid flow path through
either end of the path subsequent to catheter insertion. When a
vascular access device is contaminated, pathogens adhere to the
vascular access device, colonize, and form a biofilm. Many such
biofilms are resistant to a variety of biocidal agents and provide
a replenishing source for pathogens to enter a patient's
bloodstream and cause a BSI.
[0010] Over the past few decades, it has been a common practice to
use a thermoplastic polyurethane solution as the carrier for an
antimicrobial coating. The solvent is usually tetrahydrofuran
(THF), dimethylformamide (DMF), or a blend of both. Because THF can
be oxidized very quickly and tends to be very explosive, an
expensive explosion-proof coating facility is necessary when THF is
used as the solvent. Harsh solvents, such as THF and DMF, are also
highly toxic and environmentally hazardous. Additionally, the harsh
solvents tend to attack most of the polymeric materials (i.e.,
polyurethane, silicone, polyisoprene, butyl rubber polycarbonate,
polyvinyl chloride, PET, and acrylics) that are used to produce
medical devices (e.g., vascular access devices). Therefore, medical
devices that are made with these materials can become distorted
and/or form micro-cracks on their surfaces. Another issue with
coatings comprising harsh solvents is that such coatings generally
require a relatively long period of time (e.g., about 24 hours) for
the solvent to be completely heat evaporated. Still another issue
with coatings comprising a harsh solvent is that such solvents are
difficult to apply uniformly across the surface of a medical
device. Accordingly, conventional technologies using harsh solvents
have persistent problems with processing and performance.
[0011] Another conventional method for providing medical devices
with antimicrobial characteristics involves the use of silver salts
and elemental silver. Silver salts and elemental silver are well
known antimicrobial agents in both the medical surgical industry
and general industries. They are usually incorporated into the
polymeric bulk material or coated onto the surface of the medical
devices by plasma, heat evaporation, electroplating, or by
conventional solvent coating technologies. These technologies,
however, are often very tedious, expensive, time consuming, and
environmentally hazardous.
[0012] In addition, the performance of silver coating medical
devices is mediocre at best. For example, it can take up to 8 hours
before the silver ion, ionized from the silver salts or silver
element, can reach certain efficacy as an antimicrobial agent. As a
result, substantial microbial activity can occur prior to the
silver coating even becoming effective. Furthermore, the silver
compound or silver element has an unpleasant color, from dark amber
to black.
[0013] Accordingly, there is a need in the art for improved
coatings for providing antimicrobial capability to medical devices
of various types, and particularly to devices related to infusion
therapy. There is also a need for improved methods of applying such
antimicrobial coatings to medical devices.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention has been developed in response to
problems and needs in the art that have not yet been fully resolved
by currently available systems and methods for applying
antimicrobial coatings to medical devices. Thus, the described
methods, systems, and compositions are developed to reduce
complications (e.g., the occurrence of CRBSIs, damage to medical
devices caused by harsh solvents, environmental damage caused by
harsh solvents, etc.) by providing improved methods and systems for
coating medical devices with an improved antimicrobial coating.
[0015] Generally, the present invention includes coating a medical
device with an antimicrobial coating. The described methods can be
used to coat a medical device made from a variety of materials. In
some preferred implementations, however, the described methods are
used to coat medical devices that comprise one or more polymeric
substrates, which include, but are not limited to, polycarbonate,
polyurethane, polyvinyl chloride, acrylic, and combinations
thereof.
[0016] The described methods can be performed with one or more of a
wide variety of coatings. Nevertheless, the preferred coating is
selected from an ultraviolet light-(UV) curable, antimicrobial
composition and an antimicrobial solution.
[0017] Where the coating comprises the UV-curable, antimicrobial
composition, the UV-curable composition can comprise any suitable
ingredient. In some implementations, the UV-curable composition
comprises a UV-curable material comprising one or more urethane- or
polyester-type oligomers with at least one acrylate-type functional
group, acrylate-type monomers, and photoinitiators. Additionally,
in some implementations, the UV-curable composition further
comprises one or more Theological modifiers and antimicrobial
agents.
[0018] Where the coating comprises the antimicrobial solution, the
solution can comprise any suitable ingredient. Indeed, in some
implementations, the solution comprises one or more solvents,
coating resins, Theological modifiers, and antimicrobial
agents.
[0019] The described methods generally include providing a medical
device, dispensing an antimicrobial coating onto a surface of the
device, flushing excess coating from the device, and curing the
coating onto the device. Of course, the methods can be modified in
any suitable manner. In one example of a modification, the methods
include masking a portion of the device to prevent the coating from
being deposited on the portion of the medical device that is
covered by the masking.
[0020] In the described methods, the coating can be dispensed onto
a surface of the device in any suitable manner. In one example, a
machine injects a calculated amount of the coating into the
device.
[0021] After the antimicrobial coating has been applied to the
medical device, excess coating, if any, can be removed from the
device in any suitable manner. For example, the excess coating can
be removed by blowing the excess coating from the device with an
inert gas, spinning the medical device in a centrifuge, by wiping
the device with a material, through gravity, etc. In some presently
preferred implementations, however, nitrogen gas is used to blow
the excess coating from the medical device.
[0022] With the excess coating removed from the medical device, the
coating can be cured in any suitable manner. For example, the
UV-curable composition can be rapidly cured through exposure to UV
light. For instance, after the UV-curable composition is applied to
the medical device, the composition can be cured within seconds or
minutes, depending on the formulation and curing conditions. In
another example, the antimicrobial solution can be cured relatively
quickly by exposure to heat (e.g., infrared heat). Indeed, under
certain circumstances, the solution can be heat-cured at about
100.degree. Celsius (C.) in about 5 minutes or less.
[0023] While the methods of the present invention have proven to be
particularly useful in the area of coating IV access devices, those
skilled in the art will appreciate that the described methods can
be used for a variety of different applications in a variety of
different areas of manufacture that include coating an object with
an antimicrobial coating.
[0024] These and other features and advantages of the present
invention will be set forth or will become more fully apparent in
the description that follows and in the appended claims. The
features and advantages may be realized and obtained by means of
the instruments and combinations particularly pointed out in the
appended claims. Furthermore, the features and advantages of the
intention may be learned by the practice of the invention or will
be obvious from the description, as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order that the manner in which the above-recited and
other features and advantages of the invention are obtained and
will be readily understood, a more particular description of the
invention briefly described above will be rendered by reference to
specific embodiments thereof, which are illustrated in the appended
drawings. Understanding that these drawings depict only typical
embodiments of the invention and are not, therefore, to be
considered to be limiting of its scope, the invention will be
described and explained with additional specificity and detail
through the use of the accompanying drawings in which:
[0026] FIG. 1 illustrates a block diagram of a representative
embodiment of a method for coating a medical device with an
antimicrobial coating;
[0027] FIG. 2 illustrates a block diagram of a representative
embodiment of the method for coating a medical device with an
antimicrobial coating;
[0028] FIG. 3 illustrates a perspective view of a representative
embodiment of an IV access device;
[0029] FIG. 4A illustrates a perspective view of a representative
embodiment of a system for applying an antimicrobial coating to a
medical device; and
[0030] FIG. 4B illustrates a perspective view of a representative
pallet for holding a medical device during operation of the system
shown in FIG. 4A.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The described invention relates to methods and compositions
for coating one or more surfaces of a medical device with an
antimicrobial coating. Once the antimicrobial coating is cured onto
the medical device, an antimicrobial agent in the coating can
gradually diffuse out of the coating when the coating is softened
by IV fluids or other types of fluids. Accordingly, microbes that
come into contact with the coated surface of the medical device can
be killed and the medical device may remain sanitary for a
prolonged period of time.
[0032] FIG. 1 illustrates a representative embodiment of the
described coating methods. Specifically, FIG. 1 shows that the
method 10 for coating a medical device with an antimicrobial
coating generally comprises providing a medical device 12,
dispensing an antimicrobial coating onto the device 14, flushing
excess coating from the device 16, and curing the coating to the
device. In order to provide a better understanding of the described
coating method, the following disclosure provides a more detailed
disclosure of medical devices and antimicrobial coatings that can
be used with the coating method, the various stages of method, and
systems for performing the method.
[0033] With respect to the types of medical devices that can be
used with the described coating methods, the methods can be used
with any suitable medical device, including, but not limited to, an
IV access device, medical tubing, a catheter assembly, and any
other viable medical-grade instrument that contacts fluids flowing
into or out of a patient.
[0034] The medical device can comprise any material that is
suitable for use with the described methods. In some typical
embodiments, however, the medical device comprises one or more
polymeric substrates. For instance, the medical device can comprise
one or more polycarbonates, polyurethanes, polyvinyl chlorides,
silicones, PET plastics, styrene-butadiene rubbers, acrylics, and
combinations thereof.
[0035] The antimicrobial coating can comprise any suitable
antimicrobial composition that is suitable for use on the medical
device. Nevertheless, in preferred embodiments, the antimicrobial
coating is selected from a UV-curable, antimicrobial composition
and an antimicrobial solution. To provide a better understanding of
the UV-curable composition and the antimicrobial solution, each is
discussed below in more detail.
[0036] In some currently preferred embodiments, the antimicrobial
coating comprises the UV-curable, antimicrobial composition. In
such embodiments, the UV-curable composition may comprise any
suitable ingredient. In one aspect of the invention, the UV-curable
coating comprises materials (referred to herein the UV-curable
material) that are capable of forming a UV-curable polymer
composition. While the UV-curable material may comprise any
suitable ingredient, in some preferred embodiments, the UV-curable
material comprises one or more oligomers, monomers, and
photoinitiators. In addition to the UV-curable material, the
UV-curable composition further comprises an effective antimicrobial
agent. The various ingredients that are added together to form the
UV-curable composition are described below. In the following
discussion, the UV-curable material will comprise 100 parts by
weight. Additionally, the ingredients added to the UV-curable
material to form the UV-curable composition will be defined in
parts by weight added to 100 parts by weight of the UV-curable
material.
[0037] The UV-curable material may comprise any oligomer that is
compatible with the other components of the UV-curable composition
and that is usable within the scope of the present invention.
Nevertheless, the oligomer is generally selected from one or more
acrylated aliphatic urethanes, acrylated aromatic urethanes,
acrylated polyesters, unsaturated polyesters, acrylated polyethers,
acrylated acrylics, and the like, or combinations thereof. Indeed,
in some embodiments, the UV-curable coating comprises a urethane-
or polyester-type acrylate, such as 7104, 7101, 7124-K, 7105-5K
from Electronic Materials Inc. (EMI) (EM Breckenridge, Co.),
1168-M, 1-20781 from Dymax Corporation (Torrington, Conn.), or UV
630 from Permabond Engineering Adhesives (Somerset, N.J.). Where
the oligomer comprises an acrylated functional group, the
functional group is preferably selected from a mono-functional,
di-functional, tri-functional, tetra-functional, penta-functional,
and hexa-functional acrylate.
[0038] The oligomer may account for any suitable portion of the
UV-curable material. Typically, however, the oligomer will comprise
from about 10% to about 90% of the UV-curable material. In some
preferred embodiments, the oligomer comprises from about 20% to
about 80% of the UV-curable material. In certain other embodiments,
however, the oligomer comprises from about 30% to about 70% of the
UV-curable material.
[0039] While the monomer in the UV-curable material can be selected
from any monomer that is compatible with the other components of
the UV-curable composition and that is usable within the scope of
the invention, the monomer is preferably selected from 2-ethyl
hexyl acrylate, isooctyl acrylate, isobomylacrylate, 1,6-hexanediol
diacrylate, diethylene glycol diacrylate, triethylene glycol
diacrylate, pentaerythritol tetra acrylate, penta erythritol tri
acrylate, dimethoxy phenyl acetophenone hexyl methyl acrylate, 1,6
hexanidiol methacrylate, and the like, or combinations of these
compounds.
[0040] In typical embodiments, the monomer comprises from about 5%
to about 90% of the UV-curable material. In other embodiments,
however, the monomer comprises from about 10% to about 75% of the
UV-curable material. In still other embodiments, the monomer
comprises from about 20% to about 60% of the UV-curable
material.
[0041] The photoinitiator can comprise any photoinitiator that is
compatible with the other components of the UV-curable composition
(i.e., the UV-curable material) and that is usable within the scope
of the invention. Generally, the photoinitiator is selected from
either a single molecule cleavage type photoinitiator, such as one
or more benzoin ethers, acetophenones, benzoyl oximes, and acyl
phosphine oxides; or a hydrogen abstraction type of photoinitiator,
such as Michler's ketone, thioxanthone, anthroguionone,
benzophenone, methyl diethanol amine, and
2-N-butoxyethyl-4-(dimethylamino) benzoate.
[0042] The photoinitiator typically comprises from about 0.5% to
about 10% of the UV-curable material. Indeed, in some embodiments,
the photoinitiator comprises from about 1% to about 8.5% of the
UV-curable material. In still other embodiments, the photoinitiator
comprises from about 2% to about 7% of the UV-curable material.
[0043] The antimicrobial agent can comprise any antimicrobial agent
that is compatible with the other components of the UV-curable
composition and that is usable within the scope of the invention.
Additionally, in some embodiments, the antimicrobial agent
comprises an agent that either dissolves in the UV-curable
composition or can be uniformly distributed therein. Accordingly,
in such embodiments, sufficient antimicrobial agent can migrate
within the UV-curable composition to contact the location of
microbial activity. In any event, it is preferred that the
antimicrobial agent not react chemically with the other components
of the UV-curable composition. Some examples of antimicrobial
agents that are suitable for use with the UV-curable composition
include one or more aldehydes, anilides, biguanides, silver, silver
compound, bis-phenols, and quaternary ammonium compounds.
[0044] The antimicrobial agent is generally present in the
UV-curable composition in the amount of from about 0.5 to about 50
parts, by weight, in comparison to 100 parts by weight of the
UV-curable material. In other embodiments, the antimicrobial agent
is present in the UV-curable composition in the amount of from
about 0.5 to about 30 parts, by weight, in comparison to 100 parts
of the UV-curable material. In further embodiments of the
UV-curable composition, the antimicrobial agent is present in the
amount of from about 0.5 to about 20 parts, by weight, in
comparison to 100 parts of the UV-curable material.
[0045] In addition to the aforementioned materials, the UV-curable
composition can comprise any other suitable component. Indeed, in
certain embodiments, the UV-curable composition also includes a
Theological modifier to improve the composition's flow
characteristics and to help components be uniformly distributed
throughout the composition. In such embodiments, the Theological
modifier is preferably selected from organic clay, castor wax,
polyamide wax, polyurethane, and fumed silica. Additionally, in
such embodiments, the Theological modifier generally comprises from
about 0.1 to about 30 parts, by weight, added to 100 parts, by
weight, of the UV-curable material (i.e. the UV-curable material is
100 weight units, while the Theological modifier comprises from
about 0.1 to about 30 parts of additional weight that is added to
the 100 parts of the UV-curable material). In other embodiments,
the Theological modifier comprises from 0.1 to about 20 parts by
weight compared to 100 parts by weight of the UV-curable material.
In certain further embodiments, the rheological modifier comprises
from about 0.2 to about 10 parts by weight compared to 100 parts by
weight of the UV-curable material.
[0046] The UV-curable composition may also have any other suitable
characteristic. For instance, in some embodiments, the UV-curable
composition has a viscosity that is less than about 10,000
centipoises (cps). In other embodiments, the viscosity of the
UV-curable composition is below about 5,000 cps. In some presently
preferred embodiments, the UV-curable composition has a viscosity
that is between about 20 and about 1,000 cps.
[0047] While the UV-curable composition has been described above
with specificity, a more detailed description of the UV-curable
composition is found in U.S. patent application Ser. No.
12/397,760, filed Mar. 4, 2009, and entitled "Antimicrobial
Compositions;" the entire disclosure of which is hereby
incorporated by reference.
[0048] Where the antimicrobial coating comprises an antimicrobial
solution, the solution may comprise any suitable ingredient. In
some embodiments, the antibacterial solution comprises an acrylate
polymer or copolymer, a solvent, and an antimicrobial agent. To
provide a better understanding of the antimicrobial solution, each
of its aforementioned ingredients is described below in more
detail.
[0049] The acrylate polymer or copolymer can comprise any acrylate
polymer and/or copolymer that is compatible with the other
components of the antimicrobial solution and that is usable within
the scope of the invention. In some embodiments, the acrylate-type
polymer, copolymer, or polymer resin is insoluble in water while
being soluble in one or more of the solvents that are discussed
hereinafter. For example, the acrylate polymer or copolymer is
generally selected from one or more alkyl acrylates, alkyl
methacryloates, alkyl hydroxyl (meth) acrylates, and alkyl
methoxycinnamate acrylates. In this example, the acrylate can be
alkyl acrylate, alkyl hydroxyl (meth) acrylate, or alkyl
methacrylate. Additionally, in this example, the alkyl group can
have a carbon number from 0 to 22, wherein 0 means hydrogen, 1
means a methyl group, 2 means an ethyl group, 3 means a propyl
group, etc.), but preferably a number from 0 to 6, and more
preferably from 0 to 3.
[0050] The solvent in the antimicrobial solution can comprise any
solvent that is compatible with the other components of the
antimicrobial solution and that allows the solution to function as
intended. For instance, the solvent may comprise one or more of a
variety of solvents that are capable of dissolving the
aforementioned acrylate polymer or copolymer. Some examples of
suitable solvents include one or more low molecular weight
alcohols, low molecular weight alkanes, simple ketones, and
combinations thereof. Some examples of suitable low molecular
weight alcohols comprise alcohols having from 1 to 6 carbons (e.g.,
methanol, ethanol, propanol, isopropanol, and butanol). Because
methanol evaporates relatively quickly, however, methanol may not
be preferred in all embodiments. Instead, in some currently
preferred embodiments, the solvent comprises ethanol or
isopropanol. Some suitable examples of suitable low molecular
weight alkanes comprise alkanes having from 5 to 7 carbons (e.g.,
pentane, hexane, heptane, and isomers thereof). Indeed, in some
preferred embodiments the solvent comprises hexane and/or heptane.
Additionally, an example of a suitable simple ketone is acetone. It
should be noted, however, that in some embodiments that comprises
acetone, the solvent preferably also comprises another solvent,
such as an alcohol or an alkane.
[0051] While the solvent may comprise any suitable amount of the
antimicrobial solution, in some embodiments, the solvent comprises
less than about 67% of the dry weight of the antimicrobial
solution. For instance, where the polymer accounts for about
60%.+-.10% of the antimicrobial solution, the solvent can account
for less than about 40%.+-.10% of the solution. In other
embodiments, however, the solvent comprises less than about 50% of
the dry weight of the composition. In still other embodiments, the
solvent comprises less than about 40% of the dry weight of the
composition.
[0052] The antimicrobial agent in the antimicrobial solution can
comprise any antimicrobial agent that is compatible with the other
components of the solution and that allows the solution to function
as intended. Indeed, the antimicrobial agent for the antimicrobial
solution is generally selected from one or more aldehydes,
anilides, biguanides, silver, silver compounds, bis-pheonols, and
quaternary ammonium compounds. In certain instances, the
antimicrobial agent is preferably selected from cetyl pyridium
chloride, cetrimide, benzalkonium chloride, alexidine, chlorexidine
diacetate, and o-phthalaldehyde.
[0053] While the antimicrobial agent may comprise any suitable
amount of the antimicrobial solution, in some embodiments, the
antimicrobial agent comprises less than about 50% of the dry weight
of the solution. In other embodiments, the antimicrobial comprises
less than about 30% of the dry weight of the antimicrobial
solution. In still other embodiments, the antimicrobial agent
comprises about 0.5% and about 20% of the dry weight of the
antimicrobial solution.
[0054] In addition to the aforementioned ingredients, the
antimicrobial solution may comprise any other suitable ingredient.
Indeed, in some embodiments, the antimicrobial solution comprises a
Theological modifier that is generally selected from organic clay,
castor wax, polyamide wax, polyurethane, and fumed silica. In such
embodiments, the Theological modifier is generally present in an
amount of from about 0.2% to about 30% of the dry weight of the
antimicrobial solution. That is, the weight of the composition once
the solvent has evaporated. In certain other embodiments, the
rheological modifier is present in the amount of from about 0.2% to
about 20% of the dry weight of the antimicrobial solution. In
certain other embodiments, the rheological modifier is present in
an amount of from about 0.2% to about 10% of the dry weight of the
antimicrobial solution.
[0055] While the antimicrobial solution has been described above
with specificity, a more detailed description of the antimicrobial
solution is found in U.S. patent application Ser. No. 12/476,997,
filed Jun. 2, 2009, and entitled "Antimicrobial Coating
Compositions;" the entire disclosure of which is hereby
incorporated by reference.
[0056] The described methods can be performed or modified in any
suitable manner. By way of example, FIG. 2 illustrates one
presently preferred embodiment of the described method for coating
a medical device. Specifically, FIG. 2 shows an example in which
the method 11 begins at 12 by providing a medical device.
[0057] Next, at 13, FIG. 2 shows the method 10 optionally includes
masking one or more desired portions of the medical device to
prevent the antimicrobial coating from contacting the masked
portion(s). By way of illustration, FIG. 3 shows that where the
medical device comprises a portion of an IV access device 100
(e.g., BECTON DICKINSON's Q-SYTE.RTM. IV access device) having a
Luer component 102, the Luer component 102 can be inserted into a
medical-grade tube 104 so that the external surface of the Luer 102
is prevented from being coated with the antimicrobial coating.
[0058] Returning back to FIG. 2, box 14 shows that the method 10
continues by dispensing the antimicrobial coating (e.g., the
UV-curable composition or the antimicrobial solution) onto the
medical device. Any suitable amount of the antimicrobial coating
can be dispensed onto the desired surface(s) of the medical device.
For example, where the medical device comprises the IV access
device of FIG. 3, between about 0.01 and about 0.05 grams of the
antimicrobial coating can be dispensed into the device's inner
lumen 106. In still another example, where the medical device
comprises the IV access device of FIG. 3, between 0.02 and about
0.04 grams of antimicrobial coating are dispensed into the device's
inner lumen.
[0059] After the antimicrobial coating has been dispensed onto the
medical device, box 16 of FIG. 2 shows that any excess coating on
the device is flushed or otherwise removed from the medical device.
In this manner, the antimicrobial coating can be caused to have a
uniform thickness across the coated surface. The excess coating can
be removed in any suitable manner, including by blowing an inert
gas across the coated surface of the medical device, spinning the
medical device in a centrifuge, by allowing excess material to drip
from the device due to the pull of gravity, etc. Nevertheless, in
some presently preferred embodiments, a pressured inert gas, such
as nitrogen, helium, or argon, is blown across the coated surface.
By way of example, where the medical device comprises the IV access
device 100 of FIG. 3, an insert gas, such as nitrogen, with an air
pressure of between about 5 and about 25 pounds per square inch
(psi) (e.g., 10 psi.+-.5 psi) is preferably blown past the coated
surface.
[0060] In order to reduce the amount of antimicrobial coating that
is wasted during the described method, box 17 of FIG. 2 shows that
the excess antimicrobial coating that is flushed from the medical
device is optionally collected and recycled. In other words, the
excess antimicrobial coating can be collected and be used to coat
another medical device.
[0061] With the excess antimicrobial coating removed from the
medical device, boxes 20 and 22 show that the coating left on the
device is cured. While the antimicrobial coating can be cured in
any suitable manner, box 20 shows that in some embodiments where
the antimicrobial coating comprises the UV-curable composition, the
UV-curable composition is cured by being exposed to UV light. In
such embodiments, the UV-curable composition can be exposed to any
suitable wavelength of UV light. In one example, the UV-curable
composition is exposed to UV light with a wavelength of between
about 320 to about 500 nm. In another example, the UV-curable
composition is cross-linked by being exposed to light with a
wavelength of between about 350 and about 450 nm.
[0062] Additionally, the UV-curable composition can be exposed to
the UV light for any amount of time that allows the UV-curable
composition to dry and be cured to the medical device. Indeed, in
one example, the UV-curable composition is cured after less than
about 1 minute of exposure to the UV light. In another example, the
UV-curable coating is cured after less than about 30 seconds of
exposure to the UV light. In still another example, the UV-curable
coating is cured after less than about 10 seconds of exposure to
the UV light. In a final example, the UV-curable coating is cured
after less than about 4 seconds of exposure to the UV light.
[0063] Referring now to box 22, FIG. 2 shows that in some
embodiments where the antimicrobial coating comprises the
antimicrobial solution, the solution is cured through exposure to
heat from a heat source (e.g., an infrared heater, a convectional
heater, a conventional heater, etc.). In such embodiments, the
antimicrobial solution coating the device can be cured at any
suitable temperature. In one example, the solution is cured at a
temperature of less than about 120.degree. C. In another example,
the antimicrobial solution is cured at a temperature of less than
about 100.degree. C. In still another example, the antimicrobial
solution is cured at a temperature of less than about 60.degree.
C.
[0064] While the antimicrobial solution can be cured in any
suitable amount of time, under certain conditions, the solution is
cured after less than about 10 minutes of exposure to a temperature
of less than about 60.degree. C. Similarly, under certain
conditions, the antimicrobial solution is cured after less than
about 5 minutes of exposure to a temperature of less than about
100.degree. C.
[0065] Once the antimicrobial coating is cured, box 24 of FIG. 2
shows that any masking material is optionally removed from the
medical device. At that point, the medical device can be used and
the antimicrobial coating can be effective almost immediately after
being exposed to a fluid (e.g., an IV fluid).
[0066] The described methods can be performed by any suitable
system and/or apparatus that is capable of performing one or more
of the features illustrated in FIG. 2. Indeed, in some embodiments,
at least a portion of the described methods are performed by
medical device coating system. While such a system can comprise any
suitable component or characteristic, FIG. 4A illustrates a
representative embodiment in which the medical device coating
system 200 comprises a medical device pallet 202, a top slide 204
having coating-dispending heads 206 and gas-dispensing heads 208,
coating valves 210, gas valves 212, a gas reservoir 214, excess
funnels 216, and a pressurized coating reservoir 218.
[0067] While the medical device coating system may be used in any
suitable manner, in order to provide a better understanding of the
system, a typical example of its use is provided herein.
Specifically, FIG. 4B shows that one or more medical devices, such
as the IV access device 100, can be placed on the medical device
pallet 202 so that an opening 108 to the inner lumen 106 of the
device 100 is facing towards a coating-dispensing head 206 (shown
in FIG. 4A).
[0068] In order to ensure that the medical device stays in a proper
orientation through the coating process, the pallet may secure the
medical device in a desired orientation, in any suitable manner. By
way of illustration, FIG. 4B shows an embodiment in which the IV
access device 100 is secured to the pallet 202 when a lip 110 on
the access device 100 is slid into a groove 220 on the pallet
202.
[0069] With the medical devices secured to the pallet 202, FIG. 4A
shows that the pallet 202 is placed beneath the top slide 204. At
this point, the top slide 204 may move with respect to the pallet
202 so that a coating dispensing head 206 is disposed above the
opening of each device (not shown in FIG. 4A).
[0070] Once the dispensing heads are aligned with the surface of
the medical device that is to be coated, the coating valves 210 are
opened to allow a predetermined amount (e.g., between about 0.01
and about 0.05 g) of antimicrobial coating to be squirt from the
pressurized coating reservoir 218, through the coating-dispensing
heads 206, and onto the medical device. While this dispensing
process can take any suitable amount of time, in some instances,
the dispensing process takes as little as 4 seconds or less (e.g.,
about 2 seconds+1 second).
[0071] After the coating has been dispensed, the top slide 204
moves in the direction of arrow 222 so that a gas-dispensing head
208 is disposed above the coated surface of each medical device.
Once the gas-dispensing heads are properly aligned, the top slide
204 moves in the direction of arrow 224 so that the gas-dispensing
heads 208 form a seal against the medical device's opening (not
shown in FIG. 4A). Once a seal is formed, the gas valves 212 open
to allow a controlled amount of the inert gas, at a controlled
pressure, to flush any excess coating from the medical device. This
excess coating is then collected in the excess funnels 216, which
direct the excess coating back to the pressurized coating reservoir
218 for future use.
[0072] With the excess coating removed from the medical devices,
the pallet 202 can be removed from beneath the top slide 204 and be
placed in a curing chamber (not shown), such as a UV-light chamber
or a heated chamber-depending on composition of the antimicrobial
coating.
[0073] Following the curing process, the medical devices are
removed from the pallet and new batch of uncoated medical devices
can be placed in the pallet so that the process can be
repeated.
[0074] The described system can be modified in any suitable manner.
In one example, while FIG. 4A shows an embodiment in which the
system 200 is configured to coat 4 medical devices simultaneously,
the system can modified to simultaneously coat any suitable number
of medical devices. For instance, the system can be modified to
coat 1, 2, 3, 5, 6, 7, 8, or more medical devices, simultaneously.
In another example, instead of comprising a coating-dispensing head
and a separate gas-dispensing head, the antimicrobial coating and
the inert gas may be dispensed to a medical device through single
head so as to speed the time between the dispensing and flushing
portions of the method. In yet another embodiment, the pallet, the
gas dispensing head, or some other component in proximity to the
medical devices can comprise a UV light source. In such
embodiments, the system can cure the medical devices without
requiring the pallet to be removed from a location beneath the top
slide.
[0075] As discussed above, the described methods, apparatus, and
compositions have several beneficial characteristics. In one
example, the described methods allow a medical device to be coated
with an antimicrobial coating (e.g., the UV-curable composition) in
a relatively short period of time. For instance, instead of taking
several hours (e.g., 24) to cure a harsh solvent (e.g., THF or DMF)
onto a medical device, the UV-curable coating and the antimicrobial
solution can be cured onto a medical device in a few second or
minutes, respectively. Indeed, in some embodiments in which the
antimicrobial coating comprises the UV-curable composition, the
composition can be dispensed, flushed, and cured within about 30
seconds. In some preferred embodiments, the UV-curable composition
can be dispensed, flushed, and cured within about 10 seconds.
Similarly, in some embodiments in which the antimicrobial coating
comprises the antimicrobial solution, the solution is dispensed,
flushed, and cured within about 10 minutes. In some presently
preferred embodiments, however, the antimicrobial solution is
dispensed, flushed, and cured in less than about 5 minutes.
[0076] In another example of a beneficial characteristic of the
described methods, the methods can allow the antimicrobial coating
to be applied to the medical device with a substantially uniform
coating thickness. In still another example, because the described
methods allow for excess antimicrobial coating to be recycled, the
described methods may use less antimicrobial coating, overall, than
certain conventional coating techniques.
[0077] In yet another example, the described UV-curable and
antimicrobial solutions provide several advantages over certain
known antimicrobial coatings. For instance, the UV-curable and
antimicrobial solutions can be less toxic, less expensive, more
environmentally friendly, cause less deformation or cracking to a
medical device, be more aesthetically pleasing, and require
less-expensive equipment than do several competing antimicrobial
coatings (e.g., THF and DMF).
[0078] The present invention may be embodied in other specific
forms without departing from its structures, methods, or other
essential characteristics as broadly described herein and claimed
hereinafter. The described embodiments and examples are to be
considered in all respects only as illustrative, and not
restrictive. The scope of the invention is, therefore, indicated by
the appended claims, rather than by the foregoing description. All
changes that come within the meaning and range of equivalency of
the claims are to be embraced within their scope.
* * * * *