Title of Invention

ANTIMICROBIAL PACKAGED MEDICAL DEVICE AND METHOD OF PREPARING SAME.

Abstract TITLE: ANTIMICROBIAL PACKAGED MEDICAL DEVICE AND METHOD OF PREPARING SAME. A packaged medical device produced according to the steps of positioning an antimicrobial agent source within a package comprising an inner surface, positioning a medical device within the package; and subjecting the package,the antimicrobial agent source and the medical device to time, temperature and pressure conditions sufficient to vapor transfer an effective amount of the antimicrobial agent from the antimicrobial agent source to the medical device, thereby substantially inhibiting bacterial colonization on the medical device (FIG. - Nil)
Full Text ANTIMICROBIAL PACKAGED MEDICAL DEVICE
AND METHOD OF PREPARING SAME
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Serial No. 10/367,497, filed on February 15,
2003, which claims the benefit of U.S. Serial No. 10/603,317, filed on June 25, 2003,
which claims the benefit of U.S. Provisional Application No. 60/416,114, filed on
October 04, 2002, the content of each is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to an antimicrobial medical device and an antimicrobial
packaged medical device and their methods of making.
BACKGROUND OF THE INVENTION
Each year, patients undergo a vast number of surgical procedures in the United States.
Current data shows about twenty-seven million procedures are performed per year.
Post-operative or surgical site infections ("SSIs") occur in approximately two to three
percent of all cases. This amounts to more than 675,000 SSIs each year.
The occurrence of SSIs is often associated with bacteria that can colonize on
implantable medical devices used in surgery. During a surgical procedure, bacteria
from the surrounding atmosphere may enter the surgical site and attach to the medical
device. Specifically, bacteria can spread by using the implanted medical device as a
pathway to surrounding tissue. Such bacterial colonization on the medical device may
lead to infection and trauma to the patient. Accordingly, SSIs may significantly
increase the cost of treatment to patients.
Implantable medical devices that contain antimicrobial agents applied to or
incorporated within have been disclosed and/or exemplified in the art. Examples of
such devices are disclosed in European Patent Application No. EP 0 761 243. Actual
devices exemplified in the application include French Percuflex catheters. The
catheters were dip-coated in a coating bath containing 2,4,4 "-tricloro-2-
hydroxydiphenyl ether (Ciba Geigy Irgasan (DP300)) and other additives. The
catheters then were sterilized with ethylene oxide and stored for thirty days. Catheters
coated with such solutions exhibited antimicrobial properties, i.e., they produced a zone
of inhibition when placed in a growth medium and challenged with microorganism, for
thirty days after being coated. It is not apparent from the application at what
temperature the sterilized, coated catheters were stored.
Most implantable medical devices are manufactured, sterilized and contained in
packages until opened for use in a surgical procedure. During surgery, the opened
package, packaging components contained therein, and the medical device are exposed
to the operating room atmosphere, where bacteria from the air may be introduced.
Incorporating antimicrobial properties into the package and the packaging components
substantially prevents bacterial colonization on the package and components once the
package has been opened. The antimicrobial package and packaging components, in
combination with the incorporation of antimicrobial properties onto the medical device
itself would substantially ensure an antimicrobial environment about the sterilized
medical device.
SUMMARY OF THE INVENTION
The present invention relates to antimicrobial medical devices and antimicrobial
packaged medical devices and methods for preparing them. In accordance with
embodiments of the present invention, an antimicrobial agent source is utilized. The
medical device, with or without one or more packaging component, is positioned within
a package, and upon being subjected to sufficient conditions, a portion of the
antimicrobial agent from the antimicrobial agent source transfers to the package, the
packaging component (if utilized) and the medical device. The transfer of the
antimicrobial agent is in an amount sufficient to inhibit bacterial growth on the
package, the packaging component (if utilized) and the medical device.
In accordance with various embodiments of the present invention, the package may
contain an antimicrobial agent source, may have an antimicrobial agent source attached
to the inner surface of the package, or may have an antimicrobial agent source that is
integral with one or more packaging component in the package or with the package
itself. Alternatively, the medical device may be positioned within a package, and the
package having the medical device is exposed to an external antimicrobial agent
source. In these embodiments, the medical device is positioned within the package and
may initially be free of an antimicrobial agent or may initially comprise one or more
surfaces having an antimicrobial agent disposed thereon. The package, the
antimicrobial agent source and the medical device are then subjected to time,
temperature and pressure conditions sufficient to vapor transfer an effective amount of
the antimicrobial agent from the antimicrobial agent source to the inner surface of the
package and the medical device, thereby substantially inhibiting bacterial colonization
on the medical device.
The present invention is also directed to a method for making an antimicrobial medical
device comprising the step of positioning an antimicrobial agent source in a package
having a medical device, attaching an antimicrobial agent source to the inner surface of
a package having a medical device, or providing an antimicrobial agent source that is
integral with one or more packaging component in the package having the medical
device or with the package itself. In these embodiments, the medical device that is
positioned within the package may initially be free of an antimicrobial agent or may
initially comprise one or more surfaces having an antimicrobial agent disposed thereon.
The package, the antimicrobial agent source and the medical device are then subjected
to time, temperature and pressure conditions sufficient to vapor transfer an effective
amount of the antimicrobial agent from the antimicrobial agent source to the medical
device, thereby substantially inhibiting bacterial colonization on the medical device.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is a graph illustrating the transfer of an antimicrobial agent from the
medical device to a packaging component at 55°C as a function of time.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
Packaged Antimicrobial Medical Device
The medical devices described herein are generally implantable medical devices and
implants, including but not limited to mono and multifilament sutures, surgical meshes
such as hernia repair mesh, hernia plugs, brachy seed spacers, suture clips, suture
anchors, adhesion prevention meshes and films, and suture knot clips. Also included
are implantable medical devices that are absorbable and non-absorbable. An
absorbable polymer is defined as a polymer that will degrade and be absorbed by the
body over a period of time when exposed to physiological conditions. Absorbable
medical devices typically are formed from generally known, conventional absorbable
polymers including but not limited to glycolide, lactide, copolymers of glycolide, or
mixtures of polymers, such as polydioxanone, polycaprolactone, oxidized regenerated
cellulose and equivalents thereof. Preferably, the polymers include polymeric materials
selected from the group consisting of greater than about 70% polymerized glycolictej
greater than about 70% polymerized lactide, polymerized l,4-dioxan-2-one, greater
than about 70% polypeptide, copolymers of glycolide and lactide, greater than about
70% cellulosics and cellulosic derivatives. Preferably, absorbable medical devices are
made from polydioxanone, poliglecaprone, or a glycolide/lactide copolymer. Examples
of absorbable medical device include mono and multifilament sutures. The
multifilament suture includes sutures wherein a plurality of filaments is formed into a
braided structure. Examples of non-absorbable medical devices include mono and
multifilament sutures, surgical meshes such as hernia repair mesh, hernia plugs and
brachy seed spacers, which may be polymeric or nonpolymeric. Non-absorbable
medical devices may be made in whole or in part from polymeric materials that
include, but are not limited to, polyolefms such as polypropylene; polyamides such as
nylon; chlorinated and/or fluorinated hydrocarbons such as Teflon® material; or;
polyesters such as Dacron® synthetic polyesters; or from nonpolymeric materials that
include, but are not limited to, silks, collagen, stainless steel, titanium, cobalt chromium
alloy, nitinol. Preferably, the non-absorbable medical devices are made from nylon or
polypropylene.
Suitable antimicrobial agents may be selected from, but are not limited to, halogenated
hydroxyl ethers, acyloxydiphenyl ethers, or combinations thereof. In particular, the
antimicrobial agent may be a halogenated 2-hydroxydiphenyl ether and/or a
halogenated 2-acyloxy diphenyl ether, as described in U.S. Patent No. 3,629,477, and
represented by the following formula:
In the above formula, each Hal represents identical or different halogen atoms, Z
represents hydrogen or an acyl group, and w represents a positive whole number
ranging from 1 to 5, and each of the benzene rings, but preferably ring A can also
contain one or several lower alkyl groups which may be halogenated, a lower alkoxy
group, an allyl group, a cyano group, an amino group, or lower alkanoyl group.
Preferably, methyl or methoxy groups are among the useful lower alkyl and lower
alkoxy groups, respectively, as substituents in the benzene rings. A halogenated lower
alkyl group, trifluoromethyl group is preferred.
Antimicrobial activity similar to that of the halogen-o-hydroxydiphenyl ethers of the
above formula is also attained using the O-acyl derivatives thereof which partially or
completely hydrolyze under the conditions for use in practice. The esters of acetic acid,
chloroacetic acid, methyl or dimethyl carbamic acid, benzoic acid, chlorobenzoic acid,
methylsulfonic acid and chloromethylsulfonic acid are particularly suitable.
One particularly preferred antimicrobial agent within the scope of the above formula is
2,4,4"-trichloro-2"-hydroxydiphenyl ether, commonly referred to as triclosan
(manufactured by Ciba Geigy under the trade name Irgasan DP300 or Irgacare MP).
Triclosan is a broad-spectrum antimicrobial agent that has been used in a variety of
products, and is effective against a number of organisms commonly associated with
SSIs. Such microorganisms include, but are not limited to, genus Staphylococcus,
Staphylococcus epidermidis, Staphylococcus aureus, methicillin-resistant
Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, and
combinations thereof.

The antimicrobial agent may be delivered to the medical device from an antimicrobial
agent source that is positioned within or attached to the inner surface of a package.
Specifically, the antimicrobial agent is transferred from the antimicrobial agent source
to the medical device when the package, the antimicrobial agent source and the medical
device are subjected to time, temperature and pressure conditions, as described below.
For example, the antimicrobial agent source may be an antimicrobial agent-loaded
paper reservoir, an antimicrobial agent-loaded porous pouch reservoir, an antimicrobial
agent-loaded plastic reservoir, an antimicrobial agent-loaded sponge or foam reservoir,
an antimicrobial agent-loaded tape, or an antimicrobial agent-loaded tablet.
Alternatively, the antimicrobial agent source may be integral with the package itself,
i.e., antimicrobial agent incorporated into or on the package itself, such as but not
limited to, applied directly on the inner surface of the package. Where the
antimicrobial agent source is in a paper or plastic reservoir, such reservoir may be
integral with one or more packaging component in the package.
Additionally, the medical device may optionally have a coating thereon, and/or may
optionally comprise one or more surfaces having an antimicrobial agent disposed
thereon prior to any transfer of antimicrobial agent to the medical device from the
antimicrobial agent source. For example, it is advantageous to apply a coating
composition having an antimicrobial agent therein to the surface of the medical device.
Examples of medical devices, as well as coatings that may be applied thereto, may be
found in U.S. Patent Nos. 4,201,216, 4,027,676, 4,105,034, 4,126,221, 4,185,637,
3,839,297, 6,260,699, 5,230,424, 5,555,976, 5,868,244, and 5,972,008, each of which is
hereby incorporated herein in its entirety. As disclosed in U.S. Patent No. 4,201,216,
the coating composition may include a film-forming polymer and a substantially water-
insoluble salt of a Cg or higher fatty acid. As another example, an absorbable coating
composition that may be used for an absorbable medical device may include
poly(alkylene oxylates) wherein the alkylene moieties are derived from C(, or mixtures
of C4 to C]2 diols, which is applied to a medical device from a solvent solution, as
disclosed in U.S. Patent No. 4,105,034. The coating compositions may include a
polymer or copolymer, which may include lactide and glycolide, as a binding agent.
The coating compositions may also include calcium stearate, as a lubricant; and an
antimicrobial agent. The coating may be applied to the device by solvent-based coating
techniques, such as dip coating, spray coating, or suspended drop coating, or any other
coating means.
Absorbable medical devices are moisture sensitive, that is, they are devices that will
degrade if exposed to moisture in the atmosphere or in the body. It is known by those
of ordinary skill in the art that medical devices made from absorbable polymers may
deteriorate and lose their strength if they come into contact with water vapor prior to
use during surgery. For instance, the desirable property of in vivo tensile strength
retention for sutures will be rapidly lost if the sutures are exposed to moisture for any
significant period of time prior to use. Therefore, it is desirable to use a hermetically
sealed package for absorbable medical devices. A hermetically sealed package is
defined herein to mean a package made of a material that serves as both a sterile barrier
and a gas barrier, i.e., prevents or substantially inhibits moisture and gas permeation.
Materials useful for constructing the package for absorbable medical devices, for
example, include single and multilayered conventional metal foil products, often
referred to as heat-sealable foils. These types of foil products are disclosed in U.S.
Patent No. 3,815,315, which is hereby incorporated by reference in its entirety.
Another type of foil product that may be utilized is a foil laminate referred to in the
field of art as a peelable foil. Examples of such peelable foil and substrates are
disclosed in U.S. Patent No. 5,623,810, which is hereby incorporated by reference in its
entirety. If desired, conventional non-metallic polymer films in addition to or in lieu of
metal foil may be used to form the package for absorbable medical devices. Such fiims
are polymeric and may include conventional polyolefins, polyesters, acrylics,
halogenated hydrocarbons and the like, combinations thereof and laminates. These
polymeric films substantially inhibit moisture and oxygen permeation and may be
coated with conventional coatings, such as, for example, mineral and mineral oxide
coatings that decrease or reduce gas intrusion. The package may comprise a
combination of polymer and metal foils, particularly a multi-layer polymer/metal-foil
composite, such as a polyester/aluminum foil/ethylacrylic acid laminate.
Nonabsorbable medical devices may be packaged in any of the materials described
above. In addition, it is desirable to package nonabsorbable medical devices in a
package made of a material that serves as a sterile barrier, such as a porous material,
i.e., medical grade paper, or a polymeric film or fabric that is permeable, to moisture
and gas, i.e., TYVEK® nonwoven material, manufactured by DuPont and made from
high-density polyethylene fibers. Preferably, nonabsorbable medical devices are
packaged in the same packaging materials that are used for absorbable medical devices,
such as hermetically sealed packages, when it is desirable to have antimicrobial
medical devices having a shelf life of at least 6 months, preferably at least 1 year and
most preferably at least 2 years.
Microorganisms of the genus Staphylococcus are the most prevalent of all of the
organisms associated with device-related surgical site infection. S. aureus and S.
epidermidis are commonly present on patients" skin and as such are introduced easily
into wounds. An efficacious antimicrobial agent against Staphylococcus is 2,4,4"-
trichloro-2"-hydroxydiphenyl ether. This compound has a minimum inhibitory
concentration (MIC) against S. aureus of 0.01 ppm, as measured in a suitable growth
medium and as described by Bhargava, H. et al in the American Journal of Infection
Control, June 1996, pages 209-218. The MIC for a particular antimicrobial agent and a
particular microorganism is defined as the minimum concentration of that antimicrobial
agent that must be present in an otherwise suitable growth medium for that
microorganism, in order to render the growth medium unsuitable for that
microorganism, i.e., the minimum concentration to inhibit growth of that
microorganism. The phrases "an amount sufficient to substantially inhibit bacterial
colonization" and "an effective amount" of the antimicrobial agent, as used herein, are
defined as the minimum inhibitory concentration for S. aureus or greater.
A demonstration of this MIC is seen in the disk diffusion method of susceptibility. A
filter paper disk, or other object, impregnated with a particular antimicrobial agent is
applied to an agar medium that is inoculated with the test organism. Where the
antimicrobial agent diffuses through the medium, and as long as the concentration of
the antimicrobial agent is above the minimum inhibitory concentration (MIC), none of
the susceptible organism will grow on or around the disk for some distance. This
distance is called a zone of inhibition. Assuming the antimicrobial agent has a
diffusion rate in the medium, the presence of a zone of inhibition around a disk
impregnated with an antimicrobial agent indicates that the organism is inhibited by the
presence of the antimicrobial agent in the otherwise satisfactory growth medium. The
diameter of the zone of inhibition is inversely proportional to the MIC.
Method for Making an Antimicrobial Medical Device
In accordance with various methods of the present invention, a medical device is
directly exposed to the antimicrobial agent, i.e., the antimicrobial agent source is
located in the package having the medical device. For example, the package may
contain an antimicrobial agent source, may have an antimicrobial agent source attached
to the inner surface of the package, or the antimicrobial agent source may be integral
with one or more packaging component in the package or with the package itself. In
these embodiments, the medical device is positioned within the package and may
initially be free of an antimicrobial agent or may initially comprise one or more
surfaces having an antimicrobial agent disposed thereon. The package, the
antimicrobial agent source and the medical device are then subjected to time,
temperature and pressure conditions sufficient to vapor transfer an effective amount of
the antimicrobial agent from the antimicrobial agent source to the medical device,
thereby substantially inhibiting bacterial colonization on the medical device.
In the case where the medical device is initially free of an antimicrobial agent, the
antimicrobial agent is delivered to the medical device from an antimicrobial agent
source when the package, the antimicrobial agent source and the medical device are
subjected to time, temperature and pressure conditions sufficient to vapor transfer a
portion of the antimicrobial agent from the antimicrobial agent source to the medical
device.
In the case where the medical device initially comprises one or more surfaces having an
antimicrobial agent disposed thereon, the time, temperature and pressure conditions are
sufficient to vapor transfer a portion of each of the antimicrobial agent disposed on the
medical device and the antimicrobial agent in the antimicrobial agent source to the
inner surface of the package, such that an effective amount of the antimicrobial agent is
retained on the medical device, thereby substantially inhibiting bacterial colonization
on the medical device and the inner surface of the package. In this embodiment, the
amount or concentration of antimicrobial agent on the medical device is stabilized by
providing additional antimicrobial agent in the packaging environment.
Alternatively, the medical device may be positioned within a package, and the package
having the medical device is exposed indirectly to an external antimicrobial agent
source, i.e., the antimicrobial agent source is external to the package having the medical
device. Specifically, the antimicrobial agent source and the package having the
medical device are subjected to time, temperature and pressure conditions sufficient to
vapor transfer an effective amount of the antimicrobial agent from the antimicrobial
agent source to the medical device within the package, thereby substantially inhibiting
bacterial colonization on the medical device. In this embodiment, the package may be
made from a material that serves as a sterile barrier, such as a porous material or
polymeric film that is permeable to moisture and gas, such that a gaseous antimicrobial
agent source is capable of permeating or transmitting as a vapor through the package.
For example, the package having the medical device may be placed in a sealed
environment, and the antimicrobial agent source may be contained within the sealed
environment or may be subsequently introduced to the sealed environment. The
antimicrobial agent source may be any vapor form of the antimicrobial agent.
The rate of vapor transfer of an antimicrobial agent such as triclosan from che
antimicrobial agent source to the medical device is substantially dependent upon the
time, temperature and pressure conditions under which the package and the medical
device are processed, stored and handled. For example, Figure 1 illustrates that
triclosan is capable of transferring from a suture to a packaging component (in a closed
vial at atmospheric pressure) when the temperature is maintained at 55°C over a period
of time. The conditions to effectively vapor transfer an antimicrobial agent such as
triclosan include a closed environment, atmospheric pressure, a temperature of greater
than 40°C, for a period of time ranging from 4 to 8 hours. Also included are any
combinations of pressure and temperature to render a partial pressure for the
antimicrobial agent that is the same as or greater than the partial pressure rendered,
under the conditions described above, in combination with a period of time sufficient to
render an effective amount or concentration of the antimicrobial agent on the medical
device, i.e., the minimum inhibitory concentration (MIC) for S. aureus or greater.
Specifically, it is known to one of ordinary skill that if the pressure is reduced, the
temperature may be reduced to effect the same partial pressure. Alternatively, if the
pressure is reduced, and the temperature is held constant, the time required to render an
effective amount or concentration of the antimicrobial agent on the medical device may
be shortened. Generally, the amount of antimicrobial agent in the antimicrobial agent
source is at least that amount which is necessary to deliver the effective amount of the
antimicrobial agent on the medical device, when exposed to the conditions described
below.
Medical devices typically are sterilized to render microorganisms located thereon
substantially non-viable. In particular, sterile is understood in the field of art to mean a
minimum sterility assurance level of 10"6. Examples of sterilization processes are
described in U.S. Patent Nos. 3,815,315, 3,068,864, 3,767,362, 5,464,580, 5,128,101
and 5,868,244, each of which is incorporated herein in its entirety. Specifically,
absorbable medical devices may be sensitive to radiation and heat. Accordingly, it may
be desirable to sterilize such devices using conventional sterilant gases or agents, such
as, for example, ethylene oxide gas.
An ethylene oxide sterilization process is described below, since the time, temperature
and pressure conditions sufficient to vapor transfer the antimicrobial agent from the
antimicrobial agent source to the medical device, are present in an ethylene oxide
sterilization process. However the time, temperature and pressure conditions sufficient
to vapor transfer the antimicrobial agent from the antimicrobial agent source to the
medical device, may be effected alone or in other types of sterilization processes, and
are not limited to an ethylene oxide sterilization process or to sterilization processes in
general.
As discussed above, absorbable medical devices are sensitive to moisture and are
therefore often packaged in hermetically sealed packages, such as sealed foil packages.
However, sealed foil packages are also impervious to sterilant gas. In order to
compensate for this and utilize foil packages in ethylene oxide gas sterilization
processes, processes have been developed using foil packages having gas permeable or
pervious vents (e.g., TYVEK polymer). The gas permeable vents are mounted to an
open end of the package and allow the passage of air, water vapor and ethylene oxide
into the interior of the package. After the sterilization process is complete, the package
is sealed adjacent to the vent so the vent is effectively excluded from the sealed
package, and the vent is cut away or otherwise removed, thereby producing a gas
impervious hermetically sealed package. Another type of foil package having a vent is
a pouch-type package having a vent mounted adjacent to an end of the package, .
wherein the vent is sealed to one side of the package creating a vented section. After
the sterilization process is complete the package is sealed adjacent to the vented
section, and the sealed package is cut away for the vented section.
In one embodiment, the antimicrobial agent source is placed within the package,
attached to the inner surface of the package, or is integral with one or more packaging
component in the package or with the package itself. After the peripheral seal and side
seals have been formed in the package, the packaged medical device may be placed
into a conventional ethylene oxide sterilization unit. If the package is a foil package,
the antimicrobial agent source may be any of the antimicrobial agent sources described
above or the antimicrobial agent source may be an antimicrobial agent loaded-gas
permeable vent. For example, an antimicrobial agent such as triclosan may be loaded
onto a Tyvek gas permeable vent by coating the Tyvek strip with a solution of ethyl
acetate and triclosan; the antimicrobial agent loaded gas permeable vent is positioned
within a package by mounting it to a hermetic packaging material; the medical device is
positioned within the hermetic packaging material; the periphery of the hermetic
packaging material is sealed in a manner to enclose the medical device and to allow the
passage of gas into the interior of the hermetic packaging material through the vent; the
packaging material having the antimicrobial agent loaded gas permeable vent and the
medical device is subjected to time, temperature and pressure conditions sufficient to
vapor transfer an effective amount of the antimicrobial agent from the antimicrobial
agent loaded gas permeable vent to the medical device; the packaging material is sealed
to enclose the medical device and exclude the vent; and the vent is cut away to thereby
produce an antimicrobial medical device.
In another embodiment, the antimicrobial agent source may be introduced into the
sterilization or other unit external to the package having the medical device. For
example, the medical device is positioned within the package; the package having the
medical device is exposed to an antimicrobial agent source; and the package having the
medical device and the antimicrobial agent source is subjected to time, temperature and
pressure conditions sufficient to vapor transfer an effective amount of the antimicrobial
agent from the antimicrobial agent source to the medical device within the package,
thereby substantially inhibiting bacterial colonization on the medical device. The
package may be made from a material that serves as a sterile barrier, such as a porous
material or a polymeric film that is permeable to moisture and gas, or from a material
that results in a hermetically sealed package.
Prior to the start of the cycle, the sterilization unit may be heated to an internal
temperature of about 25°C. The sterilization unit is maintained about 22 to 37°C
throughout the humidification and sterilization cycles. Next, a vacuum may be drawn
on the sterilization unit to achieve a vacuum of approximately 1.8 to 6.0 kPa. In a
humidification cycle, steam then may be injected to provide a source of water vapor for
the product to be sterilized. The packaged medical devices may be exposed to water
vapor in the sterilization unit for a period of time of about 60 to 90 minutes. Times
may vary, however, depending upon the medical device being sterilized.
Following this humidification portion of the cycle, the sterilization unit may be
pressurized by the introduction of dry inert gas, such as nitrogen gas, to a pressure of
between about 42 and 48 kPa. Once the desired pressure is reached, pure ethyl ene
oxide may be introduced into the sterilization unit until the pressure reaches about 95
kPa. The ethyl ene oxide may be maintained for a period of time effective to sterilize
the packaged medical device. For example, the ethylene oxide may be maintained in
the sterilization unit for about 360 to about 600 minutes for surgical sutures. The time
required to sterilize other medical devices may vary depending upon the type of
product and the packaging. The ethylene oxide then may be evacuated from the
sterilization unit and the unit may be maintained under vacuum at a pressure of
approximately 0.07 kPa for approximately 150 to 300 minutes in order to remove
residual moisture and ethylene oxide from the sterilized packaged medical devices.
The pressure in the sterilization unit may be returned to atmospheric pressure.
The following stage of the process is a drying cycle. The packaged medical device may
be dried by exposure to dry nitrogen and vacuum over a number of cycles sufficient to
effectively remove residual moisture and water vapor from the packaged medical
device to a preselected level. During these cycles, the packaged medical device may be
subjected to a number of pressure increases and decreases, at temperatures greater than
room temperature. Specifically, the jacket temperature of the drying chamber may be
maintained at a temperature of between approximately 53°C to 57°C throughout the ,
drying cycle. Higher temperatures, however, may be employed, such as about 65°C to
70°C for sutures, and higher depending upon the medical device being sterilized. A
typical drying cycle includes the steps of increasing the pressure with nitrogen to
approximately 100 kPa, evacuating the chamber to a pressure of approximately 0.07kPa
over a period of 180 to 240 minutes, reintroducing nitrogen to a pressure of 100 kPa
and circulating the nitrogen for approximately 90 minutes, evacuating the chamber to a
pressure of approximately 0.01 kPa over a period of approximately 240 to 360 minutes
and maintaining a pressure of not more than 0.005 kPa for an additional 4 to 96 hours.
At the end of the humidification, sterilization and drying cycles, which takes typically
about 24 hours, the vessel is returned to ambient pressure with dry nitrogen gas. Once
drying to the preselected moisture level is complete, the packaged medical device may
be removed from the drying chamber and stored in a humidity controlled storage area.
Upon completion of the sterilization process, the antimicrobial medical device, the
package and/or the packaging component have thereon an amount of the antimicrobial
agent effective to substantially inhibit colonization of bacteria on or adjacent the
antimicrobial device, the package and/or the packaging component. The examples
below demonstrate that it is possible to produce an antimicrobial medical device having
an effective amount of antimicrobial agent for at least 6 months, preferably for at least
1 year and most preferably for at least 2 years, after sterilization and packaging of the
medical device and before its use in a surgical procedure, when a hermetically sealed
package is used.
EXAMPLE 1
27" length of VICRYL® sutures, size 5-0 and dyed (a braided multifilament suture
composed of a copolymer made from 90% glycolide and 10% L-lactide, that is
commercially available from Ethicon, Inc.), initially substantially free of an
antimicrobial agent and positioned in a polypropylene suture tray, were placed in
packages having an antimicrobial agent source located therein. In these examples,
packaging components, i.e., paper lids made from medical grade, kraft paper, weighing
about 0.45g each and used to cover the suture tray, were coated by dipping the
individual lids in a solution containing 5% by weight triclosan in ethyl acetate. Each
lid was held in the solution for approximately five seconds, allowed to air dry at room
temperature overnight, and then positioned over the suture tray. The triclosan present
on each lid ranged from 2-3% by weight of the total weight of the dried lid. The suture
assemblies, each having the suture, the suture tray and the triclosan-loaded paper lid,
were arranged in separate cavities created in a peelable foil packaging material, i.e., an
ethylacrylic acid-coated aluminum foil composite, having a TYVEK® gas permeable
vent mounted to an open end of the packaging material to allow the passage of air,
water vapor and ethylene oxide into the interior of the cavities within the packaging
material. The suture assemblies were then sterilized, which conveniently subjected the
suture assemblies to time, temperature and pressure conditions sufficient to vapor
transfer an effective amount of the antimicrobial agent from the antimicrobial agent
source, i.e., the triclosan-loaded paper lid, to the suture. After the sterilization process
was complete, the individual cavities were sealed and the gas permeable vent was
effectively excluded to form sealed packages each having a suture assembly contained
therein. The sutures were then removed from packages and subjected to zone of
inhibition testing.
The data included in the tables below was from zone of inhibition testing performed on
the sutures, when challenged with Staphylococcus. aureus ATCC 6538; methicillin-
resistant Staphylococcus. epidermidis ATCC 51625, Escherichia coli ATCC 8739,
vancomycin resistant Enterococcus faecium ATCC 700221, or Streptococcus
agalacticae ATCC 624, grown in Tryptic Soy broth at 37°C for 24 h. The culture was
diluted in sterile 0.85% saline to create inocula with concentrations of approximately
1,000,000 cfu (colony forming units) per milliliter. For each challenge organism, the
suture was aseptically cut into 5-cm pieces. The pieces were placed in separate sterile
Petri dishes with 0.1 mL of inoculum. Tryptic Soy agar was poured into the plates, and
the plates were incubated at 37°C for 48 h. Zones of inhibition were read as the
distance in millimeters from the suture to the edge of visible growth.
EXAMPLE 2
This example is identical to EXAMPLE 1, except the suture was a PDS® II suture (a
monofilament polydioxanone suture that is commercially available from Ethicon, Inc.)
and the paper lid was coated by dipping the individual lids in a solution containing 10%
by weight triclosan in ethyl acetate.
EXAMPLE 3
This example is identical to EXAMPLE 1, except the suture was a PROLENE® suture
(a monofilament polypropylene suture that is commercially available from Ethicon,
Inc.) and the paper lid was coated by dipping the individual lids in a solution containing
10% by weight triclosan in ethyl acetate.
EXAMPLES 4-5
The preparation of these samples was identical to the preparation of EXAMPLE 1,
except a solution containing 1.1% (Example 4) or 5.6% (Example 5) by weight
triclosan, 15% by weight copolymer of glycolide and lactide, and the remainder ethyl
acetate, was used as the antimicrobial agent source, instead of the triclosan-loaded
paper lid. 0.5 ml of these solutions were placed in separate cavities created in the
peelable foil packaging material, i.e., under each suture assembly, and allowed to dry at
room temperature overnight, such that Example 4 had 5 mg triclosan in each cavity,
while Example 5 had 25 mg of triclosan in each cavity. Then sutures assemblies, each
having a 27" suture wound in a polypropylene tray and covered with a paper lid, were
placed into the cavities followed by sterilization.
Examples 4 and 5 show that the use of an antimicrobial agent reservoir in the foil cavity is an
effective means of generating a product that exhibits a zone of inhibition when challenged with
S. aureus and S. epidermidis. The table below shows data from a tissue passage study using
sutures prepared by the procedure described for Example 5. Specifically, a needle was
manually attached to a sterile suture and then passed ten times through a raw chicken breast
to determine if the triclosan would be removed. The data shows that significant zones of
inhibition still remain after passing the suture through the tissue, when challenged with S.
aureus and S. epidermidis.
The preparation of EXAMPLE 6 was identical to the preparation of EXAMPLE 4,
while the preparation of EXAMPLE 7 was identical to the preparation of EXAMPLE 5,
except the suture was a PDS® II suture.
Examples 6 and 7 show that the use of an antimicrobial agent reservoir in the foil cavity is an
effective means of generating a product that exhibits a zone of inhibition when challenged with
S. aureus and S. epidermidis. The table below shows data from a tissue passage study using
sutures prepared by the procedure described for Example 7. Specifically, a needle was
manually attached to a sterile suture and then passed ten times through a raw chicken breast
to determine if the triclosan would be removed. The data shows that significant zones of
inhibition still remain after passing the suture through the tissue, when challenged with S.
aureus and S. epidermidis.
EXAMPLES 8-10
These examples are identical to EXAMPLE 1, except the suture was a dyed VICRYL®
Plus suture, size 5-0 (a braided multifilament antimicrobial suture composed of a
copolymer made from 90% glycolide and 10% L-lactide, having triclosan contained in
a coating mixture composed of a copolymer of glycolide and lactide and calcium
stearate and ethyl acetate, that is commercially available from Ethicon, Inc.). Example
8 had 1.0% by weight triclosan in the coating mixture; Example 9 had 2.0%; and
Example 10 had 3.0%, based on the total weight of the coating mixture.
EXAMPLES 11-12
These examples are identical to EXAMPLES 4-5, except the suture was a dyed
VICRYL® Plus suture, size 2-0, with 2% by weight triclosan in the coating mixture.
EXAMPLE 13
This example is identical to EXAMPLE 1, except that VICRYL® sutures, size 2-0 and
dyed, were used and the antimicrobial agent source was a Tyvek® gas permeable strip.
One side of a Tyvek strip was manually coated with ethyl acetate containing 20% by
weight triclosan. Suture assemblies, each having the suture, a polypropylene suture
tray and a paper lid, were arranged in separate cavities created in a peelable foil
packaging material having the triclosan-loaded TYVEK® gas permeable strip mout. ted
to an open end of the packaging material to allow the passage of air, water vapor and
ethylene oxide into the interior of the cavities within the packaging material. The
suture assemblies were sterilized. After the sterilization process was complete, the
individual cavities were sealed and the gas permeable vent was effectively excluded to
form sealed packages each having a suture assembly contained therein. Thereafter, the
sutures were removed from packages and subjected to zone of inhibition testing. Three
samples were taken from each suture; all samples showed zones of inhibitions when
challenged with S. aureus and S. epidermis.
WHAT IS CLAIMED IS:
1. An antimicrobial suture produced according to the steps of:
positioning a suture and an antimicrobial agent source within a package, said
antimicrobial agent being selected from the group consisting of halogenated hydroxyl
ethers, acyloxydiphenyl ethers, and combinations thereof; and
subjecting the package, the suture and the antimicrobial agent source to time,
temperature and pressure conditions sufficient to vapor transfer an effective amount of
the antimicrobial agent from the antimicrobial agent source to the suture, thereby
substantially inhibiting bacterial colonization on the suture.
2. An antimicrobial suture assembly having a suture and at least one
packaging component produced according to the steps of:
positioning a suture assembly and an antimicrobial agent source within a
package, said antimicrobial agent being selected from the group consisting of
halogenated hydroxyl ethers, acyloxydiphenyl ethers, and combinations thereof; and
subjecting the package, the suture assembly and the antimicrobial agent source
to time, temperature and pressure conditions sufficient to vapor transfer an effective
amount of the antimicrobial agent from the antimicrobial agent source to the suture,
thereby substantially inhibiting bacterial colonization on the suture assembly.
3. An antimicrobial packaged medical device produced according to the
steps of:
positioning a medical device and an antimicrobial agent source within a
package comprising an inner surface, said antimicrobial agent being selected from the
group consisting of halogenated hydroxyl ethers, acyloxydiphenyl ethers,
and combinations thereof; and
subjecting the package, the antimicrobial agent source and the medical
device to time, temperature and pressure conditions sufficient to vapor
transfer at least an effective amount of the antimicrobial agent from the
antimicrobial agent source to inner surface of the package and the medical
device, thereby substantially inhibiting bacterial colonization on the inner
surface of the package and the medical device.
The packaged medical device as claimed in claim 3, wherein the
antimicrobial agent source is an antimicrobial agent-loaded reservoir.
The packaged medical device as claimed in claim 3, wherein the
antimicrobial agent source is positioned within the package.
The packaged medical device as claimed in claim 3, where the antimicrobial
agent source is on the inner surface of the package.
The packaged medical device as claimed in claim 3, wherein the
antimicrobial agent source is integral with one or more packaging
components in the package or the package.
The packaged medical device as claimed in claim 3, wherein the medical
device comprises one or more surfaces having an antimicrobial agent
disposed thereon, said antimicrobial agent being selected from the group
consisting of halogenated hydroxyl ethers, acyloxydiphenyl ethers, and
combinations thereof; and a portion of each of the antimicrobial agent
disposed on the medical device and the antimicrobial agent in the
antimicrobial agent source is vapor transferred to the inner surface of the
package, while an effective amount of the antimicrobial agent is retained on
the medical device, when the package, the antimicrobial agent source and
the medical device are subjected to said time, temperature and pressure
conditions, thereby substantially inhibiting bacterial colonization on the inner
surface of the package and the medical device.
A method for making an antimicrobial suture comprising the steps of:
positioning a suture and an antimicrobial agent source within a package,
said antimicrobial agent being selected from the group consisting of
halogenated hydroxyl ethers, acyloxydiphenyl ethers, and combinations
thereof; and
subjecting the package, the suture and the antimicrobial agent source to
time, temperature and pressure conditions sufficient to vapor transfer an
effective amount of the antimicrobial agent from the antimicrobial agent
source to the suture, thereby substantially inhibiting bacterial colonization on
the suture.
The method as claimed in claim 9, where an effective amount of the
antimicrobial agent is vapor transferred from the antimicrobial agent source
to the inner surface of the package, thereby substantially inhibiting bacterial
colonization on the package.
The method as claimed in making an antimicrobial medical device
comprising the steps of:
positioning a medical device and an antimicrobial agent source within a
package comprising an inner surface, said antimicrobial agent being
selected from the group consisting of halogenated hydroxyl ethers,
acyloxydiphenyl ethers, and combinations thereof within the package;
subjecting the package, the antimicrobial agent source and the medical
device to time, temperature and pressure conditions sufficient to vapor
transfer an effective amount of the antimicrobial agent from the antimicrobial
agent source to the medical device, thereby substantially inhibiting bacterial
colonization on the medical device.
The method as claimed in claim 11, where an effective amount of the
antimicrobial agent is vapor transferred from the antimicrobial agent source
to the inner surface of the package, thereby substantially inhibiting bacterial
colonization on the package.
The method as claimed in claim 12, wherein the antimicrobial agent source
is an antimicrobial agent-loaded reservoir.
The method as claimed in claim 12, wherein the antimicrobial agent source
is positioned within the package.
The method as claimed in claim 12, where the antimicrobial agent source is
on the inner surface of the package.
The method as claimed in claim 12, wherein the antimicrobial agent source
is integral with one or more packaging components in the package or the
package.
The method for making an antimicrobial medical device comprising the
steps of:
exposing a medical device to an antimicrobial agent source; and
subjecting the medical device and the antimicrobial agent source to time,
temperature and pressure conditions sufficient to vapor transfer an effective
amount of the antimicrobial agent from the antimicrobial agent source to the
medical device, thereby substantially inhibiting bacterial colonization on the
medical device.
The method as claimed in claim 17, wherein the time, temperature and
pressure conditions sufficient to vapor transfer an effective amount of the
antimicrobial agent from the antimicrobial agent source to the medical
device are a pressure and a temperature sufficient to render a partial
pressure for the antimicrobial agent that is the same as or greater than the
partial pressure rendered under a temperature of 40°C and atmospheric
pressure, and a period of time ranging from 4 to 8 hours.
An antimicrobial packaged medical device having an effective amount of
antimicrobial agent for at least 6 months after sterilization and packaging,
and before opening and use in a surgical procedure.
An antimicrobial suture produced according to the steps of:
positioning a suture and an antimicrobial agent source within a package, said
antimicrobial agent being selected from the group consisting of halogenated
hydroxyl ethers, acyloxydiphenyl ethers, and combinations thereof; and
subjecting the package, the suture and the antimicrobial agent source to time,
temperature and pressure conditions sufficient to vapor transfer an effective
amount of the antimicrobial agent from the antimicrobial agent source to the
suture, thereby substantially inhibiting bacterial colonization on the suture.

Documents:

555-KOLNP-2005-(27-09-2011)-CORRESPONDENCE.pdf

555-KOLNP-2005-(27-09-2011)-OTHERS.pdf

555-KOLNP-2005-(27-09-2011)-PA.pdf

555-KOLNP-2005-CORRESPONDENCE 1.1.pdf

555-KOLNP-2005-FOR ALTERATION OF ENTRY.pdf

555-KOLNP-2005-FORM 15.pdf

555-KOLNP-2005-FORM-27.pdf

555-kolnp-2005-granted-abstract.pdf

555-kolnp-2005-granted-assignment.pdf

555-kolnp-2005-granted-claims.pdf

555-kolnp-2005-granted-correspondence.pdf

555-kolnp-2005-granted-description (complete).pdf

555-kolnp-2005-granted-drawings.pdf

555-kolnp-2005-granted-form 1.pdf

555-kolnp-2005-granted-form 18.pdf

555-kolnp-2005-granted-form 2.pdf

555-kolnp-2005-granted-form 26.pdf

555-kolnp-2005-granted-form 3.pdf

555-kolnp-2005-granted-form 5.pdf

555-kolnp-2005-granted-letter patent.pdf

555-kolnp-2005-granted-reply to examination report.pdf

555-kolnp-2005-granted-specification.pdf

555-KOLNP-2005-PA.pdf


Patent Number 219074
Indian Patent Application Number 555/KOLNP/2005
PG Journal Number 17/2008
Publication Date 25-Apr-2008
Grant Date 23-Apr-2008
Date of Filing 04-Apr-2005
Name of Patentee ETHICON INC.,
Applicant Address U.S.ROUTE NO. 22, SOMERVILLE, NJ 08876, U.S.A.
Inventors:
# Inventor's Name Inventor's Address
1 HOWARD SCALZO 16 NORTH 11TH STREET, KENILWORTH, NJ 07033
2 ROBERT CERWIN 404 CAFFERTY ROAD, PIPERSVILLE, PA 18947
3 JEROME A. FISCHER 5 MATTBEN DRIVE, WARREN, NJ 07059
PCT International Classification Number A61B
PCT International Application Number PCT/US03/030598
PCT International Filing date 2003-09-25
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/603,317 2003-06-25 U.S.A.
2 10/367,497 2003-02-15 U.S.A.
3 60/416,114 2002-10-04 U.S.A.