Note: Descriptions are shown in the official language in which they were submitted.
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PULL CAP FOR A PORT OF AN ADMINISTRATION ASSEMBLY
Field of Invention
The invention relates to a pull cap for a port on of an administration
assembly
which includes a container filled will fluid.
Background of the Invention
In the packaging arts, it is often necessary to provide the user with a port
through which the contents of the package or container may be accessed. For
example, in the medical field, ports allow a user to access the contents
within the
container such as a bag so that they can be infused into a patient,
transferred to a
second package or mixed with additional components. To access the contents, a
sealed diaphragm, located within the port must be pierced by a needle or
piercing pin.
Thus, access ports have an open end for receiving the piercing pin which
contacts and
pierces the diaphragm. In many applications, such containers and ports are
commonly
made from a material known as polyvinylchloride or PVC. However, polypropylene
material can be used as an alternative for those drugs that are incompatible
with
existing PVC delivery systems.
For intravenous solution containers made from polypropylene or any other
material, it is particularly important that the open end of the access ports
remain
sterile to prevent the transfer of contaminants into the solution by the pin
inserted into
the port to pierce the diaphragm. To protect the sterility of the access port,
current
containers employ removable caps which cover the port opening during storage
and
transportation prior to use. There are several materials that can be used for
the caps.
Thermoplastic elastomers or polypropylene plastic are examples of such
material.
However, these types of caps are complicated and costly to assemble as well as
more
cumbersome to remove when used. Therefore, caps made from rubber have been
used
to eliminate these problems.
In a typical process of assembly of components, the polypropylene container
(which includes a polypropylene tube for access to the container) is filled
with
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medicament. A rubber cap is installed on a polypropylene port and the port is
heat
sealed to the tube. The entire filled container assembly is then sterilized by
way of
autoclaving. During autoclaving, the structural components of the assembly are
exposed to high temperatures. The high temperature may cause the polypropylene
port to deform and set in undesired shapes. For example, the body of the port
may
retract inwardly due to radial compression from the rubber cap. Such
deformation
may create a problem with the integrity of the seal between the cap and port
which
may leave the assembly open to contamination. Further, inward deformation of
the
port will increase the force required for piercing pin insertion. Also, when
the cap is
installed on the port prior to sterilization, air may accumulate between the
cap and
port with no means of escape. As a result of the air accumulation, the cap may
dislodge and fail to maintain the integrity seal between the cap and port
which may
cause contamination.
It would therefore be desirable to have a cap that overcomes the problems
identified above. In particular, it would be desirable to have a cap that
would help
maintain the shape and functionality of the polypropylene port as well as
maintain the
integrity of the seal between the cap and port through the sterilization
process.
Summary of the Invention
The present invention solves the problems above by providing a cap for
covering a port of a fluid administration assembly. The cap comprises a top
wall, a
side cylindrical wall, and an opening by said side wall defined for receiving
said port;
said top and side wall define a chamber which communicates with the opening; a
handle extending from said top wall; and a solid plug extending from the
inside
surface of said top wall within said chamber. The handle is offset from the
center of
said top wall. The handle extends along the edge of said top wall and has an
arcuate
shape. The side wall has an inner diameter less than the outer diameter of
said port.
The cap is made of a flexible material called silicone rubber.
The plug is generally cylindrically shaped. The plug is constructed to enable
the plug to be easily inserted into the port, but provide physical support to
the port
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through sterilization. The plug has an outer surface. The plug's outer surface
and
inside surface of side wall define an open annular channel therebetween for
receiving
a wall of said port.
The cap further comprises an annular pocket defined by said inside surface of
said side wall, top wall and outer surface of said plug. The pocket
communicates with
said open annular channel. The pocket is rectangularly shaped in cross
section. The
plug extends beyond the end of said side wall.
In another aspect of the invention, there is provided an administration
assembly including a container filled with fluid; a port assembly connected to
said
container for administering fluid from said container, said port assembly
including a
cylindrical port; and a flexible cap for covering said cylindrical port. The
cap
comprises a top wall, side cylindrical wall extending therefrom and an opening
defined by said side wall for receiving said port; a handle extending from
said cap:
and a solid plug extending from the inside surface of said top wall. The top
and side
wall have an inside surface. The inside surface of the side wall and plug
define an
open annular channel therebetween. The cap further comprising a pocket defined
by
said the inside surface of said top wall, said side cylindrical wall and outer
surface of
said plug. The pocket communicates with said annular chamber.
Yet another aspect of the invention, a cap for covering the administration
port
on a container, said cap comprising a top wall, a side cylindrical wall, and
an opening
defined by said side wall into which said port can be inserted; a handle
extending
from said top wall; a plug extending from said top wall, said plug adapted to
be
inserted into said port; a pocket with said chamber defined by said plug, said
side
cylindrical wall and said top wall.
In another aspect of the invention, there is provided a cap for covering the
port
of an administration assembly. The cap comprises a top wall, a side
cylindrical wall,
and an opening defined by the cylindrical wall into which said port can be
inserted; a
handle extending from said top wall; a plug extending from said top wall
within said
chamber; and a pocket with said chamber defined by said side wall, said plug
and said
top wall.
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Brief Description of the Drawings
Fig. 1 is a front perspective view of the cap in accordance with the invention
installed on the port/container assembly;
Fig. 1A is a cross-sectional view of the cap of Fig. 1 prior to sterilization;
Fig. 2 is a side view of the cap of Fig. I, installed on a port shown in
dotted
lines;
Fig. 3 is a view of the cap along lines 3-3 shown in Fig 2;
Fig. 4 is a top view of the cap along the line 4-4 in Fig. 2;
Fig. 5 is cross sectional view of the cap and container/port assembly along
lines 5-5 in Fig. 1, after sterilization;
Fig. 6 is an enlarged view of the cap and port along lines 6-6 shown in Fig.
5:
Fig. 7 is a cross sectional view of the cap installed on the port shown in Fig
5,
with a user pulling on the handle; and
Fig. 8 is a view of the cap shown in Fig. 5 completely removed from the port.
Description of the Preferred Embodiment
In Fig. 1, there is shown a fluid administration assembly 10 including a
flexible solution container 12 for the maintenance and delivery of a sterile
medical
solution or fluid, a port assembly 14 and a cap 16. The port assembly 14
includes a
cylindrical tube 18 and a port 20 attached to said tube 18. The container 12
is a
pouch-type flexible bag made from webs of flexible film. The webs of film are
sealed
together along the peripheral edges. This type of container is a referred to
as a
fabricated package. The outer webs of film are made from a material known as
polyolefin. The web of film along the inside of the container in contact with
the
solution is made of a polypropylene material. The port 20 is generally
cylindrical
shaped with the exception of the flange 17.
In brief, the process of assembly is as follows. The tube l 8 is attached to
the
container 12 to enable filling of the container and later enable access to the
contents of
the container 12. One typical way to attach the tube 18 to the container is to
use a
thermal bonding process. Ultrasonic welding may also be used to seal the tube
18 to
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the container 12. Once the tube 18 is properly attached to the container 12,
the
container is filled with medicament/fluid. The cap 16 is installed on the port
20 and
the port 20 is heat sealed to the tube 18. The tube 18 and port 20 are both
preferably
made from polypropylene material. The cap 16 is made of a flexible material
which is
preferably silicone rubber. The inner and outer diameter of the wall 20a of
the port 20
are preferably .208 inches and .258 inches, respectively. However, other
dimensions
(for the diameters) can be used.
As best seen in Fig. 1 A, cap 16 is an integral component which includes a top
wall 22 and a cylindrical wall 24 extending from the top wall 22. The edge of
cylindrical side wall 24 defines an opening into which the port can be
inserted. The
top wall 22 and cylindrical wall 24 define a chamber therewithin that
communicates
with the opening to receive the port 20. The inner diameter of the side wall
24 is
slightly less than the outer diameter of said port 20 so that the flexible cap
16 fits
snugly over the port 20. Cap 16 also includes a solid cylindrical plug 26
extending
from the inside surface of the top wall 22 within the chamber. The plug 26
includes a
portion of constant diameter 26b and a portion 26a which tapers. The tapered
portion
26a extends just beyond the length cylindrical side wall 24. The portion 26b
of the
plug 26 has a diameter of a sufficient size to fit easily into port 20, but
provide
stability or support to the cylindrical wall of the port 20 to maintain its
shape during
sterilization of the entire assembly.
The inner diameter of cylindrical wall 24 (from the inside surface) is larger
than the diameter of the plug 26 to define an annular channel 28 therebetween
to
snugly receive the wall 20a of the port 20. The inside diameter of the
cylindrical wall
24 is preferably .238 inches. However, other dimensions can be used. Deep
within
cap 16, there is an annular pocket 30 which communicates with the annular open
channel 28. The pocket 30 is defined by the inside surface of the inner top
wall 22,
the inside surface 24a of the side cylindrical wall 24 and the outer surface
of the plug
26. The pocket 30 is preferably rectangularly shaped in cross section, but
could have
other shapes.
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The width of the rectangular pocket 30 is larger than the width of the annular
channel (i.e., the distance between the inside surface 24a of the wall 24 and
outer
surface of the plug 26) in order to allow air to escape down the annular
channel 28
along the exterior surface of the wall 20a of the port 20 which accumulates
under
pressure when the cap 16 is installed on the port 20. The width and length of
the
rectangular pocket 30 are preferably .027 inches and .07 inches, respectively.
However, other dimensions may be used. The pocket 30 can be merely viewed as
an
extension of the annular channel 28 which expands at the end thereof.
The cap 16 also includes an integral handle 32 which is preferably positioned
along the edge of the top wall 22 and extends away therefrom. That is, the
handle 32
is offset from the center of the top wall 22 of the cap 16. The offset handle
concentrates the force unequally on the port/cap thus allowing the removal of
the cap
at lower pull forces (see Fig. 7) as compared to a center pull handle.
However, the
handle could be positioned in other locations. The handle 32 has an arcuate
shape,
i.e., shaped in the form of a partial cylinder. The handle however could have
different
shapes.
Figs. 5-8 illustrate the administration assembly after sterilization. As
presented earlier, the cylindrical wall 24 of the cap 16 applies a radial
compressive
force on the cylindrical wall 20a of the port 20, which can reduce the
diameter of the
cylindrical wall 20a during sterilization. Because the cylindrical wall 20a is
not in
contact with the inside surface 24a of the cylindrical wall 24 inside the
pocket 30, the
diameter of the cylindrical wall 20a inside pocket 30, edge 20b, is not
reduced. This
results in a deformed shape in the cylindrical wall 20a of port 20, best
represented in
Fig. 6. The deformation is beneficial because it increases the friction fit
between the
cap 16 and the port 20 during removal. In Fig. 7, the user is removing the cap
16 off
of the port 20 by pulling the handle 32 of the cap 16 downwardly, causing the
seal to
break between the inside surface 24a of the cylindrical wall 24 and the
exterior surface
20a of the wall 20 of the port 20. The deformation of the port also provides
tamper
evidence. The cap 16 is difficult to replace on port 20 because the diameter
of edge
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20b exceeds the diameter of the inside surface 24a of the cap 16. Further, cap
16 will
not seat fully on the port 20 without extraordinary effort.
It should be understood that various changes and modifications to the
preferred embodiments described herein will be apparent to those skilled in
the art.
Such changes and modification can be made without departing from the spirit
and
scope of the present invention and without diminishing its attendant
advantages. It is
therefore intended that such changes and modifications be covered by the
appended
claims.
