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Medical Patent Abstract
A method of fusing a component to a sterilized storage or delivery
device formed of a cyclic olefin polymer which includes forming
the storage or delivery device from a cyclic olefin polymer, forming
a second member or component having at least a surface layer formed
of the second polymer, wherein the Hansen relative energy distance
Ra/Ro of the second polymer relative to the cyclic olefin polymer
is equal to or less than 0.7, applying the second member to the
storage or delivery device, and heating the assembly to the sterilization
temperature, thereby causing the second polymer to chemically interact
with the cyclic olefin polymer, fusing the second component to the
storage or delivery device. The preferred embodiment of the invention
is a medical container, such as a vial, wherein the vial is formed
of a cyclic olefin polymer and the cap, closure or collar is formed
of a second polymer heat fused to the vial or container.
Medical Patent Claims
The invention claimed is:
1. A method of forming a sealed sterilized container, comprising
the following steps: forming a container having an open end and
a closed end from a cyclic olefin polymer; forming a closure configured
to be received on said onen end of said container from a second
polymer, wherein the relative energy distance Ra/Ro of said second
polymer relative to said cyclic olefin polymer is equal to or less
than 0.7; applying said closure on said open end of said container
in contact with said container; and sterilizing said container and
said closure, thereby fusing said closure to said container, and
sealing said container.
2. The method of forming a sealed sterilized container as defined
in claim 1, wherein said method includes forming said container
form said cyclic olefin polymer having a rim portion surrounding
said open end, forming a cup-shaped closure from said second polymer
having a closed end portion and an integral tubular rim portion,
disposing said cup-shaped closure over said rim portion of said
container with said rim portion of said closure contacting said
rim portion of said container and heating said container and said
closure to the sterilization temperature thereof, fusing said rim
portion of said closure to said rim portion of said container.
3. The method of forming a sealed sterilized container as defined
in claim 1, wherein said method includes forming said closure from
said second polymer, wherein the relative energy distance Ra/Ro
of said second polymer relative to said cyclic olefin polymer is
equal to or less than about 0.5.
4. The method of forming a sealed sterilized container as defined
in claim 1, wherein said method includes forming said closure from
a polymer selected from the group consisting essentially of butyl
rubber, nitrile butadiene and an isoprene elastomer.
5. The method of forming a sealed sterilized container as defined
in claim 1, wherein said method includes adding a medicament, drug
or vaccine to said container prior to applying said closure on said
open end of said container.
6. The method of forming a sealed sterilized container as defined
in claim 1, wherein said method included heating said container
and said closure to said sterilization temperature by autoclaving
or via heating with no or little humidity.
7. The method of forming a sealed sterilized container as defined
in claim 1, wherein said step of sterilizing said container and
said closure comprises heating said container and said closure to
a temperature of about 120.degree. C. to about 130.degree. C. for
a time neriod of about 30 minutes to about 60 minutes.
8. The method of forming a sealed sterilized container as defined
in claim 1, wherein said container is a single-layer container.
9. A method of forming a sealed sterilized container, comprising
the following steps: forming a single-layer container having an
open end and a closed end from a cyclic olefin polymer; forming
a closure configured to be received on said open end of said container
from a second polymer, wherein the relative energy distance Ra/Ro
of said second polymer relative to said cyclic olefin polymer is
equal to or less than 0.7; applying said closure on said open end
of said container in contact with said container; and heating said
container and said closure to the sterilization temperature of said
cyclic olefin polymer and said second polymer, thereby fusing said
closure to said container, and sealing said container.
10. A method of forming a sealed sterilized container which is
releaseably fused, comprising the following steps: forming a container
having an open end and a closed end and having an annular rim portion
surrounding said open end, said container formed of a cyclic olefin
polymer; forming a closure configured to be received on said open
end of said container from a second polymer, said closure having
a first portion configured to cover said open end and a second portion
configured to cover said annular rim portion, wherein the relative
energy distance Ra/Ro of said second polymer relative to said cyclic
olefin polymer is equal to or less than 0.7; applying said closure
on said open end of said container such that said second portion
ot said closure is in partial face-to-face engagement with said
annular rim portion of said container; and sterilizing said container
and said closure, thereby fusing said second portion of said closure
to said annular rim portion of said container, and sealing said
container.
11. The method of forming a sealed sterilized container as defined
in claim 10, wherein a protruding rib is defined on said second
portion of said closure, said rib definina said partial face-to-face
engagement with said annular rim portion.
Medical Patent Description
BACKGROUND OF THE INVENTION
The present invention relates to medical transfer and storage devices
wherein a major component is formed of a cyclic olefin polymer and
a second component fused to such cyclic olefin polymeric component.
A preferred embodiment of this invention is a sealed sterilized
container and closure assembly, such as a sealed vial or transfer
set, wherein the closure or collar is fused on the open end of the
vial.
The development of cyclic olefin polymers has suggested the use
of such polymers for the manufacture of medical devices because
such polymers are transparent, exhibit excellent chemical resistance,
and may be sterilized by autoclaving or the like without damage.
However, the Applicant has found that certain polymers will chemically
react with and fuse to cyclic olefin polymers at elevated temperatures
required for sterilization, limiting the use of cyclic olefin polymers
for medical devices, including medical transfer and storage devices.
The Applicant proposes to utilize this apparent disadvantage to
fuse a component of a medical storage or delivery device to a cyclic
olefin polymeric component, such as a closure on a vial formed of
a cyclic olefin polymer.
A conventional vial for storing a medicament, drug or vaccine includes
an open end, a radial rim portion surrounding the open end, and
a reduced diameter neck portion adjacent the rim portion. The vial
is conventionally sealed with an elastomeric stopper which generally
includes a tubular portion inserted into the neck of the vial and
a planar rim portion which overlies the vial rim. The stopper is
normally secured to the vial with a thin malleable metal cap, such
as aluminum. The aluminum cap includes a tubular portion which surrounds
the rim portions of the stopper and vial, an inwardly projecting
annual portion which overlies the rim portion of the stopper and
a distal end portion which is crimped or deformed radially into
the neck portion of the vial, beneath the vial rim portion. Because
aluminum is malleable, the collar accommodates build-up of tolerances
of the dimensions of the stopper and vial rim. The dimensions and
tolerances of standard vials and stoppers are set by the International
Organization for Standards (ISO).
The rim portion of the aluminum cap which covers the stopper rim
portion may be closed, in which case the aluminum cap is removed
by "peeling" the aluminum cap from the vial. A pre-slit
tab located in the mid-portion may be provided which overlies the
vial rim, permitting the cap to be torn away from the top and peeled
from the vial prior to use. This method of sealing a vial has several
disadvantages. First, the tearing of the metal cap creates sharp
edges which may cut or damage sterile gloves and cut the person
administering the medicament, drug, or vaccine, thereby exposing
both the healthcare worker and the patient to disease and contamination
of the content of the vial. Second, tearing of the aluminum cap
generates metal particles which may also contaminate the content
of the vial. The dangers associated with the tearing of an aluminum
cap have been solved in part by adding a "flip-off" plastic
cap. The plastic cap is then removed by forcing the flip-off cap
away from the aluminum collar, which tears an annular serrated portion
surrounding the central opening and exposing an opening in the collar
for receipt of a hypodermic needle or the like. This embodiment
reduces, but does not eliminate the possibility of tearing the sterile
gloves of a health care worker. More importantly, however, aluminum
dust is still created which may contaminate the contents of the
vial. It is also important to note that metallic dust is created
by forming and affixing an aluminum collar to the vial because aluminum
dust is created in forming the aluminum collar, crimping the collar
and removing the flip-off plastic cap. Aluminum collars are also
used to secure a fluid transfer set on medical vials. Transfer sets
may be utilized, for example, to transfer liquid from a syringe
to a vial, such as to reconstitute a dry or powder drug in a vial,
by adding a diluent or solvent. The reconstituted drug may then
be withdrawn from the vial by a syringe. The inner surface of the
transfer set may be part of the drug fluid path and the aluminum
collar or ring may bring particles in the sterile room where the
drug is added to the vial or into the fluid path contaminating the
medicament, drug or vaccine.
More recently, the Applicant has developed plastic closures for
vials and transfer sets and a method of crimping a plastic closure
on a vial as disclosed in a co-pending application. However, this
method of securing a closure on a vial requires a separate crimping
step prior to sterilization, such as autoclaving. The method of
fusing a cap or closure to a vial or other medical container formed
of a cyclic olefin polymer of this invention solves these problems
by utilizing the apparent "disadvantage" of cyclic olefin
polymers which presently limit the use of such polymers for sterilizable
storage and delivery devices.
SUMMARY OF THE INVENTION
As set forth above, the present invention relates to sterilizable
or sterilized medical transfer or storage devices, such as vials,
transfer sets, syringes, injection devices and the like, wherein
a first component, generally the major component, is formed of a
cyclic olefin polymer and the device includes a second component,
such as a closure, label or the like, formed of a second polymer
fused to the first component, wherein the relative energy distance
Ra/Ro of the second polymer relative to the cyclic olefin polymer
is equal to or less than 0.7 or more preferably equal to or less
than about 0.5. The second component is also preferably formed of
a polymer having a lower molecular weight, less than about 5,000
to promote fusing. Following assembly of the components, the method
then includes heating the storage or delivery device to the sterilization
temperature, thereby causing the second polymer to chemically interact
with the cyclic olefin polymer, fusing the second member to the
storage or delivery device. The preferred method of sterilization
is autoclaving which heats the polymers to 120 to 125.degree. C.
for 30 to 60 minutes and fuses the polymers as described. The polymer
or polymers selected for the second member or component of the sterilizable
storage or delivery device and method of this invention is based
upon solubility and cohesion properties explained by Hansen in "The
Three Dimension Solubility Parameter and Solvent Diffusion Coefficient"
by Charles M. Hansen, Copenhagen Danish Technical Press (1967) and
the Hansen values for polymers are reported in Chapter 14 of "The
Handbook of Solubility Parameters and Cohesion Parameters"
Edited by Allen F. M. Barton (1999). Each material is defined by
three points in 3D space and these three points are known as the
Hansen Solubility Parameters (HSP). The Hansen Solubility Parameters
may be defined as follows.
The Hansen solubility region consists of a point in 3D space defined
by a non-polar dispersion interaction (Delta-D) axis, a polar or
dipole interaction (Delta-P) axis and hydrogen bonding interaction
(Delta-H) axis. From the location (Delta-D, Delta-P, Delta-H), a
radius is projected to form a sphere which encompasses the region
where liquids having HSP parameters within the inside of this sphere
are generally the "attacking" the material in question,
and liquids outside of the sphere are generally not attacking the
material in question (See also "Environmental Stress Cracking
In Plastics," Hansen and Just, Pharmaceutical and Medical Packaging
(1999), Vol. 9, 7.1 to 7.7, ISBN 87-89753-26-7). Hansen also noted
that higher stress/temperature levels will enlarge the sphere (increase
the radius) as well as the size and shape of the liquid molecules.
Generally, the larger the molecule, the harder it is for the molecule
to attack the material in question. The assignee of this application
has noted material interactions under ambient conditions, but material
interaction is found more frequently at elevated temperatures, such
as during autoclaving and annealing. As set forth above, however,
the perceived problems associated with material interaction between
cyclic olefin polymers and the polymers conventionally used for
components of medical devices has limited the use of cyclic olefin
polymers in medical transfer and storage devices.
The distance between the HSP coordinate of polymer A to HSP coordinates
of another material (liquid or Polymer B) is defined as Ra. The
radius of the Polymer A sphere is defined as Ro. Ra/Ro is now defined
by Hansen as the Relative Energy Distance (RED). Hansen reports
that if Ra/Ro is less than 1, the two materials may stress crack
or dissolve each other. If Ra/Ro is greater than 1, the materials
do not have an affinity to one another under standard conditions.
Ro is determined through experimentation described by Hansen, and
the 3D distance, Ra, is defined by the equation: 1=polymer 2=liquid
(2.sup.nd solid in this disclosure) and RED=Relative Energy Distance=Ra/Ro
Ra/Ro is inside the polymer sphere if it is less than 1 Ra/Ro is
on the surface of the sphere if it is 1 Ra/Ro is outside the polymer
sphere if it is greater than 1. For Ticona Topas, a cyclic olefin
copolymer, the Hansen Solubility Parameters have been reported by
Hansen to be: Delta-D=18.0, Delta-P=3.0 and Delta-H=2.0 and Ro=5.0
For Ticona Topas cyclic olefin copolymers that have seen cracking,
the Hansen Solubility Parameters have been reported by Hansen to
be: Delta-D=17.3, Delta-P=3.1 and Delta-H=2.1 and Ro=6.4.
Thus, the larger the Hansen solubility difference between two polymers,
the less likely the polymers will interact and the smaller the solubility
difference between two polymers, the more likely the polymers will
interact. Experimentation has shown that this difference is particularly
important in the use of cyclic olefin polymers in medical devices
which must be sterilized before use. As stated above, Hansen has
also found that an increase in temperature will enlarge the sphere
of interaction. For example, the Applicant experimented with syringe
assemblies having a barrel formed from a cyclic olefin polymer and
a plunger stopper conventionally formed of a bromo-butyl rubber
polymer. Upon sterilization by autoclaving, the bromo-butyl rubber
polymer stopper fused to the cyclic olefin polymeric barrel resulting
in a breakloose force of approximately 4.5 kg. rendering the syringe
assembly inoperative. Further experimentation by the Applicant determine
that this problem could be overcome by selecting a polymer for the
plunger stopper wherein the relative energy distance Ra/Ro of the
polymer selected for the stopper relative to the cyclic olefin polymer
was greater than 0.8 or more preferably greater than 1. This discovery
is the subject of a separate patent application filed concurrently
herewith.
As set forth above, the method of fusing a component of a sterilizable
storage or delivery device to a cyclic olefin polymeric component
of this invention utilizes this apparent problem by selecting polymers
within the range of interaction or the Hansen relative energy distance
Ra/Ro. In the preferred embodiments of this invention, the cyclic
olefin polymeric component is the major component to take advantage
of the superior property of such polymers, including transparency,
chemical resistance, etc. The second component is then formed of
a second polymer wherein the relative energy distance Ra/Ro of the
second polymer relative to the cyclic olefin polymer is equal to
or less than 0.7, or more preferably about 0.5 or less. The second
polymer may then include butyl rubber polymers, nitrile butadiene
and isoprene elastomers. The second member may be formed of the
second polymer or the second member may be formed of a composite
or laminate, wherein the interface layer is formed of the second
polymer, such as a label.
A preferred embodiment of the sterilized storage or delivery device
is a container formed of a cyclic olefin polymer, such as a medical
vial. The container is then sealed by applying a closure over the
open end of the container formed of the second polymer, wherein
the relative energy distance Ra/Ro of the second polymer relative
to the cyclic olefin polymer is less than 0.7 or more preferably
about 0.5 or less and heating the closure to the sterilization temperature,
fusing the closure to the rim portion of the container and sealing
the container. In the most preferred embodiment of a sealed container,
wherein the container is a medical vial formed of a cyclic olefin
polymer, the closure includes a portion overlying the rim portion
of the container and a tubular portion surrounding the vial rim
portion in contact with the external surface and the enclosure rim
portion is also fused to the external surface of the vial rim portion.
This embodiment assures proper orientation of the closure on the
vial prior to sterilization. The closure may have a closed end portion
for sealing a vial or utilized to secure a transfer set to a vial,
wherein the closure includes an opening through the end portion
and the radial portion is fused to a radial portion of the transfer
set, for example.
The sealed container and method of this invention thus eliminates
the problems associated with malleable metal caps, such as aluminum,
and eliminates crimping of metal or plastic closures, collars and
caps. Other advantages and meritorious features of the method of
fusing a component to a sterilized storage or delivery device and
sealed container of this invention will be more fully understood
from the following description of the preferred embodiments, the
appended claims and the drawings, a brief description of which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the steps of the method of this invention in
making a sealed container, such as a medical vial;
FIG. 2 is a side cross-sectional view of the top portion of the
sealed vial formed by the method illustrated in FIG. 1;
FIG. 3 is a partial side cross-sectional view of a label affixed
to the sealed vial;
FIG. 4 is an exploded perspective view of an alternative embodiment
of a vial and cap assembly;
FIG. 5 is a partial side cross-sectional view of the cap and vial
illustrated in FIG. 4 following fusing of the cap to the vial; and
FIG. 6 is a partial side cross-sectional view of an alternative
embodiment of the cap and vial assembly illustrated in FIG. 4 following
fusion.
DETAILED DESCRIPTION
As described above, this invention relates to a sterilized medical
transfer or storage device for delivery or storage of a medicament,
drug or vaccine, wherein a component of the device, generally the
major component, is formed of a cyclic olefin polymer and the second
component is fused to the cyclic olefin polymeric component. As
used herein, the term "cyclic olefin polymer" is intended
to broadly cover the family of cyclic olefin polymers/polymers,
including bridged cyclic olefin polymers, as disclosed, for example,
in the patents of Nippon Zeon Co., Ltd., including, for example,
U.S. Pat. No. 5,561,208 and European patent publication EP 920 989
A2. As will be understood, however, cyclic olefin polymers are available
from a variety of sources including Dow Chemical Company which makes
a polycyclohexylethylene, Ticona, a division of Celanese AG (formerly
Hoechst Technical Polymers), which makes a cycloolefin copolymer
under the tradename "Topas," and Mitsui Chemicals which
makes a cycloolefin copolymer under the tradename "Apel".
A suitable cyclic olefin polymer for the sterilizable transfer or
storage device and method of this invention is available from Nippon
Zeon Co., Ltd. under the trade name Zeonex.TM.. As set forth above,
cyclic olefin polymers have characteristics and properties which
recommend the use of such polymers for medical applications, including
excellent transparency, chemical resistance and stability at elevated
temperatures. However, such use has been inhibited by stress cracking,
particularly at elevated temperatures, and adhesion or fusion of
other polymers typically used for components of such medical devices,
including plunger stoppers conventionally formed of bromo-butyl
rubber which fuses to the inside surface of a cyclic olefin polymeric
syringe barrel. The present invention utilizes this apparent problem
to fuse a component, such as a closure or label, to the cyclic olefin
polymeric component as now described. As set forth above, the method
of fusing a second component to a sterilizable storage or delivery
device formed of a cyclic olefin polymer of this invention may be
utilized to fuse various components to medical storage or delivery
devices including, for example, labels on syringes, closures or
collars on transfer devices and caps or closures, including vials.
The invention will now be described with reference to the drawings
in regard to a sealed container, such as a medical vial, for ease
of description only.
The medical container 20 shown in the figures may be a conventional
medical vial formed of a cyclic olefin polymer. A conventional medical
vial includes a body portion 22, a reduced diameter neck portion
24 and a rim portion 26 including a planar top surface 28, an opening
30 through the rim portion and a cylindrical side surface 32. Such
vials are presently sealed by inserting an elastomeric stopper (not
shown) having a tubular portion received in the opening 30 and a
planar rim portion overlying the planar surface 28 of the rim portion.
As will be understood, however, the container 20 may be any container
formed of a cyclic olefin polymer.
The closure or cap 34 in the embodiment shown in FIGS. 1 to 3 is
a circular disc having a diameter generally equal to the diameter
of the rim portion 26. The vial may also include a label 36 discussed
further below. The cap or closure 34 is formed of a second polymer,
different from the cyclic olefin polymer, wherein the relative energy
distance Ra/Ro of the second polymer relative to the cyclic olefin
polymer is equal to or less than 0.7 or more preferably equal to
about 0.5 or less. The Hansen relative energy distance "Ra/Ro"
is discussed in detail above. The disc-shaped cap 34 is then assembled
on the planar surface 28 of the rim portion 26 prior to sterilization
as shown in the middle drawing of FIG. 1. The vial may also contain
a medicament, drug or vaccine 38 in powdered or liquid form provided
the medicament, drug or vaccine may be subject to sterilization
as illustrated in the right hand drawing of FIG. 1. Alternatively,
a medicament, drug or vaccine may be added to the sealed vial following
sterilization as discussed further below. The cap and vial assembly
is then heated, fusing the cap 34 to the rim portion 26 of the vial
as best shown in FIG. 2. Because the relative energy distance Ra/Ro
of the polymer selected for the cap 34 relative to the vial 20 formed
of a cyclic olefin polymer is equal to or less than 0.7, the polymers
will chemically interact and fuse upon heating to the sterilization
temperature of the polymers. In the preferred embodiment of the
method of this invention, the assembled components are sterilized
by autoclaving, wherein the components are heated to a temperature
of between 120 to 130.degree. C. for 30 to 60 minutes, generally
about 125.degree. C. for about 50 minutes. This assures sterilization
and fusing of the components.
Similarly, the label 36 shown in FIGS. 1 and 2 is formed of a third
polymer, which may be identical to the polymer selected for the
cap 34, wherein the relative energy distance Ra/Ro of the third
polymer relative to the cyclic olefin polymer is equal to or less
than 0.7, such that the label 36 fuses to the body portion 22 of
the vial when heated to the sterilization temperature of the polymers.
However, the label 36 may also be formed of a composite or laminate
as shown in FIG. 3, wherein the label 40 is a laminate comprising
an outer layer 42 and an inner or interface layer 44 formed of a
polymer or polymeric adhesive, wherein the relative energy distance
Ra/Ro of the interface layer 44 is equal to or less than 0.7. The
outer layer 42, for example, may be paper, foil, or any material
suitable for a label, provided the interface layer or polymeric
adhesive 44 is formed of a polymer which chemically interacts and
fuses to the body portion 22 of the vial when heated to the sterilization
temperature.
FIGS. 4 and 5 illustrate an alternative embodiment of a cap or
closure 50 including a planar end portion 52 and a tubular rim portion
54. The vial 20 may be identical to the vial shown in FIGS. 1 to
3 and described above. That is, the vial includes a rim portion
26 having a planar surface 28 surrounding the opening 30 and a cylindrical
outer surface 32. The diameter of the planar rim portion 54 of the
cap is equal to or slightly less than the diameter of the cylindrical
external surface 32 of the rim portion 26 of the vial to assure
contact between the rim portion 54 of the cap and the external cylindrical
surface 32 of the vial as best shown in FIG. 5. Again, the closure
50 is formed of a polymer different from the cyclic olefin polymer
of the container or vial 20 or a second polymer wherein the relative
energy distance Ra/Ro of the second polymer relative to the cyclic
olefin polymer is equal to or less than 0.7, such that the cup-shaped
cap 50 fuses to the vial as shown in FIG. 5. The cup-shaped cap
50 shown in FIGS. 4 and 5 has at least two advantages over the circular
disc-shaped cap 34 shown in FIGS. 1 and 2. First, the cap 50 will
remain on the vial during handling prior to and during sterilization.
Second, the rim portion 54 of the cap will fuse to the external
surface 32 of the rim portion 26 providing a more secure seal.
As set forth above, the vial 20 may be pre-filled with a medicament,
drug or vaccine prior to sterilization, provided the medicament,
drug or vaccine is able to withstand the temperature of sterilization.
It is important to note, however, that the disc-shaped cap 34 and
the planar portion 52 of the cap 50 is piercable by a conventional
hypodermic needle cannula to either add diluent, for example, to
reconstitute a powdered drug 38 or to later add a medicament, drug
or vaccine to the vial after fusing the cap on the vial. The caps
34 and 50 may also include perforations to permit removal of the
cap as is well known in this art. Alternatively, the cap may include
an integral or separate snap-off portion to provide access to the
vial as is also well known in this art. Alternatively, the cup-shaped
cap 50 may include a central opening (not shown) co-axially aligned
with the opening 30 of the vial which receives a tubular portion
of a medical transfer set, wherein the tubular portion of the transfer
set may also include a radial rim portion overlying the planar portion
28 of the vial rim. The tubular transfer member would be formed
of a cyclic polyolefin, such that the planar portion 52 of the cup-shaped
closure would be fused to the planar rim portion of the tubular
transfer member and the rim portion 54 of the collar would be fused
to the rim portion 26 of the vial. As used herein, the term "closure"
is intended to be generic to either a cap or a collar.
FIG. 6 illustrates an alternative embodiment of a cap 60 having
a generally planar end portion 62 and a cylindrical rim 64 as described
above in regard to FIG. 5. However, the cap 60 in this embodiment
includes an internal rib 66 preferably integral with the end portion
62 of the cap which is received on the top surface of the radial
rim portion 32 of the vial 20 adjacent the opening 30. The purpose
of the annular rib 66 is to limit the fusion of the cap 60 to the
vial 20, permitting removal of the cap following fusion. In the
most preferred embodiment, the annular rib 66 has a generally circular
cross-section as shown in FIG. 6 to provide essentially a point
or line contact between the rib and the rim portion 32 of the vial,
permitting removal of the cap 60 by breaking the line contact fusion.
In this embodiment, the rim portion 64 preferably has an internal
diameter greater than the external diameter of the rim portion 32
of the vial to avoid fusion of the rim portions.
As set forth above, the cap or closure 60 is formed of a polymer
different from the cyclic olefin polymer of the container or vial
20. Further, as set forth above, the relative energy distance Ra/Ro
of the polymer selected for the cap 60 relative to the cyclic olefin
polymer selected for the vial or container 20 is equal to or less
than 0.7 or more preferably between about 0.3 and 0.5. Following
heating of the assembly shown in FIG. 6 to the sterilization temperature,
the contacting surface of the rib 66 fuses to the rim portion 32
of the vial, but can be removed by lifting the rim portion 64 of
the cap or closure, breaking the line contact fusion. The same principle
may be used to secure various elements or components to a cyclic
olefin component. For example, a needle shield or sheath may be
releaseably fused to the tip portion of a syringe barrel formed
of a cyclic olefin polymer. The needle shield or sheath (not shown)
would have an annular rib extending from an inner surface of the
needle passage, such that the annular rib contacts the tip portion
of the cyclic olefin barrel of the syringe, releaseably retaining
the needle shield or sheath to the cyclic olefin barrel following
sterilization as described.
As will now be understood, various modifications may be made to
the method of fusing a component or second member to a sterilizable
storage or delivery device formed of a cyclic olefin polymer and
the sealed sterilized container and closure assembly of this invention
within the purview of the appended claims. As specifically set forth
above, the method of this invention may be utilized to fuse any
component, such as a closure, cap or label, to a storage or delivery
device formed of a cyclic olefin polymer, such as a container, vial,
transfer set, syringe, barrel or injection device, thereby eliminating
crimping, adhesive bonding or the like. The polymer selected for
the second, member or component will depend upon the application,
but may be selected from any polymer having the relative energy
distance described above. Suitable polymers for the second component
or member include isoprene elastomers, isobutylene/isoprene polymers,
nitrile butadiene, chlorobutyl rubber, butyl rubber and cis.-polybutadiene
elastomers, all having a relative energy distance Ra/Ro of such
polymers relative to cyclic olefin polymers of 0.7 or more preferably
about 0.5 or less. Having described the preferred embodiments of
the method of fusing a second component to a sterilizable storage
or delivery device formed of a cyclic olefin polymer and a sealed
sterilized container and closure assembly, the invention is now
claimed as follows.
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