BACKGROUND OF THE INVENTION
Related Application
[0001] This application is a non-provisional application of U.S. Provisional Patent Appl.
No. 60/376,149 filed April 26, 2002.
1. Field of the Invention
[0002] The subject invention relates to plastic tubes that have been prefilled with controlled
volumes and concentrations of liquid, and that are packaged to retain the liquid volume
and concentration during storage.
2. Description of the Prior Art
[0003] Many medical procedures require a specified dose of a drug to be administered to
a patient. Drugs that are administered intravenously must be in a liquid form. The
liquid must be of known volume and concentration to ensure proper dosage.
[0004] Some drugs can be stored for considerable periods of time in a liquid form. Other
drugs, however, must be stored in a powdered form, and then must be mixed with a specified
volume of a liquid additive shortly prior to administration to the patient. Efficiencies
can be achieved if the specified volume of the liquid drug and/or the specified volume
of the liquid additive is available in a prefilled tube or other such container. Prefilled
containers avoid the need for careful volummetric measuring immediately prior to administering
the drug, and hence minimize the chance for error.
[0005] Plastic tubes and other plastic containers are lightweight, relatively inexpensive
and relatively unbreakable. As a result, plastic tubes are used for medical applications
whenever possible. However, plastic tubes have an inherent permeability to water and
other liquids. This high liquid permeability of plastics can significantly affect
the volume, concentration and solubility of liquids that are stored for a long period
of time in a plastic container. Containers filled with a liquid drug or with a liquid
additive for a powdered drug desirably should have a relatively long shelf life. As
a result, plastic containers are considered unacceptable for long term storage of
liquid drugs or liquid additives for drugs.
[0006] Glass is substantially impermeable to water and other liquids. As a result, liquid
drugs or liquid additives for drugs typically are stored in glass tubes or other glass
containers. However, glass is much more breakable than plastic. A glass tube can be
broken easily while the tube is being manipulated to access the liquid stored therein.
Additionally, a small round glass tube can be dropped inadvertently and shattered
inadvertently. Sharp edges of a broken glass tube can cut a patient or health care
worker, and may create an open wound that can lead to disease transmission. Fragile
glass containers also require protective packaging that typically increases storage
space requirements and that may add to costs.
[0007] The prior art has included attempts to minimize or offset the loss of liquid from
plastic tubes. For example, one prior art attempt has bulk packaged a plurality of
plastic tubes in a plastic tub. A moisture source also has been placed in the tub
to provide a higher vapor content surrounding the bulk packaged tubes, and thereby
to impede the outflow of liquid from the tubes. This prior art bulk packaging complicates
the packaging process and adds to cost and storage space requirements. Furthermore,
vapor from the moisture source is transported through the permeable walls of the plastic
tub.
[0008] The prior art also includes tubes that are laminated with foil to prevent liquid
loss. Foil lamination of tubes adds significantly to the tube manufacturing complexity
and adds to tube manufacturing cost.
3. Summary Of The Invention
[0009] The subject invention is directed to a plastic container in which a liquid drug or
a liquid additive solution for a drug has been placed. The plastic container may be
formed from a known plastic material, such as polyethylene terephthalate (PET), polypropylene
or other plastic material that exhibits liquid permeability. The container may be
a tube of prior art construction, and may include a closed bottom, an open top and
a continuous side wall extending therebetween. A closure may be securely mounted to
the container for closing the open top, and thereby preventing spillage of the liquid
drug or the liquid additive stored in the container.
[0010] The subject invention further includes packaging formed from a high moisture barrier
material that completely surrounds the container or that completely surrounds a plurality
of such containers. The high moisture barrier material may be a film formed from a
foil lamination, a metalized polyester, SiOx coated polyesters, polyester-polyoefilins,
PVDC or the like. This high moisture barrier material may be a sheet folded around
one or more plastic containers of a liquid drug or liquid additive. Edge regions of
the sheet then may be sealed in face-to-face engagement with other areas on the sheet.
Alternatively a container may be placed between two sheets of high moisture barrier
material, and edge regions of the sheets may be sealed. The high moisture barrier
packaging material can impede the rate of water vapor transport across the plastic
material from which the container is formed by providing and maintaining a high relative
humidity environment around the container and inside the package. This enables the
volume, concentration and solubility of the liquid in the container to be controlled,
and enables a longer shelf life for the liquid therein.
4. Brief Description of The Drawings
[0011] FIG. 1 is a top plan view of a liquid-containing plastic tube packaged in accordance
with the subject invention.
[0012] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1.
[0013] FIG.. 3 is a cross-sectional view similar to FIG. 2, but showing an alternate package.
5. Detailed Description Of The Preferred Embodiment
[0014] A package in accordance with the subject invention is identified generally by the
numeral
10 in FIGS. 1 and 2. Package
10 contains a tube
12 formed from a plastic material, such as polyethylene terephthalate (PET) or polypropylene.
Tube
12 includes a closed bottom
14, an open top
16, and a cylindrical side wall
18 extending therebetween. A liquid
20 is disposed in tube
12 as shown in FIG. 2. Liquid
20 may be a liquid additive of a specified volume, concentration and solubility that
is intended for mixing with a non-liquid drug and for subsequent administration to
a patient. Alternatively, liquid
20 may be a liquid drug.
[0015] Liquid
20 is sealingly retained in tube
12 by a closure
22. Closure
22 comprises a thermoplastic elastomer or a thermoset resin material that is sufficiently
deformable and resilient for secure sealing engagement with side wall
18 of tube
12. Closure
22 may further include a more rigid plastic structure to which the thermoplastic elastomer
or thermoset resin is secured to enable closure
22 to be placed in and removed from tube
12 with ease.
[0016] The plastic material of tube
12 is inherently permeable to water. Water vapor permeation through the plastic of tube
12 has the potential for affecting the volume, concentration or solubility of liquid
additive
20 stored in tube
12. To substantially minimize vapor transport through the plastic of tube
12, package
10 comprises a high moisture barrier film
26 that completely and relatively closely surrounds tube
12. Film
26 may be a foil lamination comprising a substrate formed from a metallic foil, such
as aluminum, and at least one layer formed from a plastic material that is readily
sealable. The foil lamination may include an outer layer that is well suited to printing
indicia to identify the specific liquid additive in tube
12. Film
26 alternatively may be a metalized polyester, a SiOx coated polyester, a polyester-polyoefilin
or PVDC, all of which are substantially impermeable to water, particularly in comparison
to the PET or polypropylene from which tube
12 is formed.
[0017] Film
26 of package
10 may define an envelope formed from a single sheet that is folded at fold region
28 to closely surround tube
12. Adjacent registered edges
30 may be bonded in face-to-face relationship as shown in FIG. 2. Alternatively, package
10 may be formed from two separate sheets of film
26a and
26b as shown in FIG. 3. Sheets
26a and
26b may originally be in strip form. Tube
12 with liquid
20 therein may be placed on a lower sheet of film
26a, which may be part of a strip moving longitudinally along a conveying apparatus.
Upper sheet of film
26b may be part of a second strip that is fed into juxtaposed relationship to the strip
defining lower sheet of film
26a. The lower and upper sheets
26a and
26b may be sealed along opposed side edges
30a, and may subsequently be sealed and cut between adjacent tubes to form seals
32. In this embodiment, the lower and upper sheets of film
26a and
26b may be formed from different materials. For example, a lower sheet of film
26a may be a foil lamination having an only upper layer of a plastic material that will
bond well with a lower plastic layer on upper sheet
26b. Upper sheet
26b, however, may also include an upper laminated layer that is well suited to receiving
printed indicia.
1. Packaging for liquids of specified volume, concentration and solubility, said packaging
comprising:
at least one plastic container (12) having a closed bottom (14), an open top (16)
and a side wall (18) extending therebetween, said liquid (20) of said specified volume,
concentration and solubility being placed in said container (12), a closure (22) sealingly
engaged with said open top of said container for retaining said liquid (20) therein,
a moisture barrier film (26) completely surrounding said container (12) for preventing
vapor transport across said film (26) and maintaining a selected relative humidity
between said container (12) and said film (26) for substantially preventing permeation
of said liquid (20) from said container (12).
2. The packaging of Claim 1, wherein said container (12) is formed from polyethylene
terephthalate or polypropylene.
3. The packaging of Claims 1 or 2, wherein said film (26) is selected from the group
consisting of foil laminations, metalized polyesters, SiOx coated polyesters, polyester-polyoefilins
and PVDC.
4. The packaging of any of Claims 1-3, comprising a single sheet of said film (26) folded
around said container (12), registered edges of said sheet being secured to one another.
5. The packaging of any of Claims 1-3, comprising first and second sheets of said film
(26) having registered edges secured in face-to-face relationship with one another
entirely around said container (12).
6. A method for packaging liquids (20) to maintain a specified volume, concentration
and solubility, said method comprising:
providing a plastic container (12) having a closed bottom (14), an open top (16) and
a side wall (18) extending therebetween;
depositing in said plastic container (12) said liquid (20) of said specified volume,
concentration and solubility;
sealingly enganging a closure (22) with said open top (16) of said container (16)
for retaining said liquid (20) therein;
providing a moisture barrier film (26) completely around said plastic container (12)
and said closure (22) for preventing vapor transport across said film (26) and maintaining
a selected relative humidity between said container (12) and said film (26) for substantially
preventing permeation of said liquid (20) from said container (12).
7. The method of Claim 6, wherein said step of providing a container (12) comprises providing
a container (12) formed from polyethylene terephthalate or polypropyelene.
8. The method of Claims 6 or 7, wherein said step of providing a moisture barrier film
(26) comprises providing a moisture barrier film (26) selected from the group consisting
of foil laminations, metalized polyesters, SiOx coated polyesters, polyester-polyoefilins
and PVDC.
9. The method of any of Claims 6-8, wherein said step of completely surrounding said
container (12) with a moisture barrier film (26) comprises folding a single sheet
of said film (26) around said container (12) such that edges of said single sheet
are substantially registered with one another and securing opposed faces of said sheet
to one another adjacent said registered edges.
10. The method of any of Claims 6-10, wherein said step of completely surrounding said
container (12) with the moisture barrier film (26) comprises placing said container
between first and second sheets of said moisture barrier film (26) and securing opposed
faces of said first and second sheets to one another.
11. The method of any of Claims 6-10, wherein said step of sealingly engaging a closure
(22) with said open top (16) of said container (12) comprises providing a closure
(22) formed from a thermoplastic elastomer or a thermoset resin and urging said closure
(22) into said open top of said container (12) such that said closure (26) sealingly
engages said side wall (18) of said container (12) adjacent said open top (16).