Technical Field
[0001] This invention relates to hermetically sealed, filled thermoplastic containers from
which the container contents can be withdrawn with a syringe.
Background of the Invention
[0002] Filled and hermetically sealed containers of a thermoplastic material, usually a
polyolefin, are well known in the art. Such containers can be readily made utilizing
a form-fill-seal technique by means of which a container is molded, filled, and sealed
in a single continuous operation. This technique is described and illustrated in U.S.
Patent No. 4,671,763 to Weiler.
[0003] One application of the form-fill-seal technique is in the production of unit dose
containers such as ampoules and vials the contents of which can be withdrawn for use
by means of a syringe. One such ampoule is illustrated in Figure 8 of the aforementioned
U.S. Patent No. 4,671,763 to Weiler. Another type of unit dose vial is shown in U.S.
Patent No. 4,643,309 to Evers.
[0004] While a syringe can be used in conjunction with both of the foregoing types of containers,
each type exhibits certain shortcomings. In particular, the ampoule shown in U.S.
Patent No. 4,671,763 to Weiler usually requires a substantial container wall thickness
for engagement with a syringe tip. This is not always practical. The unit dose container
shown in U.S. Patent No. 4,643,309 to Evers, on the other hand, requires closely controlled
conicity of a relatively long neck portion for suitable seating of the conical tip
of a syringe substantially in its entirety. Such requirements undesirably contribute
to the overall cost of the container.
[0005] It has now been found, however, that the shortcomings of both of the aforementioned
container designs can be obviated, or at least mitigated to a relatively large extent,
by providing instead a press-fit receptacle in the container neck portion for receiving
but a distal portion of the syringe tip. The present design provides the further advantage
that once the syringe tip has been received in a press-fit relationship into the container
neck portion, the resulting syringe-container assembly is not likely to separate from
one another prematurely even with relatively rough interim handling.
Summary of the Invention
[0006] The present invention is directed to a filled, hermetically sealed thermoplastic
container suitable as a unit dose container for medication that is to be administered
by a syringe.
[0007] A container embodying this invention can be readily made by the well-known form-fill-seal
technique and includes a hollow body portion that is closed at one end and terminates
at the other end in an elongated neck portion provided with a press-fit receptacle
for a syringe tip. The receptacle includes a circumferential shoulder against which
the inserted syringe tip abuts when the container contents is to be withdrawn by the
syringe.
[0008] The neck portion is also provided with a closure that is unitary therewith. This
closure is joined to the neck portion by a frangible web situated in a groove about
the neck portion.
[0009] Other features of the present containers will be apparent from the accompanying detailed
description and the drawing.
Brief Description of the Drawing
[0010] In the drawing,
FIGURE 1 is a side elevational view, partly broken away to show interior detail, of
an ampoule disclosed in commonly-owned U.S. Patent No. 4,671,763;
FIGURE 2 is a side elevational view, also partly broken away to show interior detail,
of an ampoule embodying the present invention;
FIGURE 3 is a side elevational view of a thermoplastic unit dose container embodying
the present invention and provided with a tab for facilitating closure removal so
as to expose an internal press-fit receptacle for a syringe tip; and
FIGURE 4 is an enlarged fragmentary sectional view of the neck region of a container
embodying the present invention during the molding of that region.
Description of Preferred Embodiments
[0011] While this invention is susceptible of embodiment in different forms, two such forms
are described in detail hereinbelow as specific embodiments. The precise shapes and
sizes of the described containers are not essential to the invention unless expressly
so indicated.
[0012] Containers embodying the present invention can be manufactured and filled with a
desired contents utilizing the form-fill-seal technique described in detail in U.S.
Patent No. 4,671,763 to Weiler, which patent is commonly owned. The disclosure of
said U.S. Patent No. 4,671,763 is incorporated herein by reference to the extent pertinent.
[0013] In general, the manufacture includes the extrusion of a thermoplastic material such
as a polyolefin, e.g., low density polyethylene, high density polyethylene, polypropylene,
or the like, as a length or segment of a parison in the form of a vertically oriented,
elongated, hollow, semi-soft tube between a pair of main mold halves. The container
body is initially formed from this parison with an open top. Means are provided for
maintaining the opening at the top of the parison segment in the portion of the parison
extending upwardly above the main mold means.
[0014] An extendable and retractable blowing assembly with a sealing/forming mandrel and
blowing/filling nozzle is positioned into the length of parison in the main mold halves
to temporarily seal the opening. A gas is injected into the parison to mold the container
body, with or without vacuum assist, in the mold cavity defined by the main mold halves.
The resulting molded container body is then filled with the desired liquid contents
and subsequently sealed.
[0015] The main mold halves, along with the cooperating sealing mandrel on the blowing assembly,
define a structure for molding the frangible web structure as well as a press-fit
receptacle for a syringe tip.
[0016] Sealing mold halves, located above the main mold halves, are subsequently closed
to pinch the parison and seal the formed and filled container.
[0017] Each of the main mold parts is provided with a protuberance of substantially cuneiform,
i.e., wedge-shaped, cross-section that extends into the mold cavity to form a continuous
circumferential ridge with a peak. A portion of the semi-soft thermoplastic material
is pressed against the ridge to form a peripheral frangible web having a controlled
thickness less than the container wall thickness while providing an effective seal
within the main mold to permit the shaping of the container body portion by pressurization
from within. The semi-soft material that constitutes the extruded parison segment
is caused to flow across the peak of the circumferential ridge during the pressing.
The containers embodying the present invention include a seamless, smooth peripheral
band inside the neck portion of the container that is unitary with the frangible web
and defines the inside surface thereof. This smooth peripheral band terminates in
a circumferential shoulder and together with this shoulder defines a press-fit receptacle
for the syringe tip.
[0018] Thus, the apparatus for making the present container includes (1) main mold means
defining a mold cavity for initially forming from an extruded length of a parison
the container body with an open top, (2) means for maintaining an opening at the top
portion of the parison that extends upwardly from the main mold means, (3) an extendable
and retractable temporary sealing/forming assembly that includes means for temporarily
sealing the top opening and for forming a peripheral frangible web and the press-fit
receptacle in the container neck portion below the top opening (i.e., in the sealed
portion of the formed container) in cooperation with the main mold means, and (4)
sealing mold means operable upon the upwardly extending portion of the parison above
the formed frangible web for permanently sealing the top of the formed container after
the temporary sealing assembly is retracted.
[0019] The ampoule described in the aforementioned U.S. Patent No. 4,671,763 is shown in
FIGURE 1. Ampoule 10 has a body portion 12, bottom portion 14, tip 16, and a reduced
diameter neck portion 18 that joins tip 16 to body portion 12. Neck portion 18 and
tip 16 are joined to one another by unitary frangible web 20 situated therebetween.
[0020] In contradistinction, an ampoule embodying the present invention is shown in FIGURE
2. Specifically, ampoule 30 is provided with neck portion 38, which, while unitary
with hollow container body 32, includes an upstanding boss 42 that defines an elastically
deformable receptacle 44 for receiving therewithin a portion of a syringe tip, and
a downwardly extending skirt portion 39 from boss 42 that connects to body portion
32. Receptacle 44 includes a seamless band or inside wall 46 and inwardly extending
circumferential shoulder 48 against which a syringe tip usually abuts when in a press-fit
relationship with seamless band 46.
[0021] Tip 36 provides a unitary closure for neck portion 38 and thus container body 32
filled with a desired liquid contents 50. Container bottom 34 is a substantially flat
surface that can support the ampoule 30 in an upright position after it has been opened
by breaking off tip 36.
[0022] A unitary but severable juncture of tip 36 to container neck portion 38 is provided
by frangible web 40 between tip 36 and hollow boss 42 in neck portion 38.
[0023] Frangible web 40 is situated in external circumferential groove 52 provided about
container neck portion 38. When tip 36 is to be severed from the rest of the unitary
container or ampoule 30 so as to gain access to the liquid contents 50 thereof, tip
36 is twisted or bent to one side whereupon tip 36 parts from neck portion 38, and
from boss 42 in particular. Preferably, frangible web 40 and associated groove 52
that circumscribes neck portion 38 are situated so that any burrs or rough remnants
of web 40 after severance do not interfere with the receipt of a syringe tip into
receptacle 44 in a press-fit engagement therewith.
[0024] As mentioned hereinabove, a portion of a syringe tip is received in receptacle 44
and abuts shoulder 48. Thus, sufficient axial force can be applied while urging the
syringe tip into a press-fit relationship with receptacle 44 without concern that
the syringe tip may be inadvertently pushed through the container neck portion and
into the container body portion. Also, in this manner a liquid pooling region 54 is
provided in container neck portion 38 to maximize the amount of liquid that can be
withdrawn from ampoule 30 while a syringe tip is inserted into receptacle 44 and the
ampoule inverted.
[0025] Receptacle 44 is sized so as to receive at least the distal end of the nozzle of
a contents-withdrawing implement, e.g., a syringe tip, in a press-fit (or interference-fit)
relationship. That is, the inside diameter of receptacle 44 is such that band 46 of
boss 42 is elastically distorted and applies pressure on the nozzle tip received therewithin
which pressure is sufficient to hold together the nozzle tip and container neck 38
while container contents 50 is withdrawn. Stated in another way, the minimum permissible
difference between the dimensions of the male nozzle part and the female receptacle
part, i.e., the allowance, has a negative value so that the elasticity of the container
material can be utilized to grasp and hold the inserted portion of the syringe tip.
[0026] The depth-to-width ratio of receptacle 44, when exposed, can vary, but preferably
is no more than about 1, more preferably in the range of about 0.6 to about 0.8. The
receptacle inside diameter along the longitudinal axis of receptacle 44 is substantially
the same, there being but a small taper toward the container body portion as needed
for the convenient withdrawal of the mandrel-carrying nozzle after the receptacle
has been molded during container manufacture.
[0027] Another unit dose container embodying the present invention is shown in FIGURE 3
where vial 60 is provided with neck portion 68 equipped with an internal syringe tip
receptacle in elastic boss 72 of neck portion 68. The configuration and dimensions
of the receptacle defined within neck portion 68 are substantially the same as those
shown in FIGURE 2.
[0028] Vial 60 includes hollow body portion 62 closed at bottom end 64 and opening into
the neck portion 68 that includes the aforementioned boss 72 and the therein defined
elastically deformable receptacle. Unitary, oblate bottom tab 65 extends longitudinally
from bottom end 64 and is suitable for inscription of lot indicia 67, expiration dates,
or like purposes. Bottom tab 65 also facilitates the handling of container 60 in instances
where the unit dose contained therein is relatively small and the vial itself is sized
commensurately.
[0029] Container closure for vial 60 is provided by cap 66 unitary with neck portion 68
and joined thereto by unitary frangible web 70 in groove 82. To facilitate the removal
of cap 66 from neck portion 68, grip tab 68 is provided unitary with cap 66.
[0030] The molding of the nozzle or syringe tip receiving receptacle in containers embodying
the present invention is illustrated in FIGURE 4 which shows a container neck portion
98 with boss 102 and skirt 105 within main mold parts 120 and 122 that surround parison
segment 124. Receptacle 144 is molded into the inside wall portion of boss 102 by
sealing/forming mandrel 126 of blowing/filling nozzle 128. Continuous circumferential
protuberance 125 having a wedge-shaped cross-section is machined into main mold parts
120 and 122 and forms groove 112, as well as the unitary frangible web 140 associated
therewith, in cooperation with mandrel 126. The lowermost portion of mandrel 126 is
provided with beveled edge 127 that molds shoulder 148. Thus, receptacle 144 in boss
102 of neck portion 98 is defined by inner wall portion 143 and continuous circumferential
shoulder 148. Liquid pooling region 154 contiguous to shoulder 148 aids in gathering
the liquid contents to be withdrawn from the container.
[0031] The downwardly sweeping motion of mandrel 126 as it forms shoulder 148 occasionally
causes a berm of thermoplastic material to build up in the container neck portion
near the juncture of the hollow boss 102 with the skirt portion 105 that connects
to the container body portion, except at the mold parting line. Thus, even in the
event of such a berm build-up, two opposed drain channels at the mold parting lines
result and cause liquid to collect within the aforedescribed pooling region for withdrawal
from the container.
[0032] Collar 129 on mandrel 126 is provided with annular sealing surface 131 that is situated
at an angle of about 15 degrees to a plane normal to the longitudinal axis of mandrel
128. The upper bearing surface of circumferential protuberance 125 preferably is substantially
parallel to annular sealing surface 130, thus the angle theta (ϑ) in FIGURE 4 preferably
is also about 15 degrees.
[0033] For a typical unit dose container made of low density polyethylene and embodying
the present invention the frangible web such as web 140 preferably has a thickness
of about 0.005 inch to about 0.01 inch (about 0.13 mm to about 0.25 mm), and the thickness
of the receptacle wall preferably is about 0.025 inch to about 0.03 inch (about 0.6
mm to about 0.8 mm) to provide elasticity and resilience.
[0034] The container is blow molded, with or without vacuum assist, after the sealing surface
131 is seated as shown in FIGURE 4, and thereafter filled with a liquid contents.
The filled container is sealed, after blowing/filling nozzle 128 has been withdrawn,
by conventional sealing molds (not shown) that come together above main mold parts
120 and 122 and crimp closed the upper end of parison segment 124. The contour of
the opposed mold cavities in the sealing molds determines the shape of the upper portion
of the unitary closure for the container.
[0035] The foregoing detailed description is intended to be illustrative of the present
invention, and is not to be taken as limiting. Still other variants within the spirit
and scope of this invention will readily present themselves to those skilled in the
art.