U.S. patent application number 17/519627 was filed with the patent office on 2022-02-24 for mixing syringe assembly.
The applicant listed for this patent is CONSORT MEDICAL PLC. Invention is credited to Ian Anderson, Matt Ekman, Robert Glover, Rachel Koppelman.
Application Number | 20220054762 17/519627 |
Document ID | / |
Family ID | 1000005954836 |
Filed Date | 2022-02-24 |
United States Patent
Application |
20220054762 |
Kind Code |
A1 |
Anderson; Ian ; et
al. |
February 24, 2022 |
MIXING SYRINGE ASSEMBLY
Abstract
A syringe assembly comprising a barrel for containing one or
more medicaments, the barrel having a front outlet for allowing the
expulsion of said one or more medicaments from the said barrel
through said outlet, and a first stopper disposed in the barrel and
axially moveable therein and defining a first volume in the barrel
axially forwards of the first stopper and a second volume in the
barrel axially rearwards of the first stopper. The first stopper
has a two way valve that is moveable between a sealing
configuration and an open configuration to selectively put the
first volume in fluid communication with the second volume. The two
way valve is moveable from the sealing configuration to the open
configuration by an increase in fluid pressure in either of the
first and second volumes. The syringe assembly additionally
comprises a second stopper disposed in the barrel axially rearward
of the first stopper and axially moveable therein, the second
stopper providing a fluid tight seal at a rear end of the second
volume. The syringe assembly further comprises a first plunger rod
connected to the first stopper and extending axially rearwardly
through the second stopper, the second stopper sealingly engaging
with the first plunger rod but permitting axial sliding of the
first plunger rod therethrough. The first plunger rod is axially
moveable so as to axially move the first stopper and pressurise
either of the first volume and second volume causing the two way
valve to move into the open configuration and fluidly connect the
first volume and second volume.
Inventors: |
Anderson; Ian; (Newmarket,
GB) ; Ekman; Matt; (Macclesfield, GB) ;
Glover; Robert; (Sheffield, GB) ; Koppelman;
Rachel; (Cambridge, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CONSORT MEDICAL PLC |
Hemel Hempstead |
|
GB |
|
|
Family ID: |
1000005954836 |
Appl. No.: |
17/519627 |
Filed: |
November 5, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14777885 |
Sep 17, 2015 |
11185637 |
|
|
PCT/GB2014/050965 |
Mar 26, 2014 |
|
|
|
17519627 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 5/31596 20130101;
A61M 5/3137 20130101; A61M 5/31505 20130101 |
International
Class: |
A61M 5/315 20060101
A61M005/315; A61M 5/31 20060101 A61M005/31 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2013 |
GB |
1305489.5 |
Claims
1. A syringe assembly comprising: a barrel for containing one or
more medicaments, the barrel having a front outlet for allowing the
expulsion of said one or more medicaments from said barrel through
said outlet; a first stopper disposed in the barrel and axially
moveable therein, the first stopper having a two way valve that is
moveable between a sealing configuration and an open configuration;
a second stopper disposed in the barrel axially rearward of the
first stopper and axially moveable therein, the second stopper
providing a fluid tight seal to the barrel; and a first plunger rod
connected to the first stopper and extending axially rearwardly
through the second stopper, the second stopper sealingly engaging
with the first plunger rod but permitting axial sliding of the
first plunger rod therethrough; wherein the first plunger rod is
axially moveable in the barrel so as to axially move the first
stopper from an initial position to a subsequent position, wherein
in the subsequent position a first volume is defined in the barrel
axially forwards of the first stopper and a second volume is
defined in the barrel axially rearwards of the first stopper, and
in the initial position either of the first volume or second volume
is a substantially zero volume, wherein axial movement of the first
stopper in the barrel pressurises either of the first volume and
second volume causing the two way valve to move into the open
configuration and fluidly connect the first volume and the second
volume.
2. A syringe assembly according to claim 1, further comprising a
removeable transit clip that is configured to prevent axial
movement of the first plunger rod.
3. A syringe assembly according to claim 1, wherein the first
plunger rod includes one or more finger loops for facilitating
handling of the first plunger rod.
4. A syringe assembly according to claim 1, further comprising a
second plunger rod connected to the second stopper, wherein axial
movement of the second plunger rod causes axial movement of the
second stopper.
5. A syringe assembly according to claim 4, further comprising an
engagement mechanism for engaging the first plunger rod with the
second plunger rod in a predetermined position of the first plunger
rod relative to the second plunger rod.
6. A syringe assembly according to claim 5, wherein the engagement
mechanism includes engagement members connected to the first
plunger rod, the engagement members being arranged to engage with
the second plunger rod when the first plunger rod is at a
predetermined axial position and/or rotational position relative to
the second plunger rod.
7. A syringe assembly according to claim 6, wherein said engagement
members project radially inwardly from a sleeve connected to the
first plunger rod and surrounding the second plunger rod.
8. A syringe assembly according to claim 6, wherein said engagement
members are arranged to engage with a rear end of the second
plunger rod by abutting said rear end of said second plunger
rod.
9. A syringe assembly according to claim 4, further comprising a
locking mechanism for limiting axial movement of the second plunger
rod.
10. A syringe assembly according to claim 9, wherein axial movement
of the second plunger rod is permitted when the second plunger rod
is in a predetermined rotational position.
11. A syringe assembly according to claim 10, wherein the locking
mechanism comprises a collar and axial movement of the second
plunger rod is permitted when the second plunger rod is in a
predetermined rotational position relative to the collar and axial
abutment between the collar and the second plunger rod prevent
relative axial movement in rotational positions other than the
predetermined rotational position.
12. A syringe assembly according to claim 1, wherein the two way
valve comprises a resilient seal that deforms under a predetermined
fluid pressure.
13. A syringe assembly according to claim 12, wherein the resilient
seal includes a plurality of flexible flaps.
14. A syringe assembly according to claim 12, wherein the resilient
seal extends along an arc around the first stopper, wherein the
angular extent of the arc is less than 360.degree..
15. A syringe assembly according to claim 12, wherein the first
stopper includes the resilient seal and further includes a
permanent seal about an outer circumference of the first stopper
that is axially spaced from the resilient seal, and a by-pass
channel providing a fluidic passageway from between the resilient
seal and the permanent seal around the permanent seal.
16. A syringe assembly according to claim 1, wherein the fluid
tight seal provided by the second stopper is a sterile seal.
17. A syringe assembly according to claim 1, wherein the fluid
tight seal provided by the second stopper is a microbiological
seal.
18. A syringe assembly according to claim 1, further comprising a
medicament, wherein when the first stopper is in the initial
position the medicament is contained only in the one of the first
volume and the second volume that is not the substantially zero
volume.
19. A method of using a syringe assembly that comprises: a barrel
for containing one or more medicaments, the barrel having a front
outlet for allowing the expulsion of said one or more medicaments
from said barrel through said outlet; a first stopper disposed in
the barrel and axially moveable therein, the first stopper having a
two way valve that is moveable between a sealing configuration and
an open configuration; a second stopper disposed in the barrel
axially rearward of the first stopper and axially moveable therein,
the second stopper providing a fluid tight seal to the barrel; and
a first plunger rod connected to the first stopper and extending
axially rearwardly through the second stopper, the second stopper
sealingly engaging with the first plunger rod but permitting axial
sliding of the first plunger rod therethrough; the method
comprising axially moving the first plunger rod in the barrel so as
to axially move the first stopper from an initial position to a
subsequent position, wherein in the subsequent position a first
volume is defined in the barrel axially forwards of the first
stopper and a second volume is defined in the barrel axially
rearwards of the first stopper, and in the initial position either
of the first volume or second volume is a substantially zero volume
and the other of the first volume and the second volume contains
the one or more medicaments, wherein axial movement of the first
stopper in the barrel pressurises either of the first volume and
second volume causing the two way valve to move into the open
configuration and fluidly connect the first volume and the second
volume.
Description
CROSS-REFERENCE TO RELATED DISCLOSURES
[0001] This application is a continuation of U.S. application Ser.
No. 14/777,885, which was filed on Sep. 17, 2015 and which is a
U.S. national stage application under 35 U.S.C. .sctn. 371 of PCT
International Application Serial No. PCT/GB2014/050965, which has
an international filing date of Mar. 26, 2014, designates the
United States of America, and claims the benefit of GB Application
No. 1305489.5, which was filed on Mar. 26, 2013. The disclosures of
each of these prior applications are hereby expressly incorporated
by reference in their entirety.
FIELD OF THE DISCLOSURE
[0002] This invention relates to a syringe assembly, and more
particularly, to a valved mixing syringe assembly suitable for
mixing two or more medicaments prior to delivery.
BACKGROUND
[0003] It is known to provide a syringe having two or more chambers
containing different medicaments that are separated within the
syringe. Such devices may be used to mix the two or more
medicaments shortly before delivery which may be necessary if the
two or more medicaments are unstable over longer periods of time
when in a mixed state (e.g. in storage). Mixing syringes often
include a mechanism for putting the two or more medicament chambers
in fluid communication with one another at a desired time.
[0004] An example of a two-chamber injector is described in
WO-A-97/09839 (STI International Limited). The injector includes
two chambers that are separated by a flexible wall member. A
forward one of the chambers contains a dry ingredient and a
rearward one of the chambers contains a liquid ingredient. The
flexible wall member is shaped such that, when it is moved axially
rearwardly within the device, its movement through the liquid in
the rear chamber causes the flexible wall member to flex slightly.
This flexion allows the liquid ingredient to bypass or escape
around the exterior periphery of the flexible wall member and into
the forward chamber containing the dry ingredient.
[0005] In at least one embodiment, it is an object of the present
invention to provide an alternative syringe assembly that permits
the mixing of two or more ingredients, where, preferably, at least
one of the ingredients is of a viscous nature.
BRIEF SUMMARY OF THE DISCLOSURE
[0006] In accordance with a first aspect of the present invention
there is provided a syringe assembly comprising:
[0007] a barrel for containing one or more medicaments, the barrel
having a front outlet for allowing the expulsion of said one or
more medicaments from the said barrel through said outlet;
[0008] a first stopper disposed in the barrel and axially moveable
therein and defining a first volume in the barrel axially forwards
of the first stopper and a second volume in the barrel axially
rearwards of the first stopper, the first stopper having a two way
valve that is moveable between a sealing configuration and an open
configuration to selectively put the first volume in fluid
communication with the second volume, the two way valve being
moveable from the sealing configuration to the open configuration
by an increase in fluid pressure in either of the first and second
volumes;
[0009] a second stopper disposed in the barrel axially rearward of
the first stopper and axially moveable therein, the second stopper
providing a fluid tight seal at a rear end of the second volume;
and
[0010] a first plunger rod connected to the first stopper and
extending axially rearwardly through the second stopper, the second
stopper sealingly engaging with the first plunger rod but
permitting axial sliding of the first plunger rod therethrough;
[0011] wherein the first plunger rod is axially moveable so as to
axially move the first stopper and pressurise either of the first
volume and second volume causing the two way valve to move into the
open configuration and fluidly connect the first volume and second
volume.
[0012] The syringe assembly of the first aspect of the present
invention allows fluid communication between the first and second
chambers in response to an increase in pressure in either of the
first and second chambers. The two way valve is normally in a
sealing (closed) configuration when no or insufficient pressure
forces are acting on it. Upon an increase in fluid pressure in
either of the first and second volumes, the two way valve is
moveable from the sealing configuration to the open configuration.
In practice, this means that the first stopper may be moved axially
forwardly and axially rearwardly in succession, by axial
translation of the first plunger rod, in order to open the two way
valve and effectively mix medicaments initially stored in the first
and second volumes. This arrangement is particularly suitable for
the efficient and effective mixing of two medicaments where one or
both of the two medicaments is/are particularly viscous. Known
prior art arrangements do not permit fluid communication between
two adjacent chambers in response to an increase in pressure in
either chamber. As a result, known prior art arrangements do not
permit the successive forward and rearward movement of the stopper
to facilitate effective mixing of ingredients contained in the two
chambers.
[0013] In one preferable embodiment, the syringe assembly further
comprises a removeable transit clip that is configured to prevent
axial movement of the first plunger rod.
[0014] The first plunger rod may include one or more finger loops
for facilitating handling of the first plunger rod.
[0015] The syringe assembly may further comprise a second plunger
rod connected to the second stopper, wherein axial movement of the
second plunger rod causes axial movement of the second stopper.
Optionally, the syringe assembly further comprises an engagement
mechanism for engaging the first plunger rod with the second
plunger rod in a predetermined position of the first plunger rod
relative to the second plunger rod. The engagement mechanism may
include engagement members connected to the first plunger rod, the
engagement members being arranged to engage with the second plunger
rod when the first plunger rod is at a predetermined axial position
and/or rotational position relative to the second plunger rod. The
engagement members may project radially inwardly from a sleeve
connected to the first plunger rod and surrounding the second
plunger rod. The engagement members may be arranged to engage with
a rear end of the second plunger rod by abutting said rear end of
said second plunger rod.
[0016] The syringe assembly may further comprise a locking
mechanism for limiting axial movement of the second plunger rod.
Axial movement of the second plunger rod may only be permitted when
the second plunger rod is in a predetermined rotational position.
The locking mechanism may comprise a collar and axial movement of
the second plunger rod is permitted when the second plunger rod is
in a predetermined rotational position relative to the collar and
axial abutment between the collar and the second plunger rod
prevent relative axial movement in rotational positions other than
the predetermined rotational position.
[0017] The two way valve may comprise a resilient seal that deforms
under a predetermined fluid pressure, wherein the resilient seal
may include a plurality of flexible flaps. The resilient seal may
extend along an arc around the first stopper, wherein the angular
extent of the arc is less than 360.degree..
[0018] The first stopper may include the resilient seal and further
include a permanent seal about an outer circumference of the first
stopper that is axially spaced from the resilient seal, and a
by-pass channel providing a fluidic passageway from between the
resilient seal and the permanent seal around the permanent
seal.
[0019] The fluid tight seal provided by the second stopper may be a
sterile seal and/or a microbiological seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Embodiments of the invention are further described
hereinafter with reference to the accompanying drawings, in
which:
[0021] FIGS. 1A to 1D are cross sectional views of a syringe
assembly in accordance with an embodiment of the present invention,
where FIG. 1A shows the syringe assembly prior to use, FIGS. 1B and
1C show the syringe assembly during mixing, and FIG. 1D shows the
syringe assembly during delivery;
[0022] FIGS. 2A to 2E are cross sectional views of a syringe
assembly in accordance with an alternative embodiment of the
present invention, where FIG. 2A shows the syringe assembly prior
to use, FIGS. 2B and 2C show the syringe assembly during mixing,
FIG. 2D shows the syringe assembly after mixing and prior to
delivery, and FIG. 2E shows the syringe assembly during
delivery;
[0023] FIG. 3 shows a rear end view of the syringe assembly shown
in FIG. 2A;
[0024] FIG. 4 shows a rear end view of the syringe assembly shown
in FIG. 2D;
[0025] FIG. 5 shows a cross sectional view of a mechanism for
limiting axial movement of the second plunger rod in accordance
with an embodiment of the present invention;
[0026] FIG. 6 shows a detailed cross sectional view of the
mechanism of FIG. 5 taken along section C-C of FIG. 5;
[0027] FIG. 7 shows a detailed view of the first stopper of the
syringe assemblies of FIGS. 1A to 1D and FIGS. 2A to 2E;
[0028] FIG. 8 shows an example of an alternative first stopper for
use with a syringe assembly in accordance with an embodiment of the
present invention;
[0029] FIG. 9 shows an alternative view of a first stopper in
accordance with an embodiment of the present invention; and
[0030] FIG. 10 shows a detailed cross sectional view of the first
stopper of FIG. 9 taken along section D-D in FIG. 9.
DETAILED DESCRIPTION
[0031] FIGS. 1A to 1D are cross sectional views of a syringe
assembly 10 in accordance with an embodiment of the present
invention. FIG. 1A shows the syringe assembly 10 prior to use. The
syringe assembly 10 includes a barrel 12 for containing medicaments
and has a front outlet 12a for allowing the expulsion of
medicament. In the embodiment shown in FIGS. 1A to 1D, the front
outlet 12a is provided with a needle 13 for penetrating an
injection site and delivering medicament from the barrel 12
thereto. The barrel 12 has an open rear end 12b and a radially
extending flange 12c which may facilitate manual handling of the
syringe assembly 10. The syringe assembly 10 generally extends
along an axial dimension which will be referenced hereinafter to
aid the description of the syringe assembly 10 and its components.
In particular, a forward axial direction 100a points along the
length of the syringe assembly 10 towards the forward end where
medicament will be expelled (i.e. towards the injection site),
whereas a rearward axial direction 100b points in the opposite
direction, as indicated in FIG. 1A. All references herein to
forwards and backwards are intended to mean axially forwards and
axially rearwards, respectively, unless otherwise stated.
[0032] A first stopper 14 is disposed in the barrel 12 and is
axially moveable therein. The first stopper 14 defines a first
volume 16 in the barrel 12, which is axially forward of the first
stopper 14, and defines a second volume 18 in the barrel 12, which
is axially rearward of the first stopper 14. The first and second
volumes 16,18 are each suitable for containing fluidic medicaments
which may be different to one another.
[0033] A second stopper 20 is disposed in the barrel 12 axially
rearward of the first stopper 14 and defines the axially rearward
limit of the second volume 18 (the front of the barrel 12 defining
the axially forward limit of the first volume 16). Like the first
stopper 14, the second stopper 20 is axially moveable within the
barrel 12. The second stopper 20 provides a fluid tight seal at the
rear of the second volume 18 such that no fluid from the second
volume 18 can exit the open rear end 12b of the barrel 12.
[0034] The first stopper 14 has a first plunger rod 22 connected
thereto that extends axially rearwardly through the second stopper
20. The second stopper 20 sealingly engages the first plunger rod
so as to seal the rear of the second volume 18 but permits axial
sliding of the first plunger rod 22 through the second stopper 20.
Therefore, the second stopper 20 seals an annulus around between
the outside of the first plunger rod 22 and the inside surface of
the barrel 12. The first plunger rod 22 includes a finger loop 22a
for facilitating handling of the first plunger rod 22. Axial
movement of the first plunger rod 22 results in axial movement of
the first stopper 14 within the barrel 12. In alternative
embodiments, there may be no finger loop 22a provided, or an
alternative formation that facilitates handling of the first
plunger rod 22.
[0035] In the embodiment shown in FIGS. 1A to 1D, the second
stopper 20 is provided with a second plunger rod 24 that extends
axially rearwardly from the second stopper 20 radially outward of
the first plunger rod 22. Axial movement of the second plunger rod
24 results in axial movement of the second stopper 20 within the
barrel 12. The first plunger rod 22 is axially longer than the
second plunger rod 24 such that at least the rear end of the first
plunger rod (which includes the finger loop 22a) is always exposed
rearward of the second plunger rod 24 regardless of the relative
positions of the first plunger rod 24 and second plunger rod
22.
[0036] The first stopper 14 includes a two way valve portion 14a
that is moveable between a sealing configuration and an open
configuration. In the sealing configuration, the first volume 16 is
fluidically sealed from the second volume 18, whereas in the open
configuration, the first volume 16 is fluidly connected to the
second volume 18. The two way valve portion 14a is moveable from
the sealing configuration to the open configuration by an increase
in pressure either axially forwards or axially rearwards of the
first stopper 14. When disposed in the barrel 12 as shown in FIG.
1A, the first volume 16 is axially forwards of the first stopper 16
and the second volume 18 is axially rearwards of the first stopper
14 so an increase of pressure in either of the first volume 16 or
second volume 18 may cause the two way valve portion 14a to move
from the sealing configuration to the open configuration.
Crucially, the two way valve portion 14a is moveable from the
sealing configuration to the open configuration by an increase in
pressure both axially forwardly and axially rearwardly such that,
if fluid is present in the first and second volumes 16,18, axial
movement of the first stopper 14 in either the axially forward or
axially rearward direction will cause an increase in fluid pressure
in one of the first and second volumes 16,18 (depending on the
direction of movement) which will subsequently cause the two way
valve portion 14a to open and fluidly connect the first and second
volumes 16,18. The two way valve portion 14a will move back to the
sealing configuration when the axially forward and axially rearward
forces acting on it equalize (e.g. if the first stopper 14 is
stationary in the barrel 12 for a period of time).
[0037] The operation of the syringe assembly 10 will now be
described with reference to FIGS. 1B to 1D. To initiate mixing of
medicaments contained in the first and second volumes 16,18, the
first stopper 14 is moved axially forwardly and axially rearwardly
in the barrel 12 successively while the second stopper 20 remains
stationary within the barrel 12. To do this, the first plunger rod
22 is moved axially forwardly and axially rearwardly relative to
the barrel 12 whilst the second plunger rod 24 is not moved
relative to the barrel 12.
[0038] FIG. 1B shows the first stopper 14 and first plunger rod 22
moved axially rearwardly compared to the configuration shown in
FIG. 1A. In moving to the configuration shown in FIG. 1B, the fluid
in the second volume 18 would have increased in pressure to a point
where the increase causes the two way valve portion 14a to move
into the open configuration and fluidly connect the second volume
18 with the first volume 16. Due to the higher pressure in the
second volume 18, the fluid in the second volume 18 passes through
the open two way valve portion 14a into the first volume 16. This
flow of fluid permits the rearward axial movement of the first
stopper 14 resulting in the reduction of the second volume 18 and
the increase of the first volume 16. Once all of the fluid has been
allowed to enter a common volume (e.g. the first volume 16), the
first stopper 14 may be moved axially forwards once more by
translating the first plunger rod 22 to encourage mixing of the
previously separate fluids, as shown in FIG. 1C. Indeed, the first
stopper 14 may be moved successively axially forwardly and axially
rearwardly within the barrel 12 to encourage thorough mixing of the
two fluids. Such thorough mixing may be required when one or both
of the two fluids is/are particularly viscous or immiscible. In the
absence of this agitation, the two fluids may remain unmixed
despite residing in the same volume 16,18. Nevertheless, in certain
embodiments, a single rearward movement of the first stopper 14 may
be sufficient for adequate mixing such that subsequent successive
forward and rearward movements are not necessary. It is noted that
for certain drugs, the agitation of the drug caused by successive
forward and rearward movements may be detrimental and so may
preferably be limited.
[0039] Once the two fluids have been completely mixed, the first
stopper 14 is moved axially rearwardly (by pulling the first
plunger rod 22 axially rearwardly) to meet with the second stopper
20 thus reducing the second volume 18 to substantially zero so that
substantially all of the mixed fluid is in the (now larger) first
volume 16. To dispense the mixed fluid from the first volume, the
second stopper 20 is moved axially forwardly (by moving the second
plunger rod 24 axially forwardly). This action causes both of the
first stopper 14 and second stopper 20 to move axially forwardly
within the barrel 12 and pressurize the mixed fluid thus causing
the mixed fluid to exit the barrel 12 via the front outlet 12a and
needle 13.
[0040] An alternative syringe assembly 10' in accordance with an
embodiment of the present invention is shown in FIGS. 2A to 2E. The
syringe assembly 10' of FIGS. 2A to 2E shares many common features
with the syringe assembly described above in relation to FIGS. 1A
to 1D. New or modified features in FIGS. 2A to 2E are denoted with
a new or primed (') reference numeral. The syringe assembly 10' of
FIGS. 2A to 2E operates to mix two fluids in the first and second
volumes 16, 18, just as the syringe assembly of FIGS. 1A to 1D
does.
[0041] The syringe assembly 10' shown in FIGS. 2A to 2E has a
radially extending flange 12c' that is larger than that of the
syringe assembly 10 of FIGS. 1A to 1D. Either embodiment 10,10' may
include a radially extending flange of any size, however. A larger
radially extending flange 12c' may facilitate easier handling of
the syringe assembly 10,10'.
[0042] The syringe assembly 10' includes a removable transit clip
15 (which may be present in any embodiment in accordance with the
present invention, including the embodiment 10 described above)
that, when assembled on the syringe assembly 10' prevents axial
movement of the first plunger rod 22 so as to prevent accidental
mixing between the first and second volumes 16,18, for example,
when the syringe assembly is being transported and handled prior to
use. The transit clip 15 may be any removable abutment or gripping
mechanism that prevents axial movement of the first plunger rod 22
relative to the barrel 12. The transit clip 15 may additionally
prevent axial movement of the second plunger rod 24 by abutment or
gripping. In alternative embodiments, a part of an outer packaging
or other component may abut, interfere or grip the first plunger
rod 22 and/or second plunger rod 24 so as to prevent respective
axial movement thereof prior to use. When it is intended to use the
assembly 10' to administer the medicament, the outer packaging (or
other component) may be removed so as to permit axial movement of
the first plunger rod 22 and/or second plunger rod 24.
[0043] The first plunger rod 22 includes a (double) finger loop
22a' for facilitating handling of the first plunger rod 22. In the
embodiment shown in FIGS. 2A to 2E, the first plunger rod 22 is
rotatable about a longitudinal axis of the syringe assembly 10'
(i.e. a central axis of the syringe assembly 10' that is parallel
to the axial directions 100a,100b) relative to the second plunger
rod 24 and barrel 12. FIG. 3 shows a rear end view from line A-A in
FIG. 2A where the syringe assembly 10' is in a first configuration.
As shown in FIG. 3, the finger loop 22a' is orientated
perpendicularly to the flange 12c' of the barrel 12.
[0044] In order to initiate mixing in the syringe assembly 10', the
transit clip 15 must first be removed (in the specific embodiment
shown in FIG. 2A). Once removed, the first plunger rod 22 may be
moved axially forward and rearward to mix the fluids in the first
and second volumes 16,18 (via the open two way valve portion 14a).
FIG. 2B shows the syringe assembly 10' during the mixing stage with
the first stopper 14 at a forward end of the barrel. In FIG. 2B it
can be seen that the first plunger rod 22 includes an engagement
mechanism that comprises a sleeve 23 extending axially forwardly
from the finger loop 22a'. The sleeve 23 is of a diameter that is
larger than the diameter of the second plunger rod 24 so as to
surround the second plunger rod 24. The sleeve 23 has a rear set of
engagement members 23a that project radially inwardly and to abut a
rear end of the second plunger rod 24 to limit the forwardmost
position of the first plunger rod 22 relative to the second plunger
rod 24. Incidentally, in the embodiment shown in FIG. 2B, the first
stopper 14 is also at its forwardmost position in the barrel 12
when the rear engagement elements 23a abut the second plunger rod
24. Therefore the front of the barrel 12 may limit the forwardmost
axial position of the first plunger rod 22 in place of or in
addition to the rear engagement elements 23a.
[0045] When the fluids in the first volume 16 and second volume 18
have been entirely mixed, the first plunger rod 22 is moved axially
rearwardly to move the first stopper 14 axially rearwardly until
the first stopper 14 meets the second stopper 20, reducing the
second volume 18 to substantially zero and forcing all of the mixed
fluids into the (now enlarged) first volume 16. FIG. 2C shows the
syringe assembly 10' with the first stopper 14 withdrawn axially
rearwardly so that it is in contact with the second stopper 20.
[0046] Unlike the second plunger rod 24 of the embodiment described
above in relation to FIGS. 1A to 1D, the second plunger rod 24 of
the embodiment of FIGS. 2A to 2E does not have a flange (24a).
Therefore, in order to move the second plunger rod 24 axially
forwardly to deliver a dose of (mixed) medicament, the first
plunger rod 22 must engage with the second plunger rod 24. In order
to permit the required engagement, the finger loop 22a' of the
first plunger rod 22 is rotated about the longitudinal axis by
90.degree. so as to be aligned with the flange 12c' of the barrel
12. In doing so, front engagement members 23b are brought into
alignment with the rear end of the second plunger rod 24 such that
axially forward movement of the first plunger rod 22 relative to
the second plunger rod 24 is not permitted due to abutment between
the front engagement members 23b and the rear end of the second
plunger rod 24. Prior to the above-described alignment, the front
engagement members 23b are able to travel axially along grooves or
channels in the second plunger rod 24. Thus, axially forward
movement of the first plunger rod 22 causes axially forward
movement of the second plunger rod 24 also, and causes the content
of the first volume 16 to be pressurized resulting in the expulsion
of the contents through the needle 13. FIG. 2E shows the syringe
assembly 10' at the end of delivery when the entire contents of the
barrel 12 have been dispensed.
[0047] Although the sleeve 23 and front and rear engagement
elements 23b,23a represent an exemplary embodiment of a suitable
engagement means for selectively engaging the first plunger rod 22
with the second plunger rod 24, any other suitable mechanism may be
employed within the scope of the present invention. Mechanisms
using abutment or gripping means are particularly suitable, and
mechanisms requiring rotation to engage/disengage the first and
second plunger rods 22,24 are particularly preferable as they
reduce the risk of accidental engagement and provide a clear
indicator to the user as to whether the first and second plunger
rods 22,24 are engaged or not. Indeed, a 90.degree. rotation is one
preferable choice. Whilst the above-described embodiment requires a
90.degree. turn of the first plunger rod 22 for it to engage with
the second plunger rod 24, other angles may be employed in
alternative embodiments in accordance with the present invention.
In preferable embodiments, the first plunger rod 22 will be at a
predetermined axial position relative to the second plunger rod 24
before such a rotation is permitted.
[0048] FIG. 5 relates to an additional feature that may be present
in any embodiment to limit unwanted axial movement of the second
plunger rod 24. In preferable embodiments, it forms part of the
syringe assembly 10' described above in relation to FIGS. 2A to 2E.
As shown in FIG. 5, a collar 30 sits rearward of the flange 12c of
the syringe barrel 12 and surrounds a modified second plunger rod
24' and a modified first plunger rod 22'. FIG. 6 shows a sectional
view across section C-C of FIG. 5 in which it can be seen that the
collar 30 is generally circular and has first inner edges 30b and
second inner edges 30a that together define a central aperture.
Each of the first and second inner edges 30b, 30a has a circular
profile where the notional circle of the profile of the second
inner edges 30a is larger in diameter than the notional circle of
the profile of the first inner edges 30b. The result is that the
second inner edges 30a provide cut out portions in an otherwise
circular aperture defined by the first inner edges 30b. In the
embodiment shown in FIG. 6, there are two cut-out portions where
each cut-out portion extends along an arc, and each cut-out portion
is angularly spaced from the other cut-out portion. In alternative
embodiments, other angular arrangements may be possible.
[0049] Conversely, the second plunger rod 24' has two cut-out
portions each defined by an inner wall 24b'. The inner walls 24b'
have a generally circular profile and the notional circle of the
profile of the inner walls 24b' has a smaller diameter than an
outer wall 24c' of the second plunger rod 24'. In the embodiment
shown in FIG. 6, each inner wall has an angular extent and each
inner wall 24b' is angularly spaced from the other inner wall 24b'.
This angular arrangement corresponds to the angular arrangement of
the collar 30 described above. In alternative embodiments, other
angular arrangements of the collar 30 and second plunger rod 24'
may be possible. In cross-section, the cut-out portions of the
second plunger rod 24' define radially extending tabs
therebetween.
[0050] The collar 30 provides a locking mechanism that only permits
axial movement of the second plunger rod 24' in certain angular
configurations of the second plunger rod 24' relative to the collar
30. In particular, axial movement of the second plunger rod 24' is
permitted if the outer walls 24c' are axially aligned with the cut
out portions of the collar defined by the second inner edges
30a.
[0051] In a particularly preferable embodiment, the first plunger
rod 22' is initially axially moveable independent of the second
plunger rod 24' so that the above-described mixing may be achieved.
The second plunger rod 24' is meanwhile axially restrained by the
collar 30 due to an axial misalignment of the outer walls 24c' of
the second plunger rod 24' with the cut out portions of the collar
defined by the second inner edges 30a. Once mixing is complete, the
first plunger rod 22' may be rotated about its longitudinal axis so
as to axially lock the first plunger rod 22' to the second plunger
rod 24'. This may, for example, be achieved by the sleeve 23 and
engagement members 23a,23b described above. Further rotation of the
first plunger rod 22' relative to the second plunger rod 24' about
the longitudinal axis may cause a rotational engagement between the
first plunger rod 22' and the second plunger rod 24'. This may be
achieved, for example, by a splined interface between the first
plunger rod 22' and the second plunger rod 24', or another
angularly dependent mechanism or formation between the first
plunger rod 22' and the second plunger rod 24'. Due to rotational
engagement between the first plunger rod 22' and the second plunger
rod 24', further rotation of the first plunger rod 22' about the
longitudinal axis results in rotation of the second plunger rod 24'
causing the outer walls 24c' of the second plunger rod 24' to move
into axial alignment with the cut out portions of the collar 30
defined by the second inner edges 30a. In this position, axial
movement of the second plunger rod 24' is possible such that axial
movement of the first plunger rod 22' causes axial movement of the
second plunger rod 24'.
[0052] In a preferable embodiment, a 45.degree. rotation of the
first plunger rod 22' about the longitudinal axis is required to
axially lock the first plunger rod 22' to the second plunger rod
24', and a further 45.degree. rotation of the first plunger rod 22'
about the longitudinal axis is required to rotate the second
plunger rod 24' (which is then rotationally engaged with the first
plunger rod 22') into a rotational position where the relative
axial alignment with the collar 30 permits axial movement of the
second plunger rod 24'. However, in alternative embodiments, any
other suitable angles may define the axial and rotational
engagements between the first plunger rod 22' and the second
plunger rod 24'.
[0053] In one embodiment, the assembly may be provided in a
configuration where neither of the first plunger rod and second
plunger rod may move axially in the barrel. A first rotation (e.g.
of the first plunger rod relative to the second plunger rod) may
move the assembly into a configuration where the first plunger rod
may move axially relative to the second plunger rod so as to permit
mixing. A second rotation (e.g. of the first plunger rod) which may
or may not be in the same direction may axially lock the first
plunger rod to the second plunger rod. A third rotation (e.g. a
collective rotation of the first plunger rod and second plunger
rod) may unlock the second plunger rod so as to permit the second
plunger rod (and hence first plunger rod) to move axially and
deliver a dose of medicament.
[0054] In any embodiment in accordance with the present invention,
the syringe assembly 10,10' may or may not include a needle 13. For
example, another kind of applicator may be provided (or no
applicator at all) for facilitating the passage of mixed medicament
to the injection or delivery site. The syringe assembly of the
present invention may, for example, be a nasal, ocular, oral, otic,
or other medicament delivery device for delivering a dose of mixed
medicament to a patient and is not limited to needle-type syringes.
An applicator, for example a needle 13, may be attachable to the
syringe assembly 10,10' such that the medicaments may be mixed as a
closed system, following which the applicator may be attached to
the syringe assembly 10,10' to administer the mixed medicaments to
the injection site. Alternatively, a closed system may be achieved
during mixing by the needle 13 or other applicator being blocked,
capped or otherwise sealed. For example, the needle 13 may be
initially staked in a needle boot and remain so during the mixing
of the two ingredients. Then, once the ingredients are mixed to a
satisfactory level, the needle boot (or other blocking, capping or
sealing means) may be removed to allow the mixed ingredients to be
dispensed.
[0055] A detailed view of the first stopper 14 is shown in FIG. 7.
The first stopper 14 includes a rearward facing socket 14b for
receiving and engaging with the first plunger rod 22. This may be a
threaded socket or simply a recess into which the first plunger rod
22 may be affixed to the first stopper (e.g. by adhesive or
friction). Indeed, the first stopper 14 may attach to the first
plunger rod 22 by a friction fit or an interference fit (for
example a ball and socket joint). It is important that the fit
between the first stopper 14 and the first plunger rod 22 provides
positive engagement therebetween in both forward and rearward axial
directions to ensure that the first stopper 14 remains attached to
the first plunger rod 22 during use (i.e. mixing) within the barrel
12. In one example, the first stopper 14 may only loosely engage on
the first plunger rod 22 when assembled outside of the barrel 12,
and the friction of the barrel 12 acting on the first stopper 14
may be used to establish a secure fit between the first stopper 14
and the first plunger rod 22 when the first stopper 14 (and first
plunger rod 22' is inserted into the barrel 12. The two way valve
portion 14a comprises a plurality of flexible flaps that run along
one side of the first stopper 14 and create a resilient seal with
the inside surface of the barrel 12. The flaps 14a deform under
sufficient fluid pressure so as to permit the passage of fluids
between the front and rearward sides of the first stopper 14. The
resilient seal 14a may run along one side of the first stopper 14
(as shown in FIG. 7) (and have an angular extent less than
360.degree.) or they may circumvent the entire first stopper 14
(i.e. have an angular extent of 360).degree., provided that they
are stiff enough to prevent accidental opening, yet flexible enough
to open when required. In alternative embodiments, the resilient
seal 14a may be formed through the body of the first stopper 14 so
that the resilient seal 14a seals against itself in the sealing
configuration, rather than sealing against the barrel 12.
[0056] FIG. 9 shows another view of the first stopper 14 and FIG.
10 shows a detailed view of the section D-D in FIG. 9. From FIG. 9,
it can be seen that the flexible flaps 14a extend along an arc of
angle .theta. of the circular first stopper 14. The magnitude of
.theta. will have an effect on the rate and efficiency of missing.
For example, a small .theta. (or otherwise small two way valve
portion 14a) will, by conservation of mass, cause a rapid flow of
fluid in response to axial displacement of the first stopper 14
into the volume 16,18 containing the fluid. Optimization of this
flow will optimize the mixing of the ingredients and minimize both
the force and time required to achieve the desired mixing.
[0057] An alternative embodiment of a first stopper 14' in
accordance with the present invention is shown in FIG. 8. The first
stopper 14' includes a rearward facing socket 14b' for receiving
and engaging with the first plunger rod 22. Again, this may be a
threaded socket or simply a recess into which the first plunger rod
22 may be affixed to the first stopper 14 (e.g. by adhesive or
friction), or any other suitable connection means for connecting to
the first plunger rod 22, as discussed above. The two way valve
portion 14a' is provided by a plurality of flexible flaps that
circumvent an axial section of the first stopper 14'. Additionally,
the first stopper 14' includes a permanent seal 14c' that
circumvents the first stopper 14' and is axially space from the
flexible flaps 14a'. The permanent seal 14c' is configured to seal
against the inside of the barrel 12 and does not deform
sufficiently to create a fluid path across the seal. The first
stopper 14' additionally includes a by-pass channel 14d' that
passes from an outer side surface of the first stopper 14' axially
between the flaps 14a' and the permanent seal 14c' to a front
surface of the first stopper 14', thus by-passing the permanent
seal 14d'. Fluid may travel along the by-pass channel 14d' such
that the flaps 14a' may encounter fluid pressure from either side
(front and rear) and deform putting the two way valve 14a' into the
open configuration. In alternative embodiments, the flaps 14a' may
not extend around the entire circumference of the first stopper
14'. In such embodiments, an additional permanent seal may make up
the remainder of the circumference. Alternatively, the embodiment
shown in FIG. 8 may be inverted such that the permanent seal 14c'
is axially rearward of the resilient seal 14a'. In any case, the
by-pass channel 14d' should by-pass the permanent seal 14c'. In
by-passing the permanent seal 14c', the channel 14d' introduces a
radial flow direction which provides easier control of the flow
velocity of the flowing fluid.
[0058] In any embodiment, any suitable two way valve may be
employed provided that it is moveable from a sealing configuration
to an open configuration upon an increase in fluid pressure from
either side. In any embodiment, the two way valve may be provided
with a hole or other formation (e.g. a nozzle) that is configured
to cause turbulence in fluid passing through the two way valve.
Such an arrangement may improve mixing of the ingredients.
[0059] Although the syringe assemblies 10,10' have been described
as including two fluid ingredients, the syringe assembly 10,10' may
include a dry ingredient (e.g. a powder or lyophilized ingredient)
and a wet, fluid ingredient in accordance with certain embodiments
of the invention. In embodiments where a dry ingredient is present,
the first stopper 14 must first move into (i.e. move axially to
reduce the volume of) the volume 16,18 containing the fluid
ingredient so as to cause the first stopper 14 to move into the
open configuration and permit mixing of the wet and dry
ingredients. Once both volumes 16,18 contain liquid, the first
stopper 14 may be moved in either the forward or rearward axial
direction as described above. The agitation provided by the moving
first stopper 14 may result in an emulsion, a solution or a
suspension, for example, depending on the properties of the initial
separate ingredients/medicaments. Prior to use, and during assembly
of the syringe assembly 10,10', the ingredients may be introduced
into the barrel 12 either side of the first stopper 14 (e.g. via
the front outlet 12a and the rear open end 12b respectively) so as
to prevent cross contamination.
[0060] In certain embodiments, the assembly may be provided such
that only the second volume 18 contains medicament and the first
volume 16 may be empty or be a substantially zero volume (in
practice, however, it is likely that some small volume space will
remain between the first stopper 14 and the front outlet of the
barrel). In alternative embodiments, the assembly may be provided
such that only the first volume 16 contains medicament and the
second volume 18 may be empty or be a substantially zero volume
(again, in practice, it is likely that some small volume space will
remain between the first stopper 14 and the second stopper 20).
[0061] Throughout the description and claims of this specification,
the words "comprise" and "contain" and variations of them mean
"including but not limited to", and they are not intended to (and
do not) exclude other moieties, additives, components, integers or
steps. Throughout the description and claims of this specification,
the singular encompasses the plural unless the context otherwise
requires. In particular, where the indefinite article is used, the
specification is to be understood as contemplating plurality as
well as singularity, unless the context requires otherwise.
[0062] Features, integers, characteristics, compounds, chemical
moieties or groups described in conjunction with a particular
aspect, embodiment or example of the invention are to be understood
to be applicable to any other aspect, embodiment or example
described herein unless incompatible therewith. All of the features
disclosed in this specification (including any accompanying claims,
abstract and drawings), and/or all of the steps of any method or
process so disclosed, may be combined in any combination, except
combinations where at least some of such features and/or steps are
mutually exclusive. The invention is not restricted to the details
of any foregoing embodiments. The invention extends to any novel
one, or any novel combination, of the features disclosed in this
specification (including any accompanying claims, abstract and
drawings), or to any novel one, or any novel combination, of the
steps of any method or process so disclosed.
[0063] The reader's attention is directed to all papers and
documents which are filed concurrently with or previous to this
specification in connection with this application and which are
open to public inspection with this specification, and the contents
of all such papers and documents are incorporated herein by
reference.
* * * * *