U.S. patent application number 13/976198 was filed with the patent office on 2013-10-17 for three-chambered autoinjector.
The applicant listed for this patent is Robert Leavitt Hill, John Glyndwr Wilmot. Invention is credited to Robert Leavitt Hill, John Glyndwr Wilmot.
Application Number | 20130274707 13/976198 |
Document ID | / |
Family ID | 45540913 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130274707 |
Kind Code |
A1 |
Wilmot; John Glyndwr ; et
al. |
October 17, 2013 |
Three-Chambered Autoinjector
Abstract
The present invention relates to a three-chambered autoinjector
as well as to the methods of administering medicaments to a human
using the three-chambered autoinjector. In certain embodiments, the
autoinjector includes a first medicament in liquid form, a second
medicament preferably in solid form, and a liquid composition for
diluting the second medicament, and utilizes a three-chambered
design so as to administer the first medicament and a solution
comprising the second medicament and the liquid composition at
different injection depths into the body of a human. In an
alternative embodiment an autoinjector is provided that delivers
medicaments at the same injection depth.
Inventors: |
Wilmot; John Glyndwr; (Mount
Airy, MD) ; Hill; Robert Leavitt; (Columbia,
MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wilmot; John Glyndwr
Hill; Robert Leavitt |
Mount Airy
Columbia |
MD
MD |
US
US |
|
|
Family ID: |
45540913 |
Appl. No.: |
13/976198 |
Filed: |
December 28, 2011 |
PCT Filed: |
December 28, 2011 |
PCT NO: |
PCT/IB11/55989 |
371 Date: |
June 26, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61428304 |
Dec 30, 2010 |
|
|
|
Current U.S.
Class: |
604/506 ;
604/191 |
Current CPC
Class: |
A61M 5/19 20130101; A61M
5/2033 20130101; A61M 2005/206 20130101; A61M 5/2066 20130101 |
Class at
Publication: |
604/506 ;
604/191 |
International
Class: |
A61M 5/19 20060101
A61M005/19 |
Claims
1. Autoinjector comprising: a) a housing having a forward end and a
rear end; b) a rear plunger moveably situated within the housing;
c) a separation assembly moveably situated within the housing, the
separation assembly forwardly situated with respect to the rear
plunger; d) a separation plunger moveably situated within the
housing, the separation plunger forwardly situated with respect to
the separation assembly; e) a first medicament situated forwardly
with respect to the separation plunger, the first medicament in the
form of a liquid; f) a second medicament situated between the
separation plunger and the separation assembly; g) a liquid
composition situated between the separation assembly and the rear
plunger; h) a needle having a needle length, a forward end and a
rear end, the needle being moveable from a needle storage position
in which the needle is situated within the housing to a needle
fully extended position in which the needle reaches a maximal
extension out of the forward end of the housing; and i) an
activateable power assembly for moving the rear plunger forwardly
within the housing.
2. Autoinjector according to claim 1, wherein, after activation of
the power assembly, the power assembly causes the separation
plunger, the separation assembly, and the rear plunger to move
forwardly within the housing and the needle to move from the needle
storage position to the needle fully extended position.
3. Autoinjector according to claim 1 or 2, wherein the separation
assembly comprises a separation assembly bypass, the separation
assembly bypass having a closed position in which the separation
assembly bypass prohibits the liquid composition from flowing
through the separation assembly and mixing with the second
medicament and an open position for allowing the liquid composition
to flow through the separation assembly and mix with the second
medicament.
4. Autoinjector according to anyone of claims 1 to 3, wherein the
housing comprises a punctureable sheath situated over the forward
end of the needle so that the needle can puncture through the
sheath and extend from the housing after activation of the power
assembly.
5. Autoinjector according to anyone of claims 1 to 4, wherein the
needle comprises an interior, an exterior, a first opening for
allowing the first medicament and a solution comprising the liquid
composition and the second medicament to enter into the interior of
the needle from the housing, a second opening for allowing the
first medicament and the solution to be ejected from the needle,
and a passage for allowing the first medicament and the solution to
flow through the interior of the needle by entering through the
first opening and exiting from the second opening.
6. Autoinjector according to anyone of claims 1 to 5, wherein the
autoinjector further comprises a bypass within the housing, the
bypass forwardly situated with respect to the separation plunger
prior to the activation of the power assembly, the bypass forming a
bypass area within the housing for receiving the separation plunger
so that when the separation plunger is received in the bypass area,
a solution comprising the liquid composition and the second
medicament can flow around the separation plunger and into an
opening in the needle.
7. Autoinjector according to anyone of claims 1 to 6, wherein the
separation plunger rearwardly confines the first medicament.
8. Autoinjector according to anyone of claims 1 to 7, wherein the
second medicament is in the form of a solid.
9. Autoinjector according to claim 8, wherein the second medicament
is a lyophilized medicament.
10. Autoinjector according to anyone of claims 1 to 9, wherein the
liquid composition is an aqueous solution.
11. Autoinjector having three chambers, the autoinjector
comprising: a) a housing having a forward end and a rear end; b) a
rear plunger moveably situated within the housing; c) a separation
assembly moveably situated within the housing, the separation
assembly forwardly situated with respect to the rear plunger; d) a
separation plunger moveably situated within the housing, the
separation plunger forwardly situated with respect to the
separation assembly; e) a first chamber for a liquid composition,
the first chamber having a variable volume, the first chamber
forwardly confined by the separation assembly and rearwardly
confined by the rear plunger; f) a second chamber for a second
medicament, the second chamber having a variable volume, the second
chamber forwardly confined by the separation plunger and rearwardly
confined by the separation assembly; g) a third chamber for a first
medicament, the third chamber having a variable volume, the third
chamber rearwardly confined by the separation plunger; h) a needle
having a needle length, a forward end and a rear end, the needle
being moveable from a needle storage position in which the needle
is situated within the housing to a needle fully extended position
in which the needle reaches a maximal extension out of the forward
end of the housing; and i) an activateable power assembly for
moving the rear plunger forwardly within the housing.
12. Autoinjector according to claim 11, wherein, after activation
of the power assembly, the power assembly causes i) the rear
plunger to move forwardly within the housing so as to decrease the
volume of the first chamber; ii) the separation assembly to move
forwardly within the housing so as to decrease the volume of the
second chamber; iii) the separation plunger to move forwardly
within the housing so as to decrease the volume of the third
chamber; and iv) the needle to move from the needle storage
position to the needle fully extended position.
13. Autoinjector according to claim 11 or 12, wherein the
separation assembly comprises a separation assembly bypass for
allowing the liquid composition to flow from the first chamber
through the separation assembly and into the second chamber.
14. Autoinjector according to anyone of claims 11 to 13, including
a first medicament contained in the third chamber, the first
medicament in the form of a liquid.
15. Autoinjector according to anyone of claims 11 to 14, including
a second medicament contained in the second chamber, the second
medicament in the form of a solid.
16. Autoinjector according to anyone of claims 11 to 15, including
a liquid composition contained in the first chamber.
17. Method of administering a first medicament at a first depth and
a second medicament at a second depth into the body of a human
using an autoinjector, the method comprising the steps of a)
providing an autoinjector comprising i) a housing having a forward
end and a rear end; ii) a rear plunger moveably situated within the
housing; iii) a separation assembly moveably situated within the
housing, the separation assembly forwardly situated with respect to
the rear plunger; iv) a separation plunger moveably situated within
the housing, the separation plunger forwardly situated with respect
to the separation assembly; v) a first medicament situated
forwardly with respect to the separation plunger, the first
medicament in the form of a liquid; vi) a second medicament
situated between the separation plunger and the separation
assembly; vii) a liquid composition situated between the separation
assembly and the rear plunger; viii) a needle having a needle
length, a forward end and a rear end, the needle being moveable
from a needle storage position in which the needle is situated
within the housing to a needle fully extended position in which the
needle reaches a maximal extension out of the forward end of the
housing; and ix) an activateable power assembly; b) positioning the
autoinjector on the body of the human; c) activating the power
assembly of the autoinjector.
18. Method according to claim 17, wherein the second medicament is
in the form of a solid.
19. Method according to claim 18, wherein: the separation assembly
comprises a separation assembly bypass, the separation assembly
bypass having a closed position in which the separation assembly
bypass prohibits the liquid composition from flowing through the
separation assembly and mixing with the second medicament and an
open position for allowing the liquid composition to flow through
the separation assembly and mix with the second medicament; and
further comprising: after step (c), opening the separation assembly
bypass and flowing the liquid composition through the separation
assembly to dissolve the second medicament.
20. Method according to anyone of claims 17 to 19, further
comprising: moving the separation plunger and the needle forwardly
within the housing in response to pressure applied on the
separation plunger by the liquid composition.
21. Method according to anyone of claims 17 to 20, wherein the
needle comprises an interior, an exterior, a first opening for
allowing the first medicament and a solution comprising the liquid
composition and the second medicament to enter into the interior of
the needle from the housing, a second opening for allowing the
first medicament and the solution to be ejected from the needle,
and a passage for allowing the first medicament and the solution to
flow through the interior of the needle by entering through the
first opening and exiting from the second opening; the method
further comprising: after step (c), moving the needle from the
needle storage position to the needle fully extended position; and
ejecting the first medicament through the second opening in the
needle and into the body of the human as the needle moves from the
needle storage position to the needle fully extended position.
22. Method according to anyone of claims 17 to 21, wherein the
needle comprises an interior, an exterior, a first opening for
allowing the first medicament and a solution comprising the liquid
composition and the second medicament to enter into the interior of
the needle from the housing, a second opening for allowing the
first medicament and the solution to be ejected from the needle,
and a passage for allowing the first medicament and the solution to
flow through the interior of the needle by entering through the
first opening and exiting from the second opening, and wherein the
autoinjector further comprises a bypass within the housing, the
bypass forwardly situated with respect to the separation plunger
prior to the activation of the power assembly, the bypass forming a
bypass area within the housing for receiving the separation plunger
so that when the separation plunger is received in the bypass area,
a solution comprising the liquid composition and the second
medicament can flow around the separation plunger and into the
first opening in the needle; the method further comprising: after
the separation plunger moves into the bypass area, flowing the
solution into the first opening in the needle, through the passage
in the needle and ejecting the solution from the second opening in
the needle into the body of the human.
23. Method according to claim 22, further comprising: moving the
rear plunger and the separation assembly forwardly within the
housing as the solution flows through the passage in the
needle.
24. Method according to claim 23, wherein the second medicament is
in the form of a solid, the method further comprising: during the
forward movement of the rear plunger, dissolving the second
medicament in the liquid composition.
25. Method according to claim 23 or 24, further comprising: ceasing
the forward movement of the separation assembly within the housing
and ceasing the flow of the solution through the passage in the
needle.
26. Method according to anyone of claims 17 to 25, further
comprising after step (c), moving the needle from the needle
storage position to the needle fully extended position.
27. Method according to claim 26, further comprising: during the
movement of the needle from the needle storage position to the
needle fully extended position, delivering the first medicament
into the body of the human; and after the movement of the needle to
the needle fully extended position, delivering a solution
comprising the liquid composition and the second medicament into
the body of the human.
28. Autoinjector comprising a liquid medicament, a solid medicament
and a liquid composition, the autoinjector comprising: a) an
external housing having a forward end and a rear end; b) an
internal medicament housing moveably received in the external
housing; c) a rear plunger moveably situated within the internal
medicament housing; d) a first separation assembly moveably
situated within the internal medicament housing, the first
separation assembly forwardly situated with respect to the rear
plunger; e) a second separation assembly moveably situated within
the internal medicament housing, the second separation assembly
forwardly situated with respect to the first separation assembly;
f) a first medicament situated forwardly with respect to the second
separation assembly, the first medicament in the form of a liquid;
g) a second medicament situated between the second separation
assembly and the first separation assembly, the second medicament
in the form of a solid; h) a liquid composition situated between
the first separation assembly and the rear plunger; i) a needle
having a needle length, a forward end and a rear end, the needle
being attached to a forward end of the internal medicament housing;
and j) an activateable power assembly for moving the rear plunger
forwardly within the internal medicament housing.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to an autoinjector with three
chambers as well as to methods of administering medicaments to a
human using the three-chambered autoinjector.
[0003] 2. Background
[0004] Autoinjectors have become quite popular and have experienced
widespread use due to a variety of advantages autoinjectors have
over typical manual syringe injectors. A number of autoinjectors
are commercially available, including EpiPen.RTM. (King
Pharmaceuticals Inc.), Anapen.RTM. (Lincoln Medical Ltd.),
Rebiject.RTM. II (EMD Serono and Pfizer Inc.), and SureClick.TM.
(Amgen). Generally speaking, an autoinjector is an automatic
injection system that is designed to deliver a medicament into an
individual upon activation of a power assembly. Among other things,
autoinjectors generally comprise a housing, a medicament situated
within the housing, a needle, and a power assembly. After
activation of the power assembly, the needle moves from a storage
position in which the needle is situated within the housing to an
active position in which the needle extends from the housing and
delivers the medicament to a patient.
[0005] There is a continuing need for improved autoinjector
devices.
BRIEF SUMMARY
[0006] In one aspect, the present invention provides a
three-chambered autoinjector. The autoinjector includes a housing
having a forward end and a rear end. In certain embodiments, the
autoinjector further includes an activateable power assembly, a
rear plunger, a first chamber comprising a liquid composition, a
separation assembly, a second chamber comprising a second
medicament, a separation plunger, a third chamber comprising a
first medicament, a needle, and a bypass within the housing.
[0007] The first medicament is in a liquid form and, preferably,
the second medicament is in a solid form, which can be dissolved in
the liquid composition. More preferably, the second medicament is
in a lyophilized form.
[0008] In an alternative embodiment, both the first and the second
medicaments are in liquid forms.
[0009] The rear plunger is moveably situated in the housing and is
operatively linked to the power assembly so that after activation
of the power assembly, the power assembly moves the rear plunger
forwardly within the housing. The rear plunger rearwardly confines
the first chamber.
[0010] The separation assembly is moveably situated in the housing
and forwardly confines the first chamber and rearwardly confines
the second chamber. The separation assembly comprises a separation
assembly bypass having a closed position in which the separation
assembly bypass prohibits the liquid composition from flowing
through the separation assembly and an open position for allowing
the liquid composition to flow through the separation assembly and
into the second chamber. After activation of the power assembly,
the separation assembly bypass moves from the closed position to
the open position, allowing the liquid composition to enter the
second chamber.
[0011] The separation plunger is moveably situated in the housing
and forwardly confines the second chamber. After activation of the
power assembly, the separation plunger moves forwardly within the
housing.
[0012] The third chamber is rearwardly confined by the separation
plunger and comprises a liquid medicament. In addition to the
liquid medicament, the third chamber comprises a gas such as air,
so that after activation of the power assembly, the gas in the
third chamber can be compressed and allow the separation plunger to
move forwardly within the housing.
[0013] The autoinjector further includes a needle having a needle
length, a forward end and a rear end. Prior to the activation of
the power assembly, the needle is in a needle storage position in
which the needle is situated within the housing. After activation
of the power assembly, the needle moves from the needle storage
position to a needle fully extended position in which the needle
reaches a maximal extension out of the forward end of the
housing.
[0014] A bypass within the housing is forwardly situated with
respect to the separation plunger prior to the activation of the
power assembly and the bypass forms a bypass area within the
housing for receiving the separation plunger. Prior to the
separation plunger entering into the bypass area, the separation
plunger creates a seal so as to prevent a solution comprising the
liquid composition and the second medicament from flowing from the
second chamber into the third chamber. When the separation plunger
is received in the bypass area, the separation plunger no longer
creates a seal between the second chamber and the third chamber and
thus permits a solution comprising the liquid composition and the
second medicament to flow around the separation plunger and into
the needle.
[0015] The three-chambered design preferably enables all or
substantially all of the liquid medicament to be delivered to a
human as the needle moves from the needle storage position to the
needle fully extended position and the design enables a solution
comprising the liquid composition and the second medicament to be
delivered after the needle reaches the needle fully extended
position. As a result, in a preferred embodiment, the medicaments
are delivered at different injection depths so as to prevent the
medicaments from affecting the absorption of one another in the
human's body.
[0016] Another advantage of the present invention is that it allows
for the inclusion of more storage-stable forms (e.g., lyophilized
forms) of medicaments that, when stored in liquid form, tend to
become less pure, degrade and/or experience other unwanted
effects.
[0017] Another advantage is that regulatory provisions in some
jurisdictions may prohibit the storage of mixed cocktails of
multiple medicaments, and the present invention provides for
separate storage of the medicaments and the mixture of the
medicaments immediately prior to injection.
[0018] In another embodiment of the invention, a moveable internal
medicament housing has a needle assembly attached to the forward
end thereof. Two separation assemblies are received in the internal
medicament housing and separate it into three chambers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a side cross-sectional view of an
autoinjector in a loaded, activateable state.
[0020] FIGS. 2-6 illustrate side cross-sectional views of an
autoinjector after activation of the power assembly.
[0021] FIG. 7 illustrates a side schematic view and a side
cross-sectional view of an autoinjector needle resting on a concave
surface of the separation plunger and further illustrates the flow
of a medicament through the needle.
[0022] FIG. 8 illustrates a top schematic view of an autoinjector
needle and separation plunger.
[0023] FIG. 9 is a side cross-sectional view of an alternative
embodiment having a moveable internal medicament housing with two
separation assemblies received in the internal medicament
housing.
DETAILED DESCRIPTION
[0024] Referring now to the drawings, FIG. 1 illustrates a
cross-sectional view of one embodiment of an autoinjector generally
designated by the numeral 10. In the drawings, not all reference
numbers are included in each drawing for the sake of clarity. In
addition, positional terms such as "upper," "lower," "side," "top,"
"bottom," etc. refer to the apparatus when in the orientation shown
in the drawing. The skilled artisan will recognize that the
apparatus can assume different orientations when in use.
[0025] Referring further to FIG. 1, the autoinjector 10 comprises a
housing 12 having a forward end 14 and a rear end 16. The housing
12 forms the exterior surface of the autoinjector body and can
include one or more structures. For example, in FIG. 1, the housing
12 comprises a safety pin 18, a cylindrical body 20 and a needle
cover 22. The housing 12, preferably, is generally hollow and can
be comprised of any material. Preferably, the housing 12 is
plastic, but it could also be formed from glass.
[0026] Situated within the housing 12 is an activateable power
assembly 24. Power assemblies for autoinjector devices are
well-known to those of ordinary skill and are described in, for
example, U.S. Pat. No. 7,449,012, the contents of which is
incorporated herein by reference in its entirety. Preferably, the
power assembly 24 comprises deformable collet arms 26 and a spring
28. In certain embodiments, the power assembly 24 is activated by
removing the safety pin 18 and positioning the autoinjector 10 on
the body of a human. More particularly, in certain embodiments, the
power assembly 24 is activated by removing the safety pin 18 and
pressing the forward end 14 of the autoinjector housing 12 against
a desired injection site on a human's body.
[0027] FIG. 1 shows the autoinjector in a loaded, activateable
state--i.e., the power assembly 24 of the autoinjector 10 is
capable of being activated, but has not been activated and the
autoinjector 10 includes a first medicament in a liquid form, a
second medicament, and a liquid composition so that the
autoinjector 10 may deliver medicaments to a patient. The second
medicament is preferably in a solid form and the liquid composition
is for diluting the second (solid) medicament This preferred
embodiment will be further described in the rest of the
description.
[0028] However, it will be understood that the autoinjector 10 may
include a first medicament in a liquid form and a second medicament
also in a liquid form.
[0029] It will also be appreciated that other states of the
autoinjector 10, for example, prior to loading with medicaments and
the liquid composition or after activation of the power assembly
24, are also within the scope of the present invention. For
example, FIGS. 2-6 illustrate the autoinjector 10 after activation
of the power assembly 24.
[0030] Referring further to FIG. 1, the autoinjector 10 further
includes a rear plunger 30 moveably situated within the housing 12.
The rear plunger 30 is operatively linked to the power assembly 24
so that after activation of the power assembly 24, the power
assembly 24 moves the rear plunger 30 forwardly within the housing
12.
[0031] The autoinjector 10 further includes a first chamber 32
comprising a liquid composition. The first chamber 32, and liquid
composition contained therein, are rearwardly confined by the rear
plunger 30. It is also noted that the position of the rear plunger
30 relative to the power assembly 24 may be adjusted to adjust the
volume of the chamber 32.
[0032] The autoinjector 10 further includes a separation assembly
34, which is moveably situated in the housing 12 and forwardly
confines the first chamber 32. The separation assembly 34 comprises
a separation assembly bypass 36, which has a closed position in
which the separation assembly bypass 36 prohibits a liquid
composition contained in the first chamber 32 from flowing through
the separation assembly 34 and an open position for allowing a
liquid composition contained in the first chamber 32 to flow
through the separation assembly 34 and forwardly within the housing
12. After activation of the power assembly 24, the separation
assembly bypass 36 moves from the closed position to the open
position, allowing the liquid composition to flow from the first
chamber 32, through the separation assembly 34 and forwardly within
the housing 12.
[0033] Separation assembly bypasses for autoinjector devices are
described in, for example, U.S. Patent Publication No.
2004/0097874, the contents of which is incorporated by reference in
its entirety.
[0034] The autoinjector 10 further includes a second chamber 38
comprising a solid medicament. The second chamber 38, and solid
medicament contained therein, are rearwardly confined by the
separation assembly 34. In certain embodiments, the solid
medicament is in powder form. Preferably, the solid medicament is a
lyophilized medicament--i.e., a medicament that has been subjected
to lyophilization, otherwise known as freeze-drying. The solid
medicament is referred to herein as "the second medicament", as it
is the second medicament to be delivered from the autoinjector 10
to a patient.
[0035] The liquid composition included in the first chamber 32 and
the second medicament included in the second chamber 38 are
selected so that the second medicament is soluble in the liquid
composition, because, upon opening of the separation assembly
bypass 36, the liquid composition flows into the second chamber 38
and mixes with, and dissolves, the second medicament so as to
create a solution comprising the second medicament and the liquid
composition. Preferably, the liquid composition is an aqueous
solution. In certain embodiments, the liquid composition included
in the first chamber 32 comprises a medicament, thus, allowing the
autoinjector 10 to deliver three medicaments to a patient.
[0036] In addition, in certain alternative embodiments, instead of
a medicament in solid form, the second chamber 38 can comprise a
liquid medicament. In such embodiments, upon opening of the
separation assembly bypass 36, the liquid composition flows into
the second chamber 38 and mixes with the liquid medicament in the
second chamber 38 so as to form a solution comprising the liquid
medicament and the liquid composition.
[0037] The autoinjector 10 further includes a separation plunger
40, which is moveably situated within the housing and forwardly
confines the second chamber 38. After activation of the power
assembly 24 and after the liquid composition begins to move through
the separation assembly 34 and into the second chamber 38, the
separation plunger 40 moves forwardly within the housing 10.
[0038] The autoinjector 10 further includes a third chamber 42
comprising a liquid medicament. The third chamber 42, and liquid
medicament contained therein, are rearwardly confined by the
separation plunger 40. The liquid medicament is referred to herein
as "the first medicament", as it is the first medicament to be
delivered from the autoinjector 10 to a patient. In addition to the
first medicament, the third chamber 42 comprises a gas which may be
air but is preferably an inert gas, so that after activation of the
power assembly 24, the gas in the third chamber 42 can be
compressed and allow the separation plunger 40 to move forwardly
within the housing 12.
[0039] The autoinjector 10 further includes a needle 44 having a
needle length 45, a forward end 48 and a rear end 46. As shown, in
FIG. 1, the needle 44 is in a needle storage position in which the
needle 44 is situated within the housing 12. After activation of
the power assembly 24, the needle 44 moves from the needle storage
position to a needle fully extended position in which the needle 44
reaches a maximal extension out of the forward end of the housing
12.
[0040] As shown in FIG. 1, preferably, the needle cover 22
comprises a punctureable sheath 50 situated over the forward end 48
of the needle 44 so that the needle 44 can puncture through the
sheath 50 and extend from the housing 12 after activation of the
power assembly 24. It is also possible in some embodiments of a
triple chamber autoinjector to have a needle sheath that would be
manually removed prior to use.
[0041] An illustrative needle for use in the present invention is
shown in FIGS. 7 and 8. As shown, the needle 44 comprises a needle
base 52, an interior 54, an exterior 56, a first opening 58 for
allowing the first medicament and a solution comprising the second
medicament and the liquid composition to enter into the interior 54
of the needle 44 from the housing 12, a second opening 60 for
allowing the first medicament and the solution to be ejected from
the needle 44, and a passage 62 for allowing the first medicament
and the solution to flow through the interior 54 of the needle 44
by entering through the first opening 58 and exiting from the
second opening 60. The needle base 52 preferably rests on, but does
not cover, a concave surface 64 of the separation plunger 40, which
allows the first medicament and the solution to flow into an area
between the needle base 52 and the concave surface 64 of the
separation plunger 40, enter into the first opening 58 in the
needle 44, through the needle passage 62, and exit from the second
opening 60 in the needle 44. In this embodiment, the first opening
58 of the needle 44 is located in the needle base 52.
[0042] However, it will be understood that other embodiments can be
used in the present invention. For example, the first opening 58 of
the needle 44 can be forwardly situated with respect to the base 52
and can comprise multiple slits located around the needle 44.
[0043] The autoinjector 10 further includes a bypass 65 within the
housing 12. The bypass 65 is forwardly situated with respect to the
separation plunger 40 prior to the activation of the power assembly
24 and the bypass 65 forms a bypass area 66 within the housing 12
for receiving the separation plunger 40. The bypass 65 may be in
the form of grooves defined in the housing wall, an enlarged
internal diameter of the housing wall, ribs extending inward from
the housing wall, a cage-like insert received in the housing, or
any combination of such structures adequate to permit fluid to flow
around the separation plunger 40 when the separation plunger 40 is
received in the bypass area 66. Prior to the separation plunger 40
entering into the bypass area 66, the separation plunger 40 creates
a seal so as to prevent a solution comprising the liquid
composition and the second medicament from flowing from the second
chamber 38 into the third chamber 42. When the separation plunger
is received in the bypass area 66, the separation plunger 40 no
longer creates a seal between the second chamber 38 and the third
chamber 42, thus, permitting a solution comprising the liquid
composition and the second medicament to flow around the separation
plunger 40 and into the first opening 58 in the needle 44.
[0044] An exemplary mode of operation and method of use is
described below for an autoinjector loaded with the first
medicament, the second medicament, and the liquid composition. It
will be understood that the method of operation and method of use
is only exemplary.
[0045] An autoinjector 10 is provided. The autoinjector is in its
loaded, activateable state. See FIG. 1.
[0046] The safety pin 18 is removed and the forward end 14 of the
autoinjector housing 12 is pressed against a desired injection site
on the body of a human. The deformable collet arms 26 collapse to
release energy from the spring 28. See FIG. 2. It is noted that the
autoinjector may also be constructed to be activated by a
push-button rather than by pressing of the autoinjector against the
injection site.
[0047] The spring energy causes the rear plunger 30 to begin moving
forwardly within the housing 12. The forwardly movement of the rear
plunger 30 decreases the volume of and pressurizes the first
chamber 32. The pressure built up within the first chamber 32
causes the separation assembly bypass 36 to move to the open
position and the liquid composition to flow through the separation
assembly 34 and into the second chamber 38. See FIG. 3.
[0048] The liquid composition begins to dissolve the second
medicament to form a solution comprising the liquid composition and
the second medicament. The liquid composition applies pressure on
the separation plunger 40, causing the separation plunger 40 to
move forwardly within the housing 12. The forwardly movement of the
separation plunger 40, in turn, decreases the volume of, and
compresses gas in, the third chamber 42 and causes the needle 44 to
begin moving from the needle storage position to the needle fully
extended position. As the needle 44 moves from the needle storage
position to the needle fully extended position, the first
medicament enters into the first opening 58 in the needle, flows
through the passage 62 in the needle 44 and is ejected from the
second opening 60 in the needle 44 and into the body of a human.
The rear plunger 30 continues moving forwardly and aids the
dissolution of the second medicament in the liquid composition. See
FIG. 4; FIG. 7 (illustrating flow of a medicament through the
needle).
[0049] The separation plunger 40 is received in the bypass area 66
and ceases moving forwardly within the housing 12. The needle 44
reaches the needle fully extended position and the first medicament
ceases flowing through the passage 62 in the needle 44. A solution
comprising the liquid composition and the second medicament flows
from the second chamber 38, around the separation plunger 40, into
the third chamber 42, and through the passage 62 in the needle 44.
As the second medicament flows through the passage 62 in the needle
44, the rear plunger 30 and separation assembly 34 move forwardly
within the housing 12. The forwardly movement of the separation
assembly 34 decreases the volume of the second chamber 38. See FIG.
5; FIG. 7 (illustrating flow of a medicament through the
needle).
[0050] The rear plunger 30 and the separation assembly 34 cease
moving forwardly and the solution comprising the liquid composition
and the second medicament ceases ejecting from the needle 44. The
delivery of the medicaments is complete. Preferably, when the
delivery of the medicaments is complete, the volumes of the first
chamber 32, the second chamber 38, and the third chamber 42 have
approached zero, which ensures that little to no medicaments remain
in the autoinjector 10 when the delivery of the medicaments is
complete. See FIG. 6.
[0051] As mentioned, the design of the autoinjector 10 allows the
autoinjector 10 to administer the first medicament and a solution
comprising the second medicament and the liquid composition at
different injection depths into the body of a human. More
particularly, due to the seal created by the separation plunger 40
prior to entering the bypass area 66, the autoinjector 10 delivers
the first medicament as the needle 44 moves from the needle storage
position to the needle fully extended position. The autoinjector 10
delivers a solution comprising the second medicament and the liquid
composition after the needle 44 moves to the fully extended
position. It will be appreciated that a small amount of the first
medicament may be ejected from the needle 44 after the needle 44
moves to the needle fully extended position, as the solution
comprising the second medicament and the liquid composition may
wash residual amounts of the first medicament through the needle
44. However, preferably substantially all of the first medicament
is delivered before the needle 44 reaches the needle fully extended
position.
The Embodiment of FIG. 9
[0052] In FIG. 9 an alternative embodiment of the autoinjector is
generally indicated by the numeral 100. In FIG. 9 parts identical
to or analogous to those of the autoinjector 10 of FIG. 1 are
labeled with like numerals.
[0053] The autoinjector 100 includes an external housing assembly
102 and a moveable internal medicament housing 104. The rear
plunger 30 and the first separation assembly 34 are received in the
bore of the internal medicament housing 104. Also received in the
internal medicament housing 104 in place of the separation plunger
40 is a second separation assembly 106, which includes a bypass
108. A needle assembly 110 includes a needle hub 112 attached to
the forward end of moveable internal medicament housing 104 for
movement therewith relative to the external housing 102. The needle
assembly 110 further includes a needle 116 and a collapsible needle
sheath 118.
[0054] The chambers 32, 38 and 42 may contain medicaments and/or
liquid compositions as previously described. A forward end of the
third chamber 42 is preferably sealed by a burstable membrane
114.
[0055] In operation the autoinjector 100 functions generally as
follows. The forward end of the external housing 104 is placed
against a desired injection site on the body of the human. A push
button actuator 115 is then pressed to release the spring 28.
[0056] The spring energy causes the rear plunger 30 to begin moving
forwardly within the internal medicament housing 104. The bypass 36
of the first separation assembly 34 opens and the liquid
composition flows from first chamber 32 through first separation
assembly 34 into second chamber 38 and begins to dissolve the
second medicament. Once second chamber 38 fills with liquid
composition the hydraulic pressure applied on second separation
assembly 106 will open second bypass 108 and will begin moving the
entire internal medicament housing 104 and needle assembly 110
forward.
[0057] The sheath 118 will collapse and the needle 116 will pierce
the end of the collapsible needle sheath 118 and will extend from
the external housing 102 to its full insertion depth into the
human. The medicament from the third chamber 42 and the dissolved
medicament from second chamber 38 will flow substantially
sequentially through the needle 116 into the human at the full
needle insertion depth.
[0058] Having now described the invention in accordance with the
requirements of the patent statutes, those skilled in the art will
understand how to make changes and modifications to the disclosed
embodiments to meet their specific requirements or conditions.
Changes and modifications may be made without departing from the
scope and spirit of the invention, as defined and limited solely by
the following claims.
* * * * *