U.S. patent application number 15/379992 was filed with the patent office on 2017-05-25 for injector.
This patent application is currently assigned to New Injection Systems Ltd. The applicant listed for this patent is New Injection Systems Ltd. Invention is credited to Stephen Terence Dunne.
Application Number | 20170143904 15/379992 |
Document ID | / |
Family ID | 44146962 |
Filed Date | 2017-05-25 |
United States Patent
Application |
20170143904 |
Kind Code |
A1 |
Dunne; Stephen Terence |
May 25, 2017 |
INJECTOR
Abstract
An injector for delivering medicament comprises a collapsible
container (1002) for containing the liquid medicament, a
normally-closed valve (1004) coupled to the collapsible container
(1002) for retaining the liquid medicament within the collapsible
container and an injection means (1006) for delivering the liquid
medicament from the collapsible container. The liquid medicament is
maintained under pressure by a pressurising means (1003) which
pressurises the liquid medicament such that it is delivered by the
injection means (1006) when the normally-closed valve (1004) is
opened.
Inventors: |
Dunne; Stephen Terence;
(Suffolk, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
New Injection Systems Ltd |
Stowmarket |
|
GB |
|
|
Assignee: |
New Injection Systems Ltd
Stowmarket
GB
|
Family ID: |
44146962 |
Appl. No.: |
15/379992 |
Filed: |
December 15, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13637053 |
Jun 24, 2014 |
9550025 |
|
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PCT/GB2011/000437 |
Mar 25, 2011 |
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15379992 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 5/3202 20130101;
A61M 2005/208 20130101; A61M 2005/2013 20130101; A61M 5/2033
20130101; A61M 5/2425 20130101; A61M 5/3243 20130101; A61M
2005/3247 20130101; A61M 5/2053 20130101; A61M 5/3216 20130101;
A61M 2005/3128 20130101; A61M 5/326 20130101; A61M 5/5086
20130101 |
International
Class: |
A61M 5/24 20060101
A61M005/24; A61M 5/32 20060101 A61M005/32; A61M 5/20 20060101
A61M005/20 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 25, 2010 |
GB |
1005014.4 |
Apr 23, 2010 |
GB |
1006781.7 |
May 20, 2010 |
GB |
1008406.9 |
May 25, 2010 |
GB |
1008640.3 |
Jun 14, 2010 |
GB |
1009896.0 |
Jun 15, 2010 |
GB |
1009954.7 |
Jun 22, 2010 |
GB |
1010403.2 |
Aug 17, 2010 |
GB |
1013738.8 |
Claims
1. An injector for delivering a liquid medicament comprising, a
collapsible container for containing the liquid medicament, a
normally-closed valve coupled to the collapsible container for
retaining the liquid medicament within the collapsible container,
an injection means coupled to the normally-closed valve for
delivering the liquid medicament from the collapsible container,
and pressurising means for pressurising the liquid medicament
contained within the collapsible container such that the liquid
medicament is delivered by the injection means when the
normally-closed valve is opened.
2. An injector according to claim 1 in which the injection means is
a hollow needle such as a hypodermic needle, or in which the
injection means is a needleless injection element for injecting
medicament into a human or animal body.
3. An injector according to claim 1 in which the collapsible
container and the pressurising means are housed within a rigid
container, preferably in which the normally-closed valve is
connected to the rigid container.
4. An injector according to claim 3 in which at least a portion of
the rigid container is transparent, preferably in which the rigid
container is formed from a transparent polymer or glass.
5. An injector according to claim 3 in which the rigid container
includes a vent to allow displaced air within the rigid container
to escape when the collapsible container is filled, preferable in
which the vent is a closable vent.
6. An injector according to claim 3 in which the rigid container is
hermetically sealed.
7. An injector according to claim 6 in which the rigid container
has an inert gas atmosphere surrounding the collapsible container,
preferably in which the inert gas is a gas having a low solubility
in the liquid medicament, for example nitrogen.
8. An injector according to claim 3 in which the collapsible
container is defined by internal walls of the rigid container and a
piston that is slidably arranged within the rigid container, the
volume of the collapsible container varying depending on the
position of the piston.
9. An injector according to any of claim 1 in which the collapsible
container is a bellows coupled to the normally-closed valve.
10. An injector according to claim 9 in which the bellows is formed
from a transparent material.
11. An injector according to claim 1 in which the pressurising
means is a biasing element that exerts a force that acts on the
collapsible container.
12. An injector according to claim 11 in which the force acting to
collapse the collapsible container is generated by a spring, for
example a compressed helical spring arranged to urge the
collapsible container to collapse.
13. An injector according to claim 12 in which the pressurising
means comprises a spring and is an integral part of the collapsible
container.
14. An injector according to claim 11 in which the force that acts
on the collapsible container is generated by a compressed gas or a
liquefied gas.
15. An injector according to any of claim 11 in which the
pressurising means comprises a piston or ram that is urged by the
force into contact with the collapsible container.
16. An injector according to claim 1 in which the normally-closed
valve is a continuous flow valve or an aerosol valve.
17. An injector according to claim 1 in which the normally-closed
valve comprises a spring that acts to urge the valve to a closed
position, in which the spring is a non-metallic spring, for example
a plastic spring.
18. An injector according to claim 1 comprising a manually operated
switch for opening the normally-closed valve.
19. An injector according to claim 1 comprising an actuator for
opening the normally-closed valve, in which the normally-closed
valve is opened when the actuator is pressed against a patients
skin.
20. An injector according to claim 1 in which the injection means
is a needle and the normally-closed valve is arranged to open when
the needle has been inserted a predetermined distance into the
patient, the predetermined distance depending on the type of drug
that is being delivered and the tissue that the delivery is
required to be made into.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 13/637,053, filed Sep. 25, 2012, which is a 35 U.S.C. 371
national stage filing from International Application No.
PCT/GB2011/000437, filed Mar. 25, 2011, which claims priority to
British Applications Nos. 1013738.8, filed Aug. 17, 2010;
1010403.2, filed Jun. 22, 2010; 1009954.7, filed Jun. 15, 2010;
1009896.0, filed Jun. 14, 2010; 1008640.3, filed May 25, 2010;
1008406.9, filed May 20, 2010; 1006781.7, filed Apr. 23, 2010; and
1005014.4, filed Mar. 25, 2010, the teachings of all of which are
incorporated herein by reference.
[0002] The invention relates to an injector for delivering a
liquid, for example for delivering a liquid medicament to a human
or animal patient. The invention may also relate to a method of
injecting a liquid and a method of manufacturing an injector.
BACKGROUND
[0003] Pre-filled syringes and auto-injectors are devices that are
well known in the prior art for the delivery of liquids, often for
the delivery of a liquid medicament to a patient. Both pre-filled
syringes and auto-injectors tend to be constructed from a
cylindrical barrel for containing the liquid with a plunger and
needle to effect delivery of the liquid. The liquid is stored in
the barrel and sealed at one end by the plunger and at the other by
a cap. Sometimes such devices include a staked needle (i.e. a
permanently fixed needle) which will have a cap over the needle to
seal the device. The plunger is either depressed by the user to
expel the liquid drug via the needle, or, in the case of
auto-injectors, the plunger is depressed by an energy source which
is often a compression spring.
[0004] These conventional devices suffer from many drawbacks
including stability problems arising from the interaction of the
medicament with the materials forming the device, such as the
barrel glass, the plastic elastomeric plunger, the metallic needle,
the adhesive used to stake the needle, and any necessary
lubricants. The filling of these conventional devices is also
problematic. The placement of a plunger during filling makes it
difficult to fill many known devices bubble free and without risk
of contamination. Movement of a plunger during storage due to
expansion and contraction of air bubbles within the filled device
may result in contamination of the drug.
[0005] Additionally the liquid medicament is sealed within the
barrel by a moving plunger. It is, therefore, difficult to
completely seal the medicament and keep it sterile while also
allowing the plunger to be capable of movement.
[0006] Furthermore, the barrel is often made of brittle glass which
is breakable both in use and during production and filling.
[0007] In most devices the liquid is in contact with the needle
during storage. This can lead to problems such as blockages due to
drug crystallization within the needle and medicament instability
due to the interaction of the drug with the metals in the
needle.
[0008] The filling procedures for conventional pre-filled syringes
need to be complex to ensure sterility at all times.
[0009] It is an aim of the invention to provide a better
injector.
SUMMARY OF INVENTION
[0010] The invention provides an injector, a method of injecting a
liquid, and a method of manufacturing an injector as defined in the
appended independent claims, to which reference should now be made.
Preferred and/or advantageous features of the invention are defined
in various dependent sub-claims.
[0011] Thus, the invention may provide an injector for delivering a
liquid, preferably in which the liquid is a liquid medicament. The
injector comprises a collapsible container for containing the
liquid, a normally-closed valve coupled to the collapsible
container for retaining the liquid within the collapsible
container, an injection means coupled to the normally-closed valve
for delivering the liquid from the collapsible container, and
pressurising means for pressurising the liquid contained within the
collapsible container, such that the liquid is delivered by the
injection means when the normally-closed valve is opened.
[0012] The liquid is preferably a liquid medicament, for example a
drug solution or suspension, or a mixture of more than one solution
or suspension, for treatment of a disease or condition of a human
or animal. It is envisaged, however, that the liquid may not be a
medicament, but may be some other injectable liquid. For example,
it is known to inject various polymer solutions such as hydrogels
into the human or animal body.
[0013] It is envisaged that the injection means will preferably be
a needle for injection of the liquid, for example a hollow needle
such as a hypodermic needle for piercing the skin of a human or
animal patient and injecting the liquid into the human or animal
body. The injection means may, thus, be a hypodermic needle or some
other piercing element such as a micro-needle or a nozzle. The
injection means may be an array of needles for piercing the skin.
Suitable hypodermic needles may have any standard gauge, for
example any needle between G20 and G30. Needles suitable for use
with the injector may be micro-needles under 2 mm long, for
example, under 1 mm long, or between 0.1 mm and 1 mm long.
[0014] The injection means may, alternatively, be a needleless
injection element such as are known in the prior art for injecting
a liquid into the human or animal body.
[0015] The injector may be used to inject the liquid into any part
of the human or animal body. The injector may be used to provide
intramuscular, subcutaneous, intradermal, or intravenous
injections. The device may be used for injecting into other
locations, for example for delivering liquid medicaments or other
substances into a body's organs or bones.
[0016] In preferred embodiments of an injector, the collapsible
container and the pressuring means are both housed within a rigid
container or body, the rigid container or body forming a component
element of the injector. Preferably, the normally-closed valve is
connected to the rigid container.
[0017] The rigid container may be formed from any suitable
material, for example a rigid plastic or metal or glass.
Particularly preferred materials may include polyethylene,
polypropylene, PET, COC, COP, and Ethylene vinyl alcohol.
[0018] The rigid container may be hermetically sealed, such that
the contents of the rigid container are shielded from the external
environment. Alternatively, the rigid container may be a frame or
cage that acts to locate the collapsible container and the
pressurising means. It is particularly advantageous if the rigid
container is formed from a transparent material, such as a
transparent polymer or glass, such that the contents can be viewed
and monitored.
[0019] The rigid container may comprise a vent to allow displaced
air within the rigid container to escape during filling of the
collapsible container. Advantageously, the vent may be a closable
vent so that the internal contents of the container may be
re-sealed after venting. If the rigid container is not entirely
made of a transparent material, it may be advantageous that the
rigid container includes an observation window for allowing
inspection of the rigid container's contents. Such a window may be
formed from a transparent material such as glass or plastic, or may
simply be a hole in walls of the rigid container where the rigid
container is not sealed. Advantageously, the widow may be formed as
a lens, or incorporating a lens, to facilitate inspection of the
liquid contents of the collapsible container.
[0020] The liquid being delivered by the injector may be a liquid
that is adversely affected by interaction with oxygen. For example,
many liquid medicaments react adversely with oxygen and, therefore,
have a limited shelf life. Thus, it may be advantageous that the
rigid container can be fully sealed from the external environment.
In this way, a liquid medicament contained within the collapsible
container is less likely to be exposed to the external environment
and may have a longer shelf life. Thus, it is preferred that the
rigid container is fully sealed or, where the container has a vent,
that the vent may be plugged. It may be particularly advantageous
that the rigid container may be hermetically sealed, preferably
with an inert gas atmosphere surrounding the collapsible container.
For example, air within the rigid container may be purged by an
inert gas that has a low solubility in the liquid medicament, for
example nitrogen.
[0021] An inert gas atmosphere within the rigid container may be
developed during manufacture of the injector. For example, air may
be replaced by nitrogen, or any other suitable gas, during valve
placement or valve crimping procedures. This may be effected using
known under the cup filling procedures. Alternatively, a vacuum may
be created during crimping so that, when the collapsible container
has been filled with liquid, the atmospheric pressure surrounding
the container is close to atmospheric pressure.
[0022] Preferably, the collapsible container is a separate sealed
container that may expand or collapse to vary the volume within the
container. A particularly preferred configuration of the
collapsible container is in the form of a bellows. A bellows
container has pleated or corrugated sides that allow the container
to expand or contract. The collapsible bag or bellows may be made
of any material suitable for containing the liquid. For example,
where the liquid is a medicament the bag or bellows is preferably
any suitable material approved for pharmaceutical use. The bag or
bellows may be laminated in order to provide specified material
properties. For example, an internal surface of the bag or bellows
may be formed from a material having a low reactivity with the
liquid, whereas an outer layer or outer layers of the bag may be
formed from a material having low liquid transfer properties or low
gas transfer properties. The bag may advantageously be formed from
or comprise a substantially inert polymeric material such as
polyethylene or polypropylene.
[0023] It may be particularly advantageous if the collapsible bag
or bellows is formed from a transparent material. This allows the
contents of the bag or bellows to be inspected visually.
[0024] It is preferred that the collapsible container is a bellows
that is directly coupled to the normally-closed valve. This
configuration allows the bellows to be filled directly through the
normally-closed valve, thereby expanding the bellows, and the
liquid will be retained within the bellows when the normally-closed
valve is closed.
[0025] Where the injector comprises a rigid container or body, the
collapsible container may be defined within the rigid container.
For example, the collapsible container may be defined in part by
internal walls of the rigid container and in part by a piston that
is slideably arranged within the rigid container, such that the
volume of the collapsible container varies depending on the
position of the piston. In this arrangement the collapsible
container is similar to that defined within a standard syringe. In
this example, force from the pressurising means may act via the
piston to pressurise the liquid contained within the collapsible
container. Where the collapsible container is defined by internal
walls of the rigid container and a piston, the normally-closed
valve will be coupled to the rigid container, such that the liquid
may be delivered through the valve when the normally-closed valve
is open. The piston in such a piston/cylinder arrangement may be
made of plastic or any other suitable material with or without an
elastomer seal.
[0026] The pressurising means applies a continuous pressure to the
liquid once the collapsible container has been filled. Thus, the
liquid is maintained under pressure during storage before use.
Preferably, the pressurising means for pressurising the liquid
contained within the collapsible container is a biasing element
that exerts a force that acts upon the collapsible container, and
thereby upon the liquid contained within the collapsible container.
Preferably, the force acting to collapse the collapsible container
is generated by a resilient means such as a spring, for example a
compressed helical spring arranged to urge the collapsible
container to collapse.
[0027] Where the collapsible container is in the form of a
collapsible bag or bellows, the pressurising means may
advantageously comprise a spring that forms an integral part of the
collapsible container. For example, walls of the collapsible
container may be connected to or coupled to a spring that acts to
collapse the collapsible container thereby minimising the internal
volume of the collapsible container. On filling with the liquid,
the spring will be extended and the volume of the collapsible
container increased to accommodate the liquid. As the spring is
constantly urging towards its un-extended state it pressurises the
liquid medicament contained within the collapsible container. While
the normally-closed valve is closed, the liquid remains within the
collapsible container. When the normally-closed valve is opened,
however, the pressure exerted by the integral spring urges the
liquid out of the collapsible container through the normally-closed
valve.
[0028] The force that acts to collapse the collapsible container
may be a force generated by a compressed gas or a liquefied gas.
For example, the device may comprise a second collapsible container
containing a gas that is compressed when the collapsible container
is filled with liquid and exerts a force on the collapsible
container. Alternatively, where the collapsible container is
defined within walls of a rigid container, the force may be
generated by a compressed gas acting on a plunger that pressurises
the liquid within the collapsible container.
[0029] It may be preferable that the injector comprises a rigid
container within which the collapsible container and the
pressurising means are housed. The pressurising means may then
apply a force to the collapsible container and the rigid container
simultaneously. As the rigid container is unable to move, the
collapsible container is therefore urged into a collapsed state.
Thus, the injector may comprise a rigid container housing a
collapsible container coupled to a normally-closed valve that
extends through a wall of the rigid container, the rigid container
further comprising or housing a pressurising means that acts to
urge the collapsible container away from an internal surface of the
rigid container. The pressuring means may therefore be a resilient
spring housed within the rigid container, such that it is
compressed when the collapsible container is filled with liquid and
acts to collapse the collapsible container when the normally-closed
valve is opened. The pressurising means may, alternatively,
comprise a compressed gas confined within a second collapsible
container that when compressed generates a force that acts on the
collapsible container to expel liquid from the collapsible
container when the normally-closed valve is opened.
[0030] Advantageously, the pressurising means may comprise a piston
or ram that is urged into contact with the collapsible container.
The piston or ram may be urged by the force of a biasing means such
as a helical spring, or other form of spring, or may be forced into
contact with the collapsible container by means of a compressed gas
or a liquefied gas. Advantageously, the piston or ram may be shaped
to reduce or eliminate dead volume in the collapsible container
when it is collapsed. For example, the piston or ram may comprise a
shaped front portion for contacting the collapsible container, and
this shaped front portion may be any suitable shape, for example a
substantially conical shape. The shaped piston or ram may force the
collapsible container into a shaped portion of the injector, for
example a shaped portion of the rigid container, or a shaped
entranceway to the normally-closed valve, such that the majority of
the contents of the collapsible chamber may be expelled through the
normally-closed valve.
[0031] The normally-closed valve is an openable valve that may be
opened to deliver the liquid or to allow the collapsible container
to be filled with the liquid, but is normally closed to retain the
liquid in a sealed condition within the collapsible container.
Preferably the normally-closed valve is a continuous flow valve or
an aerosol valve. The aerosol valve may be a conventional type male
aerosol valve or a female aerosol valve, although any
normally-closed valve may be used. A conventional aerosol valve
with an axial movement opening may be used, or alternatively a
toggle action aerosol valve may be used, in which the valve is
opened by tilting the valve stem.
[0032] Particularly preferably, the normally-closed valve comprises
a spring that acts to urge the valve into its closed position.
Preferably this spring is a non-metallic spring, for example a
plastic spring. An aerosol valve having such a plastic spring is
described, for example in U.S. Pat. No. 4,471,893. By using a
normally-closed valve comprising a non-metallic spring, the liquid
contents of the collapsible container do not contact any metallic
surface when the injector is in storage. The stability of the drug
within the injector may thus be improved during storage, and safe
storage times may be longer than they would otherwise be. It is
particularly preferred that the normally-closed valve has a
minimised dead space to maximise the percentage of the liquid
contents of the collapsible container that may be delivered.
[0033] The injector may comprise a manually operated switch for
opening the normally-closed valve. For example, the injector may
comprise a button or toggle or switch that a user can actuate once
the injector is in a predetermined position for injection. The
manually operated switch opens the normally-closed valve, thereby
allowing the contents of the collapsible container to be delivered
or dispensed.
[0034] Preferably, the injector comprises an actuator for opening
the normally-closed valve automatically when a predetermined
condition is met. For example, the injector may comprise an
actuator that opens the normally-closed valve when the injector is
pressed against a patient's skin.
[0035] Conventional autoinjectors deliver their full dose of drug
solution after the delivery has been actuated. The use of a
normally-closed valve to control delivery of the liquid in
injectors according to the invention allows the delivery of the
drug to be stopped by closing the valve during delivery, should
this be required. This may be particularly advantageous in
embodiments of the injector that are manually-actuated. This may
allow an injection to be halted if a problem occurs, or allow a
break in the injection cycle. This flexibility is currently only
provided by standard manual injections.
[0036] An injector according to an embodiment of the invention may
comprise a collapsible container containing a liquid, a
normally-closed valve, a rigid container, means of pressurising the
contents of the collapsible bag, and means of piercing skin to
enable injection of the liquid.
[0037] In a preferred configuration, the injector may comprise a
needle injection means for delivering the liquid into the body of a
patient, and the normally-closed valve is arranged to actuate when
the needle has been inserted a predetermined distance into the
patient. This predetermined distance will depend upon the type of
drug or medicament that is being delivered to the patient, and the
tissue type that the delivery is required to be made into. For
example, the injector may be configured to automatically open the
normally-closed valve when the needle reaches a predetermined depth
into the patient's body.
[0038] The switch or actuator for opening the normally-closed valve
may include means for gaining a mechanical advantage, such as a
lever. This arrangement may be advantageous where the force keeping
the normally-closed valve closed is a high one.
[0039] It is particularly preferred that the injection means
comprises a protective sleeve or shield. This is of greatest
advantage where the injector means is a needle, and the protective
sleeve or shield thereby provides a safety mechanism to help
prevent inadvertent needle stick by the user of the injector. A
protective sleeve or shield may also help maintain sterility of the
injection means during storage. A passive needle shield is
described by US 2009/0227956 or U.S. Pat. No. 5,092,851. A manually
activated needle shield may be used, for example, of the type
described in U.S. Pat. No. 4,738,663 or U.S. Pat. No.
4,944,397.
[0040] It is preferred that the injection means is coupled to the
injector during storage, so that a user of the injector has a
minimal number of preparation steps to go through before the
injector is ready to use. It is possible, however, that the
injection means will be supplied separately from the rest of the
injector components and will need to be coupled to the
normally-closed valve by an operator prior to use.
[0041] A particularly advantageous property of the injector is
that, as the liquid within the collapsible container is under
constant pressure, any leak of liquid from the collapsible
container will result in the collapsible container moving. For
example, if a collapsible bellows is used, any leak will result in
the partial collapse of the bellows as the bellows are under a
constant pressure. If the injector has a configuration such that
the bellows can be viewed during use, then any collapse of the
bellows prior to use can be noted. Thus, it is preferred that the
injector comprises a level indicator that shows a user when liquid
has escaped from the collapsible container. A level indicator or
level indicator marks on the injector may also be useful in order
to determine the extent to which the liquid has been delivered from
the injector during use.
[0042] A further advantage of the injector is that the pressurised
system makes it harder for foreign matter or material to
contaminate the liquid contents.
[0043] In a particularly preferred embodiment, an injector for
delivering a liquid medicament comprises a collapsible bellows for
containing the liquid medicament, an aerosol valve coupled to the
collapsible bellows for retaining the liquid medicament within the
collapsible bellows, a hypodermic needle coupled to the aerosol
valve for delivering the liquid medicament from the collapsible
bellows, a rigid container housing the collapsible bellows and
coupled to the normally-closed valve, such that the collapsible
bellows are housed within the rigid container and the
normally-closed valve allows communication with the collapsible
bellows through the walls of the rigid container, and a spring
housed within the rigid container acting to urge the collapsible
bellows to a collapsed state, thereby pressuring liquid medicament
contained within the collapsible bellows such that the liquid
medicament is delivered through the hypodermic needle when the
aerosol valve is opened.
[0044] Particularly preferably, such an injector comprises a piston
or ram disposed between the spring and the collapsible bellows, in
which the spring urges the piston or ram into contact with the
collapsible bellows, thereby pressuring the liquid medicament. Such
a piston or ram may act to guide the force applied by the spring
and stabilise the engagement between the spring and the collapsible
container.
[0045] In an alternative aspect, an injector may comprise a liquid
medicament retained within a collapsible container by a
normally-closed valve, and a needle for injecting the liquid
medicament coupled to the normally-closed valve, in which a force
is arranged to act on the collapsible container, such that the
liquid medicament is delivered through the needle when the
normally-closed valve is opened.
[0046] Preferably, at least an inner surface of the collapsible
container is formed from a polymer, and the normally-closed valve
is formed from a polymer, such that the liquid medicament does not
come into contact with any metallic component while retained within
the collapsible container. Advantageously, the liquid medicament
does not contact the needle until the normally-closed valve is
opened to deliver the liquid medicament. Preferably, the injector
is an injector according to any injector described above, in which
the dead volume of the collapsible container and the
normally-closed valve are low enough to ensure that more than 85%
of the liquid medicament contained within the collapsible container
can be delivered. Many medicaments and drugs are expensive and it
is desirable to reduce waste as much as possible. Particularly
preferably, the injector is configured such that more than 90% or
more than 95%, and particularly preferably, more than 97% of the
liquid medicament contained within the collapsible container may be
delivered.
[0047] Advantageously, the injector may be a hand-held injector. A
healthcare professional may, therefore, be able to carry a number
of injectors each preloaded with a liquid medicament that are
substantially ready for employment in delivering the liquid
medicament. The injector may have improved sterility and stability
of drug contents and may allow a dose of drug to be delivered
simply and effectively.
[0048] Particularly preferably, the injector according to any
embodiment described above is filled with the liquid medicament.
The liquid medicament may comprise a constituent classified within
any one of the following categories of pharmaceuticals or
biopharmaceuticals; Alpha1-Adrenergic Antagonists, Analgesic
Agents, Anaesthetics, Angiotensin Antagonists, Anti-Inflammatory
Agents, Antianxiety Agents, Antiarrhythmics, Anticholinergics,
Anticoagulants, Anticonvulsants, Antidiarrheal Agents,
Antihistamines, Antineoplastics and Antimetabolites,
Antineoplastics and Antimetabolites, Antiplasticity Agents,
Antiulcer Agents, Beta-Adrenergic Antagonists, Bisphosphonates,
Bronchodilators, Cardiac Inotropes, Cardiovascular Agents, Central
Acting Alpha2-stimulants, Contrast Agents, Converting Enzyme
Inhibitors, Dermatologies, Diuretics, Drugs for Erectile
Dysfunction, Drugs of Abuse, Endothelin Antegonists, Hormonal
Agents and Cytokines, Hypoglycemic Agents, Hypouricemic Agents and
Drugs Used For Gout, Immunosuppressants, Lipid Lowering Agents,
Miscellaneous, Psychotherapeutic Agents, Renin Inhibitors,
Serotonergic Antagonist, Steroids, Sympathomimetics, Thyroid and
Antithyroid Agents, and Vasodilators, Vasopeptidase Inhibitors,
Salines, Insulins, Blood factors, Thrombolytic agents, Hormones,
Haematopoietic growth factors, Interferons, Interleukin-based
products, Vaccines, Monoclonal antibodies, Tumour necrosis factors,
Therapeutic enzymes, Antibody-drug conjugates, Biosimilars,
Erythropoietin, Immunoglobulin, Blood and Blood components,
Allergenics, Somatic cells, Gene therapy, Tissues, and Recombinant
therapeutic proteins. The liquid may be any other medicament
existing or in development capable of being injected into animals
or humans.
[0049] An injector as described above may further comprise an
external casing or housing. The casing or housing may itself
comprise features such as needle shields or actuating buttons that
assist in operation of the injector. The casing or housing may also
be shaped to assist a user, for example the casing or housing may
be economically shaped.
[0050] Injections for different medicaments may require different
volumes of drug to be delivered. If using conventional
autoinjectors a separate autoinjector is required for each
pre-filled syringe size. Advantageously, an injector as described
above may be used to deliver a wide range of liquid volumes. The
liquid contents are pressurised by the pressurising means whether
the collapsible container is filled to capacity, only half filled,
or filled to a low percentage of capacity. By varying the fill
volumes, a single size of injector may be used to deliver a wide
range of liquid volumes.
[0051] Conventional syringes and autoinjectors tend to be unsuited
to the delivery of viscous drug solutions. The pressure required to
deliver a viscous solution through an injection means such as a
needle may be high and there is a risk that a syringe may break
under such high pressures. The use of an injector as described
above, preferably an injector in which the collapsible container is
a collapsible bag or bellows, may overcome problems associated with
delivery of viscous drugs. Where the collapsible container is
filled with a viscous liquid, the pressurising means, for example a
spring, may apply a high pressure to the viscous liquid to enable
it to be delivered. The high pressure does not need to act on a
delicate glass syringe and, thus, the injector may be more suitable
for delivery of viscous liquids.
[0052] The invention may provide a method of injecting a liquid,
the liquid being retained under pressure within a collapsible
container of an injector by a normally-closed valve, the method
comprising the steps of positioning the injector to deliver the
liquid to a predetermined position, and opening the normally-closed
valve, such that the liquid is injected. Preferably, the liquid is
a liquid medicament, and the injector is positioned to deliver the
liquid medicament into a patient by injection.
[0053] Once in position, for example, once a needle of the injector
has been inserted into a patient's vein or elsewhere within a
patient's body, the normally-closed valve may be opened manually by
actuating a switch. This configuration allows a user to deliver the
liquid contents of the injector only when he or she is satisfied
that the injector is correctly positioned.
[0054] Where an injection is made using a conventional
auto-injector, the liquid tends to be maintained at atmospheric
pressure during storage before use. On activation, a plunger
applies a pressure to the liquid to effect injection. The sudden
application of pressure causes an initial pressure spike that may
cause discomfort to a patient. The pressure spike may also be
extreme enough to cause breakage of a syringe. Furthermore, where a
plunger is depressed, stiction between the plunger and the syringe
barrel may cause a fluctuating pressure profile during injection.
The use of an injector or method of injection as described above
may considerably alleviate these problems. As the liquid is
maintained under pressure, there is no pressure spike when the
injector is actuated. Furthermore, embodiments that use a
collapsible bellows or similar collapsible bag will not suffer from
the effects of stiction during delivery.
[0055] The method may comprise the step of the normally-closed
valve being opened automatically when the injector is correctly
positioned for delivery. For example, the injector may comprise a
needle, and the normally-closed valve may be actuated when the
needle has been inserted into the patient to a predetermined depth.
Thus, the injector may comprise an actuator that is set to
automatically open the normally-closed valve when the injector has
been positioned in a predetermined position.
[0056] Preferably, the injector used in the method of injecting a
liquid is an injector having any feature or combination of features
described above.
[0057] The invention may further provide a method of manufacturing
an injector for delivering a liquid, for example a liquid
medicament, the method of manufacturing comprising the steps of
coupling a normally-closed valve to a collapsible container,
opening the normally closed valve, filling the collapsible
container with the liquid through the normally-closed valve causing
the collapsible container to expand and deflect a pressuring means,
closing the normally-closed valve to retain the liquid within the
collapsible container, the liquid being pressurised due to a force
exerted on the collapsible container by the pressuring means, and
coupling the normally-closed valve to an injection means for
delivering the liquid from the collapsible container.
[0058] Many conventional auto-injectors have a staked needle. The
liquid drug is, therefore, in contact with the needle during
storage. By filling an injector through a normally-closed valve and
then attaching a needle downstream to the normally-closed valve,
the needle is maintained in a dry condition during storage before
use and cannot, therefore, react with the liquid medicament during
storage.
[0059] The liquid is preferably a liquid medicament.
[0060] Advantageously, the method may further comprise the step of
applying a vacuum to the collapsible container through the
normally-closed valve in order to remove air trapped within the
collapsible container and the normally closed valve prior to
filling. The removal of air may help prevent oxidation of the
liquid or the undesirable solution of gases from the air into the
liquid.
[0061] Preferably, the normally-closed valve is flushed with a
sterilising fluid, for example ethanol, prior to coupling with the
injection means.
[0062] The injector is preferably an injector having any feature or
combination of features described above.
[0063] The injector may comprise a rigid container, and the method
may further comprise the step of removing the air from the rigid
container or flushing the rigid container with an inert gas such as
nitrogen. The inert gas may be sealed within the rigid container
with the collapsible container and the pressurising means. A vacuum
may be applied to the rigid container by known "under the cup"
vacuuming techniques or the rigid container may be evacuated via a
vent defined through the walls of the rigid container.
[0064] The rigid container may contain a vent for allowing gas
within the rigid container to be expelled during filling of the
collapsible container. The method may further comprise the step of
sealing the vent after filling in order to retain sterility and/or
minimise contact between the air and the collapsible container.
[0065] Injectors according to preferred embodiments contain only a
small number of component parts relative to many conventional
auto-injectors. The low number of component parts and technical
simplicity of preferred embodiments allows the cost per unit to be
reduced relative to conventional auto-injectors.
SPECIFIC EMBODIMENTS OF THE INVENTION
[0066] The invention will now be described with reference to the
figures in which;
[0067] FIGS. 1 and 2 are schematic illustrations of an injector
according to an embodiment of the invention,
[0068] FIG. 3 is a schematic illustration of an injector according
to an embodiment of the invention,
[0069] FIGS. 4 and 5 are schematic illustrations of an injector
according to an embodiment of the invention,
[0070] FIG. 6 is a schematic illustration of an injector according
to an embodiment of the invention,
[0071] FIGS. 7 and 8 are schematic illustrations of an injector
according to an embodiment of the invention,
[0072] FIGS. 9 and 10 are schematic illustrations of an injector
according to an embodiment of the invention,
[0073] FIGS. 1 and 12 are schematic illustrations of an injector
according to an embodiment of the invention,
[0074] FIGS. 13 and 14 are schematic illustrations of an injector
according to an embodiment of the invention,
[0075] FIGS. 15 and 16 are schematic illustrations of an injector
according to an embodiment of the invention,
[0076] FIGS. 17 and 18 are schematic illustrations of an injector
according to an embodiment of the invention,
[0077] FIGS. 19, 20 and 21 illustrate the filling of an injector
according to an embodiment of the invention,
[0078] FIGS. 22, 23 and 24 illustrate the filling of an injector
according to an embodiment of the invention,
[0079] FIGS. 25, 26, 27, and 28 illustrate normally-closed valves
suitable for use in an injector according to an embodiment of the
invention,
[0080] FIGS. 29 and 30 are schematic illustrations of an injector
according to an embodiment of the invention,
[0081] FIGS. 31 and 32 are schematic illustrations of an injector
according to an embodiment of the invention,
[0082] FIGS. 33 and 34 are schematic illustrations of an injector
according to an embodiment of the invention,
[0083] FIGS. 35 and 36 are schematic illustrations of an injector
according to an embodiment of the invention,
[0084] FIG. 37 is a schematic illustration of an injector according
to an embodiment of the invention,
[0085] FIGS. 38 and 39 are schematic illustrations of an injector
according to an embodiment of the invention, FIGS. 40 and 41 are
schematic illustrations of an injector according to an embodiment
of the invention,
[0086] FIGS. 42 and 43 are schematic illustrations of an injector
according to an embodiment of the invention,
[0087] FIG. 44 is a cross-sectional representation of an injector
according to a preferred embodiment of the invention,
[0088] FIG. 45 illustrates an exploded view of the component
elements of a valve/bellows sub-assembly of the injector as
illustrated in FIG. 44 and a cross-sectional view of the
sub-assembly,
[0089] FIG. 46 illustrates the component elements of a container
sub-assembly of the injector illustrated in FIG. 44 and a
cross-section view of the subassembly,
[0090] FIG. 47 illustrates the attachment of a needle to form an
injector as illustrated in FIG. 44,
[0091] FIG. 48 illustrates the encasement of the injector as
illustrated in FIG. 44, and
[0092] FIG. 49 illustrates the steps required to use the encased
injector illustrated in FIG. 48.
[0093] FIGS. 1 and 2 schematically illustrate the components and
operation of an injector according to an embodiment of the
invention. A rigid container 1 houses a collapsible bellows 2
containing a liquid drug 10 and a spring 3 for pressurising or
compressing the liquid drug 10. A normally-closed valve 4 connects
the liquid drug 10 contained within the collapsible bellows to a
valve actuator 8 and a needle 6 for delivering the drug.
[0094] FIG. 1 shows the injector before use. The collapsible
bellows 2 are filled with the liquid drug 10 and the collapsible
bellows compresses the spring 3 against an internal wall 1a of the
rigid container 1. In its compressed condition, the spring 3 exerts
a force against both the internal wall of the rigid container 1a
and the collapsible bellows 2, thereby pressurising the liquid drug
10 contained within the bellows. A cap 9 keeps the needle free from
contamination prior to use. The cap 9 may be fixed to the device
with a tamper evident feature.
[0095] When the injector is used, the needle 6 pierces the skin and
enters the body to a predetermined depth depending on the target
location. When the actuator 8 touches the skin and is pressed
against it, the actuator 8 moves towards the rigid container (in
the direction shown by arrow 5) thereby opening the normally-closed
valve 4 and allowing the liquid drug 10 contained within the
bellows 2 to flow through needle 6 under the pressure generated by
spring 3. In FIG. 2 the device is shown after use with the spring 3
extended and the bellows 2 collapsed, the liquid drug contents 10
having been expelled.
[0096] The actuator 8 may comprise a device or element to gain a
mechanical advantage and lower the force required to operate the
actuator. An example is shown in FIG. 3. In the embodiment of an
injector illustrated in FIG. 3, the actuator 8 is coupled to an arm
8a. The arm 8a has a raised portion 8d, which when acted on by a
patient's skin forces actuator 8 inwards as shown by arrow 5. The
arm 8a is supported by a lug 8b and pivoted at a hinge 8c. Other
arrangements are possible.
[0097] Alternatively the actuator may be pressed by a separate
mechanical linkage attached to a finger button. This arrangement
may be spring loaded to aid activation.
[0098] The collapsible bellows 2 may be made of any suitable
plastic such as Polyethylene, ABS, Polycarbonate, Polypropylene,
PPO, PET or any other plastic suitable for blow moulding and
compatible with the liquid drug being stored in the bellows. The
rigid container 1 may be transparent and made from for example PET
plastic or other transparent material.
[0099] In FIG. 4 an embodiment of an injector is schematically
illustrated in which the rigid container 1 incorporates a vent hole
15. This vent hole 15 may allow gas trapped within the rigid
container 1 to escape during filling of the bellows 2.
[0100] FIG. 5 schematically illustrates an embodiment of an
injector substantially the same as that illustrated in FIG. 4, but
in which a plug 16 blocks the vent 15 to prevent further air
entering the rigid container 1 during storage and use.
[0101] If the vent 15 is placed in the rigid container 1, then
after filling the pressure within the rigid container 1 is
atmospheric. If the plug 16 is inserted after filling, the pressure
within the rigid container 1 will decrease as the liquid drug 10 is
delivered and the collapsible bellows 2 collapse.
[0102] FIG. 6 schematically illustrates an embodiment of an
injector in which the actuation of the normally-closed valve is
achieved manually. In FIG. 6 a manually-actuated button arrangement
is shown. A finger lever 18 is pivoted at a pivot point 17 and
attached to actuation member 19. When finger pressure is applied on
lever 18 in the direction of arrow 5a the actuator 8 of the
normally-closed valve 4 is depressed (in the direction of arrow 5)
thereby opening the normally-closed valve 4.
[0103] FIGS. 7 and 8 schematically illustrate an embodiment of an
injector having an automatic or passive needle shield. A shield 11
is shown in FIG. 7 in a retracted position. In FIG. 8 the shield 11
is shown in an extended position covering the needle to prevent
needle stick injuries. A passive needle shield as described in
Patent US 2009/0227956A1 may be suitable, or any other type of
needle shield may be used, preferable a shield which is activated
automatically once the needle 6 is pulled out of the body after
use. Alternatively a manual needle shield may be used which is
activated by the user after use.
[0104] FIGS. 9 and 10 illustrate an embodiment of an injector in
which the collapsible container is formed from a piston and
cylinder arrangement rather than a collapsible bellows. Components
of the injector that are common to the various embodiments of
injectors described above have been given the same reference
numerals. A rigid container 1 is cylindrical in shape and defined a
cylindrical internal cavity. The rigid container 1 houses a piston
21 with a seal 22 that contacts an internal wall 1b of the rigid
cylinder. The piston 21 and the internal walls 1b of the rigid
container 1 define a collapsible chamber for containing a liquid
drug 10.
[0105] Before use, the piston 21 rests against a seal 23, which may
be a flexible seal or a spring loaded seal, to minimise drug
evaporation and gas interchange. A spring 3 urges against the
piston 21 and an end wall 1a of the rigid container, compressing
the liquid contents 10 of the collapsible container and expelling
them via a needle 6. The piston 21 may be associated with more than
one seal 22. The piston is preferably made of a plastic or
elastomer, and in some cases a separate seal 22 may not be
needed.
[0106] FIGS. 11 and 12 are schematic illustrations of an injector
according to an embodiment of the invention in which the means for
pressurising the liquid drug 10 is provided by a gas 31. The gas 31
may be a compressed gas such as Nitrogen or Air or a liquefied gas
such as HFA134a or HFA227.
[0107] In other embodiments, a combination of a spring 3 and gas 31
may be used or a combination of gases. A gas 31 may be introduced
into the rigid container 1 by `under the cup` filling or any other
way.
[0108] FIGS. 13 and 14 illustrate an embodiment of an injector in
which an additional piston 21 is used to further separate a
pressurising gas 31 from a liquid 10 contained in collapsible
bellows 2. The gas 31 is filled through hole and plug 35. A further
vent 36 in the rigid container 1 ensures that any gas leak past
piston seal 22 does not enter bellows 2 (which may contaminate the
liquid drug) and is vented through vent 26 instead. In this way a
liquefied gas such as HFA134a can be used to keep pressure on
bellows 2 constant without the risk of any gas entering bellows 2
if there is a failure of seal 22.
[0109] FIGS. 15 and 16 are schematic illustrations of an injector
embodiment comprising a double bellows system. A first collapsible
bellows 2 contains the drug 10 and a second collapsible bellows 37
contains a compressible gas 31. The second bellows 37 may be filled
via hole and plug 35. When the first bellows 2 is filled with the
drug 10 as shown in FIG. 15, the second bellows and the
compressible gas 31 are compressed. The compressed gas 31 provides
a force that acts to pressurise the liquid drug 10 contained in the
first bellows 2. When the normally-closed valve 4 is opened the
compressed gas 31 is allowed to expand, thereby expelling the
liquid 10 through the needle 6.
[0110] FIGS. 17 and 18 illustrate an alternative embodiment of an
injector where a compressible gas 31 is stored in a collapsible
bellows 37 and the liquid drug 10 is contained by a piston/cylinder
type collapsible chamber as described above. A vent hole 36 in the
rigid container 1 is now located near the bellows 37.
[0111] FIGS. 19 to 21 schematically illustrate the assembly and
filling process of an injector of the type described above in
relation to FIGS. 1 and 2. In FIG. 19 a rigid container 1 has
within a collapsible bellows 2 attached to a normally-closed valve
4 and compressed by a spring 3. In the first assembly operation the
spring 3 is dropped into the rigid container 1. In the second
assembly operation the valve and bellows assembly is crimped to the
container, thereby pre-compressing the spring 3.
[0112] A vacuum is then applied as shown by arrow 49a to remove air
trapped in the valve and bellows.
[0113] In FIG. 20 an arrow 49b indicates the filling of contents 10
via the valve 4 into the bellows 2 thereby expanding the bellows 2
and further compressing the spring 3. If the container 1 is
completely sealed with no vent hole then any gas (usually air)
trapped within the container 1 is also compressed, creating an
additional energy source acting to compress the bellows 2. Air may
be replaced with Nitrogen before fixing valve 4 to the rigid
container 1 to minimise Oxygen within the container 1 that might
affect the content 10 of the bellows 2.
[0114] After filling the drug contents via the valve into the
bellows 2 the liquid passageways of the valve 4 are preferably
flushed with a clean liquid such as ethanol or any other suitable
liquid or any suitable gas or a gas and liquid mixture or
separately by both to ensure sterility before sealing with the cap
7 as shown in FIG. 21.
[0115] In FIG. 21 a needle assembly comprising cap 7, needle 6 and
actuator 8 is clipped sealingly into position. The cap 7 keeps all
the surfaces including the needle sterile after the assembly.
[0116] The assembly is preferably done in a clean room or aseptic
conditions or environment or in an aseptic isolator or other
sterile environment. The device components are either sterilised
before filling by any suitable means such as ethylene oxide gas,
radiation, steam autoclaving, dry heat or other method. The drug
solution may be sterilised by any suitable method or any of the
above methods or by aseptic filtration especially in the case of
biopharmaceuticals.
[0117] FIGS. 22, 23, and 24 schematically illustrate the filling of
an injector embodiment as described above in relation to FIGS. 4
and 5. The rigid container 1 of the injector defines a vent 91 that
allows any gas trapped in the container 1 to escape during filling.
A plug 92 may be placed in vent 91 to prevent any air entering
after filling.
[0118] The rigid container or body may be made of a transparent
material such as plastic or glass for visual inspection of the
device.
[0119] FIG. 25 illustrates a typical normally-closed valve which is
suitable for use in an injector according to the invention. The
valve is shown together with an attached bellows 54. FIG. 25
illustrates a male aerosol valve. It has a body 53 with a spring 52
within. A stem 57 has stem orifice 59 sealingly mounted against an
inner gasket 55. A bellows 54 is sealingly connected to the valve
body 53. When the stem 57 is depressed into the valve body 53 (the
direction of arrow 58) the valve opens by exposing the stem orifice
59 to the pressurised liquid contents which are inside the valve
cavities 61 and 63.
[0120] After filling the bellows 54 with drug contents via the
valve, the valve stem 57 passageway 62 and stem orifice 59 (or
gasket and cup in the case of a female valve) are preferably
flushed with a clean liquid such as ethanol or any other suitable
liquid or any suitable gas or a gas and liquid mixture or
separately by both to ensure sterility.
[0121] It is preferable that the dead volumes 61, 62 and 63 in the
valve are kept to a minimum.
[0122] The bellows 54 and valve body 53 may be moulded as one part
in any suitable plastic material.
[0123] FIG. 26 illustrates a normally-closed valve in which the
dead volume 61 is much reduced by eliminating the metal spring
(spring 52 in FIG. 25). In FIG. 26 the valve comprises a spring 65
that is formed as part of the plastic stem 57. This eliminates the
extra material of a separate spring and may help in minimising any
drug stability issues. The valve shown in FIG. 26 can be
manufactured from two materials. The stem 57 and spring 65, body 53
and bellows 54 can all be made from a single plastic. The only
other material in contact with the drug solution is a gasket
55.
[0124] FIG. 27 illustrates a normally-closed valve in which a stem
orifice 59 is located above an inner gasket 55 when the valve is
closed and the stem passageway 62 is shortened to end at the point
that the stem orifice 59 enters the stem 57. This may assist the
flushing and cleaning of the stem after filling.
[0125] FIG. 28 illustrates a valve/bellows arrangement in which the
bellows has concave bottom section 67. This configuration may help
to minimise dead volume in the bellows when it is fully collapsed
at the end of device use.
[0126] FIGS. 29 and 30 schematically illustrate an embodiment of an
injector comprising a manual needle shield. The rigid container 1
forming the injector body has an outer case or cover 71, which
locates and holds a shield 72 in position. A needle 6 is initially
protected by a cap 9 prior to use as shown in FIG. 29. In FIG. 29
the shield 72 is shown in a pre-use position. In FIG. 30 it is
shown in an activated position after being slid forward in
direction of arrow 73 by the user.
[0127] A mechanical arrangement (not shown) locks the shield 72 in
position so that the needle 6 is protected, thereby helping to
prevent any needle stick injuries.
[0128] FIGS. 31 and 32 schematically illustrate an embodiment of an
injector comprising an after use indicator. A window defined
through the rigid container 1 allows a view of the bellows 2
within. After use, a marker 82 is visible through the window 81
indicating that the full dose has been injected. The injector is
operated as normal by removing cap 9 and activating the injector by
moving actuator 4 and needle 6 in direction of arrow 5.
[0129] FIGS. 33 and 34 schematically illustrate an embodiment of an
injector comprising an alternative needle shield arrangement. An
injector with a needle 6 has a protective cap 9, a hinged needle
shield 92 hinged at a pivot point 93 and attached to container 1 by
a strut 91. After removing the cap 9 and using the injector by
emptying the bellows 2, the shield 92 is pivoted into its
protective position covering needle 6 as shown by arrow 96.
[0130] FIGS. 35 and 36 schematically illustrate an embodiment of an
injector having an alternative arrangement of an actuator to open
the normally-closed valve. An actuator 4 is attached to a handle
101. To operate, after insertion of the needle into the body, a
user places two fingers on finger pads 105 and another finger such
as the thumb at a thumb contact point 106 on the rigid container 1
and presses as indicated by arrows 102 and 103. The container 1 is
forced in the direction of arrow 103, depressing the actuator 8 and
opening the normally-closed valve 4. Contents of the bellows 2 are
forced out via needle 6 by spring 3.
[0131] FIG. 37 schematically illustrates an embodiment of an
injector having an alternative arrangement of an actuator to open
the normally-closed valve. The injector includes a casing defining
two finger pads 105a and 105b. When inserting the needle 6 into a
body, the finger pads 105b and thumb contact point 106 are pushed
in the direction of arrows 102b and 103. To operate the injector, a
user squeezes the finger pads 105a and point 106 on container 1 in
the direction of arrows 102a and 103. This ensures a smooth and
easy operation of the device as fingers can remain in the same
place during needle insertion and injection.
[0132] FIGS. 38 and 39 schematically illustrate an embodiment of an
injector in which an actuator 101 doubles as a needle shield. After
use, the rigid container 1 is pulled back until spring loaded catch
111 engages to prevent the container 1, which carries the needle 6,
being pushed out again, thereby making the device safe after use.
Lugs 115 and 116 prevent the container 1 and needle 6 being
completely separated from the actuator/shield 101.
[0133] FIGS. 40 and 41 schematically illustrate an embodiment of an
injector in which an actuator 101 is spring loaded by means of a
spring 112. The spring 112 is activated at the end of the injection
by a release mechanism (not shown).
[0134] FIGS. 42 and 43 schematically illustrate an embodiment of an
injector in which a piston or ram 121 is placed in between bellows
2 and spring 3 to transfer the spring's energy to the bellows 2.
The piston or ram may ensure that the bellows 2 are pressurised
evenly. The piston or ram may also act as an indicator, showing the
level of liquid drug 10 contained within the bellows 2.
[0135] An injector as described herein may be used to inject any
class of drug anywhere in the body of both humans and animals. Both
conventional drugs and biopharmaceuticals may be used with the
device. The injector may be filled with diluent for lyophilized
drug reconstitution.
[0136] A cross-sectional view of an injector according to a
preferred embodiment of the invention is illustrated in FIG. 44.
The injector 1000 comprises a substantially cylindrical rigid
container 1001 formed from transparent PET polymer. The rigid
container 1001 defines a substantially cylindrical internal cavity
1101 which houses a transparent collapsible bellows 1002, a helical
spring 1003, and a polymeric piston or ram 1121 located between the
collapsible bellows 1002 and the helical spring 1003. The
collapsible bellows 1002 is formed from polypropylene and is
coupled to a normally-open aerosol valve 1004. The normally-open
aerosol valve 1004 is crimped to an opening of the rigid container
1001, thereby sealing the contents of the rigid container.
[0137] A liquid medicament 1010 contained within the collapsible
bellows 1002 is maintained under pressure by a force exerted on the
collapsible bellows 1002 by the helical spring 1003 by means of the
ram 1121. The ram 1121 is formed as an injection moulded
polypropylene component and acts as a guide to the force exerted by
the spring 1003. The ram helps to ensure that the pressure from the
spring is applied evenly to the collapsible bellows.
[0138] A hypodermic needle 1006 is coupled to the aerosol valve
1004 by way of an actuating element 1008 which acts to open the
normally-closed aerosol valve 1004 when the actuator 1008 is
depressed. A cap 1009 shields the hypodermic needle 1006.
[0139] An upper surface of the ram 1121 is bevelled or formed into
a substantially conical shape 1122. Furthermore, an insert 1130 is
disposed within the chamber 1101 of the rigid container 1001
between the collapsible bellows 1002 and the aerosol valve 1004.
This insert 1130 has a bevelled surface that substantially matches
the bevelled surface of the ram 1121.
[0140] FIGS. 45 to 47 illustrate the steps taken to manufacture an
injector according to the embodiment illustrated in FIG. 44.
[0141] FIG. 45 illustrates the steps required to manufacture a
bellows/valve sub-assembly 1300. A bellows is physically connected
to an aerosol valve 1004 with an insert 1130 disposed in between.
This coupling may be by a suitable means such as by welding or by
adhesive connection.
[0142] FIG. 46 illustrates the components required to assemble a
container sub-assembly 1400. The container sub-assembly is formed
from the transparent rigid container 1001, the helical spring 1003
and the ram 1121. The helical spring is placed within the rigid
container 1001 and the ram 1121 slides over an upper surface of the
helical spring.
[0143] The components forming the valve/bellows sub-assembly and
the container sub-assembly are sterilised, for example by gamma
irradiation.
[0144] On assembly, any air within the rigid container cavity 1101
is removed and replaced with an inert atmosphere of nitrogen. This
is achieved by known "under the cup" vacuuming techniques. The
valve/bellows sub-assembly is inserted into the container
sub-assembly and the valve is crimped to attach the valve/bellows
sub-assembly to the rigid container sub-assembly and to seal the
rigid container.
[0145] The collapsible bellows 1002 is filled with a liquid drug,
or with a mixture of soluble powdered drug and a suitable solvent
such as water for injection such that a liquid drug is formed, and
then the normally-closed valve is closed to retain the liquid
within the collapsible bellows. The act of inserting the liquid
into the collapsible bellows causes the helical spring 1003 to
compress. Thus, the liquid within the collapsible bellows is under
pressure and will be released from the device when the aerosol
valve is opened.
[0146] FIG. 47 illustrates the coupling of the hypodermic needle to
the aerosol valve.
[0147] It is preferred that the injector comprises an ergonomic
outer casing. Thus, the injector 1000 may be further encased by an
outer casing 1500, a needle shield/actuator 1550 and a removable
cap 1600.
[0148] The outer casing 1500 includes a transparent window 1510
through which the ram 1121 and the helical spring 1003 of the
injector 1000 may be seen.
[0149] The needle shield/actuator 1550 acts to shield the
hypodermic needle 1006 until it is actually used, and
simultaneously acts to depress the actuator 1008 when the needle
has been inserted to a predetermined depth. The cap 1600 maintains
cleanliness and sterility of the device until use. The result of
the encasement of the injector 1000 is an encased injector 2000
that is ready for shipment to a user.
[0150] FIG. 49 illustrates the steps involved in using the encased
injector 2000.
[0151] In step A the user removes the cap 1600, thereby exposing
the needle shield/actuator. The encased injector 2000 is then
pressed into the user as illustrated in step C. The needle shield
is depressed and the needle extends beyond the needle shield,
thereby piercing the patient's skin. When the needle has reached a
predetermined depth the valve 1004 is opened, thereby automatically
releasing the liquid medicament contained within the injector into
the patient.
* * * * *