fig1 shows a section view of an example of an autoinjector in accordance with the present invention . the drug 1 is housed in a substantially gas - permeable inner container 2 which preferably includes a cyclic olefin polymer or other drug - compatible material in contact with the drug 1 . this is enclosed within a substantially gas - impermeable outer container 3 . the inner container 2 is sealed with a first substantially gas - permeable seal 4 which preferably includes a cyclic olefin polymer or other drug - compatible material in contact with the drug 1 . the outer container 3 is sealed by a substantially gas - impermeable second seal 5 . this is shown in fig2 , at larger scale for clarity . the outer container is made from a substantially gas - impermeable rigid material such as evoh or polyamide . both the inner and outer containers are held within a rigid syringe body which includes an outer housing , needle shield 7 , locking arm 8 and needle - holding hub 13 . in order to activate the autoinjector , the front of the autoinjector 6 is pressed onto the patient &# 39 ; s skin , which causes the needle shield 7 to move , releasing a locking arm 8 which is engaged with an engaging detail 9 on the external surface of the outer container 3 . this allows the locking arm 8 to disengage with the engaging detail 9 , releasing a main drive spring 10 . this main drive spring 10 is arranged so that it can drive the inner container 2 and outer container 3 axially through the autoinjector causing a hollow hypodermic needle 11 to be driven forward into the patient . the spring 10 also causes the first seal 4 and second seal 5 to be pierced by a piercing detail 12 on the back of the hollow hypodermic needle 11 . the needle 11 is attached to the needle - holding hub 13 which continues to move relative to the inner container 2 after the seals 4 and 5 have been pierced due to the force of the spring 10 . this in turn causes the plunger 14 to be driven axially through the inner container 2 expelling the drug 1 through the needle 11 and into the patient . fig3 shows a section view of the autoinjector of fig1 at a point after the drug has been administered to the patient . the plunger 14 has moved relative to the inner container . 2 to expel the drug through the needle 11 . the first seal 4 and second seal 5 have been broken by the needle 11 and the needle holding hub 13 . fig4 is a part view of fig3 shown at a larger scale for clarity . it will be obvious to those skilled in the art that this design can be implemented in different ways . for instance , the seals could be pierced by a component other than the back of the needle , for instance part of the back of the needle holding hub 13 . fig5 shows a sectional view of a drug container and gas barrier arrangement for one embodiment of the invention . this arrangement could be incorporated into a syringe or an autoinjector such as the autoinjector of fig1 , and comprises a drug 1 , a separate , gas - permeable inner container 2 and substantially gas - permeable first seal 4 , and a separate substantially gas - impermeable outer container 3 and second substantially gas - impermeable seal 5 , and a plunger 14 , as described above . fig6 shows a sectional view of a drug container and gas barrier arrangement for another embodiment of the invention . this differs from the design of fig5 in that it involves a substantially gas - permeable inner container 2 and a substantially gas - impermeable outer container 3 which are co - moulded together , with a separate substantially gas - permeable first seal 4 and separate second substantially gas - impermeable seal 5 . fig7 shows a sectional view of a drug container and gas barrier arrangement for another embodiment of the invention . this differs from the design of fig5 in that it involves a substantially gas - permeable inner container 2 and a separate substantially gas - impermeable outer container 3 , with a substantially gas - permeable first seal 4 in contact with the drug and second substantially gas - impermeable seal 5 joined to the back of the first seal 4 on the opposite side from the drug 1 so that the two seals comprise a single multi - laminate film 15 which seals both the substantially gas - permeable inner container 2 and the substantially gas - impermeable outer container 3 . fig8 shows a sectional view of an alternative version of the design shown in fig6 incorporating a single multi - laminate film 15 which seals both the substantially gas - permeable inner container 2 and the substantially gas - impermeable outer container 3 as described above for fig7 . fig9 shows a sectional view of an alternative version of the design shown in fig6 which incorporates a third co - moulded layer of substantially moisture - impermeable material 16 which protects the substantially gas - impermeable outer container 3 from excessive humidity . typically the inner container 2 , the outer container 3 and the third layer 16 are all co - moulded together . the design incorporates a separate substantially gas - permeable first seal 4 and separate second substantially gas - impermeable seal 5 . fig1 shows a sectional view of an alternative version of the design shown in fig9 which incorporates a single multi - laminate film 15 which seals both the substantially gas - permeable inner container 2 and the substantially gas - impermeable outer container 3 as described above for fig7 . fig1 shows an alternative version of the design shown in fig5 where a separate substantially gas - impermeable outer container 3 incorporates an additional co - moulded layer of substantially moisture - impermeable material 16 which protects the substantially gas - impermeable outer container 3 from excessive humidity . fig1 shows an alternative version of the design shown in fig1 which incorporates a single multi - laminate film 15 which seals both the substantially gas - permeable inner container 2 and the substantially gas - impermeable outer container 3 as described above for fig7 . fig1 shows an alternative version of the design shown in fig7 where the outer container comprises a thin coating 17 of a substantially gas - impermeable material such as silicon oxide or aluminium oxide applied to the external surfaces of the substantially gas - permeable inner container 2 . this coating may or may not extend partially or all of the way across that surface of the inner container 33 which is sealed to the combined first and second seals 15 . fig1 shows a section view of an example of a separate substantially gas - permeable inner container 2 containing a plunger 14 and filled with drug 1 and sealed with a substantially gas - permeable first seal 4 . in all of the designs of fig5 to 14 , the inner container 2 is enclosed by the outer container 3 , preventing any significant ingress of gases , and in particular oxygen , into the drug contact container . this is necessary in order to provide for a sufficient shelf - life for many drugs . it is envisaged that any of the designs embodied in fig5 to 14 might constitute in whole or part that portion of an autoinjector or syringe which would be filled in a first appropriate environment such as an aseptic environment and then be subsequently assembled to part or all of the autoinjector or syringe in a second separate environment as described above . although not specifically illustrated here it is envisaged that any of the seals described above could be sealed to the appropriate container by any of a number of possible different means obvious to those skilled in the art . these means include heat welding , induction welding , laser welding , ultrasonic welding , spin welding , hot plate welding , use of an adhesive including ultraviolet light curing adhesive , and use of a separate retaining component with or without an additional elastomeric compression component where the separate retaining component is itself screwed , snapped or welded to the appropriate container . fig1 , 16 , 17 and 18 illustrate another embodiment of the invention . fig1 shows a section view of an example of a syringe in accordance with the present invention . the drug container and gas barrier arrangement is shown in detail in fig1 . the syringe incorporates a needle hub assembly which includes a needle cover 28 which can be removed by the user so that the needle hub assembly 13 can then be pushed back towards the substantially gas - permeable first seal 4 and substantially gas - impermeable seal 5 by the user so that a piercing detail 12 at the back of a needle 11 is caused to pierce both the aforementioned first substantially gas - permeable seal 4 and the aforementioned second substantially gas - impermeable seal 5 so that the drug 1 is placed in fluid communication with the hollow hypodermic needle 11 . a dispensing button 21 can be pressed by the user to cause a piercing detail 22 to pierce another substantially gas - impermeable seal 24 forming part of the outer container and another substantially gas - permeable seal 23 forming part of the inner container and force the plunger 14 axially through the inner container 2 to expel the drug 1 . the needle cover 28 can be attached to the remainder of the syringe by a push fitting , as shown , by a screw fitting or by any other suitable means . similarly , the needle - holding hub 13 can be coupled to the body of the syringe by a push fitting or a screw fitting . fig1 shows the same syringe as shown in fig1 at a point after the drug has been delivered . fig1 shows an exploded view of the syringe of fig1 . fig1 shows a sectional exploded view of the syringe of fig1 . the needle - holding hub 13 is prevented from moving until desired by the user . this can be achieved in several ways , including mounting the needle cover 18 around the needle - holding hub so that it contacts the outer container of the syringe , or including a tear - off strip between the needle - holding hub and the body of the syringe . it is also possible to incorporate a mechanism into the needle - holding hub such that removal of the needle cover 28 causes the needle - holding hub to move towards the drug container 2 and break the seals 4 , 5 . the needle - holding hub 13 can include a screw thread that is received in a threaded bore formed in the syringe body . the needle cap can also be connected to the needle - holding hub by a screw connection , such that initial rotation of the needle cover 28 causes rotation of both the needle cover and the needle holding hub , causing the needle - holding hub to travel along the threaded bore . this causes the needle to pierce the first and / or second seals . continued rotation of the needle cover after the needle - holding hub has reached the end of the threaded bore , causes separation of the needle cover from the needle - holding hub . fig1 shows a section view of the drug container and gas barrier arrangement of fig1 . this comprises a substantially gas - permeable inner container 2 and a substantially gas - impermeable outer container 3 co - moulded together . in this embodiment of the design a substantially gas - impermeable seal 5 is maintained in a sealing position against an opening in the substantially gas - impermeable outer container 3 due to the action of an elastomeric compression washer 25 retained by a compression washer retainer 26 , and a separate substantially gas - permeable first seal 4 seals a substantially gas - permeable inner container 2 . the syringe of fig1 - 19 includes a rigid syringe body , held by the user when dispensing the drug . the rigid syringe body is formed by the dispensing button 21 , the inner and outer containers 2 , 3 , retainer 26 , needle hub assembly 13 and cover 28 . the other arrangements of seals and containers described in fig5 - 13 could equally be applied to the syringe design of fig1 - 18 and to other embodiments of syringes and autoinjectors . fig2 shows a section view of an alternative version of the autoinjector of fig1 where the substantially gas - impermeable seal 5 is positioned between the needle 11 and the front of the autoinjector 6 which is pressed against the patient during administration of the drug . the gas - impermeable seal 5 seals an opening in a substantially gas - impermeable lower sleeve 31 which contains a portion of the needle 11 . a substantially gas - impermeable barrier is formed from the substantially gas - impermeable outer container 3 , the substantially gas - impermeable lower container 29 , a substantially gas - impermeable lower sleeve 31 and a substantially gas - impermeable needle - holding hub 13 which includes a substantially gas - impermeable sealing feature 30 which seals with the lower container 29 and a second substantially gas - impermeable sealing feature 32 which seals with the lower sleeve 31 . fig2 is a part view of fig2 shown at a larger scale for clarity . fig2 shows a section view of the autoinjector of fig2 at a point after the drug has been administered to the patient . the plunger 14 has moved relative to the inner container 2 to expel the drug through the needle 11 . the first seal 4 has been broken by the needle 11 and the needle holding hub 13 and second seal 5 has been broken by the other end of needle 11 nearest to the patient . fig2 is a part view of fig2 shown at a larger scale for clarity . fig2 shows a section view of an alternative version of the syringe of fig1 where a substantially gas - impermeable needle cover 28 which is removed by a user before administration of the drug to a patient comprises a substantially gas - impermeable seal . a substantially gas - impermeable container , which also forms the outer rigid body of the syringe , encloses the drug contact container 2 , and is formed from the substantially gas - impermeable outer container 3 , a substantially gas - impermeable upper seal 24 , a substantially gas - impermeable elastomeric compression washer 25 , a substantially gas - impermeable compression washer retainer 26 , a substantially gas - impermeable needle - holding hub 13 , which includes a substantially gas - impermeable sealing feature 30 which seals with the compression washer retainer 26 and a second substantially gas - impermeable sealing feature 32 which seals with the needle cover 28 . on removal of the needle cover 28 , the user simply pushes the needle - holding hub 13 towards the drug container 2 , in order that the needle 11 pierces the seal 4 , allowing the drug to be dispensed through the needle . fig2 is a part view of fig2 shown at a larger scale for clarity . fig2 shows the same syringe as shown in fig2 at a point after the needle cover 28 has been removed by a user and the drug has been delivered . fig2 shows an alternative version of the syringe of fig2 where the action of the user pushing the button 21 causes the back of the needle 12 to pierce the substantially gas permeable seal 4 . in order to administer the drug to the patient the user removes a manually removable needle shield 28 , which forms part of the gas barrier as described for fig2 , and then applies the front of the syringe 6 to an appropriate area of the patient . the user then presses the button 21 which causes the inner substantially gas permeable container 2 and outer substantially gas impermeable container 3 to move axially towards the patient within rigid outer casing 34 , causing the front of the needle 11 to move forwards into the patient and the rear of the needle 12 to pierce a substantially gas permeable seal 4 . this movement of the button 21 also causes piercing details 22 to pierce an upper substantially gas impermeable seal 24 and an upper substantially gas permeable seal 23 and then cause the plunger 14 to be urged axially through the inner container 2 causing the drug to be urged through the needle 11 into the patient . fig2 shows the syringe of fig2 at a point after the drug has been administered to the patient . it will be obvious to those skilled in the art that the designs described above in fig2 and fig2 can be implemented in different ways . for instance , the seal 4 could be pierced by a component other than the needle such as the needle holding hub 13 . the outer substantially gas - impermeable container could be sealed by a substantially gas impermeable seal 5 attached directly to it as described in fig5 to fig1 so that the seal 5 is pierced by the back of the needle 12 due to movement of the button 21 . features of fig2 and 28 could also be implemented in an autoinjector .
the invention provides a syringe for dispensing a drug , comprising : a rigid syringe body ,— a first container , in contact with and enclosing the drug ; and a second container , enclosing the first container , the second container being less gas permeable than the first container , wherein the second container partially or fully forms the rigid syringe body or is held within the rigid syringe body . the invention preserves the drug but allows the drug to be easily accessed without the need for a user to remove a gas barrier structure as a separate action in addition to the other actions needed to deliver the drug .