Inhaler

1. An inhaler comprising a housing containing a strip of blisters each blister being defined by a blister cavity containing a dose of medicament and a puncturable lid, the inhaler including means to sequentially move each blister into alignment with means for puncturing said puncturable lid of a blister to enable a user to inhale said dose through said puncturable lid and, a spiral wound element in the said housing, the blister cavities, together with their punctured lids, being received in said spiral wound element to coil the strip, wherein the housing includes a common chamber to receive an unused blister strip and a used portion of that strip, wherein a flexible dividing wall separates the chamber into a used and unused blister compartment, the flexible dividing wall comprising a foam strip.

2. An inhaler according to claim 1 , wherein the flexible dividing wall is fixed to the housing at both ends.

3. An inhaler according to claim 1 , wherein the dividing wall is flexible and configured so that it extends across said common chamber between sidewalls of the inhaler to prevent passage of powdered dose between the unused and used blister compartments.

4. An inhaler according to claim 3 , wherein the width of the flexible dividing wall is greater than the distance between the sidewalls so that the flexible dividing wall is held in compression between the sidewalls.

5. An inhaler according to claim 1 , wherein the foam strip includes a stiffening element.

6. An inhaler according to claim 1 , comprising a second spiral wound element to receive an unused blister strip for insertion into the housing during assembly, the arrangement being such that the second spiral wound element retracts as the first spiral wound element expands as the size of the coil formed from a used portion of the strip increases and the size of the coil formed from an unused portion of the strip decreases.

7. An inhaler comprising a housing to receive a strip of blisters, and an actuator to sequentially move each blister into alignment with means for opening a blister to enable a user to inhale a dose, the housing including a chamber to receive used blisters and, the inhaler further comprising an indexing wheel around which emptied blisters are fed and which rotates in response to movement of said actuator to draw the blister strip through the housing and sequentially align each blister with said means for opening a blister, the indexing wheel being configured such that blister cavities are partially squashed between the indexing wheel and a wall of the housing to compress said blister cavities as they pass around the indexing wheel.

8. An inhaler according to claim 7 , wherein the indexing wheel comprises a plurality of spokes extending from a hub and the blister strip comprises a plurality of blister cavities each containing a dose of medicament and a lid sealing the dose within said cavities prior to inhalation, the blister cavities being entrained, together with their lids, between the spokes of the indexing wheel such that the blister cavities are sequentially moved into alignment with means for opening a blister in response to rotation of the indexing wheel, the indexing wheel being configured such that a distance between a surface of the hub and a wall of the housing is less than a height of a blister cavity so that the blister cavities and lids are partially squashed between the hub and said wall of the housing as they pass around the indexing wheel.

9. An inhaler according to claim 8 , wherein the lid is puncturable and the means for opening the lid of a blister comprises means for puncturing said lid to enable a user to inhale said dose through said punctured lid.

10. An inhaler comprising a housing containing a strip of blisters each having a blister cavity containing a dose of medicament with a puncturable lid extending over and sealing said dose within the blister cavity, and an actuator to sequentially move each blister into alignment with means for puncturing the lid of an aligned blister to enable a user to inhale said dose, the housing including a first compartment to contain unused blisters cavities with their lids intact and a second compartment, separated from the first compartment by a movable dividing wall, to receive used blister cavities together with their punctured lids, the inhaler further comprising an indexing wheel around which the used blister cavities and their punctured lids are fed and which rotates in response to movement of said actuator to draw the blister strip through the housing and sequentially align each unused blister cavity with said means for puncturing a blister, the indexing wheel being configured such that used blister cavities, together with their punctured lids, are partially squashed between the indexing wheel and a wall of the housing to compress said blister cavities and punctured lids as the strip passes around the indexing wheel.

11. An inhaler comprising a housing containing a strip of blisters each having a blister cavity containing a dose of medicament with a puncturable lid extending over and sealing said dose within the blister cavity, and an actuator to sequentially move each blister into alignment with means for puncturing the lid of an aligned blister to enable a user to inhale said dose, the inhaler further comprising an indexing wheel around which the used blister cavities and their punctured lids are fed and which rotates in response to movement of said actuator to draw the blister strip through the housing and sequentially align each unused blister cavity with said means for puncturing a blister, the indexing wheel being configured such that used blister cavities, together with their punctured lids, are partially squashed between the indexing wheel and a wall of the housing to compress said blister cavities and punctured lids as the strip passes around the indexing wheel, a spiral wound element being mounted in the housing such that the compressed blister cavities, together with their punctured lids, are received in the spiral wound element to coil the strip.

12. An inhaler comprising a device having a housing containing a strip of blisters each having a blister cavity containing a dose of medicament with a puncturable lid extending over and sealing said dose within the blister cavity, and an actuator to sequentially move each blister into alignment with means for puncturing the lid of an aligned blister to enable a user to inhale said dose, the housing including a first compartment to contain unused blisters cavities with their lids intact and a second compartment, separated from the first compartment by a movable dividing wall, to receive used blister cavities together with their punctured lids, the inhaler further comprising an indexing wheel around which the used blister cavities and their punctured lids are fed and which rotates in response to movement of said actuator to draw the blister strip through the housing and sequentially align each unused blister cavity with said means for puncturing a blister, the indexing wheel being configured such that used blister cavities, together with their punctured lids, are partially squashed between the indexing wheel and a wall of the housing to compress said blister cavities and punctured lids as the strip passes around the indexing wheel, a spiral wound element being mounted in the second compartment such that the compressed blister cavities, together with their punctured lids, are received in the spiral wound element to coil the strip.