Dry powder inhalers

1. A dry powder inhalation device comprising:

a chamber; a patient port in communication with said chamber;

a compartment housing an elongate carrier preloaded with a plurality of doses of finely divided powder comprising a biologically active substance, said powder being releasably retained on a surface of the carrier, said compartment being configured such that said preloaded doses are sealed within said compartment and such that the carrier may be advanced from the compartment to the chamber through an exit provided with a moisture barrier sealing system;

an advancement mechanism for advancing a portion of the carrier from the compartment to within the chamber so that the powder associated with an advanced area of the carrier can be released from the carrier for inhalation by the patient through the patient port;

wherein the moisture barrier sealing system is configured and arranged such that it is relaxable during advancement of the carrier, said sealing system being in sealing configuration prior to an advancement of the carrier, relaxed upon an advancement of the carrier and returned to its sealing configuration at the latest after release of the powder associated with said area of the carrier.

2. A device according to claim 1 , wherein the compartment is provided within a cassette and said cassette is reversibly removable from the dry powder inhaler.

3. A device according to claim 2 , wherein the cassette is a refill cassette.

4. A device according to claim 1 , wherein said exit of the compartment is the only opening in the compartment; and/or wherein the compartment further houses a desiccator; and/or wherein part or all the interior portions of the walls of the compartment comprise a desiccant.

5. A device according to claim 1 , wherein the moisture barrier sealing system comprises a seal.

6. A device according to claim 5 , wherein the seal comprises a material having a Shore A durometer value equal to or less than 75 and/or wherein the seal comprises a material having a Shore A hardness value equal to or greater than 35; and/or wherein the seal comprises an elastomeric material selected from the group consisting of silicone rubber, EPDM, polypropylene blends, styrene-isoprene copolymers, combinations and mixtures thereof.

7. A device according to claim 1 , wherein the moisture barrier sealing system is configured and arranged such that the sealing system is returned to its sealing configuration at least prior to release of the powder associated with said area of the carrier.

8. A device according to claim 7 , wherein the device further comprises a clamping system, wherein said clamping system is configured and arranged such that it is moved into a clamping configuration at least prior to release of the powder associated with said area of the carrier and wherein said clamping system and said moisture barrier sealing system are configured and arranged relative to one another such that said area of the carrier will be clamped between the clamping system and the moisture barrier sealing system during release of the powder associated with said area of the carrier.

9. A device according to claim 8 , wherein the clamping system is configured and arranged so that when the carrier is being advanced, the clamping system is out of its clamping configuration.

10. A device according to claim 1 , wherein the moisture barrier sealing system is configured and arranged such that the sealing system is returned to its sealing configuration upon cessation of advancement of the carrier.

11. A device according to claim 1 , wherein the moisture barrier sealing system comprises a seal coupled to a moveable member that is engaging a spring, said spring urging the moveable member in a first direction such that the moisture barrier seal seals the compartment exit, and wherein upon advancement of the carrier under the tension associated with the advancement of the carrier the moveable member moves in the opposite direction, so that the moisture barrier seal disengages, opening the compartment exit thereby allowing the carrier to advance through the exit, and wherein upon cessation of advancement of the carrier, the moveable member moves in its original direction under the force of the spring, so that the moisture barrier seal seals the compartment exit, in particular wherein said movement of said moveable member comprises a substantially rotational or linear movement.

12. A device according to claim 1 , where the device further comprises a first clamping system and a second clamping system, wherein the first and second clamping systems are configured and arranged such that said first and second clamping systems are moved into a clamping configuration at least prior to release of the powder associated with said area of the carrier, so that said area of the carrier will be clamped between the first and the second clamping systems during release of the powder associated with said area of the carrier.

13. A device according to claim 12 , wherein the clamping systems are configured and arranged so that when the carrier is being advanced, the clamping systems are out of their clamping configurations.

14. A device according to claim 1 , wherein the elongate carrier is in the form of a tape or a web.

15. A device according to claim 1 , wherein the elongate carrier is wound on a spool within said compartment, in particular a spool comprising an anti-unspooling mechanism, more particularly a spool comprising a friction brake.

16. A device according to claim 1 , wherein the elongate carrier does not comprise a lid component.

17. A device for storing dry powder for use in a dry powder inhaler, said device provided in the form of a cassette comprising:

a compartment housing an elongate carrier preloaded with a plurality of doses of finely divided powder comprising a biologically active substance, said powder being releasably retained on a surface of the carrier; said compartment being configured such that preloaded doses are sealed within said compartment and such that the carrier may be advanced from the compartment to the outside of the compartment through an exit provided with a moisture barrier sealing system,

wherein said device is configured and arranged such that during use in a dry powder inhaler wherein a portion of the carrier is advanced so that the powder associated with an advanced area can be released from the carrier for inhalation by the patient through the patient port of the inhaler, the moisture barrier sealing system is relaxable during advancement of the carrier, so that said sealing system is in sealing configuration prior to an advancement of the carrier, will relax upon an advancement of the carrier and will be returned to its sealing configuration at the latest after release of the powder associated with said area of carrier.

18. A device according to claim 17 , wherein the device is configured and arranged such that during use in a dry powder inhaler, the sealing system will be returned to its sealing configuration at least prior to release of the powder associated with said area of the carrier.

19. A device according to claim 18 , wherein the device further comprises a clamping system, wherein the device is configured and arranged such that during use in a dry powder inhaler, the clamping system is movable, said clamping system being moved into a clamping configuration at least prior to release of the powder associated with said area of the carrier and such that said area of the carrier will be clamped between the clamping system and the moisture barrier sealing system during release of the powder associated with said area of the carrier.

20. A device according to claim 17 , wherein the device is configured and arranged such that during use in a dry powder inhaler, the sealing system will be returned to its sealing configuration upon cessation of advancement of the carrier.