A dry powder inhalation device comprising: a chamber; a patient port in communication with said chamber; a storage device comprising a cassette, 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, and a moisture barrier sealing system; an advancement mechanism for advancing a portion of the carrier within the chamber so that the powder associated with an advanced area of the carrier can be released from the carrier for inhalation by a patient through the patient port; and a hammer configured to strike the portion of the carrier within the chamber to release at least some of the powder from the carrier, characterized in that, the moisture barrier sealing system comprises a first clamping system and in that the storage device further comprises a second clamping system, wherein said storage device is configured and arranged such that during use in a dry powder inhaler a portion of the carrier is advanced out of the cassette so that the powder associated with an advanced area can be released from the carrier for inhalation by a patient, and the first and second clamping systems (111,125) are configured to be 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 (111,125) during release of the powder associated with said area of the carrier; further characterized in that at least one of the first and second clamping systems (111,125) comprises a grip. a chamber; a patient port in communication with said chamber; a storage device comprising a cassette, 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, and a moisture barrier sealing system; an advancement mechanism for advancing a portion of the carrier within the chamber so that the powder associated with an advanced area of the carrier can be released from the carrier for inhalation by a patient through the patient port; and a hammer configured to strike the portion of the carrier within the chamber to release at least some of the powder from the carrier, characterized in that, the moisture barrier sealing system comprises a first clamping system and in that the storage device further comprises a second clamping system, wherein said storage device is configured and arranged such that during use in a dry powder inhaler a portion of the carrier is advanced out of the cassette so that the powder associated with an advanced area can be released from the carrier for inhalation by a patient, and the first and second clamping systems (111,125) are configured to be 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 (111,125) during release of the powder associated with said area of the carrier; further characterized in that at least one of the first and second clamping systems (111,125) comprises a grip.