591957 Disclosed are an inhaler； a method of priming an inhaler and a method of a medicament from an inhaler. The breath activated inhaler ensures that sealed medicament compartments (16) are properly aligned with the outlet prior to releasing the medicament (16) to the patient, and indexes the next compartment (16) into alignment with the outlet so that next time the patient uses the inhaler； a dose is ready for delivery. The inhaler comprises an outlet； a plurality of sealed compartments (16) containing medicament； an opening mechanism (32)； an indexing mechanism and a latch (56). The opening mechanism (32) moves between an energised position and an unloaded position. During movement from the energized position to the unloaded position the opening mechanism (32) opens a sealed compartment (16) aligned with the outlet. The indexing mechanism sequentially aligns the compartments (16) with the outlet. The indexing mechanism is adapted to align the next compartment (16) with the outlet after the opening mechanism (32) has been moved from the unloaded position to the energised position. The latch (56) moves between a first position and a second position. In the first position, the latch (56) latches the opening mechanism (32) in the energised position. In the second position the latch (56) allows the opening mechanism (32) to move to the unloaded position. The latch (56) is partly arranged in a flow path such that an inhalation flow through the flow path affects the latch (56) to move from the first position to the second position. The latch (56) is prevented from returning to the first position before the indexing mechanism has aligned the next compartment (16) with the outlet. A catch connected to and movable with the indexing mechanism prevents the latch (56) from reaching the first position.
