Abstract: An inhaler, such as a breath-actuated metered-dose inhaler, for delivering medicament to a patient. The inhaler includes a housing for holding the medicament and having an air inlet and a medicament delivery port which together define an air flow path into which the medicament is dispensed. The air inlet includes an array of elongate apertures formed in the housing, the long sides of adjacent apertures facing each other. Each aperture is provided with a respective different opening in an outer surface of the housing. The opening of each aperture extends in two different planes such that, if at least a part of the opening is covered in one of the two different planes during inhalation by the patient, a void space is created between the cover and the aperture so as to provide an air flow path through the void space to the at least one aperture.

Abstract: A manually operated metered dose inhaler includes a dose counter chamber including a dose display tape driven by a ratchet wheel which is driven in turn by an actuator pawl actuated by movement of a canister, the tape unwinding from a stock bobbin during use of the inhaler, a rotation regulator being provided for the stock bobbin and including a wavelike engagement surface with concavities which engage against control elements in the form of protrusions on resilient forks of a split pin thereby permitting incremental unwinding of the stock bobbin yet resisting excessive rotation if the inhaler is dropped onto a hard surface.