Inhalers and Related Methods

Abstract

A nasal inhaler for the inhalation of inhalable substances comprise: a canister having an interior reservoir containing pressurised inhalable substances including fluid; a metering valve including a metering chamber and a valve stem defining a communication path between the metering chamber and the interior reservoir, the communication path including an opening configured to permit flow between a transfer space inside the valve stem and the interior reservoir, the interior reservoir being arranged for orientation above the metering chamber whereby gas located within the metering chamber is replaced with liquid from the interior reservoir.

What is claimed is: 
     
         1 . A nasal inhaler for the inhalation of inhalable substances, the inhaler comprising:
 a canister having an interior reservoir containing pressurized inhalable substances including fluid;   a metering valve including a metering chamber and a valve stem defining a communication path between the metering chamber and the interior reservoir, the communication path including an opening configured to permit flow between a transfer space inside the valve stem and the interior reservoir, the interior reservoir being arranged for an orientation above the metering chamber whereby gas located within the metering chamber is replaceable with liquid from the interior reservoir.   
     
     
         2 . The nasal inhaler of  claim 1 , in which the opening is configured to permit flow in a direction with an axial component along the valve stem directly between the transfer space inside the valve stem and the interior reservoir. 
     
     
         3 . The nasal inhaler of  claim 1  in which the communication path is configured to permit liquid to flow under pressure along the communication path to the metering chamber and gas to flow in a reverse direction therealong from the metering chamber into the interior reservoir. 
     
     
         4 . The nasal inhaler of  claim 1  in which the opening comprises an elongated opening. 
     
     
         5 . The nasal inhaler of  claim 1  further comprising at least one additional opening into the communication path. 
     
     
         6 . The nasal inhaler of  claim 5  in which the at least one additional opening is diametrically opposed to the first said opening. 
     
     
         7 . The nasal inhaler of  claim 1  in which the valve stem has at least one opening into the interior reservoir with an axially oriented portion facing directly axially along a longitudinal axis of the valve stem into the interior reservoir for the flow of fluid directly into the communication path in an axial direction along the valve stem. 
     
     
         8 . The nasal inhaler of  claim 1  further comprising a metering chamber exit port for venting the metering chamber to atmosphere via a stem block and/or nozzle. 
     
     
         9 . The nasal inhaler of  claim 8 , further comprising a canister fire system for ejecting inhalable substances from the inhaler in response to air flow by closing communication between the metering chamber and the interior reservoir and opening communication between the metering chamber and atmosphere. 
     
     
         10 . The nasal inhaler of  claim 9  further comprising a drive for driving the canister relative to the valve stem, the drive including a drive spring. 
     
     
         11 . The nasal inhaler of  claim 10  further comprising an actuator system for operating the drive, wherein the actuator system is actuatable by air flow. 
     
     
         12 . The nasal inhaler of  claim 9  in which the canister fire system is adapted to depress the valve stem into the canister to cause inhalable substances to be ejected from the inhaler and to hold the valve stem depressed with the metering chamber communicating with atmosphere. 
     
     
         13 . The nasal inhaler of  claim 12  in which the canister fire system includes a reset actuator which is operable so as to extend the valve stem relative to the canister in order to close communication between atmosphere and the metering chamber and to open communication between the metering chamber and the interior reservoir. 
     
     
         14 . The nasal inhaler of  claim 1  which includes inhalable substances in the interior reservoir which include at least one propellant. 
     
     
         15 . The nasal inhaler of  claim 14  in which the at least one said propellant comprises a hydrofluoroalkane comprising 1,1,1,2-tetrafluoroethane. 
     
     
         16 . The nasal inhaler of  claim 14  in which the at least one said propellant has a surface tension at 25° C. of about 6 to 10 mN/m, about 7 to 9 mN/m, or about 8 mN/m. 
     
     
         17 . The nasal inhaler of  claim 1  which includes at least one inhalable substance in the interior reservoir as an active ingredient, wherein the active ingredient comprises beclomethasone dipropionate or tiotropium bromide in suspension or in solution. 
     
     
         18 . The nasal inhaler of  claim 1  which includes a dose counter for counting doses, wherein the dose counter is configured to make one count with each inhalation of a dose. 
     
     
         19 . The nasal inhaler of  claim 1  in which the dose counter includes: (a) a tape bearing dose indicia for displaying counts and/or (b) an actuator pin for contact with the canister, or a body movable therewith, for counting doses, and preferably a dose counter chamber separated by a barrier from an inner space of the inhaler for containing the canister, the actuator pin extending out of the dose counter chamber through an aperture in the wall for contact during counting with the canister or the body movable therewith. 
     
     
         20 . The nasal inhaler of  claim 1  which is a breath actuated inhaler. 
     
     
         21 . The nasal inhaler of  claim 1  which is a metered dose inhaler. 
     
     
         22 . The nasal inhaler of  claim 1  which includes a reset actuator which when actuated prevents exposure of the metering chamber to atmosphere, wherein the inhaler provides 75 to 125% of a dose following exposure of the metering chamber to atmosphere for a time period which is more than one minute. 
     
     
         23 . The nasal inhaler of  claim 1  in which the inhaler provides 75 to 125% of a dose following exposure of the metering chamber to atmosphere for a time period which is more than two minutes. 
     
     
         24 . The nasal of  claim 1  in which the inhaler provides 75 to 125% of a dose following exposure of the metering chamber to atmosphere for a time period which is one hour, more than one hour, 24 hours or more than 24 hours. 
     
     
         25 . The nasal of  claim 1  which includes a metering valve spring and an opposing canister spring for drivingly firing the canister, the metering valve spring, canister spring and metering valve being arranged in the inhaler such that an equilibrium of various forces is achieved in at least one ready-to-fire configuration of the inhaler. 
     
     
         26 . The nasal inhaler of  claim 25  which is adapted to operate including at least one suction force; the suction force configured to operate against the canister spring.