WO1992012799A1 - Metered dose atomising and delivery device - Google Patents
Metered dose atomising and delivery device Download PDFInfo
- Publication number
- WO1992012799A1 WO1992012799A1 PCT/GB1992/000087 GB9200087W WO9212799A1 WO 1992012799 A1 WO1992012799 A1 WO 1992012799A1 GB 9200087 W GB9200087 W GB 9200087W WO 9212799 A1 WO9212799 A1 WO 9212799A1
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- WIPO (PCT)
- Prior art keywords
- flow
- duct
- fluid
- hydraulic diameter
- spray
- Prior art date
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M15/00—Inhalators
- A61M15/0091—Inhalators mechanically breath-triggered
- A61M15/0093—Inhalators mechanically breath-triggered without arming or cocking, e.g. acting directly on the delivery valve
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M15/00—Inhalators
- A61M15/0028—Inhalators using prepacked dosages, one for each application, e.g. capsules to be perforated or broken-up
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
- B05B7/1404—Arrangements for supplying particulate material
- B05B7/1413—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising a container fixed to the discharge device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/24—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device
- B05B7/2402—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising containers fixed to the discharge device
- B05B7/2405—Apparatus to be carried on or by a person, e.g. by hand; Apparatus comprising containers fixed to the discharge device using an atomising fluid as carrying fluid for feeding, e.g. by suction or pressure, a carried liquid from the container to the nozzle
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B9/00—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
- B05B9/03—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
- B05B9/04—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump
- B05B9/08—Apparatus to be carried on or by a person, e.g. of knapsack type
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2202/00—Special media to be introduced, removed or treated
- A61M2202/06—Solids
- A61M2202/064—Powder
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2205/00—General characteristics of the apparatus
- A61M2205/07—General characteristics of the apparatus having air pumping means
- A61M2205/071—General characteristics of the apparatus having air pumping means hand operated
- A61M2205/073—Syringe, piston type
Definitions
- the present invention relates to a metered dose atomising * and delivery device, notably one in which a dose of 5 medicament is atomised by the velocity gradient within a flow of fluid having an annular flow.
- 35 sized spray without the need for a very fine nozzle orifice By suitable selection of the operating parameters of the spray device, it is possible to achieve sprays with a mass median particle size of less than 12 micrometres, which is the size required for administration of medicamants via inhalation into the lung of a user. Since the need for a fine nozzle orifice to achieve such fine particle sized sprays may be avoided, the present invention reduces the problems of nozzle blockage with the earlier proposal.
- the present invention provides a method for forming a flow of fluid into a spray of fine particle size, notably one with a mass median particle size less than 12 micrometres, which method is characterised in that the flow is caused to adopt an annular flow through a duct and in that the velocity gradient within that flow is sufficient to cause shear between components of the flow to break the flow up into a spray, preferably without the need to use a fine nozzle aperture to atomise the flow.
- annular flow denotes a flow having substantially concentric annular zones flowing parallel to one another, but with the axial flow velocity increasing towards the radially innermost zone.
- the flow velocity can increase towards the radially outward zone.
- the invention will be described hereinafter in terms of a flow whose velocity increases towards the centre.
- the velocity gradient represents the increase in velocity from one zone to the next and will be a positive gradient towards the centre or longitudinal axis of the duct in which the fluid flows.
- the velocity gradient may increase progressively so that the zones effectively have no sharp boundary or interface between one another.
- the gradient it is within the scope of the present invention for the gradient to increase stepwise, for example at the interface between two phases of the flow, as when a gas flows through a static measured dose of a powder or fluid to entrain the powder or fluid, or when one fluid flows as a faster stream within a sheath of a slower flowing other fluid, the atomisation being due to the shear action of the velocity differential between the gas flow and the static material or the two fluid flows at the interface between them.
- the velocity differential between the radially inward and outward components of the flow will be at least 250 to 350 metres per second.
- shear forces due to the velocity differential which are required to form a flow into a spray will depend upon a number of factors: for example the viscosity and surface tension of the fluid; the pressure drop to which the flow is subjected and the hydraulic diameter of the duct through which the fluid flows; and the particle size required in the spray to be produced.
- the fluid can be a gas or a liquid and the flow can be substantially homogeneous, as when an aqueous solution of a medicament is passed through a duct; or can be composed of different phases, as when a gas is used to spray a dose of a fluid or powdered medicament.
- the viscosity and surface tension of the fluid can vary over very wide ranges.
- a homogeneous fluid it will usually be preferred that this be an aqueous solution so that the viscosity and surface tension of the fluid typically be similar to that of water, eg. within the ranges 0.75 to 10 Cps at 25°C and 30 to 80 dynes per cm at 25°C.
- the fast flowing fluid is preferably a gas, notably a pulse of pressurised air, and the other phase is provided by a measured dose of a fluid or powdered medicament through which the gas stream is directed.
- the optimum flow velocity differential will also depend upon the pressure drop to which the fluid is exposed as it flows through the duct, in that the higher the pressure drop, the larger the hydraulic diameter which can be used to achieve a given droplet size range spray.
- the term hydraulic diameter is used herein to denote the cross-sectional area of the duct divided by the one quarter of the circumference of the duct. In the case of a circular cross-section duct, the hydraulic diameter will be the same as the actual diameter.
- the volume of fluid required to be atomised at each operation of the atomising device will also affect the pressure and hydraulic diameter selected.
- the method of the invention for example, where it is desired to form a spray of an aqueous solution with a mass median droplet size less than 12 micrometres, we prefer to operate the method of the invention with an hydraulic diameter in the range 1 to 1000, eg. 5 to 100, micrometres at a pressure differential of from 150 to 500 bar, preferably 200 to 400 bar.
- the pressure differential required to atomise the outer layer of the flow may be as low as from 5 to 50 bar, for example from 6 to 15 bar in the case of a powder which is atomised by a gas flow
- the hydraulic diameter of the duct may be from 500 to 2000, preferably from 500 to 1000, micrometres.
- the optimum pressure drop and hydraulic diameter can readily be determined in any given case by simple trial and error tests.
- the volume of the gas stream required is less than 5%, typically about 1 to 2% of that required in a nebuliser, thus enabling the method of the invention to be operated in hand portable devices.
- the volume of the air stream at ambient temperature and pressure is typically from 100 to 1500 times the volume of the fluid or powder to be atomised.
- the atomisation of the fluid flow can be achieved in a tubular duct, in which case the spray is usually formed at the open end of the duct as the flow exits the duct.
- the duct is typically the outlet tube to a pressure generating device, for example pressurised gas container or a spring loaded gas or fluid pump, notably one which is held in the cocked state against the action of a compression spring by a trigger or latch mechanism.
- the duct can be a smooth walled duct and the length of the duct can be selected over a wide range provided that the length of the duct does not affect the formation of the annular flow by imposing excessive frictional forces at the outer layers of the flow in contact with the duct wall.
- the bore of the duct can taper so as to accelerate the flow as it passes along the duct to enhance the atomisation when the flow exits the open end of the duct.
- the flow may be preferred to atomise the flow by passing it through a restricted nozzle orifice at the outlet end to a broader diameter duct, the nozzle aperture having a hydraulic diameter in the range specified above and the duct having a greater hydraulic diameter.
- the cross-sectional shape of the bore of the duct or of the nozzle aperture is preferably circular, but other cross- section shapes, for example an irregular cross-section or a polygonal cross-section may be used if desired.
- several ducts or nozzles may be used to form a more broadcast spray pattern and/or to increase the volume output from a given device, in which case each duct or nozzle aperture preferably has the same hydraulic diameter to provide a substantially even spread of the spray pattern. Where a nozzle aperture is used, it is preferred that any changes in the diameter of the duct or tube feeding the flow of material to the nozzle aperture be decreases in the hydraulic diameter and not increases.
- the method of the invention provides a simple method by which the fluid can be atomised into fine droplet sized sprays without the need for a nozzle orifice and thus reduces the cost and complexity of the atomizing devices required and the risk of nozzle orifice blockage.
- the required dose of such a fluid to be dispensed can be achieved by any suitable means, for example by sucking the required dose into the cylinder of a spring loaded pump which generates the required high pressure and hence flow velocity differentials when the pump mechanism is released and the fluid ejected through a smooth walled duct.
- the dose of fluid can be achieved by feeding a dose of fluid into an atomisation chamber by injecting the required dose by any suitable mechanism or by a suitable invert and fill dosage mechanism.
- the dose can be achieved by mounting a cartridge or other container containing the required amount of fluid or powder upon the outlet to the pump mechanism or other pressurised gas generator, and releasing the pulse of pressurised air or gas through the cartridge or container.
- a cartridge can be formed as a disposable item so that each operation of the pressure generating device requires a new cartridge, thus ensuring accuracy of dosage and minimising the risk of any blockage of the outlet tube which is carrier by the cartridge and hence is replaced with the cartridge.
- the fluid or powder to be atomised is preferably a medicament and the invention provides a process for dispensing a medicament which comprises atomising a flow containing the medicament using the method of the invention.
- Figure 1 is a diagrammatic axial cross-section through a device for dispensing a measured dose of a powdered or fluid medicament
- Figure 2 is a diagrammatic axial cross- section through an alternative form of the device of Figure 1.
- a piston 11 is located in a cylinder 12 and loaded by a spring 13.
- the piston 11 is connected by an axial rod 14 to a handle 17 which allows the piston 11 to be pulled back against the bias of spring 13.
- a latch or other detent mechanism acting on handle 17 or rod 14 retains piston 11 in the fully retracted position against the bias of spring 13, ie. in the loaded position.
- piston 11 moves axially within cylinder 12 to pressurise the air in the cylinder 12 to a pre-determined value dependant on the spring 13 and piston 11 diameter.
- An aerosol valve of the conventional female kind is located at the outlet to cylinder 12 and comprises a body 30, a spring 31, a stem 32, a stem holder 33 and a gasket 36.
- An actuator 40 is mounted above stem 32 and a retaining ring 41 holds said gasket 36 in position.
- a predetermined dose of liquid or powdered drug 50 is stored within the stem 32 and this is forced out of the stem and atomised when said actuator 40 is depressed, allowing the pressurised gas in cylinder 12 to flow into passageway 52 via orifice 53.
- the orifice 53 is sized to control the flow of air into the stem.
- stem 32 When depressed by actuator 40, stem 32 depresses stem holder 33 breaking contact between said holder 33 and seal 36 allowing gas to enter the base of stem 32 and flow through the stored drug 50.
- the volume of air at atmospheric pressure is larger than the volume of liquid drug, substantially annular flow will be set up within stem 32 atomising the liquid as the gas passes up said stem 32 and actuator 40.
- the annular flow reduces the risk of blockage of the ste bore.
- the ratio of the volume of gas at atmospheric pressure to the volume of liquid drug is greater than 100:1 and preferably between 500:1 and 1500:1. In the case of the powdered drug this ratio can be less than 100:1.
- the stem 32 with drug 50 and actuator 40 are formed as a detachable unit which can be replaced after each use. In this way, a clean stem and actuator are used for every dose, minimising blockage and contamination.
- the exit orifice 41 of actuator 40 and the bottom of stem 32 are preferably each sealed with a transverse membrane which is punctured before use.
- the actuator 40 could be spring loaded and actuated by a predetermined amount of air flow into lungs set up when the user breathes in.
- a body 80 is secured to the cylinder 12 by a snap fit lug 81.
- a spring 83 is located within said body 80 and exerts a force on the actuator 40 which is prevented from moving by a catch 85, which forms part of a flap 86 hinged at point 87 which when in the ready position blocks off an air passageway 88.
- a mouthpiece 90 is formed within body 80.
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- Heart & Thoracic Surgery (AREA)
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Abstract
The present invention provides a method for forming a flow of fluid into a spray of fine particle size, notably one with a mass median particle size less than 12 micrometres, which method is characterised in that the flow is caused to adopt an annular flow through a duct and in that the velocity gradient within that flow is sufficient to cause shear between components of the flow to break the flow up into a spray, preferably without the need to use a fine nozzle aperture to atomise the flow.
Description
TITLE: METERED DOSE ATOMISING AND DELIVERY DEVICE
V The present invention relates to a metered dose atomising * and delivery device, notably one in which a dose of 5 medicament is atomised by the velocity gradient within a flow of fluid having an annular flow.
BACKGROUND TO THE INVENTION:
10 Many forms of device exist for dispensing powders or fluids as sprays. Many of those devices utilise a pressurised propellant to discharge the powder or fluid through a spray nozzle aperture. However, the use of CFC and liquefied gas propellants is becoming increasingly unacceptable from
15 environmental aspects and alternative methods for forming powder or liquid sprays are being saught. This is particularly important where the fluid is a medicament where the medicament is not readily soluble in the propellants used hitherto and the use of co-solvents may introduce
20 secondary components into the medicament composition which are undesirable.
It has been proposed to subject a fluid to a sudden increase in pressure which has been generated mechanically and to
25 eject the pressurised fluid through a very small nozzle aperture to form a spray. However, this requires that the fluid be substantially free from solid particles and/or that the fluid be filtered upstream of the nozzle orifice. Problems of nozzle blockage may thus arise and limit the
30 utility of this method for atomising the fluid.
*>
We have now found that the velocity differential within a t flow can be used to generate sufficient shear forces within the flow to cause the flow to break up into a fine particle
35 sized spray without the need for a very fine nozzle orifice.
By suitable selection of the operating parameters of the spray device, it is possible to achieve sprays with a mass median particle size of less than 12 micrometres, which is the size required for administration of medicamants via inhalation into the lung of a user. Since the need for a fine nozzle orifice to achieve such fine particle sized sprays may be avoided, the present invention reduces the problems of nozzle blockage with the earlier proposal.
SUMMARY OF THE INVENTION:
Accordingly, the present invention provides a method for forming a flow of fluid into a spray of fine particle size, notably one with a mass median particle size less than 12 micrometres, which method is characterised in that the flow is caused to adopt an annular flow through a duct and in that the velocity gradient within that flow is sufficient to cause shear between components of the flow to break the flow up into a spray, preferably without the need to use a fine nozzle aperture to atomise the flow.
The term annular flow as used herein denotes a flow having substantially concentric annular zones flowing parallel to one another, but with the axial flow velocity increasing towards the radially innermost zone. Alternatively, the flow velocity can increase towards the radially outward zone. For convenience, the invention will be described hereinafter in terms of a flow whose velocity increases towards the centre.
The velocity gradient represents the increase in velocity from one zone to the next and will be a positive gradient towards the centre or longitudinal axis of the duct in which the fluid flows. The velocity gradient may increase progressively so that the zones effectively have no sharp
boundary or interface between one another. However, it is within the scope of the present invention for the gradient to increase stepwise, for example at the interface between two phases of the flow, as when a gas flows through a static measured dose of a powder or fluid to entrain the powder or fluid, or when one fluid flows as a faster stream within a sheath of a slower flowing other fluid, the atomisation being due to the shear action of the velocity differential between the gas flow and the static material or the two fluid flows at the interface between them. Typically, the velocity differential between the radially inward and outward components of the flow will be at least 250 to 350 metres per second.
The shear forces due to the velocity differential which are required to form a flow into a spray will depend upon a number of factors: for example the viscosity and surface tension of the fluid; the pressure drop to which the flow is subjected and the hydraulic diameter of the duct through which the fluid flows; and the particle size required in the spray to be produced.
The fluid can be a gas or a liquid and the flow can be substantially homogeneous, as when an aqueous solution of a medicament is passed through a duct; or can be composed of different phases, as when a gas is used to spray a dose of a fluid or powdered medicament. Thus, the viscosity and surface tension of the fluid can vary over very wide ranges. Where a homogeneous fluid is used, it will usually be preferred that this be an aqueous solution so that the viscosity and surface tension of the fluid typically be similar to that of water, eg. within the ranges 0.75 to 10 Cps at 25°C and 30 to 80 dynes per cm at 25°C. Where a multi-phase fluid is used, the fast flowing fluid is preferably a gas, notably a pulse of pressurised air, and
the other phase is provided by a measured dose of a fluid or powdered medicament through which the gas stream is directed.
The optimum flow velocity differential will also depend upon the pressure drop to which the fluid is exposed as it flows through the duct, in that the higher the pressure drop, the larger the hydraulic diameter which can be used to achieve a given droplet size range spray. The term hydraulic diameter is used herein to denote the cross-sectional area of the duct divided by the one quarter of the circumference of the duct. In the case of a circular cross-section duct, the hydraulic diameter will be the same as the actual diameter. The volume of fluid required to be atomised at each operation of the atomising device will also affect the pressure and hydraulic diameter selected.
For example, where it is desired to form a spray of an aqueous solution with a mass median droplet size less than 12 micrometres, we prefer to operate the method of the invention with an hydraulic diameter in the range 1 to 1000, eg. 5 to 100, micrometres at a pressure differential of from 150 to 500 bar, preferably 200 to 400 bar. However, where a non-homogeneous flow is used so that an interface is formed at which the shear forces act, the pressure differential required to atomise the outer layer of the flow may be as low as from 5 to 50 bar, for example from 6 to 15 bar in the case of a powder which is atomised by a gas flow, and the hydraulic diameter of the duct may be from 500 to 2000, preferably from 500 to 1000, micrometres. The optimum pressure drop and hydraulic diameter can readily be determined in any given case by simple trial and error tests.
Specifically, in the case where an air stream is used to
atomise a dose of a fluid or powder, we have found that satisfactory atomisation can be achieved with a surprisingly smaller amount of the gas flow than with a conventional nebuliser or other means and with a low pressure drop. Typically, the volume of the gas stream required is less than 5%, typically about 1 to 2% of that required in a nebuliser, thus enabling the method of the invention to be operated in hand portable devices. The volume of the air stream at ambient temperature and pressure is typically from 100 to 1500 times the volume of the fluid or powder to be atomised.
The atomisation of the fluid flow can be achieved in a tubular duct, in which case the spray is usually formed at the open end of the duct as the flow exits the duct. The duct is typically the outlet tube to a pressure generating device, for example pressurised gas container or a spring loaded gas or fluid pump, notably one which is held in the cocked state against the action of a compression spring by a trigger or latch mechanism. The duct can be a smooth walled duct and the length of the duct can be selected over a wide range provided that the length of the duct does not affect the formation of the annular flow by imposing excessive frictional forces at the outer layers of the flow in contact with the duct wall. If desired, the bore of the duct can taper so as to accelerate the flow as it passes along the duct to enhance the atomisation when the flow exits the open end of the duct.
However, it may be preferred to atomise the flow by passing it through a restricted nozzle orifice at the outlet end to a broader diameter duct, the nozzle aperture having a hydraulic diameter in the range specified above and the duct having a greater hydraulic diameter.
The cross-sectional shape of the bore of the duct or of the nozzle aperture is preferably circular, but other cross- section shapes, for example an irregular cross-section or a polygonal cross-section may be used if desired. If desired, several ducts or nozzles may be used to form a more broadcast spray pattern and/or to increase the volume output from a given device, in which case each duct or nozzle aperture preferably has the same hydraulic diameter to provide a substantially even spread of the spray pattern. Where a nozzle aperture is used, it is preferred that any changes in the diameter of the duct or tube feeding the flow of material to the nozzle aperture be decreases in the hydraulic diameter and not increases.
Where the fluid is a liquid, the method of the invention provides a simple method by which the fluid can be atomised into fine droplet sized sprays without the need for a nozzle orifice and thus reduces the cost and complexity of the atomizing devices required and the risk of nozzle orifice blockage. The required dose of such a fluid to be dispensed can be achieved by any suitable means, for example by sucking the required dose into the cylinder of a spring loaded pump which generates the required high pressure and hence flow velocity differentials when the pump mechanism is released and the fluid ejected through a smooth walled duct. Alternatively, the dose of fluid can be achieved by feeding a dose of fluid into an atomisation chamber by injecting the required dose by any suitable mechanism or by a suitable invert and fill dosage mechanism.
Alternatively, notably when a dose of a powder is to be dispensed, the dose can be achieved by mounting a cartridge or other container containing the required amount of fluid or powder upon the outlet to the pump mechanism or other pressurised gas generator, and releasing the pulse of
pressurised air or gas through the cartridge or container. Such a cartridge can be formed as a disposable item so that each operation of the pressure generating device requires a new cartridge, thus ensuring accuracy of dosage and minimising the risk of any blockage of the outlet tube which is carrier by the cartridge and hence is replaced with the cartridge.
As indicated above, the fluid or powder to be atomised is preferably a medicament and the invention provides a process for dispensing a medicament which comprises atomising a flow containing the medicament using the method of the invention.
DESCRIPTION OF THE DRAWING:
To aid understanding of the invention, a preferred form thereof will now be described by way of illustration only with respect to the accompanying drawings, in which Figure 1 is a diagrammatic axial cross-section through a device for dispensing a measured dose of a powdered or fluid medicament; and Figure 2 is a diagrammatic axial cross- section through an alternative form of the device of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT:
A piston 11 is located in a cylinder 12 and loaded by a spring 13. The piston 11 is connected by an axial rod 14 to a handle 17 which allows the piston 11 to be pulled back against the bias of spring 13. As the piston 11 is withdrawn in cylinder 12, it sucks air at ambient pressure into the headspace above the piston 11 in cylinder 12 via port in the wall of the cylinder provided with a non return valve 20. A latch or other detent mechanism (not shown) acting on handle 17 or rod 14 retains piston 11 in the fully
retracted position against the bias of spring 13, ie. in the loaded position. When the detent is released, piston 11 moves axially within cylinder 12 to pressurise the air in the cylinder 12 to a pre-determined value dependant on the spring 13 and piston 11 diameter.
An aerosol valve of the conventional female kind is located at the outlet to cylinder 12 and comprises a body 30, a spring 31, a stem 32, a stem holder 33 and a gasket 36. An actuator 40 is mounted above stem 32 and a retaining ring 41 holds said gasket 36 in position.
A predetermined dose of liquid or powdered drug 50 is stored within the stem 32 and this is forced out of the stem and atomised when said actuator 40 is depressed, allowing the pressurised gas in cylinder 12 to flow into passageway 52 via orifice 53. The orifice 53 is sized to control the flow of air into the stem.
When depressed by actuator 40, stem 32 depresses stem holder 33 breaking contact between said holder 33 and seal 36 allowing gas to enter the base of stem 32 and flow through the stored drug 50. By arranging that the volume of air at atmospheric pressure is larger than the volume of liquid drug, substantially annular flow will be set up within stem 32 atomising the liquid as the gas passes up said stem 32 and actuator 40.
In the case where drug 50 is a powder, the annular flow reduces the risk of blockage of the ste bore.
Preferably the ratio of the volume of gas at atmospheric pressure to the volume of liquid drug is greater than 100:1 and preferably between 500:1 and 1500:1. In the case of the powdered drug this ratio can be less than 100:1.
Preferably, the stem 32 with drug 50 and actuator 40 are formed as a detachable unit which can be replaced after each use. In this way, a clean stem and actuator are used for every dose, minimising blockage and contamination. The exit orifice 41 of actuator 40 and the bottom of stem 32 are preferably each sealed with a transverse membrane which is punctured before use.
To help co-ordination of the operation of the device with the breathing in of the user, the actuator 40 could be spring loaded and actuated by a predetermined amount of air flow into lungs set up when the user breathes in. Thus as shown in Figure 2, a body 80 is secured to the cylinder 12 by a snap fit lug 81. A spring 83 is located within said body 80 and exerts a force on the actuator 40 which is prevented from moving by a catch 85, which forms part of a flap 86 hinged at point 87 which when in the ready position blocks off an air passageway 88. A mouthpiece 90 is formed within body 80.
When the patient sucks in through mouthpiece 90, the pressure drops to below atmospheric within body 80 and the difference between atmospheric pressure and the pressure within body 80 causes the flap 86 to move, opening the air passageway 88 to allow air into the mouth through the mouthpiece 90 and releasing catch 85 and allowing spring 83 to push actuator 40 down, activating the device and atomising the drug.
Claims
1. A method for forming a flow of a fluid into a spray of fine particle size, which method is characterised in that the flow is caused to adopt an annular flow through a duct and in that the velocity gradient within that flow is sufficient to cause shear between components of the flow to break the flow up into a spray.
2. A method as claimed in claim 1, characterised in that the flow is a non-homogeneous flow and the shear occurs at the interface between the phases.
3. A method as claimed in either of claims 1 or 2, characterised in that one phase is a stream of gas and the other phase is a measured dose of a liquid or particulate solid.
4. A method as claimed in claim 1, characterised in that the flow is a substantially homogeneous flow of a liquid.
5. A method as claimed in any one of the preceding claims, characterised in that the velocity differential between the radially inward and external components of the flow is at least 250 metres per second.
6. A method as claimed in any one of claims 1 to 3, characterised in that the pressure differential along the duct is from 5 to 50 bar and the hydraulic diameter of the duct is from 500 to 2000 micrometres.
7. A method as claimed in claim 6, characterised in that the ratio of volume of the gas flow to the volume of the solid or liquid to be atomised is from 100:1 to 1000:1.
8. A method as claimed in claim 4, characterised in that the pressure differential along the flow is from 150 to 500 bar and the hydraulic diameter of the duct is from 5 to 100 micrometres.
9. A method as claimed in any one of the preceding claims, characterised in that the flow is generated by a pressurised gas container or by a pump mechanism which ejects a component of the flow through a tubular duct.
10. A method as claimed in any one of the preceding claims, characterised in that the flow contains a medicament.
11. A method as claimed in claim 10, characterised in that the flow is atomised to a mass median particle size less than 12 micrometres.
12. A method as claimed in any one of the preceding claims, characterised in that the duct is provided with a nozzle aperture outlet having a smaller hydraulic diameter than the hydraulic diameter of the duct.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB919100950A GB9100950D0 (en) | 1991-01-16 | 1991-01-16 | Metered dose atomising and delivery device |
GB9100950.6 | 1991-01-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1992012799A1 true WO1992012799A1 (en) | 1992-08-06 |
Family
ID=10688538
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1992/000087 WO1992012799A1 (en) | 1991-01-16 | 1992-01-16 | Metered dose atomising and delivery device |
Country Status (3)
Country | Link |
---|---|
AU (1) | AU1162892A (en) |
GB (1) | GB9100950D0 (en) |
WO (1) | WO1992012799A1 (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0734737A2 (en) * | 1993-04-08 | 1996-10-02 | Oxford BioSciences Limited | Particle delivery of particularly therapeutic powdered agents |
US6119688A (en) * | 1991-08-26 | 2000-09-19 | 3M Innovative Properties Company | Powder dispenser |
WO2006037636A2 (en) * | 2004-10-06 | 2006-04-13 | Boehringer Ingelheim International Gmbh | Dispensing device, storage device and method for dispensing powder |
EP1792660A1 (en) | 2005-12-02 | 2007-06-06 | Boehringer Ingelheim Pharma GmbH & Co. KG | Dispensing device |
US7237697B2 (en) | 2001-12-14 | 2007-07-03 | Boehringer Ingelheim Microparts Gmbh | Apparatus for dispensing an atomized liquid product |
WO2010032028A1 (en) * | 2008-09-18 | 2010-03-25 | Anthony Martin Gardiner | Portable applicator for dispensing powder |
US7841338B2 (en) | 2006-04-13 | 2010-11-30 | Boehringer Ingelheim International Gmbh | Dispensing device |
US8061006B2 (en) | 2001-07-26 | 2011-11-22 | Powderject Research Limited | Particle cassette, method and kit therefor |
WO2017112451A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Auto-reset dose release firing systems, medicinal inhalers comprising same, and methods of using same |
WO2017112400A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Medicinal inhalers |
WO2017112748A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Flow govenors for use in medicinal inhalers |
WO2017112476A2 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Dose release firing systems and medicinal inhalers comprising same |
WO2017176693A1 (en) | 2016-04-05 | 2017-10-12 | 3M Innovative Properties Company | Medicinal inhaler refill assemblies comprising a lockout override mechanism |
WO2017176704A1 (en) | 2016-04-05 | 2017-10-12 | 3M Innovative Properties Company | Medicinal inhaler refill assemblies comprising a lockout mechanism |
EP3154613A4 (en) * | 2014-06-16 | 2018-03-14 | Meway Pharma Ltd | A novel operated nebulizer and means thereof |
US11376379B2 (en) | 2015-12-21 | 2022-07-05 | Kindeva Drug Delivery L.P. | Flow governor assemblies for use in medicinal inhalers |
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US3605744A (en) * | 1969-04-22 | 1971-09-20 | Edward M Dwyer | Injection apparatus and method of injecting |
FR2256084A1 (en) * | 1973-12-26 | 1975-07-25 | Ciba Geigy Ag |
-
1991
- 1991-01-16 GB GB919100950A patent/GB9100950D0/en active Pending
-
1992
- 1992-01-16 AU AU11628/92A patent/AU1162892A/en not_active Abandoned
- 1992-01-16 WO PCT/GB1992/000087 patent/WO1992012799A1/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US3605744A (en) * | 1969-04-22 | 1971-09-20 | Edward M Dwyer | Injection apparatus and method of injecting |
FR2256084A1 (en) * | 1973-12-26 | 1975-07-25 | Ciba Geigy Ag |
Cited By (32)
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US6119688A (en) * | 1991-08-26 | 2000-09-19 | 3M Innovative Properties Company | Powder dispenser |
EP0734737A3 (en) * | 1993-04-08 | 1997-03-12 | Oxford Biosciences Ltd | Particle delivery of particularly therapeutic powdered agents |
EP0951917A2 (en) * | 1993-04-08 | 1999-10-27 | PowderJect Research Limited | Particle delivery of particularly a powdered therapeutical agent |
EP0951917A3 (en) * | 1993-04-08 | 2000-01-05 | PowderJect Research Limited | Particle delivery of particularly a powdered therapeutical agent |
US6881200B2 (en) | 1993-04-08 | 2005-04-19 | Powderject Research Limited | Needleless syringe using super sonic gas flow for particle delivery |
US7942846B2 (en) * | 1993-04-08 | 2011-05-17 | Powderject Research Limited | Needleless syringe using supersonic gas flow for particle delivery |
US7618394B2 (en) | 1993-04-08 | 2009-11-17 | Powderject Research Limited | Needleless syringe using supersonic gas flow for particle delivery |
EP0734737A2 (en) * | 1993-04-08 | 1996-10-02 | Oxford BioSciences Limited | Particle delivery of particularly therapeutic powdered agents |
US8061006B2 (en) | 2001-07-26 | 2011-11-22 | Powderject Research Limited | Particle cassette, method and kit therefor |
US7237697B2 (en) | 2001-12-14 | 2007-07-03 | Boehringer Ingelheim Microparts Gmbh | Apparatus for dispensing an atomized liquid product |
WO2006037636A3 (en) * | 2004-10-06 | 2006-07-20 | Boehringer Ingelheim Micropart | Dispensing device, storage device and method for dispensing powder |
US9283335B2 (en) | 2004-10-06 | 2016-03-15 | Boehringer Ingelheim International Gmbh | Dispensing device, storage device and method for dispensing powder |
US9089658B2 (en) | 2004-10-06 | 2015-07-28 | Boehringer Ingelheim International Gmbh | Dispensing device, storage device and method for dispensing powder |
EP2277577A1 (en) | 2004-10-06 | 2011-01-26 | Boehringer Ingelheim International Gmbh | Storage device for powder and dispensing device for dispensing powder |
WO2006037636A2 (en) * | 2004-10-06 | 2006-04-13 | Boehringer Ingelheim International Gmbh | Dispensing device, storage device and method for dispensing powder |
EP1792660A1 (en) | 2005-12-02 | 2007-06-06 | Boehringer Ingelheim Pharma GmbH & Co. KG | Dispensing device |
US7841338B2 (en) | 2006-04-13 | 2010-11-30 | Boehringer Ingelheim International Gmbh | Dispensing device |
WO2010032028A1 (en) * | 2008-09-18 | 2010-03-25 | Anthony Martin Gardiner | Portable applicator for dispensing powder |
US11020542B2 (en) | 2014-06-16 | 2021-06-01 | Sanara Tech Ltd. | Operated nebulizer and means thereof |
EP3154613A4 (en) * | 2014-06-16 | 2018-03-14 | Meway Pharma Ltd | A novel operated nebulizer and means thereof |
WO2017112748A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Flow govenors for use in medicinal inhalers |
WO2017112476A2 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Dose release firing systems and medicinal inhalers comprising same |
WO2017112400A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Medicinal inhalers |
WO2017112451A1 (en) | 2015-12-21 | 2017-06-29 | 3M Innovative Properties Company | Auto-reset dose release firing systems, medicinal inhalers comprising same, and methods of using same |
US11071837B2 (en) | 2015-12-21 | 2021-07-27 | Kindeva Drug Delivery L.P. | Dose release firing systems and medicinal inhalers comprising same |
US11083855B2 (en) | 2015-12-21 | 2021-08-10 | Kindeva Drug Delivery L.P. | Auto-reset dose release firing systems, medicinal inhalers comprising same, and methods of using same |
US11376378B2 (en) | 2015-12-21 | 2022-07-05 | Kindeva Drug Delivery, L.P. | Flow governors for use in medicinal inhalers |
US11376379B2 (en) | 2015-12-21 | 2022-07-05 | Kindeva Drug Delivery L.P. | Flow governor assemblies for use in medicinal inhalers |
WO2017176693A1 (en) | 2016-04-05 | 2017-10-12 | 3M Innovative Properties Company | Medicinal inhaler refill assemblies comprising a lockout override mechanism |
WO2017176704A1 (en) | 2016-04-05 | 2017-10-12 | 3M Innovative Properties Company | Medicinal inhaler refill assemblies comprising a lockout mechanism |
US11110234B2 (en) | 2016-04-05 | 2021-09-07 | Kindeva Drug Delivery L.P. | Medicinal inhaler refill assemblies comprising a lockout mechanism |
US11344684B2 (en) | 2016-04-05 | 2022-05-31 | Kindeva Drug Delivery L.P. | Medicinal inhaler refill assemblies comprising a lockout override mechanism |
Also Published As
Publication number | Publication date |
---|---|
GB9100950D0 (en) | 1991-02-27 |
AU1162892A (en) | 1992-08-27 |
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