Patent Application
20130047981
The present invention relates to a pressurised-liquid, dispensing container.
Dispensers such as metered dose inhalers enable users to self administer doses of inhaled medication for relief and control of diseases such as asthma.
There is an increasing requirement for these inhalers to be fitted with counters, to count the number of doses dispensed, so that users know when their devices are nearly empty. However, since counters are either intricate mechanical devices or electronic devices, they add considerably to the cost of the inhaler to which they are fitted.
Metered dose inhalers use a pressurised-liquid, dispensing container of the following type, “the type defined”, namely a pressurised-liquid, dispensing container comprising:
a valve for dispensing the liquid from the container; and
a vessel containing the liquid under pressure, the vessel having:
The object of the present invention is to provide an improved means of indicating the quantity of liquid, typically medication, remaining in a container of this type.
According to the invention there is provided a pressurised-liquid, dispensing container of the type defined, the container containing a pressurised liquid and a propellant gas, the container including:
As used herein, the term “rattle” means an object which produces its noise when the container is acted on as aforesaid. Normally the container and/or a dispenser having the container will have instructions to shake, tap or otherwise act on the container to induce the noise for estimation of the amount of liquid in the container, at least as the liquid approaches final depletion to the container being empty, the instructions including which of the end wall and the valve end of the vessel should be uppermost when the rattle is excited to induce noise. The instructions can be provided with the container or dispenser or printed on the container or dispenser.
The or each rattle can be any suitable object which can move within the vessel and produce a noise when the container is acted upon to induce a noise. Normally the rattle will be small with respect to the vessel. Again, preferably it is solid, although it can be envisaged to be hollow. Examples of suitable objects include a ball, pellet, cone, wedge, cylinder, pyramid, torus, cube, prism, tetrahedron, octahedron, dodecahedron, icosahedron or fragment thereof, or a wire based object, such as a spring, folded wire or other arrangement of wire.
Normally the liquid is a medicament liquid having:
a medicament dissolved in a solvent or
a medicament dispersed in a liquid as a colloid or emulsion or
a medicament suspended in a liquid as a suspension.
The vessel can be any suitable type of vessel to hold medicament liquid. Preferably it is an aluminium vessel.
In certain embodiments, the liquid is one having a vapour phase at room temperature acting as a propellant gas pressuring the liquid for its dispensing. In others, a propellant gas is included which is different from the liquid for pressurising the liquid for its dispensing.
In certain embodiments, the or one of the rattles is buoyant in the liquid. In these embodiments, the buoyant rattle can be between 15% & 50% and preferably 20% & 30% of the cross-sectional dimension of the vessel.
In other embodiments, the or one of the rattles is non-buoyant in the liquid. In these embodiments, the non-buoyant rattle can be between 5% & 15% and preferably 7.5% & 12.5% of the cross-sectional dimension of the vessel. In these embodiments, the preferred rattle is a solid bearing ball.
Advantageously, the rattle will be composed of an inert material, such that it does not react with the container's contents.
Whilst most embodiments use one rattle, more than one can be provided, conceivably up to five or even ten or more. Furthermore, the types of rattles used can be the same (e.g. two balls) or different (e.g. one ball and one spring).
The movement restrictor can be a physical restriction limiting the rattle to part only of the internal space of the container, such that as the level of the medicament liquid within the container sinks below a threshold, the rattle is able to move within the propellant gas, i.e. in space no longer occupied by liquid. Such a movement restrictor can be:
In one embodiment, the container includes two rattles and two movement restrictors, the restrictors limiting their rattles to movement along different lengths of the vessel, whereby on continued depletion of the liquid with dispensing, first one rattle and then the other is able to move in space no longer occupied by liquid.
In other embodiments, the movement restrictor can be arranged to be movable so as to restrict the rattle progressively as the medicament is used. In such arrangement, the restriction means can be a separator separating the propellant gas from the medicament liquid and limiting movement of the rattle within the medicament liquid, whereby as the medicament liquid is consumed by successive dispensing, the rattle is progressively restricted in its noise-producing movement.
The separator can be a piston with a spring urging the piston towards the medicament in its carrier.
Alternatively, the separator can be a diaphragm separating propellant gas from the medicament in its carrier.
Where a separator is provided two rattles can be provided, with one being larger than the other, whereby the large one can become held by the restriction means before depletion with the other still movable, where the noise of the smaller one only indicates a small quantity only of contained liquid remaining.
It can also be envisaged that the separator can act to free the rattle progressively as the medicament liquid is dispensed.
The physical restriction can be a cage arranged within the container or one of more indents in a side wall of the container or indeed a link attaching the rattle to an end of the container.
Various alternative configurations of the cage are envisaged:
with the cage limiting the rattle from reaching one end only of the vessel,
with the cage limiting the rattle from reaching either end of the vessel,
with the cage located by crimps in the sidewall of the vessel.
In a somewhat different embodiment:
For all embodiments, two discrete alternatives are possible, i.e. that:
Normally, the container will be in combination with instructions to shake, tap or otherwise act on the container to induce the noise at least as the liquid approaches final depletion to the container being empty, the instructions including which of the end wall and the valve end of the vessel should be uppermost when the rattle is excited to induce noise. The instructions can be printed on a label on the container or on a dispenser having the container.
To act on the container to induce the noise, it can be shaken, juddered, rocked, tapped etc. This action will induce movement of the rattle, if it is free to move within the vessel, causing it to impact with the walls of the vessel or means for restricting its movement. This impact will make a noise. If the container is shaken, the resultant succession of short noises or sounds are likely to be heard as a rattling of the rattle.
Where, as in some embodiments, the rattle is progressively freed with use of the medicament liquid, the movement of the rattle is restricted and on impact with the walls of the vessel it will produce little noise. The presence of liquid around the rattle is liable to dampen the impact. When the rattle is able to move more freely with dispensing of liquid, it will be able to impact harder on the vessel walls and produce a discernibly different sound. This is particularly the case when the rattle is free to move in the propellant gas, i.e. in space no longer occupied by liquid.
Thus, as the freedom of the rattle can be correlated with the amount of liquid within the vessel, acting upon the container to produce a noise (e.g. shaking the container) can determine approximately how much liquid is remaining by the noise made. The user can know whether or not there is liquid left in the container simply by shaking it. The extent of use of the liquid is indicated by the noise produced by the rattle.
To help understanding of the invention, various specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings, in which:
Referring to first to
Within the vessel is a piston 5, urged by a spring 6 into contact with the medicament liquid 7. A bearing ball 8 is included in the medicament liquid.
As the medicament liquid is dispensed in successive doses, the piston is kept in contact with the liquid 7 by the spring 6, with an edge seal 9 ensuring that the liquid does not pass to the spring side of the piston.
Initially there is no restriction on movement of the ball 8 if the inhaler is shaken, causing the ball to rattle. As the medicament liquid is dispensed, the piston begins to restrict the movement of the ball, until it is scarcely able to move longitudinally of the vessel. This change is discernible as a change in noise of the rattle. Thus the user can know whether there is plenty of medicament liquid left and when he needs to use a new inhaler.
It is envisaged that the seal might not be needed if the piston were of strongly hydrophobic or oleophobic material according to the nature of the medicament material. Further, it may be that the spring can be dispensed with if the piston is of a material to remain preferentially in contact with the medicament.
It is also envisaged that the spring could have a free length such that it is free to rattle between the piston and the end wall of the vessel when the piston has reached a position in which the medicament liquid is nearly used up. In this alternative, the spring performs the noise producing function. Provision of two springs can also be envisaged, with one acting to move the piston and the second having a limited free length. When the piston has moved more than the free length, the second spring expands no further and as such becomes free to rattle as the piston moves further.
Further it is also envisaged that two different sized rattle balls could be provided, possibly of different materials. Initially rattling of the container will produce a dull rattle of a lighter larger ball and a sharper rattle of the heavier smaller ball. As dispensing continues, the reassuring thump of the larger ball ceases as it is captivated between the piston and the valve end of the vessel; this leaves the shriller alarm of the smaller ball indicating that depletion is nearly complete.
Referring to
As an alternative to the diaphragm, a sealed piston with propellant gas as opposed to a spring urging the piston against the medicament liquid can be envisaged.
Whilst in the two embodiments and alternatives just described the piston and diaphragm move to a position increasingly restricting the freedom of the ball to make noise on dispensing (except for the possibility of the spring becoming free to rattle on dispensing); in the three embodiments described below fixed—or at least tightly limiting—means are provided for restricting movement of a noise producing ball, which is freed to make noise when the medicament liquid level falls through dispensing to allow the ball to move more freely in propellant gas or in the space that is no longer fully filled with medicament liquid.
In
The cage is shown in
In a non-illustrated embodiment, a second cage and a second rattle ball is provided spaced longitudinally in the vessel from the first. At first with the container full, neither ball can rattle audibly. Then as the level falls to the first cage, its ball can be rattled and heard. As the liquid level falls further with depletion, the second rattle ball can be heard, indicating imminent complete depletion.
The container 31 of
A third alternative is shown in
It is also envisaged that two balls, suspended at different depths and separated by an internal wall, could be provided so that as the liquid level drops first one ball impacts the side wall and then with further liquid depletion the two balls can hit the side walls, giving a recognisably different noise.
A somewhat different embodiment is shown in
In an non-illustrated alternative, with the main float longer & narrower and the extension shorter, the container can be tested with the end wall uppermost. In this case, the buoyant rattle float will float up against the end wall until much of the contents has been dispensed. Then when it is floating freely it will be able to rattle in a dulled manner, with the liquid dampening the rattle. On continued dispensing, as the liquid nears complete depletion, the extension will hold the float up and it will be able to rattle against the sidewall with no dampening at all at the end of the float remote from the down-most valve end of the container.
So that the container does not have to be removed from the dispenser body that it is intended to be used with, the instructions can be printed on a label adhered to the dispenser body.
Finally, it can be envisaged that the change in noise of the rattle can be detected externally to the container by an electrical transducer, enabling an electronic indication of medicament liquid presence.
Normally in the above described embodiments, the amount of medicament liquid in the container will vary in accordance with the amount already dispensed from it. Thus the noise produced will normally indicate the amount remaining and thus the amount dispensed. However, occasionally a particular dispensing device's valve will leak. In this case the amount remaining varies without dispensing and a conventional dose counter would not indicate the amount remaining. However, advantageously in the above embodiments, the noise produced by the rattle will vary with both dispensing usage and leakage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1003581.4 | Mar 2010 | GB | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/GB2011/000311 | 3/4/2011 | WO | 00 | 11/14/2012 |
