WO2005044438A1

WO2005044438A1 - Agitation of a suspension product within a container of fluid having no head space

Info

Publication number: WO2005044438A1
Application number: PCT/GB2004/004422
Authority: WO
Inventors: Christopher John Eames
Original assignee: Bespak Plc
Priority date: 2003-10-23
Filing date: 2004-10-19
Publication date: 2005-05-19
Also published as: GB2408220A; GB0324848D0; GB0423224D0

Abstract

A method and apparatus for re-suspending a suspension product (31) within a container (10) of fluid (30) with no head space. A helical body (40) is provided in the container (10) and the helical body (40) is rotated about its axis relative to the fluid within the container. The helical body (40) presents a surface area to the fluid as it rotates to cause sufficient turbulence to agitate and re-homogenise the contents of the container (10). The container (10) may have an outlet (11) and a piston (20) arranged to force homogenised fluid and suspension product out of the outlet as the piston (20) is forced into the container (10). The axial length of the helical body (40) may be reduced as the piston (20) progresses into the container (10) so that it does not impede progress of the piston (20).

Description

Agitation of a Suspension Product Within a Container of Fluid having no Head Space

The present invention relates to the agitation of a suspension product within a container of fluid having no head space and to containers for agitating fluids containing settled suspension products with no effective headspace. In many industries such as the food, petrochemical, chemical, packaging and the pharmaceutical industry, it is desirable for suspension products within container systems and vials of fluids without a head space to be agitated to re-suspend the suspension product within the fluid. There are a number of reasons for not having a headspace in a container or vial for a fluid containing a suspension product, including physical limitations of an application device and/or the physical and/or chemical nature of the product. Over time, many formulations separate with suspension products accumulating at the bottom of a container or vial. However, when the formulation is to be used or dispensed it is generally desirable for the suspension product to be substantially homogeneously distributed throughout the fluid in the container or vial. However, without a headspace, shaking or agitation of the container will have a very limited, if any, homogenising effect on an accumulated suspension product within the container. It is an object of the present invention to provide a method and a container which when used with fluid contents with no effective headspace is able to be used to re-homogenise a suspension product within the fluid. According to a first aspect of the present invention there is provided a method of re-suspending a suspension product with substantially no head space, the method comprising providing a helical body within a container such that the helical body engages the inside surface of the container by friction or is formed on and as part of the inside surface of the container, providing fluid with a suspension product and substantially no head space within the container and rotating the helical body and container about their axes relative to the fluid within the container with the helical body presenting a surface area to the fluid as it rotates. The fluid could be, for example, a solution or a combination of product, solution and/or a suspension. The principle of operation is based on the inertial mass of a body of liquid acting independently from the movement of its containment vessel. This is observed when a body of fluid tends to initially resist movement of its container, for example bubbles on the top of a cup of tea remain approximately in the same orientation when the cup is turned sharply through 90°. The inner wall of the container will impart a shear moment at the interface with the fluid contents when the container is revolved axially. The helical body on the inner face of the container body will create turbulence at the interface. It is the turbulence from the trailing edge of the helical body that agitates and re-homogenises the contents of the container. The rotational movement of the helical body can be created in a number of ways such as for example, physically, mechanically or by electro-mechanical means.

An effective method of agitation is achieved by three rapid revolutions in one direction, immediately followed by three rapid revolutions in the opposite direction making one cycle. This process may be repeated for three consecutive cycles performed in rapid succession. According to a further aspect of the present invention there is provided a container for a fluid with a suspension product and no headspace, the container comprising a container body into which a fluid with a suspension product is, in use, provided such that there is no or no effective headspace within the container body and a helical body within the container body which engages the inside surface of the container by friction or is formed on and as part of the inside surface of the container, the helical body presenting a surface area to fluid within the container body when the helical body is rotated about its axis relative to fluid within the container body. The helical body could be separate from the container body, and could engage the inside surface of the container body by friction to be able to rotate with the container body. If desired the helical body could be formed on and as part of the inside surface of the container body. The container may have an outlet and a movable piston arranged when pushed into the container to force the contents of the container out through the outlet. The helical body is preferably arranged to be reduced in axial length as the piston is pushed into the container. The container may be a vial. As the helical body is able to reduce in axial length or 'collapse' as the piston forces the contents of the container out through the outlet, the helical body does not impede the action of the piston. The helical body could be tapered to enable it to collapse inside itself reducing ullage in the piston design. The helical body may be constructed from a single or multiple elements that has or have a cross-sectional profile that presents a surface area to the fluid relative to the direction of axial rotation. A rotational movement will cause the helical body within the container to create turbulent eddies within the fluid that re-homogenises the suspension. An axis of the helical body is preferably arranged in the same direction as the axis of the container body so that when the piston is pushed into the container in the direction of its axis, the turns or coils of the helical body are forced closer together so that they do not impede the movement of the piston. Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an example of a container of a fluid with a separated suspension product and no headspace; Figure 2 is a perspective view of the container of Figure 1; Figure 3 shows a helical body to be inserted into a container; Figure 4 shows the container of Figure 1 undergoing manual rotation to re- suspend its contents; Figure 5 show the container of Figure 1 after its contents have been re- suspended; and Figure 6 shows the container of Figure 1 being actuated to dispense its contents. Figure 1 shows an example of a container 10 illustrating the present invention. The container 10 in this example is a vial arranged to convey a pharmaceutical formulation. However, the invention could be used with any type of container and with any type of fluid for any purpose. The container 10 in this example has an outlet 11 in a base 12 at one axial end of the container and a stopper 20 at the other axial end. The container 10 is provided with a fluid 30 from which a suspension product 31 has settled at the bottom of the container 10 over time. The fluid could be, for example, a solution or a combination of product, solution and/or a suspension. The container 10 does not have a headspace. There may be various reasons for not having a headspace, such as possible undesirable interaction between the contents of the container, in this example a pharmaceutical formulation and the gas, such as air, in the head space or physical limitations of the application device. The container 10 has a helical body 40 provided therein. The container 10 with helical body 40 could be provided as a discrete product to be supplied to, for example, pharmaceutical formulation suppliers to be filled with a pharmaceutical formulation and then sealed with a stopper 20 without a head space. The container 20 could then be supplied to a user to be dispensed in a suitable manner using a suitable dispensing device such as an inhaler, for example an MDI (Metered Dose Inhaler) or pMDI (pressurised Metered Dose Inhaler). When the container 10 is installed in a suitable dispensing device the outlet 11 may be opened or pierced ready for use. The helical body 40 is arranged to be rotated relative to the fluid 30 contained in the container to re-suspend the suspension product 31 in the fluid 30 prior to being dispensed. In the container 10 shown in Figure 1 the helical body 40 is fixed within the container 10 and the container rotated around its axis. In this example the helical body 40 is made from a length of resilient or elastic material, such as an elongate portion of rubber or elastomeric material which when inserted into the container engages the inside surface of the container 10 through friction so that when the container 10 is rotated, the helical body 40 also rotates relative to the contents of the container 10 to re-suspend the suspension product 31 in the fluid 30. However, the helical body 40 could be made from any suitable material and instead of being made from a single element, could be made from a plurality of interconnected elements. Figure 2 is a perspective view of the container 10 and helical body 40 with a portion of the container wall shown removed. As can be seen in this example, the helical body 40 made from a length of resilient or elastic material engages the inside surface of the container 10. Figure 3 shows the helical body 40 prior to insertion into a container 10. Figure 4 shows the container of Figure 1 being agitated to re-suspend the suspension product 31 in the fluid 30. In this example the container 10 is being agitated by being manually rotated about its axis. It has been found that an effective method of agitation is achieved by three consecutive cycles performed in rapid succession, with each cycle consisting of three rapid revolutions of the container in a clockwise direction immediately followed by three rapid revolutions in a counter- clockwise direction. However, any suitable rotation of the helical body 40 and/or container 10 will be suitable and the rotational movement can be created by any suitable means such as physically, mechanically or electro-mechanically as is well known by those skilled in the art. Figure 5 shows the container 10 after having been rotated as shown in Figure 4 with the suspension product re-suspended within the fluid. As shown in Figure 6, once the container 10 has been rotated about its axis suitably to re-suspend the suspension product within the fluid 30, the stopper 20 may be pushed into the container 10, preferably using a suitable dispensing device (not shown), to act as a piston to force the contents 30, 31 of the container 10 out through the outlet 11. In this arrangement the helical body 40 is arranged to progressively collapse as the stopper 20 proceeds further into the container 10 so that the helical body 40 does not impede the progress of the stopper acting as a piston. The helical body 40 could be tapered so that it collapses inside itself reducing ullage in the container 10. Instead of the container 10 being a discrete product as shown in Figures 1 to 3, it could be part of a dispensing device with an appropriate inlet and outlet through which a fluid 30 with associated suspension product 31 is passed. The helical body 40 could be rotated by rotating the whole dispensing device, or an appropriate portion of the dispensing device. If the fluid 30 and suspension product 31 are dispensed from the container 10 illustrated in Figures 1 to 3 or the dispensing device described above by some other means than the piston 20 described, such as a valve, then the helical body 40 need not be collapsible. In this case, the helical body could be permanently formed on the inside surface of the container and could be formed from any suitable material, such as the same material as the container 10. The container 10 could be used in any suitable application such as baby formula milk bottles/ready mixed bottles, medicine mix, blood and diagnostic agitation reconstitution e.g. vacuum vial, over the counter products e.g. resolve single shot vial, re-suspending silt in riverbeds, drinks/dispensers e.g. pure juice, hot chocolate etc, inject able medication, cosmetics/hair spray /hair colouring/nail varnish etc., analytical instruments, paint mixing/paint tints in a syringe/spray gun, spirit and mixing package, spray cans e.g. metallic spray cans and emulsions. The container 10 could be used in an inhaler such as an MDI (Metered Dose

Inhaler) or pMDI (pressurised Metered Dose Inhaler) or a nebuliser. The inhaler could be used, for example, as a nasal inhaler or a pulmonary inhaler. The helical body 40 could have any suitable number of turns or coils.

However, it preferably has a turn of at least 180° along its length and, more preferably a turn of at least 360° along its length.

Claims

1. A method of re-suspending a suspension product with substantially no head space, the method comprising providing a helical body within a container such that the helical body engages the inside surface of the container by friction or is formed on and as part of the inside surface of the container, providing fluid with a suspension product and substantially no head space within the container and rotating the helical body and container about their axes relative to the fluid within the container with the helical body presenting a surface area to the fluid as it rotates.

2. A method according to claim 1, wherein the container has an outlet and a piston which forces fluid out of the outlet as it is pushed into the container.

3. A method according to claim 2, wherein the piston reduces the axial length of the helical body as it is pushed into the container.

4. A method according to any one of the preceding claims, wherein the helical body is rotated physically, mechanically or electro-mechanically.

5. A method according to any one of the preceding claims, wherein the helical body undergoes three consecutive cycles performed in rapid succession, with each cycle consisting of three rapid revolutions in one direction immediately followed by three rapid revolutions in the other direction.

6. A method substantially as hereinbefore described with reference to the accompanying drawings.

7. A container for a fluid with a suspension product and substantially no head space, the container comprising a container body into which a fluid with a suspension product is, in use, provided such that there is no or no effective head space within the container body and a helical body within the container body which engages the inside surface of the container by friction or is formed on and as part of the inside surface of the container, the helical body presenting a surface area to fluid within the container body when the helical body is rotated about its axis relative to fluid within the container body.

8. A container according to claim 7, wherein the helical body is resilient.

9. A container according to claim 7 or claim 8, wherein the container body has an outlet and a piston arranged to force fluid out of the outlet when it is forced into the container body.

10. A container according to claim 9, wherein the piston is arranged to reduce the axial length of the helical body as it is forced into the container body.

11. A container according to claim 10, wherein the helical body is tapered along the direction of its axis.

12. A container according to any one of claims 7 to 1 1, wherein the axis of the helical body is arranged in the same direction as the axis of the container body.

13. A dispensing apparatus including a container according to claim 7.

14. A container according to any one of claims 7 to 12, wherein the helical body has a turn of at least 180° along its length.

15. A container according to claim 14, wherein the helical body has a turn of at least 360° along its length.

16. A container according to any one of claims 7 to 12, 14 or 15, including fluid and a suspension product and no effective head space.

17. An inhaler including a container according to any one of claim 7 to 12 or 14 to 16.

18. An inhaler according to claim 17, wherein the inhaler is a Metered Dose Inhaler, a pressurised Metered Dose Inhaler or a nebulizer.

19. A container substantially as hereinbefore described with reference to the accompanying drawings.

20. A dispensing apparatus substantially as hereinbefore described with reference to the accompany drawings.