Technical Field

The present invention relates to a method and a device for filling a cavity with a quantity of particulate material, comprising the step of filling a chamber with its open side facing at least partially upwards with the quantity of particulate material. The method and device according to the present invention are suitable for filling packs containing doses of powdered medicament, the doses being housed in cavities of the packs, which packs can be used in inhalation devices.

Background of the Invention

Today supply and distribution of medicament is accomplished in many different ways. Within health care more and more is focused on the possibility to dose and distribute medicaments in the form of powder directly to the lungs of a user by means of a dispensing device, for example an inhalation device, to obtain an efficient and user friendly administration of the specific medicament. In most cases, some form of dosing process is used for preparing the dose to be inhaled. Usually, the doses of medicament are provided in packs having several cavities for housing a dose of medicament. The cavities filled with a dose is subsequently sealed by a sealing sheet, for example a foil of aluminium. These packs are loaded into a dispensing device, in which the foil above the cavity is penetrated and the dose of medicament is released for inhalation by the user. By this sealing, the medicament is well protected before inhalation. There are also other cases where it is suitable to provide doses of medicament in packs having cavities for housing a dose of medicament, which cavities are sealed by a foil. The packs containing the doses of medicament can be in the form of blister packs or injection moulded discs provided with blisters and cavities, respectively, for housing the powdered medicament, the packs can have various shapes, and the cavities can be distributed in various patterns. The method for filling said cavities must provide an accurate and changeable dosing into the cavities, to provide packs containing accurate doses of medicament of different sizes.

EP 1 354 795 A2 discloses a method and apparatus for the metered transport of fine powders into receptacles. The apparatus is provided with a hopper having an opening.

The hopper is adapted to receive fine powder. Further, the apparatus comprises a vibrating element vibrating within the powder, and a rotatable member provided with a plurality ^' of chambers aligned about its periphery. The rotatable member may be rotated to align the chambers with said opening to allow powder to be transferred from the hopper and into the chambers. The rotatable member is rotated 180° to a dispensing position where the chambers are aligned with said receptacles, and the receptacles are filled with the powder. US 5 187 921 A describes a method and apparatus for filling a blind cavity with a quantity of powder, which comprises urging the cavity, with its open side facing a least partially downwards, into a reservoir of powder, withdrawing from the cavity having the quantity of powder therein while the open side continues to face at least partially downwards, and subsequently applying a lid to cover the cavity having the powder therein. WO 03/066437 Al discloses a method and apparatus for introducing powder into a pocket having an open side, including orientating the pocket with the open side facing at least partially upward, providing the pocket with a volume of powder greater than that of the pocket, compressing the volume of the powder to a predetermined bulk density, and removing excess powder so as to leave the pocket full of powder with the predetermined bulk density.

US 6 035 905 A describes a method for introducing each of a plurality of doses of particulate material into a respective compartment of a container, the method comprising the steps of inserting a respective protuberance, preferably a conduit through which said particle material is introduced into said compartment, into each compartment so as to reduce the capacity thereof, and filling each compartment with said particulate material, with the respective protuberance inserted in said compartment, and removing said protuberance, wherein the volume of each dose of material is less than that of its respective compartment.

However, above-mentioned solutions have several drawbacks. Some of above- mentioned methods and apparatuses cannot distribute a specified dose of powder having a smaller volume than the volume of the cavity housing the dose, or cannot do this accurate enough. The methods and apparatus which are adapted to distribute a dose of powder having a smaller volume than that of the cavity are complicated in construction and can only be used to fill cavities in linear patterns or patterns consisting of several linear patterns, e.g. a matrix pattern, and cannot fill cavities arranged in various kinds of patterns

of cavities, for example arbitrary and non- linear patterns. None of the above mentioned methods or apparatuses are able to simultaneously fill all cavities or blisters in a disc or pack, but require several repetitive filling operations.

The Object of the Invention The object of the present invention is therefore to provide a method and device for filling at least one cavity with a quantity of particulate material, which can fill cavities or blisters arranged in any kind of pattern in a pack or disc, for example arbitrary and nonlinear patterns, are uncomplicated and manage to fill cavities with particulate material to a low cost, can distribute an accurate dose of powder having a smaller volume than that of the cavity housing the dose, are flexible and easy to adapt to new patterns of cavities, and can simultaneously fill all cavities or blisters in a disc or pack, thereby providing a high production capacity.

Summary of the Invention

The above mentioned object is achieved by providing a method of the kind defined in the preamble of claim I, comprising the special measures of positioning the opening of the cavity opposite the opening of the filled chamber, and thereafter rotating the chamber together with the cavity so that the cavity is positioned with its open side facing at least partially upwards and the chamber is positioned with its open side facing at least partially downwards, whereby the quantity of particulate material is emptied into the cavity, and by providing a device of the kind defined in the preamble of claim 8, comprising operating means for positioning the opening of the cavity opposite the opening of the chamber, and guiding means for rotating the chamber together with the cavity so that the cavity is positioned with its open side facing at least partially upwards and the chamber is positioned with its open side facing at least partially downwards, whereby the quantity of particulate material is emptied into the cavity.

By this method and device according to the present invention, cavities or blisters arranged in any kind of pattern in a pack or disc, for example arbitrary and non-linear patterns, can be filled. The cavities can be filled with an accurate dose of powder having a smaller volume than that of the cavity housing the dose. AU cavities or blisters in a disc or pack can be filled simultaneously thereby providing a high production capacity. There is

no loss of excess formulation, and the invention provides a high operative safety and a small physical size of the device. The method and device provide an uncomplicated filling and manage to fill cavities with particulate material to a low cost. Advantageously, the chamber is exchangeable to adapt to the size of the dose to be dosed in said cavity. The quantity of particulate material is emptied into the cavity by the force of gravity, but the release of material from the chamber can be enhanced in the method of the present invention, by knocking or vibrating the chamber when emptying the quantity of particulate material into the cavity, or by subjecting the particulate material to additional forces in the form of pressurized gas or vibrations, for example by way of ultra-sonic waves. Correspondingly, the device can be equipped with vibration means for vibrating the chamber when emptying the quantity of particulate material into the cavity, or other additional means for subjecting the particulate material to additional forces in the form of pressurized gas or vibrations, for example caused by ultra-sonic waves.

The method and device according to the present invention are suitable for fill quantities above one mg. The filling accuracy increases with the flow ability and the weight of the particulate material. Further, the method and device are suitable for free flowing or moderately free flowing particulate material, e.g. carrier-based formulations. The filling method has been tested in a bench-top set-up, where 8 mg of a carrier-based formulation was manually scrape filled into 100 chambers. The filling accuracy was established to 2.4 % RSD.

Advantageously, the size and shape of the opening of the chamber is equal to the opening of the cavity, or the opening of the chamber is smaller than the opening of the cavity and enclosed by the boundary of the opening of the cavity, when the openings of the chamber and cavity are facing each other. According to an advantageous embodiment of the method according to the present invention, the cavity is detachably locked to the chamber before said rotation, and the cavity is detached from said chamber when the cavity is filled.

According to a further advantageous embodiment of the method according to the present invention, said chamber is filled by way of scrape filling, and advantageously said scrape filling is achieved by at least one rotating scraper.

According to another advantageous embodiment of the method according to the present invention, said chamber is filled with a quantity of particulate material forming a

volume which is smaller than the volume of the cavity. Advantageously, said method is used for particulate material comprising powdered medicament.

According to an advantageous embodiment of the device according to the present invention, the device comprises locking means for detachably locking the cavity to the chamber before said rotation, and advantageously the device comprises detaching means for detaching the cavity from said chamber when the cavity is filled.

According to a further advantageous embodiment of the device according to the present invention, the filling means comprises scraper means for scrape filling the chamber, and advantageously said scraper means comprises at least one rotating scraper, According to another advantageous embodiment of the device according to the present invention, the volume of the chamber is smaller than the volume of the cavity. By this embodiment, the cavity can be accurately and easily filled with a quantity of particulate material having a volume smaller than the volume of the cavity.

According to yet another advantageous embodiment of the device according to the present invention, the device comprises at least one filling element provided with said at least one chamber, and the device is adapted for at least one cavity provided in a disc.

Advantageously, The element is interchangeable with other elements having chambers of others sizes and distributed in other patterns, to adapt to the other sizes of doses and to other patterns of the cavities. According to an advantageous embodiment of the device according to the present invention, the filling element comprises several chambers, the amount of which is the same as the amount of cavities, and the positions of the chambers correspond to the positions of the cavities in the disc, whereby the opening of each chamber is facing an opening of a cavity when the filling element is locked to a disc. Advantageously, the device comprises several filling elements.

According to another advantageous embodiment of the device according to the present invention, the guiding means comprises a conveyor belt to which the element is attached.

Advantageously, the device is adapted for a particulate material comprising powdered medicament. Further, the present inventions provides a method for producing packs containing doses of medicament of the kind defined in the preamble of claim 19, where said method comprises the special measures mentioned in any of the claims 1 to 7.

The present inventions also provides an apparatus for producing packs containing doses of medicament of the kind defined in the preamble of claim 20, where said device comprises the special features mentioned in any of the claims 8 to 18.

Brief Description of the Drawings The present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which:

Fig. 1 is a schematic top view of a circular drug disc provided with cavities in a circular pattern,

Fig. 2 is a schematic top view of an embodiment of the filling element, and an embodiment of the scraper means according to the present invention, which filling element corresponds to the drug disc of Fig.

1, Fig. 3a-3h are schematic partial side views of a filling element according to the invention applied to a disc having cavities, illustrating an embodiment of the method according to the present invention, and

Fig. 4 is a schematic side view of an embodiment of the device according to the present invention.

Detailed Description of Embodiments

Fig. 1 shows a top view of a circular drug disc 1 provided with several cavities 2 for housing powdered medicament. The cavities 2 are distributed in a circular pattern. This kind of disc 1 can for example be loaded into an inhalation device.

Fig. 2 shows a top view of an embodiment of the filling element 3 according to the present invention, adapted to the disc of Fig. 1. The filling element 3 is provided with several chambers 4, the amount of which is the same as the amount of cavities in said disc. The positions of the chambers 4 correspond to the positions of the cavities in the disc, whereby the opening of each chamber 4 is facing an opening of a cavity when the filling element 3 is locked to the disc. Further, Fig. 2 shows scraper means 5 for scrape filling the chambers 4, the scraper means 5 comprising four rotating scrapers 6. A dosing device (not shown) is arranged to dispense the powdered medicament on the surface of the filling element 3. In Fig. 2 four portions 7 of powdered medicament have been dispensed onto the

surface of the filling element 3. In order to scrape fill all the chambers 4, advantageously an amount of powder equalling at least two times the total volume of all chambers 4 is used. The filling element 3 is provided with a radial emptying slit 8 in which excess powder not filled into the chambers 4 is collected during the rotation of the rotating

5 scrapers 6, and can be reused in the subsequent filling of chambers. Means for disposal of excess powder may be through a slit or opening in proximity of the chambers. In the case of circularly arranged chambers, the slit may be radial, as shown in the figure, or coaxial inside of the chambers or coaxial outside of the chambers. Excess powder can also be disposed using suction, brushing or adhesive surfaces.

I ₀ Figs. 3a to 3h show a disc having cavities and a filling element adapted to said disc, illustrating an embodiment of the method according to the present invention. Only two cavities and two chambers are shown in the Figures. Fig. 3a shows two chambers 10.1, 10.2 provided in a filling element 11, the open side of each chamber 10.1, 10.2 facing substantially upwards. In this case, the volume of each chamber is about 75 - 100 % of the is volume of the cavity to be filled, but the filling element 11 can be interchanged by a filling element with chambers having a different volume in order to adapt to the size of the dose wanted in the cavities. In Fig. 3b the whole volume of each chamber 10.1, 10.2 is scrape filled with a quantity 12.1, 12.2 of powdered medicament by means of rotating scrapers 13. In Fig. 3c, all chambers 10.1, 10.2 are filled with a quantity 12.1, 12.2 of powdered

20 medicament and all excess powder has been removed. In Fig. 3d, a disc 14 having several cavities 15.1, 15.2, the amount of which being the same as the amount of chambers 10.1, 10.2 in said filling element 11, and the positions of which corresponding to the positions of the chambers 10.1, 10.2 in the filling element 11, is positioned on top of the filling element 11, so that the opening of each cavity 15.1, 15.2 is positioned opposite and in close

2 ₅ proximity to the opening of a corresponding chamber 10.1, 10.2. The disc 14 is detachably locked to the filling element 11. In Fig. 3e, the interlocked filling element 11 and disc 14. have been rotated about 180°, whereby each chamber 10.1, 10.2 has been rotated together with a corresponding cavityl5.1, 15.2, so that each cavity 15.1, 15.2 is positioned with its open side facing substantially upwards and each chamber 10.1, 10.2 is positioned with its

30 open side facing substantially downwards. In Fig. 3f, the quantities 12.1, 12.2 of powdered medicament have and been emptied into each cavityl5.1, 15.2, whereby each chamber 10.1, 10.2 is cleared from powder. In Fig. 3g, the filling element 11 has been detached

from the disc 14, and the volume of each cavity 15.1, 15.2 is filled to 75 - 100 % by powdered medicament. In Fig. 3h, the cavitiesl5.1, 15.2, each filled with the quantity 12.1, 12.2 of powdered medicament, are sealed by a sealing sheet 16 of aluminium.

Fig. 4 shows a schematic side view of an embodiment of the device for filling cavities s with a quantity of particulate material according to the present invention. The device comprises a conveyor belt 20 to which several filling elements 21 are attached. The filling elements 21 can have the same design as the filling element of Fig. 2, and be adapted to fill cavities provided in discs having the same design as the disc of Fig. 1. The device comprises filling means comprising a dosing device 22, a first scraper means 23, and a o second scraper means 24, each scraper means 23, 24 comprising a plurality of scrapers 25, 26 rotating around an axis 27, 28. The dosing device 22 is arranged to dispense a plurality of portions of powdered medicament onto the surface of the filling element 21. The first scraper means 23 is arranged to provide a first scrape filling of all chambers, when each chamber has its open side facing substantially upwards, through rotation of its scrapers 25, s and the second scraper means 24 is arranged to provide a second scrape filling of the chambers and also to remove excess powder into the emptying slit of the filling element 21 (see Fig. T). The emptying slit is closed during the filling of the chambers and is only open during the action of the second scraper means 24 when excess powder is to be removed. The device comprises operating means 29 for positioning a disc 30 on top of the filling 0 element 21 so that the opening of each cavity is positioned opposite and in close proximity to a corresponding opening of a chamber. Each filling element 21 is provided with locking means 37 for detachably locking the disc 30 to the filling element 21, whereby the opening of each chamber is locked in position facing an opening of a cavity. The conveyor belt 20 to which each filling element 21 is attached is arranged to guide each filling element 21 5 between the different process steps and to rotate the interlocked filling element 21 and disc 30 approximately 180°, whereby the filled chamber is rotated together with the corresponding cavity, so that the cavity is positioned with its open side facing substantially upwards and the chamber is positioned with its open side facing substantially downwards, whereby the quantity of particulate material is emptied from the chambers of the filling 0 element 21 into the corresponding cavities of the disc 30. Further, the device comprises detaching means 31 for detaching the disc from the filling element 21 when each cavity is filled. The device also comprises a first and second cleaning unit 32, 33 arranged to clean

the filling elements 21 after their chambers have been cleared from the powdered medicament, by means of pressurized air and suction. Further, the device is provided with a first and a second monitoring unit 34, 35. The first monitoring unit 34 is arranged to scan the chambers subsequent to the filling means 22, 23, 24, to confirm complete filling, and the second monitoring unit 35 is arranged to scan the filling element 21 subsequent to the first and second cleaning unit 32, 33, to confirm complete cleaning of the filling element 21. The device can optionally be provided with a third monitoring unit 36 arranged to confirm complete filling of the disc 30.