MXPA99006248A - Inhalation device - Google Patents

Abstract

Inhalation device comprising a body (55) defining a reservoir (56) for medicament in the form of a powder, an outlet (57) through which a user can inhale, and a dosing member (53) with at least one metering recess formed therein. The dosing member (53) is moveable between a first position in which the at least one metering recess communicates with the reservoir (56) to receive a dose of powder therefrom and a second position in which the at least one metering recess communicates with the outlet (57) to permit the user to inhale the dose. The at least one metering recess is formed in a face of the dosing member which is urged into contact against a similar mating face of the body at the lower end of the reservoir to form a dynamic seal. At least one of the faces (51) is made of a flexible material having a hardness of less than 80 Shore A.

Description

INHALATION DEVICE.

Field of Invention This invention relates to an inhalation device by means of which measured doses of medicament in the powder form can be dispensed to a user. In particular, it relates to a device of the type in which the powdered medicament = is kept in bulk in a reservoir with which the device is provided, and is measured or dosed to the user from the reservoir.

Background of the Invention Publication No. WO 96/08284 of the International Patent Application discloses an inhalation device of the described type, comprising a body defining a reservoir for medicaments in the powder form, an outlet through which a user can inhale and a dosage member with at least one recess or dosage cavity formed therein. The dosing member can be moved between a first position in which the dosing recess is Ref: 030698 communicates with the reservoir to receive a dose of powder therefrom and a second position in which the recess or dosage cavity communicates with the outlet to allow the user to inhale the dose. The dosing recess is formed on a flat, smooth surface of the body of the lower end of the reservoir. The flat contact surfaces are made of a hard material having smooth, highly polished surfaces, which form an effective dynamic seal between the dosing member and the body to avoid both the loss of dust therefrom and the ingress of moisture into the body. deposit through the interconnection between the base and the dosing member.

To provide the desired sealing characteristics, both contact surfaces must be superimposed and polished to ensure that the contours or edges fit very fairly and a high degree of smoothness. Any ripple of the contour or edges and roughness of the finish on any of the contact surfaces would deteriorate the sealing characteristics. Then, the precision of the finish required on these surfaces demands accuracy in overlapping and polishing operations that add considerably to manufacturing costs.

Description of the invention.

It is an object to provide a device of the type described using an effective dynamic seal that is cheaper and easier to produce.

According to the present invention, there is provided an inhalation device comprising a body defining a reservoir for medicament in the form of a powder, an outlet through which a user can inhale, and a dosing member with at least one a dosing recess formed therein, the dosing member is movable between a first position in which at least one dosing recess communicates with the reservoir to receive a dose of powder therefrom and a second position in which at least one dosing recess communicates with the outlet to allow the user to inhale the dose, the at least one dosing recess is formed on one face or surface of the dosing member, the surface is pressed to contact against a face or coupling surface similar to the body at the lower end of the reservoir to form a dynamic seal, characterized in that at least one of the surfaces or faces is It makes a flexible material that has a hardness of 80 Shore A. The term "dynamic seal" in this context means a seal that allows and can resist the relative movement of the two faces or surface s.

Making at least one of the sealing surfaces of a flexible material is not necessary for any of the faces or surfaces to have a precision finish to ensure that the contours are fitted very tightly since the flexible material will compensate for any undulation to maintain a tightness. effective stamp Preferably the flexible material has a coefficient of friction of 0.4 or less. By using a material having a low coefficient of friction, the faces or surfaces will move smoothly and easily over one another to aid in the smoothness or smoothing operation of the device.

Suitably the faces or surfaces are flat.

Suitably the surface or coupling face of the body is made of a flexible material. Preferably, the engagement surface of the body comprises a rubber insert. Suitably, the rubber or rubber insert has a hardness between 40 and 60 Shore A.

Preferably the rubber or rubber insert comprises chlorinated butyl laminate with a contact surface or face made of a layer of polyethylene terephthalate, polypropylene or polyethylene.

Suitably, the face of the dosing member is of a unitary construction with the dosing member.

The invention is described below with reference to the accompanying drawings in which: Figure 1 is a section through a device according to the invention.

Figure 2 is a section on the line X-X in Figure 1; Figures 3 to 5 are perspective views showing the three stages in the operation of the device according to figures 1, 2 and 6 to 9; Figure 6 is a section through a second embodiment of a device according to the invention; Figure 7 is a section the line Y-Y in Figure 6: Figure 8 is an exploded view of the embodiment shown in Figures 6 and 7; Figure 9 is an exploded perspective view, partly broken away, showing the dose indicating mechanism of the embodiment shown in Figures 6 to 8; Figure 10 is a section through a tamper resistant container cover assembly for use with a device according to the invention; Y Fig. 11 is a partially sectioned and exploded view through the tank cover assembly shown in Fig. 10.

The device shown in the cross section in Figures 1 and 2 comprises a main body portion 5 defining a reservoir 6 and a reservoir cover or end cap 2. The reservoir 6 contains a medicament supply in the form of a powder (not shown). The medicament is one which is suitable for inhalation, and many such medicaments are well known to those skilled in the art, for example, for the treatment of asthma. Suitable powdered medicaments for this purpose include salbutamol, beclomethasone, salmeterol, fluticasone, formoterol, terbutaline, budesonide and flunisolide and physiologically acceptable salts, solvates and esters or any combination thereof. Preferred drugs are salbutamol, salbutamol sulfate, salmeterol, salmeterol xinafoate, fluticasone propionate, beclomethasone dipropionate and terbutaline sulfate. Individual isomers such as R-salbutamol can also be used. It is understood that the powdered medicament may consist solely of one or more active ingredients or there may additionally be a carrier, for example lactose powder.

The cover 2 of the tank can be provided with a desiccant cartridge (not shown) to absorb moisture and reduce the risk of dust in the moisture-absorbing tank and the agglomeration of the particles thereof. The cover 2 can be removably secured to the body 5 by any known means, for example by means of a screw screw or a press fit, to allow the filling of the tank 6 with dust. Alternatively, it may be sought that the device be disposable after the completion of the supply of powder in the reservoir, in case the cover 2 can be permanently secured to the body 5 by means of an interference fit or by the use of an adhesive, welding ultrasonically or by another method, such as that described below with reference to Figures 10 and 11. A rubber seal ring 4 of pharmaceutical grade can be incorporated between the cover 2 and the body 5 to prevent the ingress of moisture in depot 6.

At its lower end the portion 5 of the main body is adjusted with a base 10 which together with the body 5 defines an opening 11 which deviates from the vertical axis of the device and through which the powder passes from the reservoir towards the member 3 of dosage. The powder is guided towards the opening by the walls of the tank forming a hopper. Extending laterally from the lower end of the body 5 is mainly the multiple piece 7. HoweverIf the device is intended for nasal inhalation, it could be replaced by a piece for the nose. The dosing member 3 has a dosing recess 22 which is mounted in the lower body portion 9 which is rotatably connected to the main body 5 so as to rotate about the vertical axis of the device. As will be explained in more detail below, the portion 9 of the lower body serves to allow rotation of the dosing member while maintaining the same in axial alignment with the base 10. It also presses the dosing member 3 to contact the base 10. The pole cover 33 is attached to the portion 9 of the lower body through the pivot 34.

A weight 31 in the shape of a ring surrounded the tank 6 and is longitudinally slidable thereto. The place of movement of the weight 31 is defined towards the upper part of the tank by an end stop 32 formed as an integral part of the body 5, and towards the lower part of the tank by the base 10 which behaves like an anvil. It will be understood that while the device described herein incorporates a weight for the purpose described below, the weight is not an essential element of the invention and weight incorporation could be omitted.

The surface or lower face of the base 10 is formed by a flexible, flat rubber insert (not shown), while the upper face of the dosing member 3 is molded with a flat contact surface to form a dynamic seal between the dosing member and the body. These flat faces provide contact surfaces between which - there is no separation substantially. Then air and dust are excluded from the interface between the base 10 and the dosing member 3 both during the static state and during the sliding movement of one face or surface on the other, minimizing both the loss of dust and the input of moisture to the reservoir 6 through the interface between the base 10 and the dosing member 3. This type of dynamic or sliding seal eliminates the need for any other sliding means between the base 10 and the dosing member 3.

The faces or contact surfaces do not need to be provided with precision finishes to provide an effective seal. Any undulation in the smoothness of the face or upper surface of the dosing member will be compensated by the flexible rubber insert to maintain an effective seal. Although proper operation of the seal can be achieved by using a rubber material having a hardness below 80 Shore A, it has been found that optimum performance of the seal is achieved by using a rubber material having a hardness between 40 and 60. Shore A. If the hardness of the rubber is below 40 Shore A, the rubber insert tends to deform in the dosing recess 22, removing the powder away from the recess and reducing the amount of powder dosed. On the other hand, if the hardness of the rubber is above 60 Shore A, the effectiveness of the seal can be reduced. Smooth finishes and both faces or contact surfaces are desirable to maintain a good seal, but good results have been obtained from contact surfaces molded directly from highly polished tooling without additional manufacturing processes.

The rubber insert can be made from butyl to provide the desired hardness and flexibility. However, butyl has a high coefficient of friction and tends to hide the movement of the surfaces of relative contact with each other. Therefore, it is preferable to use either chlorinated butyl or laminated burin with a contact surface made of a layer of PTFE, polypropylene or polyethylene. Such rubber inserts can be manufactured by standard techniques and provide a contact surface with reduced coefficient of friction. Alternatively, the contact surface can be attached to any other surface treatment that reduces friction, such as modification with plasma or varnish.

PTFE is a particularly suitable material for this purpose due to its low coefficient of friction (below 0.1), although materials that have coefficients of friction up to around 0.4 are acceptable. Good results have been obtained using laminated butyl with a contact surface made of PTFE sheet having a thickness of about 0.2 mm. The sheet or sheet can be adhered to the rubber insert without glue, using standard manufacturing techniques. If the PTFE laminate is thinner than 0.2 mm, the sheet tends to wrinkle during rubber vulcanization, whereas if the sheet is thinner than 0.2 mm, the insert becomes harder and the effectiveness of the seal can be reduced.

The contact surface of the dosing member can be integrally molded with the dosing member of any suitable material, for example, acetal resin. Alternatively, it will be understood that the contact surface of the dosing member can be formed by a flexible, flat rubber insert, as described above and the surface or underside of the base 10 can be integrally molded in one piece as part of the base 10 from a suitable material. Alternatively, both surfaces can be formed by flexible, flat rubber inserts as described.

In the described embodiment, the two faces or surfaces are formed by the surfaces of the flat discs. It will be appreciated that the shapes of the discs are not essential. The faces or contact surfaces can be formed by the surfaces of a frusto-cone and a correspondingly frusto-conical adapter bushing, by the contact surfaces of two coaxial cylinders or by two spherical contact and adapter bushing surfaces, partially spherical , corresponding.

In the operation, the user initially shakes the device in a generally up and down movement, while keeping the device in a generally clockwise orientation, as shown in Figure 3. The weight 31 is caused by upward movement and downwardly of the reservoir, thus repeatedly hitting the end retainer 32 and the base 10. The shaking that this causes causes the powder in the reservoir to be pressed down and into the dosing recess 22.

The user then opens the cover 33 of the powder, as shown in Figure 4, and rotates the cover that is connected to the lower portion 9 of the body as described above and shown in Figure 5, to move the cover 33 of the powder away from the part 7 for the mouth to allow access to it and bring the recess 22 in alignment with the opening 8 leading towards the part 7 of the mouth. The user knows when this position has been reached as the lower portion 9 of the body engages with a detent (not shown) and will not move further. The user then inhales through piece 7 of the mouth. After inhalation, the user returns the lower portion 9 of the body to its initial position and closes the cover 33 of the powder.

In the device shown in Figures 1 and 2 the opening 11 is easily deflected at an angle of 90 ° about the vertical axis of the device from the opening 8 and the inner end of the mouth piece to allow the dust cover and the lower portion 9 of the body moves through 90 ° for easy access to the mouth piece. However, it will be appreciated that this angle can be substantially increased or decreased slightly according to the desired angle of rotation of the powder cover, the lower body portion and the dosing member.

Further possible modifications to the described device include the incorporation of a suitable dose quantization mechanism to give the user an indication of the amount of powder remaining in the device.

A further embodiment of the invention is shown in Figures 6 to 9. As in the previous embodiments, the device shown in cross section in Figures 6 and 7 and in the exploded view of Figure 8, comprise a main body portion 55. , elongated, defining a reservoir 56 and a reservoir cover or an end cap 52. The reservoir 56 contains a supply of medicament in the form of a powder (not shown). The reservoir cover 52 is secured to the body 55 by a snap fit and a pharmaceutical grade rubber seal ring 54 is incorporated between the cover 52 and the body 55 to prevent moisture from entering the reservoir 56.

At its lower end the portion 55 of the main body defines an opening 51 that deviates from the vertical axis of the device and through which the powder can pass from the reservoir to a recess 65 in the dosing member 53. The base member 60 fits the lower end of the body 55, the face or bottom surface of the base member 60 is provided with a flat, flexible rubber insert 51a similar to that described with reference to the embodiment shown in Figures 1 to 5 while the surface or top face. of the metering member 53 is molded with a flat face or contact surface. The powder is guided towards the opening by the walls of the tank forming a hopper. Extending laterally from the lower walls from the lower end of the main body is the part 57 of the mouth. The dosing member 53 is mounted on the lower assembly 59 of the body which is rotatably connected to the main body such that it can rotate about the vertical axis of the device. The lower body assembly 59 serves to transmit the rotational movement thereof to the dosing member 53 while maintaining the same in axial alignment with the base member 60. It also presses the dosing member 53 into very close contact with the base 60 by means of the spring 61. The cover 63 of the powder is attached to the lower portion 69 of the body through the pivot 64.

A dose indicating drive means comprises an axis or arrow 70 provided with a screw thread over most of its length, a lug 71 mounted on springs at the base of the thread and a sprocket 72 with slanted teeth, placed below of the tab is rotatably mounted within a hole 73 in the wall of the main body 55 (see Figure 9). An indicator nut 77 is threaded onto the shaft with a projection projecting through an indicator window 74 in the wall of the bore 73 which prevents the indicator nut 77 from rotating with the shaft or arrow 70. The lug 71 mounted on springs it engages the teeth 75 formed within the bore 73 to form a ratchet wheel that allows the arrow 70 to rotate in one direction only. The gear 72 is located adjacent to the periphery of the metering member 53 which is provided with a second lug 76 mounted on springs.

The operation of the device is similar to that described with reference to the embodiment shown in Figures 1 to 5. The user initially waves the device in a generally upward and downward movement as shown in Figure 3. This makes the powder flow down and into the metering recess 65 within the metering member 53.

The user then opens the dust cover 63, as shown in Figure 4, and makes the cover which is connected to the lower body assembly 59 as described above and as shown in Figure 5, to move the cover 63 of the powder away from the mouth piece 57 to allow access thereto and to couple the recess 65 in alignment with the opening 66 in the direction of the mouth piece 57. As the dosing member 53 rotates with the lower body assembly 59, the lug 76 (FIG. 9) engages with an inclined tooth presented by the sprocket 72 of the driving means of the dose indicator. The actuation means of the dose indicator is prevented from rotating in the direction pressed by the lug 76 by virtue of the ratchet wheel mechanism formed by the teeth 75 and the lug 71. As a result, the lug 76 travels on the inclined tooth and out of engagement with the gear 72. The lower mount 59 of the body engages a detent (not shown) and will not move when the recess 65 is correctly aligned with the opening 66.

The user now inhales through piece 57 of the mouth. The air is drawn through a grid 80 and the passage 81, defined by the body 55 and the hole 82 in the base member 60, and entrains the powder in the recess 65 of the metering member 53. The air flow extracts the dust entrained through the piece 57 of the mouth and is inhaled by the user. In addition, air is drawn into the mouth piece through holes 83 on either side of the mouth piece 57 and this creates turbulence that helps break up any agglomerates of the entrained powder.

After inhalation, the user returns the lower assembly 59 of the body to its initial position and closes the cover 63 of the powder. As the dosing member 53 rotates, the lug 76 engages again with the cogwheel 72 of the driving means of the dose indicator - As the ratchet wheel mechanism formed by the teeth 75 and the lug 71 allows movement of the medium actuator of the dose indicator in the direction as now pressed by the lug 76, the actuator means of the dose indicator rotates a tooth gap through the coupling with the lug 76 as the sprocket 72 passes. The rotation of the actuator means of the Dose indicator causes the nut 73 of the captive dose gauge to travel under the threaded shaft or shaft 70. The spacing or pitch of the thread and the number of teeth in the sprocket 72 are selected to ensure that the dose indicator nut travels from the "full" upper position to the "empty" bottom position when the device has been used sufficiently to supply its prescribed dose number, thus indicating to the user that the device is empty.

Figures 10 and 11 show an alternative design for a tamper-resistant reservoir cover assembly, which can be used with a device according to the invention or for other applications where it is necessary to seal a container to prevent access to its contents. The cover assembly comprises a cover 90 having a circular upper portion 91 and an annular dependent cylindrical portion 92 formed with an outwardly directed projection or lip 93, which extends around its lower periphery. The lid 90 is made of a material such as polypropylene which allows some elastic flexibility of the cylindrical portion 92, the purpose of which is explained below.

The upper part of the body 94 is formed with an outer peripheral wall 97 and a concentric inner peripheral wall 96 that together define the mouth of the reservoir 100. An annular channel 95 is further defined between the inner and outer peripheral walls 96, 97. The outer wall 97 has an increasing wall thickness extending towards the channel 95 to different locations around its inner face which forms retention flanges under which the lip 93 engages, as seen in Figure 10. For the purposes of In this embodiment, the ridges are formed by means of five equally spaced slots 98, which extend radially through the channel 95 from a groove 102, which is provided around the periphery of the outer wall 97 at the same level as the lower part of the wall. channel 95. The inner surface of the inner wall forms an inclined slope that goes from the upper part of the channel 95 to the point of maximum thickness of the wall just above each slot 98.

To adjust the cover 90 to the body 94, the cylindrical portion 92 is inserted into the channel 95. As the lower periphery of the cylindrical portion 92 comes into contact with the inclined slopes formed in the outer wall 97, the cover 90 is pushed towards down in the body 94 so that the cylindrical portion 92 flexes inwardly due to its elastic flexibility in the contact regions to allow further movement towards the channel 95, until the lips 93 reach the slots 98 and fit outwardly. to make sure under the retention flanges. When assembled, the cylindrical portion 92 is substantially surrounded by outer peripheral walls 97 such that they are sealed and inaccessible from the outside. The sealing ring 99 is placed between the upper part of the interior wall 96 and the lower side of the upper portion 91 to seal the reservoir 100 of the atmosphere. Finally, the band 101 of polypropylene or polypropylene-polyethylene copolymer is stretched around the groove 102 to hide the grooves 98 and to prevent access and tampering with the lips 93. Once in place, the band 101 is not removes easily.

It will be understood that the present disclosure is for purposes of illustration only and the invention extends to modifications, variations and improvements thereto.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Having described the invention as above, the content of the following is claimed as property.

Claims (10)

Claims

1. An inhalation device comprising a body defining a reservoir for medicament in powder form, an outlet through which a user can inhale, and a dosing member with at least one dosing recess formed therein, the The dosing member is movable between a first position in which at least one dosing recess communicates with the reservoir to receive a dose of powder therefrom, and a second position in which at least one dosing recess communicates with the reservoir. outlet to allow the user to inhale the dose, the at least one dosing recess is formed on one face or surface of the dosing member, the surface or each is pressed to come into contact against a similar engaging surface or face of the body in the lower end of the reservoir to form a dynamic seal, characterized in that at least one of the faces or surface is made of a flexible material having a at hardness of less than 80 Shore A.

2. The inhalation device according to claim 1, characterized in that the flexible material has a coefficient of friction of 0.4 or less.

3. The inhalation device according to claims 1 or 2, characterized in that the surfaces or faces are flat.

4-. The inhalation device according to any of the preceding claims, characterized in that the surface or coupling face of the body is made of a flexible material.

5. The inhalation device according to claim 4, characterized in that the surface or coupling face of the body comprises a rubber insert having a hardness between 40 and 60 Shore A.

6. The inhalation device according to claim 5, characterized in that the rubber insert comprises chlorinated butyl or laminated butyl with a face or contact surface made of a layer of polyethylene terephthalate (PTFE), polypropylene or polyethylene.

7. The inhalation device according to any of the preceding claims, characterized in that the face or surface of the dosing member is of a unitary construction with the dosage member.

8. A tamper-resistant closure, which closes an opening in a container, the container defines an outer peripheral wall adjacent to the opening and having at least one interior rim below the opening, the closure is characterized in that it comprises a portion of cylindrical skirt that has a lip on its outer periphery, so when the lip is assembled it forms a snap fit with the flange to hold the closure in place.

9. The tamper-resistant closure according to claim 8, characterized in that the container further defines a peripheral wall that is sealed against the closure when assembled.

10. The tamper resistant closure according to claim 8 or 9, characterized in that when assembled, the outer peripheral wall is sealed with the skirt portion such that it is substantially inaccessible from the outside.