TECHNICAL FIELD

This invention relates to the nebulisation of liquids. In particular, though not exclusively, this invention relates to a nozzle arrangement for delivering a liquid from a liquid delivery device. This invention also relates to a liquid delivery device comprising a nozzle arrangement.

BACKGROUND

Drug delivery devices such as soft mist inhalers (SMIs) can be used to produce an aerosol of droplets for inhalation through the mouth and pharyngeal cavity into the lungs of a patient, for nasal administration, or for spraying the surface of the eye.

In a drug delivery device of this kind, liquid pharmaceutical formulations are typically stored in a reservoir. From there, they are conveyed through a riser tube into a pressure chamber from where they are forced through a nozzle under pressure and atomised. In this way, drug delivery devices such as SMIs are able to nebulise a small amount of a liquid formulation according to the required dosage within a few seconds to produce an aerosol suitable for therapeutic inhalation. Moreover, this can be achieved without requiring the use of a propellant.

The nozzle is typically held in place in the device by a fixing mechanism and/or structure. As the liquid formulation is forced through the nozzle under pressure, a small amount of the liquid may be deposited as a film or as an accumulation of small droplets on the surface of the nozzle and/or the fixing means. It has been found that the deposited liquid can disrupt the flow of further liquid through the nozzle, which can affect the pharmaceutical quality of the aerosol mist.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a nozzle arrangement which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

It is a further object of the invention to provide a liquid delivery device comprising a nozzle arrangement which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice. Accordingly, in a first aspect the present invention may broadly be said to consist in a nozzle arrangement for delivering a liquid from a liquid delivery device, comprising: a nozzle holder configured to form a nozzle, the nozzle having an inlet side at or towards the narrower end for receiving a liquid to be delivered and an outlet side at or towards the wider for delivering the liquid; a fixing device configured to in use fix the nozzle holder in the delivery device; and at least one recess located at or near the outlet side of the nozzle, wherein the recess is configured to wick away liquid deposited on the nozzle and/or fixing device.

In an embodiment, the nozzle holder and the fixing device are mutually configured so that the at least one recess is formed and located between the fixing device and the nozzle.

In an embodiment, the at least one recess is formed so as to run substantially around the entirety of the perimeter of the nozzle holder.

In an embodiment, the at least one recess is formed as multiple recesses around the perimeter of the nozzle holder.

In an embodiment, a first recess and a second recess are formed/arranged between the nozzle holder and the fixing device, each of the recesses having a length that extends about 3/8 of the way around the circumference of the nozzle, so that the recesses form two separate partial ring segments separated at each end by about 1/8 of the circumference of the nozzle.

In an embodiment, the at least one recess is square or rectangular in cross section.

In an embodiment, the at least one recess has a depth extending substantially in parallel with the depth of the nozzle.

In an embodiment, the at least one recess is aligned so that the open end of the recess faces in substantially the same direction as the nozzle outlet side.

In an embodiment, the depth of the at least one recess is less than the depth of the nozzle.

In an embodiment, the at least one recess has a depth extending substantially perpendicular to the depth of the nozzle.

In an embodiment, the at least one recess opens inwards towards the nozzle.

In an embodiment, the nozzle holder and the fixing device are mutually configured so that the recess narrows with depth.

In an embodiment, the recess is triangular or trapezoidal in cross-section.

In an embodiment, the recess is chamfered or curved.

In an embodiment, the recess has a depth that extends away from the opening of the recess in a direction generally parallel to the cylindrical axis of the nozzle, the recess gradually curving away such that at the lowermost end the recess extends generally perpendicular to the cylindrical axis of the nozzle.

In an embodiment, the opening width of the recess is substantially between 0.1 mm and 5mm, and most preferably substantially between 0.1 mm and 1 mm.

In an embodiment, the depth of the recess is substantially between 0.5mm and 10mm, and most preferably substantially between 0.5mm and 5mm.

In an embodiment, the fixing device comprises a nut.

In a second aspect the present invention may broadly be said to consist in a liquid delivery device comprising a nozzle arrangement according to any one of the preceding statements.

In an embodiment, the liquid delivery device comprises an inhaler for nebulising pharmaceutical liquids.

In an embodiment, the liquid delivery device comprises a soft mist inhaler (SMI).

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 A shows a cross-sectional side view of a nozzle arrangement in accordance with a first embodiment of the invention, the nozzle arrangement having a nozzle which has an inlet side for receiving a liquid to be delivered and an outlet side for delivering the liquid, and a recess located at or near the outlet side of the nozzle, the recess arranged to wick away liquid deposited on the nozzle.

Figure 1 B shows a cross-sectional view of the nozzle arrangement of Figure 1 A from the same angle as Figure 1 A, with the recess highlighted. Figure 2 shows a perspective cross-sectional side view of the nozzle arrangement of Figures 1 A and 1 B in use with and forming part of a liquid delivery device.

Figure 3 shows a perspective view from the same angle as Figure 2 of the nozzle arrangement of Figure 1 A and Figure 1 B in use with and forming part of a liquid delivery device.

Figure 4 shows a top view of the nozzle arrangement of any one of the preceding figures with the recess highlighted.

Figure 5 shows a top view of a nozzle arrangement in accordance with a second embodiment of the invention, the nozzle arrangement similar to that shown in Figures 1 A to 4, the nozzle arrangement in this embodiment having first and second recesses, each of the recesses having a length that extends about 3/8 of the way round the circumference of the nozzle, so that the recesses form two separate partial ring segments separated at each end by about 1/8 of the circumference of the nozzle.

Figure 6 shows a cross-sectional side view of a nozzle arrangement in accordance with a third embodiment of the invention.;

Figure 7 shows a cross-sectional side view of a nozzle arrangement in accordance with a fourth embodiment of the invention.; and

Figure 8 shows a cross-sectional side view of a nozzle arrangement in accordance with a fifth embodiment of the invention.

DETAILED DESCRIPTION

First Embodiment

A nozzle arrangement 100 in accordance with a first embodiment of the invention comprises the following main parts: a nozzle holder 110; a nozzle chip 107; a nut 120, and; an annular seal 111. This embodiment is shown in figures 1 A, 1 B, 2, 3, and 4.

The nozzle holder 110 is configured so that one side of the holder 110 is nozzle-shaped. That is, it forms a nozzle - nozzle 102 - that has the form of a conical-shaped recess 108 in one end of the nozzle holder 110. The nozzle 102 has an inlet side 104 (at the narrower end of the conical-shaped recess 108) for receiving a liquid to be delivered, and an outlet side 106 (the wider end of the conical shaped recess 108) for delivering the liquid. An aperture 112 is formed at the narrower end of the conical-shaped recess 108.

The nozzle chip 107 is configured to locate in use on the inlet side 104 next to the aperture 112. The central aperture 112 is configured to allow a flow of liquid from the nozzle chip 107 to exit the nozzle arrangement 100 through the nozzle holder 110, from the inlet side 104 to the outlet side 106. A “nozzle chip” as defined herein is a component having an inlet end and an outlet end connected by a plurality of microstructured channels. The inlet end of the nozzle chip comprises a filtering structure, comprising one or more microstructured channels that are generally zig-zag shaped (i.e. form a generally zig-zag structure). In this way, the filtering structure advantageously prevents any coarse debris from blocking the microstructured channels at the outlet end. The outlet end of the nozzle chip comprises one or more spray jets. If a nozzle chip is used that has two or more spray jets are present, the geometries of the spray jets can be arranged to cause two or more jets of liquid exiting the spray jets to impinge upon one another (i.e. collide with each other).

The nut 120 is configured for fixing the nozzle holder 110 in place in, and as part of, a larger delivery device (not shown). The nut 120 in this embodiment substantially surrounds and encloses the nozzle holder 110. The nozzle holder 110 and nut 120 are mutually configured so that in use a recess 130 is formed between the nozzle holder 110 and the nut 120, at each side of the nozzle holder 110. In this embodiment, the nozzle holder 110 and the nut 120 are configured so that the recess 130 appears rectangular in cross-sectional side view (e.g. the view shown in figures 1 A and 1 B) at either side of the nozzle holder. The recess 130 is highlighted as a shaded area in Figure 1 B. The recess 130 extends circumferentially around the nozzle 102 to form a continuous loop (i.e. ring) in plan view. The recess 130 has a depth - that is, the dimension that extends generally parallel to the cylindrical axis or axis of rotation of the nozzle holder 110 and nozzle 120. In this embodiment, the depth is less than the depth of the nozzle 102. The recess is open-topped - that is, it is open in the same direction as the outlet side 106.

The annular elastomeric seal 111 surrounds the nozzle chip 107, around the perimeter of the nozzle chip 107, between the nozzle chip 107 and the nozzle holder 110.

In use, liquid is forced under pressure through the nozzle chip 107 from that side of the nozzle chip 107 opposite the aperture 112, through the chip 107 to the aperture 112, and then out through the aperture 112 from the inlet side 104 to the outlet side 106. As the liquid exits the aperture 112 it is atomised to form an aerosol mist, which is directed away from the aperture 112 through the conical-shaped recess 108. During this atomisation process, a small amount of the liquid can be deposited on the surfaces of the conical-shaped recess 108, the nozzle holder 110 and/or the nut 120, on the outlet side 106. This deposition can for example be in the form of an accumulation of small droplets.

The deposited liquid is wicked away by the recess 130, the liquid entering the recess 130 at the open top or open end, and then moving through the recess 130 for example via capillary action . This reduces the amount of deposited liquid accumulating on the surfaces of the conical-shaped recess 108, the nozzle holder 110 and/or nut 120. This helps to minimise or prevent disruption of the flow of further liquid as it exits the nozzle chip 107 through the aperture 112. Second Embodiment

Figure 5 shows a top view of a nozzle arrangement 200 in accordance with a second embodiment of the invention.

The nozzle arrangement 200 in this embodiment is similar to the nozzle arrangement of the first embodiment of the invention, and comprises broadly similar elements to those of the first embodiment. Similar numbering is used for this embodiment as for the first embodiment - e.g. nozzle holder 210 in this embodiment is equivalent to nozzle holder 110 in the first embodiment, nozzle chip 207 to nozzle chip 107, nut 220 to nut 120, etc.

The nozzle arrangement 200 has substantially the same elements and structure as for the first embodiment, except that the nozzle holder 210 and the nut 220 are configured so that two recesses - a first recess 230 and a second recess 232 - are formed/arranged therebetween. In this example, each of the recesses 230, 232 is rectangular in cross-section (as for the first embodiment). In plan view, and as shown in figure 5, each of the recesses 230 and 232 has a length that extends about 3/8 of the way round the circumference of the nozzle 202, so that the recesses 230, 232 form two separate partial ring segments separated at each end by about 1/8 of the circumference of the nozzle 202. Each of the recesses 230, 232 has a depth that extends generally parallel to the cylindrical axis of the nozzle 220. As for the first embodiment, the depth is less than the depth of the nozzle 202.

Third Embodiment

A nozzle arrangement 300 in accordance with a third embodiment of the invention is shown in Figure 6. As for the first and second embodiments described above, the nozzle arrangement 300 in this embodiment comprises: a nozzle holder 310; a nozzle chip 307; a nut 320, and; an annular seal 311 (with similar numbering used for similar/equivalent parts, as for the first and second embodiments).

A recess 330 is arranged between the nozzle holder 310 and the nut 320. This has the same or a similar function to the recesses described for the other embodiments, and works in a similar manner. In this example, the recess 330 is rectangular in cross-section, and has a length that extends the whole way round the circumference of the nozzle 302 to form a continuous loop (i.e. ring). The recess 330 has a depth that extends generally orthogonal to the cylindrical axis of the nozzle 302, as shown in Figure 6, in which the recess 330 is highlighted as a shaded area.

Fourth Embodiment

A nozzle arrangement 400 in accordance with a fourth embodiment of the invention is shown in figure 7. The nozzle arrangement 400 in this embodiment has similar elements to the preceding embodiment, and equivalent numbering is used for equivalent elements. In this embodiment, a recess 430 is arranged between the nozzle holder 410 and the nut 420. The recess 430 is triangular (i.e. wedge shaped) in cross-section, and has a length that extends the whole way round the circumference of the nozzle 402 to form a continuous loop (i.e. ring). The recess 430 has a depth that extends generally orthogonal to the cylindrical axis of the nozzle 402, as shown in Figure 7, in which the recess 430 is highlighted as a shaded area.

Fifth Embodiment

A nozzle arrangement 500 in accordance with a fifth embodiment of the invention is shown in figure 8. The nozzle arrangement 500 in this embodiment has similar elements to the preceding embodiments, and equivalent numbering is used for equivalent elements. In this embodiment, a recess 530 is arranged between the nozzle holder 510 and the nut 520. The recess 530 is curved in cross-section, and has a length that extends the whole way round the circumference of the nozzle 502 to form a continuous loop (i.e. ring). The recess 530 has a depth that extends away from the opening of the recess 520 in a direction generally parallel to the cylindrical axis of the nozzle 502, the recess 530 gradually curving away such that at the lowermost end (the bottom end) the recess 530 extends generally perpendicular to the cylindrical axis of the nozzle 502.

For all of the embodiments described above, the width or opening of the recess is in a range of from 0.1 mm to 5 mm, but the best results are achieved in a range of between 0.1 mm to 1 mm. The overall depth or length of the recess is in a range of from 0.5mm to 10mm, with the best results achieved in a range of 0.5mm to 5mm.

It has been found that in nozzle arrangements such as those described above and shown in the figures, the recess helps to control liquid deposition on the outlet side of the nozzle and/or the fixing device by pulling any deposited liquid droplets away. This reduces the amount of dispensed liquid deposited on the nozzle and/or the fixing device and helps to minimise or prevent disruption of the flow of further liquid through the nozzle. This allows for greater consistency of drug delivery from a delivery device through improved retained droplet control.

The recess wicks away liquid deposited on the nozzle and/or fixing device by capillary action. In this way, the recess helps to control liquid deposition on the outlet side of the nozzle and/or the fixing device by drawing any deposited liquid droplets away by capillary action.

The nozzle arrangement is particularly suitable for delivering a liquid from a inhaler. Suitably, the liquid may be a pharmaceutical liquid. The term “pharmaceutical liquid” as defined herein refers to a solution, emulsion, or suspension of one or more active pharmaceutical ingredients in a suitable solvent. The inhaler may, for example, be a soft mist inhaler (SMI). Thus, the liquid delivery device may be an inhaler for nebulising pharmaceutical liquids. For example, the liquid delivery device may suitably be a soft mist inhaler (SMI). Suitable materials for the nozzle and/or fixing device may include, but are not limited to, polyether ether ketone (PEEK), stainless steel and/or polyoxymethylene (POM).

EXAMPLES

Comparative Example (not in accordance with the invention) - Control Test

A Malvern Panalytical ^(RTM) Spraytec ^(TM) laser diffraction system was used to observe the droplet diameters over a number of actuations (i.e. spay events) for a delivery device comprising a nozzle arrangement in accordance with the first embodiment of the invention, but with the recess (recess 130) filled in (i.e. blocked). In this test, a high average Dv90 was observed, along with a high variability in the droplet size. The Dv90 value indicates that 90% of the spray volume is contained in droplets that are smaller than the Dv90 value, and 10% is contained in droplets that are larger than the Dv90 value. The high average Dv90 was attributed to droplets forming on the nozzle and running back into the path of the central aperture of the nozzle holder and disrupting the spray formed by the nozzle chip.

Example 1 - Test using a nozzle arrangement according to the first embodiment

A Malvern Panalytical ^(RTM) Spraytec ^(TM) laser diffraction system was used to observe the droplet diameters over a number of actuations (i.e. spay events) for a delivery device comprising a nozzle arrangement 100 as described above for the first embodiment. That is, the same nozzle arrangement used in the comparative/control example above. However, in this example the wicking recess was not filled in (i.e. blocked)

In this test, a lower average Dv90 was observed, with less variability in the size of droplets within an actuation and between actuations. The wicking recess was found to reduce the occurrence of droplets running back into the path of the central aperture of the nozzle holder and therefore reduce disruption to the spray formed by the nozzle chip. This resulted in less variability in the droplet sizes and a reduction in the average Dv90.