WO2013076682A1

WO2013076682A1 - Multidose dispenser nozzle

Info

Publication number: WO2013076682A1
Application number: PCT/IB2012/056633
Authority: WO
Inventors: Massimo Ronchetti; Alfredo PULPITO
Original assignee: Luso Pharma Sagl
Priority date: 2011-11-24
Filing date: 2012-11-22
Publication date: 2013-05-30
Also published as: CH705799A1

Abstract

Multidose dispenser head, in particular for pharmaceutical products, comprising a dispensing nozzle (21) with shutter (10) housed inside a pressurized chamber (23), wherein the means for housing the shutter comprise an elastically deformable membrane (9) which is arranged so as to sealingly close off said chamber (23) and is connected to the shutter so as to act as an elastic suspension element of the shutter itself.

Description

MULTIDOSE DISPENSER NOZZLE

Field of application

The present invention relates to a controlled-dosage dispenser, also known as multidose dispenser or metering device, in particular for medical or cosmetic applications.

Prior Art

In the pharmaceutical or cosmetic sector there often exists the need for a controlled-dosage dispenser, i.e. a dispenser which is able to supply a predetermined and constant quantity of product, for each single use. Dispensers of this type, which are also known as multidose dispensers, are widely used, for example, for pharmaceutical products for topical use and requiring a precise dosage, such as ophthalmic solutions.

A known multidose dispenser comprises a prefilling volume, or prefilling chamber, which has dimensions such as to contain exactly the quantity of product intended for the single dispensing operation (for example 50 microlitres). Dispensing is performed by operating a movable element of a dispensing system, such as a pushbutton which is opposed by a spring.

A technical problem which arises in multidose dispensers is that of avoiding contamination of the product by external agents, in particular the external air. Contact with the external air is damaging not only owing to the possible presence of pathogenic agents, but also because contact with oxygen is often harmful for the product.

An attempt to eliminate this problem consists in adding a preservative and/or antibacterial agent to the product; this measure, however, involves an additional cost and the need to modify the formulation of the product and furthermore is not always acceptable. The preservative in fact may cause allergic reactions or other problems for the user: for example it is known that preservatives used in ophthalmic products have a number of non-negligible side-effects which prompt not to adopt this measure. Another solution consists in dispensers provided with a nozzle having a protective filter, but this is likewise not satisfactory because the barrier effect of the filter is limited by the size of the pores, and in particular a filter is absolutely ineffective against viruses and also because a small quantity of product remaining downstream of the filter - and therefore in contact with the outside - may in any case contaminate the quantity dispensed.

Hence, there is the need in dispensers of the type considered here to maintain the sterility of the product without using preservatives and therefore of effectively insulating the container from the external environment. In particular, it is necessary to prevent operation of the dispenser unit from causing the entry of air and/or the outflow of product which may be contaminated towards the container. Other requisites of a multidose dispenser are reliability over time, a constant quantity supplied and the compatibility with different products both in terms of state (liquids of varying density, sprays, etc.) and composition. In addition, the economic aspect must also be taken into account. These dispensers in fact consist of devices which cannot be reused and therefore there is an incentive to reduce as far as possible the complexity, the number of parts and their cost.

A multidose dispenser for liquid products without preservatives is known, for example, from EP 2152599. Said dispenser consists of a bottle provided with a dropper nozzle and a flexible sleeve for sealing the nozzle. However, it is substantially suitable only for liquid products to be dispensed in the form of droplets, i.e. substantially for aqueous solutions, and is not very suitable, for example, for gel preparations; moreover it requires a relatively complex design of the nozzle which comprises sections of varying conicity and also comprises the aforementioned sleeve. Also known is a dispenser comprising a rigid body, for example a cylindrical body, and a dispensing head which is screwed or fixed in some other manner to the top of the cylindrical body. The cylindrical body contains a reservoir, the bottom of which is formed by a sealingly slidable piston which is pressed by a contact spring against the bottom of the cylindrical body itself, so as to pressurize the product.

The dispensing head comprises a cylinder communicating with the reservoir. Said cylinder also communicates with a chamber from which a dispensing nozzle extends. The nozzle is closed by a needle valve which is housed slidably inside the said chamber and is normally closed by the action of a spring. A dispensing pushbutton is connected to the stem of the piston sliding inside the cylinder and, when displaced, compresses the product contained in the said cylinder and at the same time closes the opening communicating with the reservoir, essentially isolating said cylinder from said reservoir. Consequently, the advancing movement of the piston has the effect of increasing significantly the pressure inside the cylinder and inside the chamber communicating therewith. When a sufficiently high pressure is reached, the force exerted by the product on the needle valve overcomes the thrust of the spring, thus opening the valve and allowing dispensing. The quantity of product dispensed essentially depends on the travel of the piston inside the cylinder and may be adjusted. At the end of operation a new quantity of product is recalled into the cylinder from the container, without any contact with the external environment. In fact, immediate closure of the needle valve, as soon as the pressure drops at the end of the piston travel, prevents the entry of air into the chamber and into the storage cylinder.

This dispenser has a series of advantages, including the possibility of using liquid products of any density, as well as oily solutions, protecting the product from contact with the air. There still exists, however, room for improvement.

The needle valve requires a sliding seal on the walls of the chamber, adjacent to the nozzle, where said valve is housed. The sliding seal may be formed by a small O-ring or gasket, but requires a good dimensional precision of the components. The valve must be guided with great precision inside the sliding seat and the same seat of the seal must be made with minimum tolerances. Moreover it is required to insert a small metallic spring which is compressed between the head of the needle valve and a suitable contact surface.

All the above results in a certain increase of costs. Moreover, it has been found that the needle valve, this designed, could seize up in the presence of a solution which is highly saline and/or contains solid bodies, or which tends to form crystals. The valve in fact is in direct contact with the product and a solid body even with microscopic dimensions may prevent the flow thereof. In order to attempt to overcome the problem of jamming or "seizing" of the needle valve, it is possible to envisage a second communication path between cylinder and reservoir, which however must be equipped with a non-return valve, thereby increasing the number of components and the manufacturing cost.

Summary of the invention

The technical problem forming the basis of the present invention is to overcome the abovementioned limitations and drawbacks. This object is achieved with a multidose dispenser head according to the accompanying claim 1 , namely comprising:

- a body with at least one product inlet opening;

- at least one dispensing nozzle;

- a chamber communicating with said opening and with said dispensing nozzle;

- actuator means for compressing the product inside said chamber;

- a movable shutter which is housed inside said chamber so as to close said nozzle and which can be opened by the effect of the pressure inside said chamber; characterized in that the means for housing the shutter comprise an elastically deformable membrane which is arranged so as to sealingly close a section of said chamber, in a zone where the shutter is housed, and is connected to the shutter so as to react elastically to an opening movement of said shutter.

Said membrane, essentially, acts both as an elastic recall element for the shutter and as a sealing element. Said membrane, in other words, may replace both a conventional return spring and the seal (O-ring or the like) between the shutter and a related guide. In some embodiments of the invention, the presence of a further means for recalling the shutter is not excluded; however, in the preferred versions, the membrane acts as the sole elastic recall element.

Preferably the shutter is fixed directly to a portion of said membrane, for example to a central portion surrounded by a sealing region. More preferably said membrane has a surface portion communicating with the product storage chamber, i.e. directly exposed to the pressure of the product during the use. Thus, the pressure induced by the actuator means acts directly on the membrane, deforming it and causing opening of the shutter.

In an even more preferred embodiment, said membrane comprises a region for supporting the shutter, for example in the central part of the membrane itself, and a sealing region around said supporting region. The sealing region is clamped against a contact surface of the body, for example by means of a ring or equivalent means; clamping of said membrane region has both the effect of fixing the membrane itself, and consequently also the movable shutter associated with it, and of providing a sealing zone.

In a preferred embodiment, the membrane comprises at least one wave or bellows portion which connects said- region supporting the shutter to said fixing and sealing region. Said wave acts essentially as a suspension element for the movable shutter, between a membrane portion which is substantially fixed, for example being clamped by the above mentioned ring, and a membrane portion movable together with the shutter itself. ln the preferred embodiment the membrane has substantially the form of a disc and the sealing and fixing region is substantially an annular edge or peripheral rim of said disc. _

Advantageously, the membrane is made of plastic or rubber or elastomer resistant to wear caused by the use of oxidising or saline substances.

The shutter is for example formed by a needle valve, with or without a seal in the region of the nozzle, depending on requirements. In a preferred embodiment, the needle is guided by a fixed sleeve, which is mounted inside said chamber; the head of the needle comprises a blind threaded hole, and the needle is fixed to said membrane by means of a screw passing inside a central hole of the membrane itself and engaged inside said blind hole.

According to one of the possible embodiments, the shutter consists of a needle valve which is integral with said membrane. A membrane with a shutter formed as one piece advantageously may be made by means of die-casting and using a suitable material, for example polyethylene. This reduces the production and assembly costs.

The nozzle may have a passage cross-section which is substantially constant or diverges towards the outlet. Moreover, the nozzle may be aligned in the axial sliding direction of the needle valve or inclined at a suitable angle.

The actuator means advantageously comprise a sliding piston, the advancing movement of which compresses the product inside the chamber and at the same time sealingly obstructs the product inlet opening, thus obtaining compression and subsequent dispensing of a controlled volume of product.

In some embodiments of the invention, said piston is provided with a lip-type sealing ring which replaces a conventional sealing means such as an O-ring. Said ring is advantageously integrally formed with the piston, for example a piston with an integrated sealing ring may be obtained by means of a die- casting operation. The dispenser head according to the invention is connected to a product container, thus forming a multidose dispenser. Said container, in accordance with various embodiments, may be rigid or also flexible. In some of further embodiments, a dispenser may comprise a dual system comprising two reservoirs for the components of a dual-component product; two dispensing heads operated simultaneously by a single actuating pushbutton; a common output nozzle where the individual components of the product are mixed.

An advantage of the invention consists in the significant constructional simplification. Owing to the membrane, which acts both as an elastic recall element and as a sealing element, neither a precise nor a sealed assembly of the shutter and associated guide is required; nor is a sliding seal associated with the shutter itself necessary. Since less precise machining operations are employed, a considerable reduction in costs may be achieved without adversely affecting the reliability. Another advantage is that the needle valve is substantially not affected by jamming problems. Since less rigid tolerances may be adopted, the unit is less prone to jamming caused by micro bodies or crystals, for example when a highly saline product is present and local precipitation and the formation of solid micro granules may occur. Since the risk of jamming (seizing) of the shutter is practically eliminated, the design may be simplified, avoiding the need for a further connection channel between nozzle head and reservoir and associated non-return valve.

The invention is applicable to a wide range of pharmaceutical, cosmetic or other products, independently of their composition and their physical state (density, viscosity, etc.). The invention is applicable, among other things, to products which take the form of aqueous solutions, gels or sprays. An example of preferred application consists in multidose dispensers of ophthalmic products in gel form.

Another advantage of the invention consists in the fact that the product container may also be flexible, for example made of PE, and not necessarily rigid. This is due to the fact that pressurization of the product is caused entirely by the actuator means, advantageously formed by a piston, with which the nozzle head is equipped. The dispenser head according to the invention more specifically is defined as being isobaric, the pressure being generated by the actuator means, and does not require a product which is pressurized or contains a propellant, as in certain embodiments of the prior art. This constitutes a further advantage.

Operation occurs in a gentle and gradual manner owing to the elastic reaction effect of the membrane to the pressure exerted by the product.

Further advantages of the present invention will become clear from the detailed description provided by way of example, with reference to the accompanying drawings.

Brief description of the drawings

Fig. 1 is a cross-sectional view of a dispenser head according to a first preferred embodiment of the present invention.

Fig. 2 is a view, on a larger scale, of a detail of Fig. 1.

Fig. 3 is a cross-sectional view of a dispenser head according to another preferred embodiment of the present invention.

Fig. 4 is a plan view of the internal membrane of the dispenser head according to Fig. 1 or Fig. 3.

Fig. 5 is cross-sectional view of the membrane according to Fig. 4.

Fig. 6 shows an example of a dispenser comprising a dispenser head according to the invention.

Fig. 7 shows an example of a dispenser for a dual-component product according to another application of the invention. Fig. 8 shows another particularly preferred form for the internal membrane of the dispenser head.

Fig. 9 shows an example of an assembly comprising a dispenser head combined with a flexible container for the product.

Detailed description of a preferred embodiment

With reference to Figure 1 , this shows a cross-section of a dispenser head according to a preferred embodiment of the invention.

The head comprises a body denoted generally by 30 which is preferably made of plastic and which, in the example, is formed essentially by joining together a half-body 1 and a half-body 2.

The dispenser head has an inlet opening for the product, which communicates with a chamber 23 via a duct 20. The dispenser head shown in Fig. 1 , during the use, is mounted on a product container, not shown in Fig. 1 , communicating with said opening 22. The container may be rigid or flexible. An example of a flexible product container is shown in Fig. 9.

Said chamber 23 communicates with a dispensing nozzle 21 which is closed by a movable shutter, which is represented here by a needle valve 10 housed inside the chamber 23.

The nozzle 21 in the figure is a diverging duct suitable for the dispensing of sprays, but in other embodiments, which are entirely equivalent, the dispensing nozzle may have a constant cross-section. The orientation of the nozzle may also vary according to the needs, depending on the type of product, the mode of use, etc., for example being aligned axially with the needle valve 10, or inclined.

The end of the dispensing nozzle 21 and the needle 10, in some embodiments of the invention, may undergo a silver-coating process in order to ensure improved sterility. The needle valve 10 may be provided with a seal 13 (Fig. 2) for sealing against an inlet seat of the nozzle 21 ; this seal is optional and may be omitted in other embodiments of the invention. In some embodiments, the shutter may comprise a zone lined with deformable material, such as silicone material, with a sealing effect. For example, the needle valve 10 may comprise a silicone-lined tip instead of said seal 3.

The needle valve 10 is intended to open (moving from right to left in the figure) following a pressure increase inside the chamber 23.

In greater detail, the pressure increase is caused by an operating pushbutton 3 which acts against a piston 4 housed inside the half-body 1 and slidable inside a cylindrical portion 20a of said duct 20 connecting the opening 22 and said chamber 23.

The piston 4 is opposed by a coaxial spring 6 and is provided with at least one seal 5 for sealing against the wall of the duct part 20a. The seal 5 is located on the opposite side to the section 20 for connection to the chamber 23, relative to the product inlet opening 22. In the example the seal 5 is a double seal formed by two O-rings.

Depending on the machining precision, the O-ring seals present on the actuator piston 4 may be dispensed with or replaced by forming an elastic sealing ring (of the "herringbone" type) on the piston itself.

A screw 7 acts as adjusting element for the end of travel of the button 3 and the piston 4.

With reference now in greater detail to the needle valve 10, said valve 10 is slidable inside a guide sleeve 8 which is fixed inside a suitable seat of the half- body 2, inside the chamber 23.

The needle valve 10 is fixed to an elastically deformable membrane 9 by means of a screw 12. Said membrane 9 operates substantially both as an elastic suspension and recall element, keeping the valve closed against the closing seat of the nozzle 21 , and as a sealing element for sealing the chamber 23 from the exterior by means of a clamping ring 11 which compresses the edge of the membrane. The ring in greater detail is mounted, for example screwed, into a seat 15 of the half-body 2, closing the chamber 23 on the opposite side to the dispensing nozzle 21.

In the embodiment shown, the membrane 9 is substantially a disc with a peripheral portion 9a and a central portion 9b connected by a wave 9c which acts as a suspension element. The part 9a, as can be seen is compressed by the ring 11 against a surface 16 of the half-body 2, thus sealing the chamber 23 with respect to the mounting seat 15 of the ring (Fig. 2).

The needle 10, which is slidable inside the guide 8, is fixed to the central membrane portion 9b, by means of said screw 12 which engages a threaded blind hole 14 formed in the head of the needle 10. It should be noted that said screw 12 passes through a central hole 9e in the membrane 9; however, another hermetic seal is created by means of compression of the membrane zone 9b, between the head of the needle 10, on one side, and the head of the screw 12, on the opposite side. In this way, the chamber 23 remains perfectly sealed.

The needle valve 10 slides with a sufficient precision inside the guide, sleeve 8; however, the coupling arrangement is not sealed and has a certain play, visible in Fig. 2, such that the region 24 between the front end of the guide 8 and the membrane 9 communicates with the chamber 23. Consequently the membrane surface indicated as 9d is substantially exposed to the pressure of the product contained in the chamber 23 or in the region 24 communicating therewith.

Basically it will be noted from the figure that the movable assembly formed by the needle 10 and screw 12 is able to move, elastically opposed by the membrane 9, With respect to the fixed guide 8, with a hermetic sealing action being ensured by the same membrane 9 sealingly compressed between ring 11 and contact surface 16 and also clamped by the screw 12 in the region where the needle 10 is fixed.

Fig. 3 shows another preferred embodiment in which the details are indicated by the same reference numbers as in Figs. 1 and 2. In this embodiment, it may be noted that the duct 20 follows a different path with an "elbow" curve and that the nozzle 21 has a cross-section which is constant and not diverging. In Fig. 3 the nozzle 21 is coaxial with the needle 10, but in other embodiments the nozzle 21 may be "tangential", i.e. inclined with respect to the axis of the needle. The choice of nozzle and/or the inclination depend on the product and use.

Figs. 4 and 5 show in greater detail the membrane 9 and the respective sealing part 9a and part 9b for fixation of the needle 10, connected by the suspension part 9c. The hole 9e for the screw 12 shown in Figs. 1 and 2 may also be noted.

Fig. 6 shows a dispenser head according to the invention, for example with the embodiment of Fig. 3, forming part of a multidose dispenser 100 comprising a product reservoir 01 with an opening 102 which communicates with the above- described product inlet opening in the head.

Fig. 7 shows an example of application to a dispenser for a dual-component product. The dispenser 200 comprises two reservoirs 201 and 202 for two components of a product, each with an opening 203, 204 which communicates with a dispensing unit according to the invention and, for example, of the type shown in Figs. 1 and 2 or Fig. 3. Each of the units 31 , 32 comprises a respective shutter 10 and membrane 9; preferably the units 31 , 32 are operated simultaneously by the pressure of a single button 3 and the respective nozzles dispense a predetermined quantity of the component. The components are mixed at the common outlet nozzle 33.

Fig. 8 shows another embodiment of the membrane 9, indicating the sealing portion 9a, the portion 9b for fixing the needle 10, the suspension part 9c and the hole 9e for the screw 12. A preferred embodiment is shown where the sealing portion 9a has a protrusion 9f.

Fig. 9 shows a dispenser 300 comprising a head substantially similar to the head 30 described above. The dispenser 300 comprises a product container formed by a flexible bag 40 fixed to a rigid support 41. Advantageously, the product inlet opening 22 in the dispensing head is sealed by a breakable membrane; the rupture of said membrane is caused by screwing of the support 41 onto the head, thus connecting the aforementioned opening 22 with the inside of the product-containing bag 40.

With reference again to Figs. 1 and 3, operation takes place as follows. In the rest condition, a certain quantity of product is present inside the duct 20 and the chamber 23, which communicate via the opening 22 with the product container.

When the button 3 is pressed, the piston 4 slides inside the guide section 20a and intercepts and substantially closes the opening 22, thus isolating the duct 20 and the chamber 23. While advancing to the end of its travel path, as shown in Fig. 1 , the piston 4 acts as a piston pump, compressing the product. The pressure inside the propagation chamber 23 spreads into the zone 24 in contact with the membrane 9 and acts on the face 9d of the membrane. When the pressure exceeds a threshold value, the membrane is deformed with a displacement (towards the right in the figures) of the portion 9b, which is substantially suspended to the edge 9a by means of the suspension part 9c. Together with the membrane, the needle 10 fixed thereto is displaced, thus opening the product dispensing path through the nozzle 21.

As will be clear to a person skilled in the art, the dimensions of the duct 20, the chamber 23 and the piston 4 determine the quantity supplied. The outflow of the product causes a drop in the pressure and, consequently, closure of the needle 10 owing to the elasticity of the membrane, which returns to the original shape.

The division of the body into the parts 1 and 2 allows easy assembly of the guide 8, the needle 10 and the membrane 9. Basically the components may be easily inserted from the side of the opening 15, and the whole assembly is then closed and sealed by the ring 11. Preferably, the guide 8 is glued to the body 2 in the region of the contact surface 17 shown in Fig. 2; gluing is possible since the components are usually made of plastic. Then the_.needle 10 is inserted into the guide 8, followed by the membrane 9 to which the needle is screwed by means of the screw 12 (which may be for example an M1 screw); finally the ring 11 is screwed until tight compression of the edge 9a of the membrane.

The invention, as can be understood, not only reduces the number of components, but also facilitates assembly compared to a design which has very precise tolerances, metal springs, etc.

A dual-component dispenser of the type shown in Fig. 7 is used for products which must be mixed together only at the moment of use, for example a carbonate salt with an acid, which cannot coexist in the same reservoir (generation of carbon dioxide). This dispenser structure is suitable also for administering certain drugs which are soluble or stable in an acid environment, for example fluoroquinolones, but the acidity of the environment in which they are stable is incompatible with the human body; for example with the eyes, into which a slightly basic solution must be injected. Other examples are hydrophilic substances or solutions with lipophilic substances; these substances require the use of a stabilization surfactant which however is damaging for the ocular surface or the mucous membranes.

Claims

1. Multidose dispenser head comprising:

- a body with at least one product inlet opening (22);

- at least one dispensing nozzle (21);

- a chamber (23) communicating with said opening (22) and with said dispensing nozzle;

- actuator means (4) suitable for compressing a predefined quantity of product inside said chamber;

- a movable shutter (10) which is housed inside said chamber so as to close said nozzle, said shutter being openable by the effect of a pressure induced inside said chamber (23) by the actuator means; characterized in that the housing means of the shutter comprise an elastically deformable membrane (9) which is arranged so as to tightly seal a section of said chamber (23), in a zone where the shutter (10) is housed, and is connected to the shutter so as to react elastically to an opening movement of said shutter.

2. Dispenser head according to claim 1 , wherein the shutter is fixed directly to a ^ portion of said membrane.

3. Dispenser head according to claim 1 or 2, said membrane comprising a region (9d) which communicates with said chamber (23) and is thus exposed directly to the product under pressure inside said chamber, and at least one sealing region (9a) which surrounds said region in contact with the product.

4. Dispenser head according to claim 3, said membrane comprising a region (9b) supporting the shutter, and said sealing region being arranged around said region supporting the shutter.

5. Dispenser head according to claim 3 or 4, said sealing region being clamped against a contact surface (16) of the body, with the effect of fixing the membrane itself and sealingly closing said chamber (23).

6. Dispenser head according to claim 4 or 5, wherein said membrane comprises at least one wave or bellows portion (9c) which connects said membrane region (9b) supporting the shutter to said fixing and sealing region (9a).

7. Dispenser head according to any one of the preceding claims, the membrane

(9) being formed substantially as a disc.

8. Dispenser head according to claim 7, comprising a ring (1 ) for clamping the membrane to the body, the ring being inserted inside a mounting seat of the body and sealingly compressing a peripheral annular region of said membrane against a surface of the body which substantially surrounds the housing zone of the shutter.

9. Dispenser head according to any one of the preceding claims, said shutter

(10) being represented by a needle valve and said housing means comprising a guide sleeve (8) mounted inside said chamber (23).

10. Dispenser head according to claim 9, wherein the head of the needle comprises a blind threaded hole (14) and the needle is fixed to said membrane by means of a screw (12) passing through a central hole of the membrane itself and engaged in said blind hole, a part (9d) of the membrane being tightly clamped between said screw and an edge of said threaded hole.

11. Dispenser head according to any one of the preceding claims, said shutter (10) consisting of a needle valve which forms a single piece with said membrane.

12. Dispenser head according to claim 11 , wherein the shutter and the membrane formed as one piece are made by means of a die-casting process.

13. Dispenser head according to any one of the preceding claims, said membrane being made of an elastomer material.

14. Dispenser head according to any one of the preceding claims, said nozzle (21) having a cross-section which is substantially constant or diverging towards the outlet.

15. Dispenser head according to any one of the preceding claims, wherein said actuator means comprise a pushbutton (3) associated with elastic return means (6) and a piston (4) sealingly slidable inside a duct (20a) communicating with said chamber (23), said piston being also arranged so as to seal the product inlet opening (22).

16. Dispenser head according to claim 15, wherein said piston (4) comprises a lip-type sealing ring formed integrally with the piston itself.

17. Multidose dispenser (100, 200, 300), in particular for a pharmaceutical or cosmetic product, comprising a dispenser head according to any one of the preceding claims.