Patent Application
20220409798
The present invention relates to the technical sector of methods and means of production of a medication utilisable for the treatment of skin lesions and osteochondral or joint pathologies, and in particular for the regeneration of tissues.
The medication is obtained by combining a blood derivative with suitable biomaterials that are bioresorbable. When of an autologous type, the medication is created only at point of need, following a collection of blood from the patient to be treated. The blood derivative contained therein is a platelet-rich plasma (thrombocytes) which is also called PRP, using the acronym. The PRP is obtained by centrifugation of blood and has a high concentration of growth factors. For this reason it has high effectiveness in the regeneration of tissues. Obviously PRP has a concentration of platelets greater than that of the blood plasma from which it has been obtained; typically that concentration is 4×-6×, preferably 6×-9×. To obtain the PRP, a procedure can be operated that includes a single stage of centrifugation of the blood in which, the red blood cells (or erythrocytes) on the bottom of the receptacle of centrifugation deposit, and wherein the relative supernatant has a variable composition. This is because, in a first region, in proximity of the sediment of red blood cells, the supernatant has a greater concentration of platelets, while in a second region above the first region, it has a lower concentration of platelets. Therefore, the supernatant is first collected from the second region (which is poor in platelets) and discarded, and then the supernatant is collected from the first region, thus obtaining the PRP. It is necessary to collect as much PRP as possible, without also collecting the red blood cells. In fact, the presence thereof in the medication determines a negative effect on the relative effectiveness. In this matter, to facilitate the collection of the PRP, the container (which can be a test tube or a vial) for centrifuging, in which the blood is transferred, can include a narrowing in a relative vertical section. For the interface between the sediment of red blood cells and the first region to be at the position of the narrowing, it is necessary to carry out a collection of a precise quantity of blood which must have a composition that is not far removed from the standard composition. Alternatively, to obtain the PRP, a procedure can be included that includes two successive stages of centrifugation. In the first stage, a first sterile container is used to centrifuge the collected blood so that the red blood cells deposit on the bottom and a first supernatant, free of red blood cells, is collected. Thereafter, in a different sterile container, the first supernatant is centrifuged so that the platelets are deposited on the bottom, and a second supernatant is collected, known as platelet-poor plasma or “PPP” and the PPP is added for a volume of about 10% of the collected volume of whole blood to the platelets deposited on the bottom so as to re-suspend the platelets, obtaining the platelet-rich plasma, in which the platelets must be vital and distributed as homogeneously as possible, while conserving the sterility thereof. This can be done under a fume hood with a laminar flow of sterile air using a laboratory pipette and opening the container, or vigorously shaking the closed container. In the last modality, the PRP obtained is not homogeneous but has platelet aggregates. Consequently, the medication obtainable therewith will have an application and effectiveness that are not uniform. In relation to the resuspension under the fume hood, not all departments of a hospital, clinics and veterinary surgeries have a fume hood available.
In the medical field, a connector called a “needle free connector” is known, which is interposable between a medical device for collection and/or storage and a manual collecting and injecting medical device of a liquid to place the two devices in fluid communication without altering the relative sterility thereof. The first of these can be a medical container for collecting or storing a biological liquid (blood, plasma, urine etc.) or a medical liquid (saline solution, pharmacological system etc.). The collection and injection device can comprise a cylinder (62)-piston (61) system and relative connection means, and typically a needle-free syringe. The needle free connector, at a first longitudinal end thereof, is engageable with an opening of the medical device for collection and/or storage and defines internally thereof a channel having a relative longitudinal axis and comprises, at a second longitudinal end, a compression valve. The compression valve is constituted by an elastically longitudinally-deformable element respective to the axis thereof. The connector is conformed so that, when the second longitudinal end is free, the valve obstructs the channel, preventing the passage of liquids and airborne bodies. The needle free connector is also conformed so that, when the second longitudinal end of the needle free connector engages with the connecting means of the manual collecting and injecting medical device, the valve is compressed, opening the channel and enabling a liquid to flow.
The above-described centrifugation steps are carried out with a bench centrifuge. It includes at least two centrifuge stations (to balance the load during the centrifugation) in which the containers for the bench centrifuge are inserted, which typically are constituted by test tubes or vials and optionally a relative cap.
Typically, to realise the medications comprising PRP, the PRP is mixed with a gelling agent and optionally the gel obtained thus can be supported on a support layer made of a bio-resorbable and porous material also known as a “scaffold”; this simplifies the topical application of the medication.
From the above, in relation to the means and methods of production of the medication, the need to manually produce a medication comprising PRP strongly emerges in which the platelets are uniformly diffused, without any need to operate under a fume hood to maintain the sterility of the PRP and the medication with simple procedures and without expensive equipment.
Further, an especially known need is to minimise the possibility of contamination of the PRP produced and thus the medication obtained using the PRP, especially when a medication in gel form is obtained following the addition of calcium salts and incubation for at least 30 minutes in order to obtain the gelling of the PRP; since if this process took place in an environment that was not closed and sterile, the risk of contamination of the PRP with particles and micro-organisms would be high.
The aim of the present invention consists in reducing and/or obviating the above-cited disadvantages with respect to the means and method of production of a medication comprising platelet-rich plasma.
In particular, the present invention has the aim of being able to produce PRP in which the platelets are re-suspended homogeneously and, consequently, also a medication which comprises it avoiding external contaminations without having to operate under a fume hood, using laboratory centrifuges of a known type and with modest costs. A further aim of the invention is to provide means and methods for obtaining the PRP and the medication produced with the PRP by using a closed and sterile hydraulic circuit with the aim of excluding any form of contamination due to the opening of a hydraulic circuit or a container.
These aims and objectives are attained by a separation container, an adapter device for centrifuge stations of bench centrifuges, a production device of a medication comprising platelet-rich plasma, comprising platelet-rich plasma, a manual production method of platelet-rich plasma and a manual production method of a medication, which are respective in accordance with claim 1, claim 2, claim 3, claim 8 and claim 9 appended to the present description.
The present invention enables being able to use a common bench centrifuge utilisable in the above-mentioned and known PRP production procedures that can be used in the production of a medication which comprises PRP. It is clear that, according to the invention, it is possible to produce the PRP and the medication in a closed circuit and in conditions that prevent contamination thereof. Therefore, the presence of a fume hood is superfluous.
Note that, in accordance with the present invention, thanks to the adapter device it is possible to centrifuge the collected blood directly in a medical bag for collecting biological liquids in which the collected blood is stored. Thus the adapter device enables carrying out both step A) and step G) of the manual production method of platelet-rich plasma according to the invention preventing the bag from collapsing at the moment of centrifugation, causing a re-mixing of the steps of blood components separated in centrifugation. Consider that the separation container and step L) of the manual production method of platelet-rich plasma according to the invention, by virtue of the Venturi effect, enable uniformly re-suspending the platelets present in the relative sediment, obtaining a homogeneous solution.
Comparative tests between compositions realised according to the invention and realised with means and methods of known type for the production of PRP have demonstrated that the percentage of retrieved platelets and the factor of concentration obtained according to the invention are higher than those relative to the means of known type, enabling higher factors of platelet concentration to be obtained, and totally avoiding the formation of aggregates. In particular, with the single-use kit of the invention it is possible to recuperate a percentage of platelets comprised between 70% and 95%, with a concentration of 6×-8× and with a reduction of white blood cells of 96% and of red blood cells of 98-100%, with respect to whole blood. This is extremely important to reduce the risk of excessive and damaging inflammatory reactions.
In the present description, as the invention is relative to methods of manual production, each time reference is made to the following terms: “hydraulically connecting”, “hydraulically disconnecting”, “hydraulic disconnection”, “inject”, “aspirate” and “collect” the following are to be understood “hydraulically and manually connecting”, “hydraulically and manually disconnecting”, “manual hydraulic disconnection” “manually inject”, “manually aspirate” and “manually collect”. Further, although not expressly indicated, when reference is made to “a medical bag”, it is to be understood that the medical bag is for the collection of biological liquids. This medical bag preferably has walls made of PVC.
The characteristics of the invention will be described in the following in which some preferred but not exclusive embodiments of the separation container, of the adapter device and the production device of a medication comprising platelet-rich plasma and embodiments of the manual production methods of platelet-rich plasma and the manual production of the medication according to the invention and with reference to the appended tables of drawings, in which:
With reference to the figures, reference numeral (1) denotes a separation container according to the invention, reference numeral (2) denotes an adapter device for centrifuge stations of bench centrifuges according to the invention, and reference numeral (85) denotes a production device of a medication comprising platelet-rich plasma (PRP) according to the invention.
The separation container (1) is sterilisable and comprises:
Starting from the first supernatant liquid obtained from a first centrifugation of whole blood, the separation container is suitable to obtain, by centrifugation, a sediment of platelets and a second supernatant liquid which is constituted by platelet-poor plasma. Further, the container (1) enables remixing, by Venturi effect, the platelets of the relative sediment and a part of the second supernatant liquid up to the disappearance of the sediment (see steps L) and M) of the manual production method of platelet-rich plasma according to the invention). It must however be noted that the separation container (1), by virtue of the Venturi effect, can likewise also enable remixing of other types of sediments.
The applicant has experimentally noted that if a container is used for the production of PRP in which, given equal other characteristics with respect to the separation container (1), the tube (14) does not have a tapered portion, or the relative terminal end is not arranged distally of the cap (18) at the conical bottom portion (12) of the test tube (11), or the bottom portion of the test tube (11) is not conical, the resulting PRP does not have the platelet aggregates and is therefore not suitable to be used for the production of the medication. It is obviously that the cap (18) is configured, once engaged with the first opening (19) of the test tube (11), to prevent passage of liquids or air with the outside.
An adapter device (2) for centrifuge stations of bench centrifuges according to the invention comprises:
The adapter device (2) is insertable in the relative second longitudinal end, in a cylindrical station of a bench centrifuge for, when inserted, enabling housing, in the second housing (22), between the first and second longitudinal sector (25, 26), a test tube (11) for centrifuges having a smaller diameter than the maximum width (L2) and having dimensions such that, during the centrifugation, the test tube (11) remains between the first and second longitudinal sector (25, 26), or enable housing, in the second housing (22), a medical bag (3) for collecting biological liquids, having dimensions such that, at least partially filled, and once housed, it extends from the third and fourth longitudinal sector (27, 28). Considering that the medical bag for collection of biological liquids when empty has a substantially rectangular planar extension, the width and length of the bag will be comparable, with respect to the depth and length (L1) of the second housing (22).
The first and the second longitudinal sector (25, 26) have relative sections, transversal to the axis (23), conformed as arcs of a circular crown and are therefore suitable for retaining a test tube (11) during the centrifugation. The arcs advantageously extend by 3-175°, preferably by 50°.
It is obvious that the adapter device (2) for centrifuge stations of bench centrifuges enables being able to centrifuge a composition, for example blood, while it is contained in the second medical bag (3) for collection of liquids in which it has been collected, by housing the medical bag (3) in the second housing (22) without having to include any decanting of liquids, leading to a possible contamination of the composition. This is particularly important when the composition is blood and it is desired to use it to produce PRP and, subsequently, a medication comprising platelet-rich plasma. It is also obvious that the adapter device (2) alternatively enables housing the test tube (11) for centrifuges, comprised in the separation container (1) of the invention, in the second housing (22), between the first and second longitudinal sector (25, 26). In this way the same centrifuge station and the same adapter device can be used to centrifuge a composition (for example blood) contained in the medical bag for collecting the liquids and a further composition (for example the first supernatant obtainable from the centrifugation of the blood, by centrifuging the blood in the second medical bag) in the test tube (11) for centrifuges of the separation container (1).
It is preferable for the base wall to be perpendicular to the axis (23) and therefore to the tubular wall (21). The second housing (22) preferably has a relative plane of symmetry passing through the axis (23). The production device (85) of a medication comprising platelet-rich plasma according to the invention, is sterile and comprises:
The first support layer thus constitutes a polymeric scaffold and can be advantageously obtainable by 3D printing. This enables controlling the relative thickness and dimension of the relative pores, if porous, which advantageously have dimensions comprised between 0.2 and 2 mm, preferably comprised between 0.5 and 1 mm.
In particular, when porous, the first layer degrades before a non-porous layer and guarantees air permeability, thus facilitating healing of wounds. The grid structure also represents an ideal support for the growth of cells during the regenerating process.
In a preferred embodiment, the first support layer has a thickness comprised between 5 and 500 μm, preferably comprised between 5 and 350 μm and more preferably 150 μm. It is worthy of note that a first layer having a porosity comprised between 0.2 and 2 mm, preferably comprised between 0.5 and 1 mm and a relative thickness of 150 μm, is able to support and/or contain a mixture of the second bio-resorbable material and the PRP which forms by actuating the manual production method of a medication set out in the following. The mixture separating from the first layer is thus avoided. The first bio-resorbable material, preferably porous material, can be: polycaprolactone (PLC), polylactic glycolic acid (PLGA), polyglycolic acid (PGA), and polyvinyl alcohol (PVA), polylactic acid (PLA), NYLON 680, polypropylene (PP), polyethylene (PE), polystyrene, high-impact polystyrene (HIPS), polycarbonate (PC), polyester ether ketone (PEEK), polyetherimide (PEI) and polysulphone (PSU) The preferred embodiments are those in which the first bio-resorbable material is polylactic acid (PLA).
The second layer can have a relative thickness comprised between 1 mm and 10 mm, preferably between 1 mm and 5 mm. The second layer is preferably constituted by the polymeric sponge, preferably made of a substance chosen from the group constituted by: sodium alginate, gelatin, collagen and/or chitosan and combinations thereof. More preferably, this substance is gelatin and is advantageously pork skin gelatin to facilitate absorption of the PRP and the gradual release of growth factors following the application of the medication on the wound. The polymeric sponge advantageously has a relative degree of porosity of 40-60%, preferably of 45-55%. This is because, in this case, the polymeric sponge absorbs and distributes the PRP more uniformly, enabling the obtaining of a medication with a greater uniformity of distribution of the PRP and starting from a collection of a volume of blood from the patient of a small entity, while maintaining a high concentration of platelets in the final medication.
As the production of PRP requires sterile means, it is particularly advantageous to have a single-use kit for manual production of platelet-rich plasma that enables obtaining a PRP-based medication free of contaminants. The single-use kit comprises:
a second medical bag (3) for collection of biological liquids having a relative second pair of walls, opposite one another and defining a relative fourth internal housing, which is accessible from a third opening (32) of the second medical bag (3), a fourth needle free connector (31) arranged in and engaged with the third opening (32) in such a way that a relative compression valve is arranged distally to the fourth housing;
The first inlet (52) can comprise a luer-lock connector (57), i.e. a connector that has a relative threading engageable with a needle free connector to compress the relative compression valve. The first hydraulic conduit (51) advantageously comprises a first single-acting hydraulic valve (59) arranged upstream of the bifurcation and contiguous to the bifurcation. The second hydraulic conduit (53) advantageously comprises a first single-acting hydraulic valve (50) arranged upstream of the second outlet (54) and contiguous to the second outlet (54).
According to an embodiment, not illustrated, the single-use kit preferably further comprises: a second manual collecting and injecting medical device, which is sterile; a third manual collecting and injecting medical device, which is sterile and filled with an anti-coagulant agent; and a female-female hydraulic connector for mutually connecting the second and third manual collecting and injecting medical device, enabling introduction of the anti-coagulant agent into the second collecting and injecting medical device the anti-coagulant agent.
A preferred embodiment of the invention relates to a reutilisable centrifugation kit for manual production of platelet-rich plasma, comprising:
The third medical bag, once having been appropriately filled and inserted in one of the two adapter devices (2) of the reutilisable kit, is destined to be used as a counterweight to the second medical bag (3) during step A) of the manual production method of platelet-rich plasma according to the invention and to the foregoing. Obviously the two adapter devices (2) must be inserted in two different centrifuge stations opposite one another across the rotation axis and the second medical bag (3), containing the blood, will be inserted in the second housing (22) of one of the two adapter devices, and the third medical bag, filled with a suitable quantity of liquid for counterbalancing the quantity of blood present in the second medical bag (3), will be inserted in the second housing (22) of the other of the two adapter devices. While the further separation container (1) according to the invention, once having been appropriately filled and inserted in one of the two adapter devices (2) of the reutilisable kit (at the second housing 22), is destined to be a counterweight to the separation container (1) containing the first supernatant liquid (34) during step G) of the method in which the first separation container (1) is in the second housing (22) of the remaining adapter device of the re-utilisable centrifugation kit. This enables carrying out step A) and step G) of the manual production method of platelet-rich plasma according to the invention. Note that both the second and the third medical bag (3), even though at least partially filled with a liquid and inserted directly in a cylindrical station of a bench centrifuge, would not be suitably retained by the cylindrical station. This does not allow, in relation to the second medical bag (3), for a suitable separation of the red blood cells by centrifugation.
In a relative preferred embodiment, the invention relates to a single-use kit for manual production of a medication. It comprises a production device (85) of a medication according to the invention; a single-use kit for manual production of platelet-rich plasma according to the invention, and a gelling agent, preferably a calcium salt such as calcium gluconate or calcium chloride or thrombin, most preferably calcium gluconate.
A manual production method of platelet-rich plasma comprises following steps:
A) centrifuging blood collected from a patient, and added-to with an anti-coagulant agent, while it is contained in the second medical bag (3) for collection of biological liquids so at to obtain, on the bottom of the second medical bag (3), a sediment (33) of red blood cells and a remaining first supernatant liquid (34): B) predisposing a closed and sterile hydraulic pathway comprising: a first hydraulic portion having a first inlet (52) that is hydraulically connectable to a needle free connector to compress the relative compression valve thereof and a first outlet and being flowable through by a liquid only in a first direction from the inlet to the outlet; a hydraulic bifurcation arranged downstream of the first hydraulic portion, with respect to the first direction, the bifurcation comprising a second hydraulic portion which can be flowed through by a fluid only in a second direction, concordant with the first direction, towards a relative second outlet (54) hydraulically connectable to a needle free connector to compress the relative compression valve thereof; and a third hydraulic portion which can be flowed through in both directions, from or towards a relative third outlet:
C) hydraulically connecting: the first inlet (52) to the second medical bag (3) (obviously by means of the fourth needle free connector (31) thereof by compressing the relative compression valve); the second outlet (54) to a separation container (1) according to the invention and sterilised (preferably by means of the second needle free connector (16) thereof by compressing the relative compression valve); and the third outlet to the first manual collecting and injecting medical device (6) of a liquid;
D) aspirating the first supernatant liquid (34) from the second medical bag (3), via the first manual collecting and injecting medical device (6) while the first manual collecting and injecting medical device (6) is connected to the third outlet for storage thereof in the first manual collecting and injecting medical device (6) (see
E) injecting into the closed hydraulic pathway, via the first manual collecting and injecting medical device (6) connected to the third outlet, the first supernatant liquid (34) stored there in order to transfer the first supernatant liquid (34) into the separation container (1) (see
F) hydraulically disconnecting the separation container (1) from the second outlet (54);
G) centrifuging the first supernatant liquid (34) while it is contained in the separation container (1) obtaining a sediment of platelets and a second supernatant liquid which is constituted by platelet-poor plasma, or PPP;
H) hydraulically connecting a fourth manual collecting and injecting medical device a liquid to the second needle free connector (16) in order to compress the relative compression valve; overturning the separation container (1) and collecting the second supernatant liquid, via the fourth manual collecting and injecting medical device for, and storing the second supernatant liquid therein, newly overturning the separation container (1) and injecting, via the fourth manual collecting and injecting medical device, a predetermined part of the stored second supernatant liquid, obtaining a third liquid contained in the separation container;
I) disconnecting the fourth collecting and injecting medical device from the second needle free connector (16) and hydraulically connecting, to the first needle free connector (15) of the separation container (1), a fifth manual collecting and injecting medical device;
L) via the fifth manual collecting and injecting medical device, connected to the first needle free connector (15), collecting the third liquid from the separation container (1) and re-injecting the third liquid, obtaining a Venturi effect in order to remix the platelets of the sediment of platelets and the third liquid;
M) reiterating step L) up until the disappearance of the sediment and the obtaining of a platelet-rich plasma, wherein the relative platelets are uniformly suspended, and storing the plasma in the fifth manual collecting and injecting medical device.
It is to be considered that step A) of the manual production method of PRP mentioned in the foregoing can be carried out following insertion of the second medical bag 3 in un adapter device 2 for centrifuge stations of bench centrifuges according to the invention and following insertion of the adapter device (2) in a centrifuge station of a bench centrifuge. Further, the step G) can be obtained following insertion in the separation container (1) in the second housing (22) of the adapter device (2) between the first and second longitudinal sector (25, 26), and following insertion of the adapter device (2) for centrifuge stations in the centrifuge station. Note that in the second housing (22) a test tube for centrifuges can be housed, and therefore also the test tube relative to the separation container (1).
Additionally, it is particularly remarkable that the closed and sterile hydraulic circuit contained in the single-use kit for manual production of PRP enables carrying out step B) of the manual production method of platelet-rich plasma. The hydraulic circuit (5) comprises characteristics corresponding to those mentioned in step B). Therefore, the single-use kit for manual production of PRP enables carrying out steps B), C) D). Further, the re-utilisable centrifugation kit enables carrying out step A) and G) of the method, respectively using the third medical bag and the separation container (1) contained therein as counterweights. Note that in step H), differently to the numerous other sediments obtained by centrifugation, given the nature of the sediment of platelets, during the overturning of the separation container (1) it does not detach from the bottom thereof. The fact that the second supernatant liquid is collected in the overturned position means that it can all be collected. The tapered terminal portion (13) of the tube (14) enables obtaining, in step L), the Venturi effect and therefore effectively homogeneously re-suspending the platelets without having to open the separation container (1).
The fourth manual collecting and injecting medical device can be the same first collecting and injecting medical device (6) used previously, if it is hydraulically connectable to a needle-free connector. The fifth manual collecting and injecting medical device can be the same fourth manual collecting and injecting medical device, but is preferably different and has a smaller capacity to increase the Venturi effect.
A manual production method of a medication comprising platelet-rich plasma, according to the invention, comprises following steps:
N) predisposing platelet-rich plasma;
O) manually injecting the platelet-rich plasma, optionally added-to by a coagulating agent, into the third housing of a production device (85) of a medication, according to the invention:
P) homogeneously distributing the platelet-rich plasma in the support element (43) of the production device (85) of a medication, preferably by compression of the support element (43), and of the platelet-rich plasma injected, contained in the third housing between the first wall and the second wall.
Step P), relating to distribution, enables obtaining a medication in which the PRP is also homogeneously distributed on large surfaces with small volumes of PRP, to cover large lesions.
It is advantageous for step N) of predisposing the platelet-rich plasma to comprise predisposing the platelet-rich plasma obtained according to the manual production method of platelet-rich plasma according to the invention. In this case the use is included of the fifth medical device for collection and step O) of injecting the platelet-rich plasma comprises following sub-steps:
O1) hydraulically connecting the fifth manual collecting and injecting medical device to the third needle free connector (41) of the production device (85) of a medication; and
O2) injecting the platelet-rich plasma into the third housing, via the fifth manual collecting and injecting medical device connected to the third needle free connector (41).
It is further of considerable importance that the manual production method of the medication enables directly obtaining a package (not illustrated) comprising the medication enabling the avoiding of further packaging steps when it is not expected to have to use the medication produced immediately. The package comprises a packaging and a medication containing in the packaging, where the medication comprises platelet-rich plasma, a support element (43) which in time comprises: a first support layer made of a first bio-resorbable and porous material; a second layer, in a second bio-resorbable material, arranged on the first layer, wherein the second bio-resorbable material is a polymeric sponge or is a substance selected from a group constituted by: sodium alginate, gelatin, collagen and/or chitosan and combinations thereof, wherein the platelet-rich plasma is dispersed in the second bio-resorbable material, and wherein the second layer is arranged on the first layer. The package is characterised in that the packaging is a medical bag, preferably made of PVC, for collection of biological liquids having a relative first wall and a relative second wall, opposite one another and defining a relative internal housing; in that the first layer is in contact with the first wall; in that the second layer is in contact with the second internal wall, and in that the housing is accessible from an opening of the medical bag in which a needle free connector is arranged, in such a way that a relative compression valve is arranged distally to the housing of the medical bag. The preferred embodiments described in the foregoing in relation to the production device (85) and to the support element (43), to the first and second layer, to the first and a second bio-resorbable material are applied also to the package.
Purely by way of example some dimensions of some elements described herein are given. The medical bags for collection of biological liquids can have a relative housing of 70 ml and can be filled up to 60 ml to be introduced in the adapter device (2) according to the invention and subject to centrifugation.
Consequently it is preferable for the test tube (11) for a centrifuge of the separation container (1) according to the invention has a relative length comprised between 40 and 160 mm, more preferably comprised between 60 and 95 mm; and for the relative first opening (19) to have a diameter comprised between 20 and 60 mm, more preferably comprised between 28 and 50 mm. The tube (14) can instead have a relative length comprised between 37 and 157 mm, more preferably comprised between 57 and 92 mm, a relative maximum diameter comprised between 1 and 6 mm, more preferably comprised between 3 and 4 mm, with a minimum diameter of the tapered terminal portion, i.e. the diameter of the terminal hole of the tube (14) comprised between 0.1 and 3 and preferably between 0.5 and 1.5 mm.
The distance of the terminal end of the tube (14), with respect to the conical bottom portion (12), is advantageously comprised between 0.5 and 38 mm, more preferably comprised between 1 and 16 mm.
It is understood that the above has been described by way of non-limiting example and that technical-functional variants are considered to fall within the protective scope of the invention as claimed in the following.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019000022947 | Dec 2019 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2020/061274 | 11/30/2020 | WO |
