Oral medicine dispensing system

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] ORAL MEDICINE DISPENSING SYSTEM

[0002] FIELD OF THE INVENTION

[0003] This invention relates to dispensing system that is suitable for supply and oral administration of medicines, particularly to infants and small children (who are collectively referred to as “children” herein). However, the invention can also be used for dispensing other liquids.

[0004] BACKGROUND TO THE INVENTION

[0005] Medicines can be harmful if ingested accidentally and while adults usually know to avoid doing so, children are at risk and there is a need to prevent accidental ingestion of medicines.

[0006] Further, liquid medicines need to be administered in measured dosages, usually orally, and in order to allow measurement of the correct dosages and administration, the medicines are typically supplied in bottles with large enough openings to allow the medicine to be poured (e.g. in to a spoon) or withdrawn (e.g. with a syringe). These operations are cumbersome and are often performed in the presence of children and often by a person who is also tasked with controlling a child. As a result, there are significant risks of spillage (whether through handling error by the adult or by the child), inaccurate dosage measurement (because the adult is distracted or physically hindered), accidental ingestion (if the medicine container is not closed immediately), and unsuccessful or incomplete administration of the medicine. These risks are increased in instances where more than one child is present and / or where a child is restless - which is common in the cases of children who are unwell or who resist medication.

[0007] Many attempts have been made to prevent unwanted opening of the containers in which liquid medicines are supplied, but these do not address the problems mentioned above, which necessarily arise at the time that the adult has to open the container to administer medicine.

[0008] Attempts have been made to avoid the risks and inconvenience associated with measuring dosages of liquid medicines and to reduce the volume of liquid in packaging that could be ingested, by supplying liquid medicines in unit dosages in sachets and small plastic containers with twist-off caps, but the sachets and other containers do not provide for convenient administration of the medicine. It is also very difficult to administer a fraction of a dosage (e.g. a half dosage) from such a sachet or container.

[0009] Unit dosages of liquid medicines have also been supplied in glass vials with necks that need to be severed - creating dangerous edges around the necks of the vials and creating small glass fractures - both of which pose considerable risk of injury.

[0010] Many devices for dispensing medicines are made from multiple materials and / or from materials that are difficult to recycle or that cannot be recycled.

[0011] Devices intended to prevent accidental ingestion or to assist in administration of medicines are typically costly.

[0012] Devices intended to dispense liquid medicines, with components that come into contact with the medicine and that are re-used need to be cleaned and it would be more convenient if the cleaning can be avoided.

[0013] The present invention seeks to provide for dispensing of liquids that overcomes most or all of the shortfalls mentioned above.

[0014] SUMMARY OF THE INVENTION

[0015] According to one aspect of the present invention there is provided a system for dispensing a liquid, said system comprising: at least one cartridge that includes; a hollow, elongate shell that has a longitudinal axis and that defines an internal cavity and that is closed near one end with a septum, at least part of said septum being thin enough to rupture under pressure from a sharp object, said shell protruding beyond the septum to form a recess on a side of the septum opposite from the internal cavity, with a female formation defined on the inside of the recess; a piston that is disposed inside the shell and that can slide axially inside the cavity, while sealing against the inside of shell; said liquid, which is held inside the cavity between the closed end and the piston; and a head defining an internal passage extending between a discharge opening and sharp protuberance, and defining a male formation on the outside of the head, said head being receivable in the recess with the male formation and female formation interacting in a helical manner, so that rotation of the head about the axis relative to the shell causes the head to move axially relative to the shell and such axial movement is configured to bring the sharp protuberance into contact with the septum, to rupture the septum; and a dispenser that includes: a body defining a receiving formation in which at least the head is receivable in a manner that resists rotation of the head relative to the body; and a plunger that is displaceable in the axial direction towards the protuberance.

[0016] The dispenser may include a receiver defining a recess in which the cartridge is receivable, at least in part, and the plunger may be attached to the receiver, to slide relative to the receiver and cartridge shell in the axial direction.

[0017] The shell of the cartridge may be held in place in the recess of the receiver in a manner that resists rotation of the shell relative to the receiver.

[0018] The receiving formation of the body may define a female formation and the receiver may define a male formation, said male and female formations being configured to interacting in a helical manner, so that axial movement of the receiver relative to the body causes the receiver to rotate about the axis, relative to the body.

[0019] The receiving formation of the body may be a cavity in which the receiver and cartridge are receivable to engage the receiver and body. According to another aspect of the present invention there is provided a cartridge for dispensing liquid, said cartridge comprising: a hollow, elongate shell that has a longitudinal axis and that defines an internal cavity and that is closed near one end with a septum, at least part of said septum being thin enough to rupture under pressure from a sharp object, said shell protruding beyond the septum to form a recess on a side of the septum opposite from the internal cavity, with a female formation defined on the inside of the recess; a piston that is disposed inside the shell and that can slide axially inside the cavity, while sealing against the inside of shell; said liquid, which is held inside the cavity between the closed end and the piston; and a head defining an internal passage extending between a discharge opening and sharp protuberance, and defining a male formation on the outside of the head, said head being receivable in the recess with the male formation and female formation interacting in a helical manner, so that rotation of the head about the axis relative to the shell causes the head to move axially relative to the shell and such axial movement is configured to bring the sharp protuberance into contact with the septum, to rupture the septum.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a better understanding of the present invention, and to show how the same may be carried into effect, the invention will now be described by way of non-limiting example, with reference to the accompanying drawings in which:

[0022] Figure 1 shows a sectional side view of a cartridge according to the present invention;

[0023] Figure 2 shows a sectional side view of a dispenser body according to the present invention;

[0024] Figure 3 shows a sectional side view of the cartridge of Figure 1 in combination with the body of Figure 2;

[0025] Figure 4 shows a sectional side view of a receiver according to the present invention; Figure 5 shows a sectional side view of a plunger according to the present invention; Figure 6 shows a sectional side view of the receiver of Figure 4 in combination with the plunger of Figure 5;

[0026] Figure 7 shows the receiver / plunger combination of Figure 6; with the cartridge of Figure 1 partly inserted into the receiver;

[0027] Figure 8 shows the receiver / plunger combination and cartridge of Figure 7, with the receiver and cartridge inserted into the body of Figure 2;

[0028] Figure 9 shows the dispenser and cartridge of Figure 8 after liquid has been dispensed; and

[0029] Figure 10 is a detail sectional view of part of the dispenser and cartridge of Figure 9.

[0030] DETAILED DESCRIPTION OF THE DRAWINGS

[0031] Referring to the drawings, a system according to the present invention for dispensing liquid in the form of medicine for oral administration includes a cartridge 14, a body in the form of a barrel 16, a plunger 18 and a receiver 20. Each of the components shares a common, central longitudinal axis, which has been omitted from the drawings for clarity.

[0032] The cartridge 14 has a shell that comprises of a hollow cylinder 22 with an internal cavity 23 and a disc 24 that closes off the cavity near the end of the shell. The disc 24 forms a central septum 26, at least part of which is thinner than the remainder of the disc, so that the septum can rupture when under pressure from a sharp object. The part of the shell 22 on the opposite side of the disc 24 from the cavity 23, forms a hollow cylindrical protuberance 25 with an internal recess 27 and a female formation in the form of a helical groove 29.

[0033] A piston 28 is disposed inside the cylinder 22 and can slide axially inside the cylinder with the circumference of the piston sealing against the inner circumference of the cylinder. The piston 28 is also injection moulded from recyclable plastics material and it has circumferential ridges 30 that slide along the inside of the cylinder 22 with light interference, to provide the necessary seal. The piston 28 is shown at the start of its stroke, in which it travels in an axial direction from the open end of the cavity 23 towards its closed end. The part of the cavity 23 between the piston 28 and the disc 24 is filled with a liquid medicine. On a leading side of the piston 28, it defines a leading recess 32 for receiving an end of a sharp protuberance (see below) that ruptures the septum 26, as well as the ruptured part of the septum, when the piston is at the end of its stroke. The leading recess 32 allows the piston 28 to continue with its stroke up to a point where the piston buts against the disc 24, so that the only part of the cavity 23 that remains between the piston 28 and the disc 24 is the inside of the leading recess 32. The leading recess 32 thus assists in purging medicine from the cavity 23 and minimises medicine waste. It also increases dispensing accuracy, and reduces the necessary piston stroke length for optimum cartridge length - i.e. the cartridge does not need to be longer, to provide sufficient internal space for the full piston stroke.

[0034] On a trailing side of the piston 28, it defines a trailing recess 34, in which the plunging head of the plunger (see below) is receivable to drive the piston during its stroke.

[0035] At its open end, the cylinder 22 has a small inner retaining ridge 36, which prevents the piston 28 from exiting the cylinder. In addition, when the cartridge 14 is supplied, i.e. in the condition shown in Figure 1 , before the piston 28 begins its stroke, its circumference at its trailing side is preferably welded to the retaining ridge 36, to ensure that the piston does not dislodge prematurely from its position in the cylinder and to ensure that the cavity 23 is perfectly sealed. The weld is very small and is severed easily when the piston 28 is driven during its stroke, but assists the retaining ridge 36 in preventing accidental dislodgement of the piston and spillage, e.g. if the cartridge 14 is bent or compressed.

[0036] On the outside of the cylinder 22, near the disc 24, lock formations are provided in the form of small keys 37.

[0037] The cartridge 14 also includes a head 39 that is received inside the recess 27. The head 39 defines an axial internal discharge passage 42 extending between a discharge opening defined in a protruding spout 41 and a sharp protruding piercing formation 44. The piercing formation 44 is sharp and hard enough to rupture the septum 26 of the cartridge 14, if the piercing formation is pressed against the septum with a moderate force. The head 39 has male protruding formations in the form of small stubs 43 that are received in the helical groove 29 so that the stubs and groove interact in a helical manner and if the head is rotated relative to the protuberance 25 of the shell, about the axis, the head moves axially relative to the protuberance. Such a helical movement of the head 39 relative to the protuberance 25 is configured to bring the piercing formation 44 into contact with the septum 26, to rupture the septum. A plurality of small recesses 31 are defined circumferentially around the head 39 at the base of the spout 41 .

[0038] The helical groove 29 resembles a course thread, but the part of the groove 29 in which the stubs 43 are received when the head 39 is in its initial position (the position relative to the protuberance 25 shown in Figures 1 , 3, 7 and 8, i.e. the position when the cartridge 14 is supplied) extends purely circumferentially and the remainder of the groove 29 extends helically. The result is that, if the head 39 is pressed axially when it is still in its initial position, e.g. when the cartridge 14 is dropped and lands on the spout 41 , the stubs 43 will not be in the helical part of the groove 29, but once the head 39 has been rotated through a small angle, the stubs reach the helical part of the groove and helical action can commence. In a preferred embodiment, the helical groove 29 is configured so that the head 39 travels about 5mm in the axial direction, during a relative rotation of 180° between the head and the protuberance 25 - which is sufficient for the piercing formation 44 to rupture the septum 26.

[0039] The cylinder 22, disc 24, septum 26, and protuberance 25 are injection moulded as a unitary moulding from a recyclable plastics material and the head 39 is similarly injection moulded from a recyclable plastics material. The recyclable plastics materials from which the cartridge 14 (apart from the medicine) is made, are selected such that the cylinder 22 can be mechanically flattened or completely bent, without breaking. The cylinder 22 also has very thin walls and can be produced at very low cost. The fact that the entire cartridge 14 is made from recyclable materials (apart from the medicine), allows the cartridge to be recycled easily, once the medicine has been dispensed, without a need to separate components of the cartridge. The cartridge 14 is intended to be a disposable item.

[0040] The barrel 16 is a unitary moulding that has an elongate shape with a peripheral wall 38 around a receiving formation in the form of an internal recess 40. A discharge opening 45 is defined at one end of the barrel 16 and the circumference of the discharge opening is about the same as the circumference of the head 39 and the inner circumferential surface on the discharge opening includes formations (not shown) that are shaped complementally to the recesses 31 . As seen in Figure 3, the head 39 can be gripped firmly in the discharge opening 45, with the recesses 31 and the inner circumference of the discharge opening resisting rotation of the head relative to the barrel 16.

[0041] Two tabs 48 extend from opposing sides of the recess 40’s opening and two female formations in the form of helical grooves 47 are defined in the wall 38 on opposing sides of the barrel 16, near the open end of the recess 40. Each of the helical grooves 47 extends axially for a short part near the recess 40’s opening.

[0042] The plunger 18 is a unitary moulding that includes an elongate plunging head 52, with one or more generally parallel guides 54 on opposing sides of the plunging head, the plunging head and guides being joined by a plunger disc 56. The ends of the guides 54 that are opposite from the disc 56 are wider, to form steps 58

[0043] The receiver 20 defines a recess 60 inside which the shell 22 of the cartridge 14 is snugly receivable. Near an open end of the recess 60, locking formations 62 are defined in which the keys 37 of the cartridge 14 are receivable to prevent rotation of the cartridge relative to the receiver. At a closed end of the recess 60, a central plunge passage 64 is defined, extending axially from the recess, with a shoulder 66 extending around the plunge passage. The retaining ridge 36 rests against the shoulder 66 when the shell 22 of cartridge 14 is received inside the recess 60,

[0044] The receiver 20 defines guide passages 68 in which the guides 54 can slide and tabs 70 extend on opposing sides of the receiver and partially obstruct the openings of the guide passages, with shoulder formations 72. Two male formations in the form of stubs 74 protrude from the receiver near the tabs 70 and these stubs are configured to be received in the grooves 47 of the barrel 16 in bayonet fashion and to cause the receiver 20 to rotate about the axis relative to the barrel when the receiver moves axially inside the barrel, in a helical manner.

[0045] Referring to Figure 6, the receiver 20 and plunger 18 are preferably pre-assembled, with the guides 54 being received inside the guide passages 68 and being held captive within the guide passages by the steps 58 and shoulder formations 72, which prevent withdrawal of the guides from the guide passages. The plunger 18 can slide easily relative to the receiver 20.

[0046] In use, when a liquid medicine is to be dispensed, e.g. to be administered orally to a patent, a cartridge 14 is selected that contains the required unit dosage of the required medicine and the shell 22 of the cartridge is inserted into the recess 60 of the receiver 20 as shown in Figure 7, until the disc 24 is generally flush with the open end of the recess 60, the keys 37 are received in the recesses 62, and the plunger 18 is in its fully retracted position, in which the steps 58 in contact with the shoulder formations 72. The plunger 18 can either be in its fully retracted position before the cartridge 14 is inserted, or the cartridge will push the plunger to its fully retracted position.

[0047] The keys 37 and recesses 62 are preferably configured to prevent an incorrect cartridge 14 (which will have a different key) from being inserted into the receiver 20. The keys 78 could be unique for different medicines, dosages, suppliers, or the like.

[0048] Once the cartridge 14 has been loaded into the receiver 20, the receiver is inserted into the recess 40 of the barrel 16 and it slides relatively easily up to the position shown in Figure 8, at which point the recesses 31 make locking contact with the circumference of the discharge opening 45 and the stubs 74 are received in the first axial parts of the grooves 47 of the barrel 16.

[0049] Urging the receiver 20 and cartridge 14 deeper into the recess 40 will require a noticeable, yet moderate increase in force and will result in rotation between the receiver and the barrel 16, caused by the helical interaction between the stubs 74 and the grooves 47. The rotation of the receiver 20 is transferred to the cartridge 14 through the interaction between the keys 37 and recesses 62, so that the cartridge rotates along with the receiver as they travel axially deeper into the recess 40. While the cartridge 14 rotates relative to the barrel 16, the head 39 is prevented from rotation by the interaction between the recesses 31 and the discharge opening 45 and the remainder of the cartridge 14 (apart from the head 39) thus rotates relative to the head, causing the head to be driven deeper into the recess 27 through the helical interaction between the stubs 43 and the groove 29, until the piercing formation 44 ruptures the septum 26. The helical progress of the receiver 20 into the recess 40 and of the head 39 into the recess 27, are generally equal and at the end of these movements, the receiver 20 is fully inserted into the recess 40, with the tabs 70 butting against the tabs 48 and the dispenser is ready to discharge the medicine, with the discharge passage 42 in flow communication with the cavity 23 via the ruptured septum 26.

[0050] The user gently pushes the plunger disc 56 towards the barrel 16, receiver 20 and cartridge 14 and while doing so, the plunging head 52 urges the piston 28 along its stroke, as described above and the piston expels the medicine from the cavity, via the discharge passage 42. The spout 41 can be inserted into a patient’s mouth for direct oral administration of the medicine, or the medicine can be dispensed in any other way, e.g. into a spoon.

[0051] The diameter of the cylinder 22, stroke of the piston 28, and length and diameter of the discharge passage 42 are designed to minimise the flow rate at which the liquid medicine is dispensed - which assists in minimising spillage when dispensing, e.g. into a spoon or cup, or orally. This is a significant improvement over the short length syringes with wide bodies that are often used for dispensing medicines and which have high liquid delivery flow rates.

[0052] Once the piston 28 has completed its stroke, the remaining volume of the cavity 23, and thus the remaining volume of medicine in the cartridge is very small and the apparatus are in the condition shown in Figure 9. The receiver tabs 70 can now be pulled to withdraw the receiver 20 from the barrel 16 and once the receiver 20 has been completely withdrawn, the plunger disc 56 is pushed towards the receiver, to expel the spent cartridge 14 from the receiver.

[0053] Referring to Figure 10, in a preferred embodiment of the invention, two detents are provided, which are not shown in Figures 1 to 9. The first detent 78 is provided on the outside of the receiver 20, between the stubs 74 and the tabs 70 and is biased to protrude to the outside of the receiver. When the plunger 18 is fully retracted, the detent 78 locks the plunger and receiver 20 relative to each other and this lock is only released when the receiver 20 is fully inserted into the recess 40 of the barrel 16, so that the wall 38 pushes the detent inwardly to release the lock.

[0054] The second detent 80 is provided in the inner wall of the receiver 20 and is biased to extend into the recess 60 and locks the plunger 18 against sliding relative to the receiver 20. The detent 80 is configured to be displaced outwards against its bias by the open end of the shell 22 when the cartridge 14 is fully inserted into the recess 60, to release the detent’s lock so that the plunger 18 can slide relative to the receiver 20.

[0055] The dispenser (comprising the barrel 16, plunger 18 and receiver 20) is made entirely from recyclable plastics and if necessary, different moulding techniques or materials can be used to achieve material properties required for different components. The dispenser can be a single use or multiple use disposable device, can be made inexpensively and can be recycled easily.

Claims

CLAIMS1 . A system for dispensing a liquid, said system comprising: at least one cartridge that includes; a hollow, elongate shell that has a longitudinal axis and that defines an internal cavity and that is closed near one end with a septum, at least part of said septum being thin enough to rupture under pressure from a sharp object, said shell protruding beyond the septum to form a recess on a side of the septum opposite from the internal cavity, with a female formation defined on the inside of the recess; a piston that is disposed inside the shell and that can slide axially inside the cavity, while sealing against the inside of shell; said liquid, which is held inside the cavity between the closed end and the piston; and a head defining an internal passage extending between a discharge opening and sharp protuberance, and defining a male formation on the outside of the head, said head being receivable in the recess with the male formation and female formation interacting in a helical manner, so that rotation of the head about the axis relative to the shell causes the head to move axially relative to the shell and such axial movement is configured to bring the sharp protuberance into contact with the septum, to rupture the septum; and a dispenser that includes: a body defining a receiving formation in which at least the head is receivable in a manner that resists rotation of the head relative to the body; and a plunger that is displaceable in the axial direction towards the protuberance.

2. A system according to claim 1 , wherein the dispenser includes a receiver defining a recess in which the cartridge is receivable, at least in part, said plunger being attached to the receiver, to slide relative to the receiver andcartridge shell in the axial direction.

3. A system according to claim 2, wherein the shell of the cartridge is held in place in the recess of the receiver in a manner that resists rotation of the shell relative to the receiver.

4. A system according to claim 2 or claim 3, wherein the receiving formation of the body defines a female formation and the receiver defines a male formation, said male and female formations being configured to interacting in a helical manner, so that axial movement of the receiver relative to the body causes the receiver to rotate about the axis, relative to the body.

5. A system according to any one of claims 2 to 4, wherein the receiving formation of the body is a cavity in which the receiver and cartridge are receivable to engage the receiver and body.

6. A cartridge for dispensing liquid, said cartridge comprising: a hollow, elongate shell that has a longitudinal axis and that defines an internal cavity and that is closed near one end with a septum, at least part of said septum being thin enough to rupture under pressure from a sharp object, said shell protruding beyond the septum to form a recess on a side of the septum opposite from the internal cavity, with a female formation defined on the inside of the recess; a piston that is disposed inside the shell and that can slide axially inside the cavity, while sealing against the inside of shell; said liquid, which is held inside the cavity between the closed end and the piston; and a head defining an internal passage extending between a discharge opening and sharp protuberance, and defining a male formation on the outside of the head, said head being receivable in the recess with the male formation and female formation interacting in a helical manner, so that rotation of the head about the axis relative to the shell causes the head to move axially relative to the shell and such axial movement isconfigured to bring the sharp protuberance into contact with the septum, to rupture the septum.