WO2011114343A1

WO2011114343A1 - Multi dose parental drug delivery system with exchangeable glass cartridge

Info

Publication number: WO2011114343A1
Application number: PCT/IN2010/000305
Authority: WO
Inventors: Pawan Trilokchand Agrawal; Zameer Pawan Agarwal
Original assignee: Pawan Trilokchand Agrawal; Zameer Pawan Agarwal
Priority date: 2010-03-19
Filing date: 2010-05-13
Publication date: 2011-09-22

Abstract

The present invention discloses Multi dose parental drug delivery system. Such system except cartridge is made up from plastic polymers of (PP) grade works on a novel screw mechanism principle with the help of compression spring. When the drug delivery has to be made it can be charged 0.5 ml to 2 ml at a time by twisting the knob which is on the other end of the drug delivery system. Consequence to this when lever is pushed to eject the dose which have been set or charged already, the delivery of drug is possible as the injecting assembly distally advances in the longitudinal direction and pushes in the cartridge.

Description

Multi Dose Parental Drug Delivery System with Exchangeable Glass

Cartridge

Field of the invention

This invention relates to an injection device or drug delivery system with exchangeable glass cartridge. This invention specially adapted to provide multiple measured injections of preset dose of all homogeneous liquid formulations which are very frequent used in the hospitals, (e.g: Amicacin). This invention also uses simple, comfort and novel mechanism to deliver multiple injectable doses.

Background of the invention

The subject matter in the European Patent Application No. 058536 discloses device in which by rotating the drive member of a gear mechanism which is constituted by a threaded sleeve in contact with plunger, the later of the pre filled syringe of this device is advanced. The rotating motion of the drive member is limited by a stop, and a coupling means takes care that the drive member can be turned backwards away from the stop without engagement with the gear mechanism. The drive member is in each case turned backward to select desired amount of liquid and then it turned forward for dispensing the pre selected amount of liquid to the patient through the needle.

Such conventional device requires one more person other than the user for injection of the drug because during injection the device must be held with one hand, and the drive member must be turned with the other hand. Furthermore, when the turning step is limited by a stop, there is the danger that the device and thus also the needle are tilted. An especially grave drawback resides in that only a small amount of liquid can be injected with one turning motion, and, for injection of a relatively large amount of liquid, the drive member-with the needle having been inserted-would have to be turned back and forth repeatedly.

While in the present invention there is a compression spring inside it and when the drug delivery has to be made, the desired amount of dose is charged by twisting the knob which is on the other end of the drug delivery system. When lever is pressed to eject after charging, the drug delivery is possible as the piston pushes distally in the cartridge. Hence by means of single pressure - exerting on lever the preset dose can be injected through the hyperdermic needle by the user himself with single hand. US Patent Application No. 5295976 discloses two specific multi dose embodiments. In one embodiment, a collar coupled by thread threads to the syringe housing is selectively adjustable to vary the desired dosage. Indicia in the form of a dose - indicating scale situated on the collar is hidden by a cap fixed to the plunger rod. A window in the cap permits only a portion of the scale to be viewed, the visible portion being indicative of the dose selected. In this embodiment of the invention, as the liquid is repeatedly dispensed from the syringe, the overall length of the pen diminishes. In second illustrated embodiment a collar is rotatably coupled to, but is not longitudinally adjustable with respect to, the syringe housing. A liquid filled cap coupled by threads to the plunger rod is selectively adjustable to vary the desired dosage. Indicia in the form of a dose-indicating scale situated on the cap is hidden by the collar except for a window in the collar which permits only a portion of the scale to be viewed, the visible portion being indicative of the dose selected. In this embodiment of the invention, the overall length of the pen remains substantially unchanged with repeated use. Both the above embodiment involves some what complicated mechanical steps during charging of the desired amount of dose as well as during injection of the dose through needle which increase the cumbersome during manufacturing as well as operation and in the above mentioned device once drug holding container is empty the whole device is to be thrown and one is to purchase the new device for use which increases the medical waste other materials and there by increase the cost.

Hence need exists for a disposable multi-dose device or with exchangeable liquid filled container having simple working mechanism during the operation and less medical wastages, more economical and capable of use with the user J himself. The present invention over comes all the disadvantages and fulfils all the above requirements by providing an injection device wherein exactly preset or pre selected amount of liquid is being administered repeatedly through needle by means of single pushing pressure exerted on the lever. This invention further objects to provide simple mechanical arrangement, comfort and novel mechanical steps during operation; it also objects to provide reduction of 80% medical waste and thereby provides more economical than the conventional system.

Regular syringes that available in the market uses 10 glass ampoule of 22 grams, 10 needles of 1.5 grams, 20 individual packing (10 ampoule +10 syringe) and 10 syringe and 10 needle cover of 39 grams for the same formulation of liquid quantity as used in the present multi dose drug delivery device within the cartridge, while our present system or device only uses 1 cartridge of 8 grams, 10 needles of 0.3 grams, 11 individual packing (10 needles + 1 cartridge cover) and 1 syringe and 10 needle cover of 2 grams respectively and thereby saves 175% of glass materials, 400% SS (Stainless steel) materials and 1850% of plastic materials respectively. Hence in overall calculation the present multi dose drug delivery system would helps to reduce 80% of medical waste and provides more economical than the conventional devices or syringes.

Object of the invention

The main object of the invention is to provide portable pen like multi dose parental drug delivery system enable to use for longer term by providing exchangeable long glass cartridge, injecting assembly, rotatable knob, compressing spring and lever.

This invention also objects to provide the system that uses novel screw mechanism with the help of compression spring and said mechanical screw drive assembly and this invention also object to provide reduction of nearly 80% of the medical waste and more economical than the conventional parental drug delivery system.

Summary of the invention

The present invention discloses Multi dose parental drug delivery system comprises two protecting housing at the distal and proximal sections of the ' system mated with teethed clip like structure. The distal protecting housing encompasses glass cartridge while the proximal one encompasses mechanical screw drive assembly, compression spring, reverse mechanism knob, fixed rod.

Such system except cartridge is made up from plastic polymers of (PP) grade works on a novel screw mechanism principle with the help of compression spring. When the drug delivery has to be made it can be charged 0.5 ml to 2 ml at a time by twisting the knob which is on the other end of the drug delivery system. During this action the compression spring plays very important role. Consequence to this when lever is pushed to eject the dose which have been set or charged already, the delivery of drug is possible as the injecting assembly distally advances in the longitudinal direction and pushes in the cartridge.

Brief description of the drawing

1. Figure 1 is a cross - sectional view of the multi dose drug delivery system of the present invention in stable or static condition prior to mounting of needle assembly.

2. Figure 2 is the cross sectional view of the bottom or rear part of the system. 3. Figure 3 is the cross sectional view of the state of whole system just later to rotating the bottom knob.

4. Figure 4 is the cross sectional view of state of the whole system just later to pushing mechanism of lever in the direction of the arrow shown.

5. Figure 5 is the cross sectional view of the system during the exchange of the cartridge. Best mode for carrying out invention

Injection pen (15) includes external cap (1), external protective housing (13) of the proximal section of the system mating with the external cartridge holder (2) fixedly secured together through the teethed clip like structure as diagrammatically shown in fig. 1, and such an external protecting made up of plastic polymers is extending from outer proximal end to a distal end of the system, within the liquid filled interior of tubular body of glass cartridge (10) a multi dose quantity of fluid (liquid) medicine being sealed to deliver by operation of pen (15). Medicine may be of any homogeneous liquid drug variety, _*· which do not react with the external glass structure; at the distal end of cartridge (10) head like tubular hub (16) is disposed and such hub is made up of external aluminium covering and synthetic rubber or septum inside the covering on which hyperdermic needle of known design is to be mounted by piercing the membrane or septum and entering and communicating with the interior of the cartridge. The glass_cartridge (10) may be transparent to allow the contained medicine to be visible to let a user to estimate the amount remaining. Whole device except cartridge is made up from plastic polymers of (PP) grade. At the proximal end of the cartridge Mechanical Screw Drive assembly (18) made up of piston like structure (17) at the front end which follows movable teethed plunger rod (5) extends up to the rear or proximal end of the compression spring (14) within which the later is mounted and this movable plunger rod has been made slidable over the fixed rod like structure (4). Screw holder (7) being mechanically disposed over fixed rod (4) to provide mechanical support for the screw drive assembly (18) as diagrammatically shown in fig. 1 and 2, clip trigger (11) being operably disposed with the leg like portion of the screw holder (7) and at the proximal end of clip trigger spring holder (12) being connected through washer ring (8) to provide mechanical support to the spring (14) during operation. Reverse mechanism knob (9) projecting from the proximal end of cartridge provides holding support for piston (17) during initial equilibrium state of the system and it also helps to bring the screw drive (18) into initial stable equilibrium position by rotating it manually, once when all the liquid contents have been dispensed by it. The said piston like structure (17) axially slides within liquid filled interior of cartridge (2) along a middle interior section of the cartridge length and further the piston (17) has sealing periphery in a fluid tight engagement with the liquid filled interior-defining internal surface of cartridge to contain the fluid medication.

Positioned proximally of piston (17) are the components that function, in a preferred embodiment, to allow any one of a number of quantities of medicine to be selected and expelled from the pen by a user. As diagrammatically represented in fig. 2 these components include a manually operable dosage knob (6) that projects from the proximal end of the protective housing (13); a fixed rod (4) with slidable plunger rod (5) and spring (14) is operably connected to knob (6), this fixed rod extending in an axial or longitudinal direction within the centre of the proximal section of the system over which movable plunger rod (5) slides: The advancing height of the plunger rod (5) depends on the potential energy stored inside the compression spring (14) during rotation of the knob (6).

Dosage knob (6) is rotatable in a conventional clock wise direction to set the dose to be injected, which rotation causes the spring (14) to compress in the downward direction that results into detachment of washer ring (8) from spring holder (12) as diagrammatically shown in figure (3) and due this compressing operation potential energy is stored inside the spring (14). This action causes the desired amount of dose to be set. Consequence to this the pushing employment of lever in the direction as shown in fig.4, triggers the clip trigger (11) to cause plunger rod (5) to advance in the distal direction to shift piston (17) distally forward for dispensing the set dose of medicine through needle. Here the longitudinal advancing height of the plunger rod (5) depends on the potential energy stored inside the spring which in turn depends on number of rotating turns of knob (6). In this shown embodiment while particular pieces of the drive assembly (18) may axially move use, the drive assembly (18) overall is axially secured within the volume of the proximal part of the system. Such securement may be achieved by attaching, such as via compression spring (14), the screw drive assembly (18) to the interior wall of fixed rod (4).

The foregoing general description of the mechanism used to advance piston (17) is intended to be illustrative and not limiting in any way. A variety of injection pens, including pull to prepare/push to inject type injection pens, are known in the art which include different mechanisms that allow setting and administering doses, and the mechanisms may be readily adapted for use in a multi dose injecting pen as described herein. Still further, if pen (15) were intended to always deliver the same or a fixed dose, the mechanism could be configured to appropriately advance piston (17) to achieve such fixed dose, upon each activation of the lever (3).

Claims

We Claim,

1. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge comprising: a external cap (1), external protecting housing (13), external cartridge holder (2), cartridge (10), tubular hub (16), compression spring (14), a screw drive assembly (18), fixed rod (4), lever (3), reverse mechanism knob (9);

wherein said head like tubular hub (16) being disposed at the distal end of the cartridge (10) and made up of external aluminium covering and synthetic rubber or septum inside the covering on which hyperdermic needle is to be mounted;

wherein dosage knob (6) being disposed at the postal end of the system to rotate to set the desired amount of liquid medicine dose;

wherein said external protective housing (13) of the proximal section of the system being mated with the external cartridge holder (2) fixedly secured together through the teethed clip like structure and such protecting is extending from outer proximal end to a distal end of the system;

wherein said screw drive member assembly (18) disposed at the proximal portion of the system being made up of piston like structure (17) at the front end which follows movable teethed plunger rod (5) extends up to the rear end of the compression spring (14) within which the later is mounted and this movable plunger rod being made slidable over the fixed rod like structure (4) and wherein compression spring (14) is operably connected to knob (6);

wherein Screw holder (7) being mechanically disposed over fixed rod (4) to provide mechanical support for the screw drive assembly (18), clip trigger (11) being operably disposed with the leg like portion of the screw holder (7) and at the proximal end of clip trigger, spring holder (12) being connected through washer ring (8) ;

wherein said piston like structure (17) axially slides within liquid filled interior of cartridge (10) along a middle section of the housing body length and further the piston (17) has sealing periphery in a tight engagement with the mterior-defining internal rubber piston being disposed at the proximal end of the cartridge with fluid tight engagement;

wherein reverse mechanism knob (9) projecting from the proximal end of cartridge provides holding support for piston (17) during initial equilibrium state of the system and it brings the screw drive (18) into initial stable equilibrium position by rotating it manually, once when all the liquid contents have been dispensed by it.

2. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge as claimed in claim 1, wherein said dosage knob (6) being rotatable in a conventional clock wise direction to charge or set the liquid dose of 0.5 ml to 2ml at a time to be injected, which rotation causes the spring (14) to compress in the downward direction to detach contact between washer ring (8) and spring holder (12) and such workdone on the spring is stored in side the spring as a potential energy.

3. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge as claimed in claim 1, wherein the pushing employment of lever (3) in- the forward direction, consequence to steps as claimed in claim 2, triggers the trigger ring (11) to cause plunger rod (5) to advance in the distal direction to shift piston (17) distally forward for dispensing the set dose of medicine through needle.

4. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge as claimed in claims 2 and 3, wherein delivered drug quantity from needle being depends on the longitudinal distal advancing height of piston (17) moving within liquid filled interior glass barrel of the cartridge (2);

wherein advancing height of the piston (17) being depends on the stored potential energy inside the compression spring (14);

wherein stored potential energy inside the spring (14) being depends on the number of rotating turn of the knob (6).

5. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge as claimed in any of claims 1 to 4 wherein being made up from plastic polymers of (PP) grade, except cartridge & spring (14) and which reduce medical waste upto 80%. i

6. Multi Dose Parental Drug Delivery System with Exchangeable Glass Cartridge substantially as herein described and illustrated in the accompanying drawings.