WO2021220146A1

WO2021220146A1 - Single use safety syringe and method thereof

Info

Publication number: WO2021220146A1
Application number: PCT/IB2021/053444
Authority: WO
Inventors: Atul Sardana
Original assignee: Alfa Corpuscles Pvt Ltd
Priority date: 2020-04-29
Filing date: 2021-04-27
Publication date: 2021-11-04

Abstract

The invention relates to single use Safety Syringe with Integrated Passive Re- Use and Needle Stick Injury Prevention mechanism. More particularly, the Invention provides an improved single use integrated safety syringe with fewer number of parts and a simpler assembly, having a passive spring actuated barrel retract and locking mechanism leading to Re-Use and Needle Stick Injury Prevention which can be used to deliver Injectable Drugs applicable to both conventional clinical use as well as prefilled syringes for drugs and vaccines in a manner whereby minimal space is occupied in the cold chain during transport and storage.

Description

Single Use Safety Syringe and method thereof

FIELD OF INVENTION:

The invention relates to single use Safety Syringe with Integrated Passive re- use and needle stick injury prevention mechanism. More particularly, the Invention provides an improved single use integrated safety syringe with fewer number of parts and a simpler assembly, having a passive spring actuated barrel retract and locking mechanism leading to re use and needle stick injury prevention which can be used to deliver injectable drugs applicable to both conventional clinical use and as well as prefilled syringes for drugs and vaccines in a manner whereby minimal space is occupied in the cold chain during transport and storage.

BACKGROUND OF THE INVENTION:

The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

Injections are the most common health care procedure worldwide. WHO reference definition for a safe injection states that, “A safe injection does not harm the recipient, does not expose the provider to any avoidable risk and does not result in any waste that is dangerous for other people”.

Once an injection is administered and the needle is withdrawn, it is contaminated with the blood/ body fluids of the patient which may contain microorganisms. Thereafter any pricking of the contaminated needle to another person or healthcare worker carries with it the risk of transferring these microorganisms from the patient to the other person or healthcare worker.

It is well documented that such injuries occur most often to nurses, followed by physicians and most injuries occur while administering injections. Unsafe injection practices remain a major challenge worldwide. Unsafe injections place patients at risk of disability and death. Unsafe injection practices include reuse of syringes and needle stick injuries to healthcare workers and other members of the society. There is a huge global burden of diseases such as AIDS, Hepatitis C and Hepatitis B, that is added on each year due to these. The development of the syringe and needle has gone through various phases that can be broadly seen in four generations: The First Generation of syringes and hypodermic needle are the most prevalent form of device available worldwide. It has no auto disable or needle stick injury prevention mechanism. The Second-Generation syringes have auto disable features such as a locking ring or tab or break away plungers but require active participation of the user to deploy these. Once the auto-disable feature has been activated it is not possible to re-use the syringe under the normal conditions of use. The second-generation syringes address the problem of reuse but do not prevent the risk of inadvertent needle stick injury or reuse of the needle. The Third Generation of syringes offers needle stick injury prevention mechanism by deployment of a sheath or cover over the needle or retraction of the needle into the barrel thereby covering the needle and rendering the syringe unusable. However, these require active participation of the user to deploy these, and the success is operator dependant. It requires training of the user and the disposal handling staff. The Fourth Generation of syringes incorporates both auto disable and needle stick injury prevention features in the same syringe and has the advantage of auto deployment of these features thereby reducing operator dependency and ensuring compliance.

W003/101513 describes a safety syringe provided with an outer sleeve that is automatically guided into a position of safety, once the injection has been completed. However, it does not disclose an auto disable feature whereby the plunger is locked to prevent re-use of the syringe. Further, it does not cover 360 degrees of the lock and hence has a chance of accidental firing if the syringe is not handled carefully.

US Patent No. 5,049,133 provides a safety-syringe wherein a spring is coiled around a needle with a hollow core. The spring is capable of expanding to retract the needle into the body of the syringe. The construction of this syringe involves many intricate parts resulting in high manufacturing costs. The needle in the syringe is also fixed. Furthermore, since the mechanism of retraction of the spring is very delicate it results in increased probability of the syringe being accidentally fired. WO 2006/105583 discloses a safety syringe incorporating a means for causing retraction of the needle into the syringe barrel by engaging the plunger of the syringe with the hub of the needle. However, it requires active participation of the user to pull the plunger back to retract the needle into the body.

US Patent No. 5, 057, 086 discloses a sliding needle cover mounted on the syringe to prevent accidental needle pricks. This spring-loaded syringe needs to be manually retracted back while injecting. Hence it requires a two-hand operation to initiate the safety mechanism. Further, since the user’s hands stay in front of the safety mechanism it poses higher risk of injury while operating. Also, this syringe provides no feature to prevent reuse.

US Patent No. 5,460,611 discloses a safety syringe wherein the needle is covered by a sleeve on the action of a pushrod being pushed by the plunger at the end of the injection process. US Patent No. 5,720, 727 also discloses a safety syringe wherein the needle is covered with a sheath before it is removed from the patient. However, both the syringes feature a fixed needle, require active participation of the user to initiate the safety mechanism and do not include any feature for preventing its reuse. This syringe has only limited application especially for deep injections such as intra muscular since the drug would be delivered to varying depth as one goes on injecting because needle will keep getting covered. Also, a very small length of the needle is exposed during injection so to gain a deeper penetration the user has to insert the sleeve into the body thereby increasing possibility of vein damage in IV injections.

WO 99/37345 discloses a syringe with a slidably fitted needle -covering sleeve. This syringe is built up of a number of parts resulting in high cost of production, it does not provide an auto disable feature to prevent its reuse and also has high probability of accidental firing of the syringe. Furthermore, this syringe has a radially expanding lock which would require force to activate it which increases the possibility of injuring the patient during the injection process, especially during IV injections. There is more recognition than ever before that injection safety represents a very cost-effective intervention in preventing the transmission of blood borne pathogens, mainly Hepatitis B, hepatitis C and HIV to patients through reuse of injection equipment and mishandling of multi dose vials, to health care workers through needle stick injuries and to the community at large through improper sharps waste management. 457/DEL/2010 discloses single use safety syringe with spring actuated needle stick injury prevention and auto disable mechanism. It further relates to a single use safety syringe with a spring actuated needle cover to prevent needle stick injury and auto disabling of the syringe by locking of the plunger to the syringe to prevent reuse. The single use safety syringe comprises a body, a plunger, a sheath, and a spring. At the end of the injection stroke, the spring actuates the sheath which glides over the body to cover a needle attached to the body. Further pressing the plunger locks the plunger into the body thereby rendering the syringe non-reusable. This syringe has a possibility of mishandling and injury while administering to the patient.

Hence, there is a need of a Single Use Safety Syringe having Integrated Passive Re Use and Needle Stick Injury Prevention mechanism for delivering Injectable Drugs and Vaccines along with its method of operation.

OBJECTIVE OF THE INVENTION:

Primary object of the present invention is to overcome the drawback associated with the prior systems and methods.

The object of the present invention is to provide a single use safety syringe for hypodermic injection with reuse and needle stick injury prevention mechanism.

Yet another object of the present invention is to provide a single use safety syringe which is passive and does not require active participation of the user in activating the reuse and needle stick injury prevention mechanism.

Yet another object of the present invention is to provide a single use safety syringe which is capable of administering any medication and vaccine for injection.

Yet another object of the present invention is to provide a single use safety syringe which can be used for any form of hypodermic injection such as IV (Intravenous), IM (Intramuscular), SC (Subcutaneous) etc.

Yet another object of the present invention is to provide a single use safety syringe which can be used for phlebotomy (to draw blood for investigations) and then be disposed safely and prevents reuse and needle stick injury. Yet another object of the present invention is to provide a single use safety syringe which has an option for interchangeable needles and provides freedom of choice to user.

Yet another object of the present invention is to provide a single use safety syringe which has minimum number of parts for assembling the syringe.

Yet another object of the present invention is to provide a single use safety syringe which requires minimum or no training at all to healthcare workers for use.

Yet another object of the present invention is to provide a single use safety syringe having the safety feature integral to the design.

Yet another object of the present invention is to provide a single use safety syringe compatible with universally available needles and accessories.

Yet another object of the present invention is to provide a single use safety syringe with inbuilt anti rotation feature to prevent accidental misfiring when connected to universally available needles and accessories.

Yet another object of the present invention is to provide a single use safety syringe that is permanently disabled after safety mechanism is activated and cannot be used again and the needle is covered completely to prevent injury and transmission of blood borne infections.

Yet another object of the present invention is to provide a single use safety syringe wherein the hands and fingers of the user stay behind the needle when the safety mechanism is activated to minimize the risk of accidental injury to the user.

Yet another object of the present invention is to provide a single use safety syringe use of the syringe should be as similar to the use of a conventional syringe as possible.

Yet another object of the present invention is to provide a single use safety syringe which does not require any priming action prior to its use.

Yet another object of the present invention is to provide a single use safety syringe capable of one-handed operation by the user. Yet another object of the present invention is to provide a single use safety syringe in which the sheath gets locked such that it is not possible to push it back to expose the needle once used.

Yet another object of the present invention is to provide a single use safety syringe having a design that is be adaptable to all existing sizes of syringes commonly used for injection purpose.

Yet another object of the present invention is to provide a single use safety syringe which is safe and able to prevent accidental needle stick injury after use thereof.

Yet another object of the present invention is to provide a single use safety syringe with fewer number of parts and a simpler assembly making it practical, versatile, economical, and easy to make.

Yet another object is to make an integrated safety prefilled syringe that can be filled and assembled as a conventional pre filled syringe.

Yet another object of the present invention is to make an integrated safety pre filled syringe that can be presented and filled as a ready to fill system alike a conventional ready to fill system.

Yet another object of the present invention is to make an integrated safety pre filled syringe that can be supplied either with an integrated staked needle or without a needle for use with universally available needles and accessories.

Yet another object of the invention is to make a cold chain sparing integrated safety pre filled syringe containing vaccines for hypodermic injection which has a cartridge that holds the vaccine which requires storage and transportation at special temperature and an injector that can be stored and transported at room temperature thereby reducing the burden on the cold chain.

Yet another object of the present invention is to make a cold chain sparing integrated safety pre filled syringe containing vaccines for hypodermic injection which has a cartridge that can be supplied either with an integrated staked needle or without a needle for use with universally available needles and accessories. Yet another object of the invention is to make a vaccine cartridge and an injector such that when the cartridge is inserted into the injector such that the completed assembly is a single use safety syringe for vaccine injection with passive integrated reuse and needle stick injury prevention mechanism.

Yet another object of the present invention is to provide for the method of operation of the single use safety Syringe having Integrated Passive Re Use and Needle Stick Injury Prevention mechanism for delivering Injectable Drugs and Vaccines.

SUMMARY OF THE INVENTION:

In an aspect of the Invention, there is provided a Safety syringe (100), for delivery of injectable drugs including but not limited to vaccine or thermolabile drug, comprising; a barrel (3), made of material comprising glass or polymer, hollow on the inside for holding the product, intended for injection and open at a proximal end (25) and a distal end (26), the distal end (26) having a luer connector (27) to connect a needle hub, a spring base (28) towards the distal end (26), a proximal locking feature (29) having a proximal anti-rotation feature (18) disposed circumferentially on an outer surface of the barrel towards the proximal end (25), and a barrel distal anti rotation feature (13) and a barrel counter check profile (14) disposed circumferentially on the outer surface of the barrel towards the distal end (26); a sheath (1) slidably mounted over the barrel (3) having a sheath proximal end (30) and a sheath distal end (31), inside the sheath distal end (31) having a sheath distal anti rotation feature (12); a plunger (32) slidably located within the barrel (3), having a plunger distal end (34), to prevent leakage of the product intended for injection, having a stem (6) and a plunger proximal end (33) having a lock deployer profile (8); a spring (2) compressed between said spring base (28) of the barrel and the distal anti rotation feature of the Sheath (19); the plunger (32) is axially slid towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from a sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with an anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) comprises an anti-wobble feature (10), the anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath(l); where said safety syringe comprises prefilled safety syringe.

In another aspect of the Invention, there is provided a method of operation of Safety syringe (100) as described above, comprising: axially sliding the plunger (32) towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, the said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from the sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with the anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) having an anti-wobble feature (10), an anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath(l). In another aspect of the Invention, the cartridge, filled with vaccine or thermolabile drug, is merely required to be maintained in the cold chain thereby reducing burden on cold chain space while the injector sub assembly is kept outside and wherein prior to use, the cartridge is inserted into the barrel of the injector sub assembly making the assembly a prefilled vaccine safety syringes with an Integrated Passive Re Use and Needle Stick Injury Prevention mechanism.

DETAILED DESCRIPTION OF DRAWING:

The foregoing detailed description of preferred embodiments are better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary constructions of the invention; however, the invention is not limited to the specific methods and system disclosed. In the drawings:

Figure 1: (a) illustrates an overview of the safety syringe; (b) illustrates exploded view of clinical safety syringe

Figure 2: illustrates clinical safety syringe with new features of sheath lock and safety tab, as an exemplary embodiment provided by the present invention. In this embodiment, the sheath lock has proximal anti-rotation features, anti-wobble feature and anti-recocking lock.

Figure 3(a), 3(b): Figure 3(a) illustrates clinical safety syringe with features of sheath and Figure 3(b) illustrates barrel as an exemplary embodiment provided by the present invention.

Figure 4: illustrates exploded overview of a Prefilled safety syringe

Figure 5: illustrates exploded overview of the Prefilled safety syringe provided by the present invention. In this embodiment, the syringe comprises barrel with proximal anti-rotational feature, proximal adaptor with anti-wobble feature, distal adaptor with anti-rotation feature and counter check profile.

Figure 6: illustrates pre-filled safety syringe with sheath lock and barrel assembly, according to an exemplary embodiment of the present invention. Figure 7: illustrates (a) exploded view of cartridge load safety syringe (b) illustrates cartridge with locking tabs

Figure 8: illustrates mechanism of cartridge Insertion into syringe

Figure 9: illustrates cartridge load safety syringe showing sheath lock and barrel features provided by the present invention.

DETAILED DESCRIPTION OF INVENTION:

In the following description of some embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration, embodiments of the disclosure that may be practiced. It is to be understood that other embodiments may be utilized.

The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.

It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred, systems and methods are now described.

The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

The elements illustrated in the Figures inter-operate as explained in more detail below. Before setting forth the detailed explanation, however, it is noted that all of the discussion below, regardless of the particular implementation being described, is exemplary in nature, rather than limiting. This Invention provides a Single Use Safety Syringe having Integrated Passive re use and Needle Stick Injury Prevention mechanism for delivering Injectable Drugs and Vaccines and its operation thereof. For the present invention, “integrated” denotes that the Safety Syringe is complete in itself and is not an add on mechanism to a conventional syringe. “Passive” denotes that the safety feature requires no active user participation in deploying the safety mechanism at the end of the syringe stroke.

In an embodiment, the Safety syringe (100), for delivery of the product comprising vaccine or thermolabile drug, comprises following components: a barrel (3), made of material comprising glass or polymer, hollow on the inside for holding the product, intended for injection and open at a proximal end (25) and a distal end (26), the distal end (26) having a luer connector (27) to connect a needle hub, a spring base (28) towards the distal end (26), a proximal locking feature (29) having a proximal anti-rotation feature (18) disposed circumferentially on an outer surface of the barrel towards the proximal end (25), and a barrel distal anti rotation feature (13) and a barrel counter check profile (14) disposed circumferentially on the outer surface of the barrel towards the distal end (26); a sheath (1) slidably mounted over the barrel (3) having a sheath proximal end (30) and a sheath distal end (31), inside the sheath distal end (31) having a sheath distal anti rotation feature (12); a plunger (32) slidably located within the barrel (3), having a plunger distal end (34), to prevent leakage of the product intended for injection, having a stem (6) and a plunger proximal end (33) having a lock deployer profile (8); a spring (2) compressed between said spring base (28) of the barrel and the distal anti rotation feature of the Sheath (19); the plunger (32) is axially slid towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from a sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with an anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) comprises an anti-wobble feature (10), the anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath(l).

In an embodiment, the safety syringe is a prefilled safety syringe.

In an embodiment, the syringe comprises a distal adaptor (15) having an anti -rotation feature (16) and counter check profile (17) engaged with the distal anti rotation feature (13) of the barrel (3), configured to lock the barrel distal end with the luer connector to connect the needle hub.

In an embodiment, the syringe comprises a cartridge (38) defining a chamber for holding a product intended for injection, having an inward projecting radial feature to lock with the barrel proximal end and a guiding feature to allow the axial sliding of the cartridge in line with the barrel and wherein said cartridge is made of material comprising glass or polymer.

In an embodiment, the barrel (3) has a cartridge tab guiding feature (24) and a cartridge tab locking feature (23) around its outer circumference to allow the axial sliding of the cartridge (38) in line with the barrel (3).

In an embodiment, the sheath lock (4) clasps the sheath (1) inbuilt anti-wobbling and guiding features to prevent accidental misfiring of the Syringe during transport, storage, and use.

In an embodiment, in the Injector Subassembly of the Cartridge Load Safety Syringe for vaccine delivery, a locking ring (37) is mounted over the plunger (6) before it is inserted into the barrel (3) during assembly, such that it locks the plunger to the barrel and prevents it from falling during transportation or storage but allows the plunger to freely glide in the barrel so as to push the piston of the cartridge to inject the drug/ vaccine. In an embodiment, the plunger (32) is connected to a safety tab (7) that can be attached during assembly that restricts the complete forward movement of the plunger (32) to engage the proximal locking feature (29) of the barrel (3) by the lock deployer profile (8) on the plunger thereby preventing accidental firing of the safety syringe during transport and handling.

In an embodiment, the syringe comprises a proximal adaptor with an anti-wobble feature (20), such that the proximal adaptor anti-wobble feature (20) engages with the proximal anti-rotation feature circumferentially disposed on the inner surface of the sheath lock (4) towards the proximal end.

In an embodiment, the cartridge, filled with vaccine or thermolabile drug, is merely required to be maintained in the cold chain thereby reducing burden on cold chain space while the injector sub assembly is kept outside and wherein prior to use, the cartridge is inserted into the barrel of the injector sub assembly making the assembly a prefilled vaccine safety syringes with an Integrated Passive Re Use and Needle Stick Injury Prevention mechanism.

In an embodiment, the Safety syringe (100) operates through the following steps: axially sliding the plunger (32) towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, the said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from the sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with the anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) having an anti-wobble feature (10), an anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath (1). Referring to Figure 1(a), a single use safety syringe (100) is illustrated . Figure 1(b) illustrate the exploded view of the syringe illustrated in figure 1(a). According to a first embodiment, preferably Figure 1(b) of the present invention comprises a barrel, a plunger, a sheath, a spring and a sheath lock. As shown in exploded view, the plunger slidably slides within the barrel and the sheath slidably slides over the barrel. The barrel has a luer connector towards its distal end which further connects with a needle hub (not shown in figure). The essential feature sheath lock comprises a clasping or locking feature (such as an anti-wobble feature, an anti recocking feature and an anti-rotation feature), engaged with the barrel proximal locking feature and additionally, engaged with the sheath inbuilt anti-wobbling and guiding features such that the sheath lock clasp the sheath with the barrel.

Referring to figure 2, illustrates the detailed structure of the sheath lock having an anti wobble feature, an anti recocking feature and an anti-rotation feature, which engages with the sheath and the barrel so that both can be locked, and the sheath cannot be pushed back to expose the needle accidentally. Moreover figure 2, also illustrates the safety tab, in this embodiment of the present invention, the safety tab prevent accidental misfiring of the syringe during its transportation and an anti-wobbling feature on the sheath lock prevent accidental misfiring of the syringe during its handling. In an embodiment of the present invention, the single use safety syringe has a safety tab that can be attached to the feature on the plunger for preventing the accidental firing of the safety syringe during transport / handling and can be pulled/ removed by the user prior to injection to ensure the completion of the injection and engaging of the lock deployer profile.

Figure 3(a) illustrates the detailed view of the sheath. In said figure there is a distal anti rotation feature towards the sheath distal end. The anti-rotation feature restrict the slidable movement of the sheath over the barrel so that the sheath after use cannot be pushed back to expose the needle accidentally and to accommodate the luer connector. The proximal end of the sheath has a proximal sheath locking feature. The proximal sheath locking feature rest on the sheath lock.

Figure 3(b) illustrates the barrel of the syringe, comprises counter check profile and distal anti-rotation feature towards the barrel distal end. The counter check profile and the distal anti-rotation feature locks with the anti-rotation feature of the sheath when the sheath slide over the barrel. The sheath in all variants has inbuilt anti rotation feature, that engage that engage to the said counter check profile of the barrel such that the sheath locks firmly to the barrel and cannot be pushed back to expose the needle accidentally.

Figure 4 illustrates exploded overview of a Prefilled safety syringe. In this embodiment, there is provided Ready to Fill System for Prefilled Syringes - RTFS (Type 2) which can be made in all nominal capacities and can be Luer Lock or Luer Slip or Staked Needle. The barrel can be a polymer or glass barrel. It has two embodiments viz. Centric Luer Connector and Eccentric Luer Connector. The RTFS type comprises following components: Sheath, Spring, Barrel, Distal Adaptor, Proximal Adaptor, Plunger and Piston. In this embodiment the barrel that having an inside surface defining a chamber for holding a product intended for injection is made of polymer or glass having features such as the counter check profile and the distal anti-rotation feature at the distal end that can connect to a counter feature or an anti-wobble feature on a distal adaptor that is outwardly open, to connect a needle hub with radially outward projecting multiple distal anti rotation features. In this embodiment the lock deploy er profile positioned on the plunger proximal end engages with the proximal locking feature on the barrel thereby releasing said sheath resulting in a forward motion of said sheath over said body due to expansion of a spring compressed between spring base towards the distal end of the barrel and a sheath distal anti rotation feature. The sheath slidably mounted over the barrel having a sheath proximal end and a sheath distal end, inside the sheath distal end having a sheath distal anti rotation feature and the sheath proximal end engage with the barrel via a sheath lock such that the sheath locks the barrel and cannot be pulled back.

In this embodiment, the plunger is axially slid towards said distal end of said barrel, said lock deployer profile positioned on the plunger proximal end engages with the distal anti rotation feature thereby releasing said sheath resulting in a forward motion over said barrel due to expansion of said spring till sheath lock and the proximal adaptor firmly locks the barrel with the sheath and cannot be pulled back, thereby stopping the forward motion of the sheath. The sheath in this embodiment has inbuilt anti rotation feature, that engage with distal adaptor in the Ready to Fill System for Prefilled Syringes - RTFS (Type 2, as shown in figure 4) embodiment, to prevent accidental misfiring when connected to universally available needles and accessories.

Figure 5 illustrates the barrel with, proximal adaptor with anti-wobble feature and proximal anti-rotational feature and distal adaptor with distal anti-rotation feature and counter check profile. The proximal adaptor anti-wobble feature engage with the proximal anti-rotation feature circumferentially disposed on the inner surface of the sheathlock towards the proximal end. The distal anti-rotation feature of the barrel accommodates the anti-rotation feature and counter check profile of the distal adaptor.

Figure 6 illustrates sheath lock of the pre-filled safety syringe and barrel assembly, according to another exemplary embodiment of the present invention. The sheath lock is illustrated with an anti-wobble feature, an anti recocking feature and an anti-rotation feature and additionally engaged with the sheath inbuilt anti-wobbling and guiding features such that the sheath lock clasp the sheath with the barrel. The sheath has radially inward projecting multiple anti wobbling projections that maintains the axial alignment of the barrel and sheath, to prevent wobbling and prevent accidental firing of the safety syringe during transport and handling.

Figure 7 illustrates an embodiment of the present invention, a novel cartridge -based design of the Safety Syringe for vaccine delivery VL (also referred as Type 3, hereinafter) is provided such that minimal space is occupied in the cold chain during transport and storage. In another embodiment of the present invention, the structure of the Cartridge based variant of the safety syringe is majorly a cartridge with an integrated staked needle or without a needle for use with universally available needles and accessories. It also contains an injector sub assembly.

In an embodiment of the present invention, the design consists of a sub assembly called the cartridge with an integrated staked needle or without a needle for use with universally available needles and accessories. The cartridge can be prefilled with vaccines and other thermolabile drugs and biologies and be maintained in a cold chain during its transportation and storage.

In another preferred embodiment of the present invention, the design consists of another sub assembly called the injector that need not be stored and transported in a cold chain and which has a guiding mechanism leading to a receptacle with lock to which the cartridge can be securely connected with a single step making the assembly a prefilled vaccine syringes having an Integrated Passive Re Use and Needle Stick Injury Prevention mechanism.

In an embodiment of the present invention, the single use safety syringe intended for vaccine delivery is such that minimal space is occupied in the cold chain during transport and storage. The syringe consists of a cartridge which can be prefilled with vaccines, other thermolabile drugs or biologies and can be maintained in a cold chain during its transportation and storage. The syringe can be inserted into the barrel of the injector sub assembly making the assembly a prefilled vaccine safety syringes with an Integrated Passive Re Use and Needle Stick Injury Prevention mechanism.

Figure 7(a) illustrates exploded view of cartridge load safety syringe having the Injector subassembly of the cartridge load safety syringe which can be made in all nominal capacities and along with the Cartridge which can be Luer Lock or Luer Slip or Staked Needle. The Injector subassembly comprises following components: Sheath, Spring, Barrel, Plunger with Locking Ring (11) and Piston. The locking ring holds the plunger in the Injector Subassembly during transportation so that the Injector Subassembly is integrated and the Plunger can be connected to the piston which is part of the cartridge, when the cartridge is connected to the Injector Subassembly.

Figure 7(b) illustrates the cartridge with locking tabs that is having an inside surface defining a chamber for holding a product intended for injection is made of polymer or glass having features such as the Locking Tabs.

Figure 8 illustrates mechanism of cartridge Insertion into syringe by the placement of the Cartridge with intended drug/vaccine filled and piston in place into the Injector Subassembly by aligning the Locking Tabs on the proximal end of the cartridge with the counter groove in the Sheath as well as the Barrel for correct placement of the Cartridge in to the Injector subassembly by sliding inside. The sliding action ultimately leads to the locking of the cartridge into the Injector Subassembly by locking the Locking Tabs to the Tab Locks (23) in the proximal part of the barrel when it is sided axially from the opening at the distal end of the sheath.

Figure 9 illustrates cartridge load safety syringe showing sheath lock and barrel features provided by the present invention. The sheath lock is illustrated with an anti-wobble feature, an anti recocking feature and an anti-rotation feature and additionally engaged with the sheath inbuilt anti-wobbling and guiding features such that the sheath lock clasp the sheath with the barrel.

The Barrel is open from the distal end (21) and has distal anti -rotation features (11) that engage with the distal anti-rotation features of the sheath. It has a counter groove (24) that extends from the open distal end upto the tab locks (23) and has radially outward projecting multiple anti wobbling (35) and anti recocking projections (36) below the counter check profile that maintains the axial alignment of the barrel and sheath, to prevent wobbling and accidental misfiring during transport and handling and prevent re-cocking of the cartridge load safety syringe after deployment/ firing.

The Invention is further described with the help of non-limiting examples:

Example 1:

The Inventors have conducted an ICMR Sponsored and Monitored, multicentric, open labelled, prospective study to evaluate the safety and effectiveness of the safety syringe developed by Alfa Corpuscles Pvt. Ltd., in patients who require dose administration by parenteral route using the syringe or phlebotomy procedure as a part of their treatment/diagnosis.

This study was performed in compliance with ICH Good Clinical Practise (GCP) including the archiving of essential documents at four out of the five selected centres located at Jaipur, Pune, Belgaum, and Ahmedabad after due approval from the, Site IEC, the CDSCO and CTRI registration.

A total of 2000 subjects were recruited for the trial and were equally divided into Test and Comparator group. The Objectives of the study were to assess the effectiveness of Alfa Corpuscles safety syringe by evaluating usage, acceptance, perception of safety & other determining factors on which users base their decision for routine usage and to monitor the safety of patient. Each group comprised of 400 Intramuscular, 400 Intravenous, 50 Subcutaneous injections and 150 Phlebotomy procedures.

The Criteria for evaluation of Efficacy included ease of use, ability to activate mechanism single handed, time to operate and accuracy in delivery of contents. For Safety we assessed the Pain /Trauma experienced by the Administrator and the subject, Blood Splatter, triggering of safety mechanism and Pain or discomfort experienced by the subject, if any upon Sheath activation.

No training was provided to the users except for a single demonstration of the safety activation to alleviate any doubts that they may have.

There was a comparator group of conventional commercially available syringes of the same nominal capacity. Information on the needle stick injury occurred with conventional syringes within past 3 months at site were considered as comparator group. These data will be compared with the needle stick injury occurred with Alfa Corpuscles Safety Syringe during the study.

Collected date indicates successful and complete drug delivery of the injection/ phlebotomy using the Safety Syringe similar to the conventional syringes. There has been no report of accidental misfiring during transport or handling, non-activation of safety mechanism after single use, Blood spatter nor has there been any significant difference been observed in the pain caused during the procedure. Further none of the subjects has reported any discomfort on sheath activation. The users have found the use of the safety syringe similar to that of the conventional syringe and have successfully been able to activate mechanism single handed in all studies. There is no difference in the time to operate when compared to conventional syringes. There were no reported AE/ SAE and needlestick injuries with the Safety Syringe during the study.

Claims

Claims:

1. A Safety syringe (100), for delivery of injectable drugs comprising vaccine or thermolabile drug, comprising; a barrel (3), made of material comprising glass or polymer, hollow on the inside for holding the product, intended for injection and open at a proximal end (25) and a distal end (26), the distal end (26) having a luer connector (27) to connect a needle hub, a spring base (28) towards the distal end (26), a proximal locking feature (29) having a proximal anti-rotation feature (18) disposed circumferentially on an outer surface of the barrel towards the proximal end (25), and a barrel distal anti rotation feature (13) and a barrel counter check profile (14) disposed circumferentially on the outer surface of the barrel towards the distal end (26); a sheath (1) slidably mounted over the barrel (3) having a sheath proximal end (30) and a sheath distal end (31), inside the sheath distal end (31) having a sheath distal anti rotation feature (12); a plunger (32) slidably located within the barrel (3), having a plunger distal end (34), to prevent leakage of the product intended for injection, having a stem (6) and a plunger proximal end (33) having a lock deployer profile (8); a spring (2) compressed between said spring base (28) of the barrel and the distal anti rotation feature of the Sheath (19); the plunger (32) is axially slid towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from a sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with an anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) comprises an anti-wobble feature (10), the anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath(l); where the safety syringe comprises prefilled safety syringe.

2. The safety syringe as claimed in claim 1, wherein the syringe comprises a distal adaptor (15) having an anti-rotation feature (16) and counter check profile (17) engaged with the distal anti rotation feature (13) of the barrel (3), configured to lock the barrel distal end with the luer connector to connect the needle hub.

3. The safety syringe as claimed in claim 1, comprises a cartridge (38) defining a chamber for holding a product intended for injection, having an inward projecting radial feature to lock with the barrel proximal end and a guiding feature to allow the axial sliding of the cartridge in line with the barrel and wherein said cartridge is made of material comprising glass or polymer.

4. The safety syringe as claimed in claim 1, wherein the barrel (3) has a cartridge tab guiding feature (24) and a cartridge tab locking feature (23) around its outer circumference to allow the axial sliding of the cartridge (38) in line with the barrel (3).

5. The safety syringe as claimed in claim 1, wherein the sheath lock (4) clasps the sheath (1) inbuilt anti-wobbling and guiding features to prevent accidental misfiring of the Syringe during transport, storage, and use.

6. The safety syringe as claimed in claim 1, wherein in the Injector Subassembly of the Cartridge Load Safety Syringe for vaccine delivery, a locking ring (37) is mounted over the plunger (6) before it is inserted into the barrel (3) during assembly, such that it locks the plunger to the barrel and prevents it from falling during transportation or storage but allows the plunger to freely glide in the barrel so as to push the piston of the cartridge to inject the drug/ vaccine.

7. The safety syringe as claimed in claim 1, wherein the plunger (32) is connected to a safety tab (7) that can be attached during assembly that restricts the complete forward movement of the plunger (32) to engage the proximal locking feature (29) of the barrel (3) by the lock deployer profile (8) on the plunger thereby preventing accidental firing of the safety syringe during transport and handling.

8. The safety syringe as claimed in claim 1, wherein the syringe comprises a proximal adaptor with an anti-wobble feature (20), such that the proximal adaptor anti-wobble feature (20) engages with the proximal anti-rotation feature circumferentially disposed on the inner surface of the sheath lock (4) towards the proximal end.

9. The syringe as claimed in claim 1, wherein the cartridge, filled with vaccine or thermolabile drug, is merely required to be maintained in the cold chain thereby reducing burden on cold chain space while the injector sub assembly is kept outside and wherein prior to use, the cartridge is inserted into the barrel of the injector sub assembly making the assembly a prefilled vaccine safety syringes with an Integrated Passive Re Use and Needle Stick Injury Prevention mechanism.

10. A method of operation of Safety syringe (100) as claimed in claim 1, comprising: axially sliding the plunger (32) towards said distal end (26) of said barrel (3) during injection, and when the injection is complete, the said lock deployer profile (8) positioned on the plunger proximal end (33) engages with the proximal locking feature (29) of the barrel, releasing it from the sheath lock (4) thereby releasing said sheath (1) resulting in a forward motion over said barrel (2) due to expansion of said spring (2) till the barrel counter check profile (14) engage with the anti-recocking feature of the sheath lock (9) thereby stopping the forward motion of the sheath (1) and locking the plunger (32) proximal end (33) with the barrel proximal locking feature (29) wherein the sheath lock (4) having an anti-wobble feature (10), an anti recocking feature (9) and an anti-rotation feature (11), engages with the proximal locking feature (29) of the barrel such that the sheath lock (4) clasp the sheath with the barrel (3) during retraction of the sheath(l).