WO2014001880A1

WO2014001880A1 - Dual chamber syringe

Info

Publication number: WO2014001880A1
Application number: PCT/IB2013/001358
Authority: WO
Inventors: Nagaraj Hutchappa NANDEESH
Original assignee: Dominions Healthcare Pvt. Ltd.
Priority date: 2012-06-26
Filing date: 2013-06-26
Publication date: 2014-01-03

Abstract

The subject matter described herein relates to a dual chamber syringe (100). In an embodiment, the dual chamber syringe (100) comprises an outer barrel (102) and an inner barrel (104). The inner barrel (104) is adapted to slide inside the outer barrel (102). The inner barrel (104) comprises a head member (106) at a proximal end. Further, the head member (106) comprises a frustum shaped conduit (108) opening into the outer barrel (102).

Description

DUAL CHAMBER SYRINGE

TECHNICAL FIELD

[0001] The present subject matter relates, in general, to syringes and, in particular but not exclusively, to dual chamber syringes.

BACKGROUND

[0002] With an increasing number of drugs being delivered parenterally, the importance of parenteral drug syringes and other ways of delivery of parenteral drugs has been increasing rapidly. Pre-filled syringes have been designed and developed for the delivery of parenteral drug. The pre-filled syringes are syringes that are pre-filled with a necessary drug before they are sold. A needle and a plunger are coupled with a pre-filled syringe at the time of administration of a drug.

[0003] Further, often times, while administering a drug, the drug may need to be combined with other drugs or materials to be effective. Examples of such drugs are lyophilized drugs and combination drugs. Such drugs may be mixed with materials, such as biological glues. The lyophilized drugs are drugs that are not stable for a long time when mixed with a solvent. Therefore, in order to increase shelf life, the lyophilized drugs are freeze dried, and the dried drug and the solvent are sold as two components. The combination drugs are drugs that are active or have increased efficacy on combination with another drug or a solvent. The biological glues are a form of surgical glues, having components, such as glutaraldehyde and albumin, which acts as tissue adhesives. Generally, the biological glues and combination drugs are mixed together, just before delivery, for bonding between native tissues, for plugging surgical needle holes, and also for serving as a better tissue substrate to hold the sutures. SUMMARY

[0004] This summary is provided to introduce concepts related to dual chamber syringe, which is further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter. [0005] The subject matter described herein relates to a dual chamber syringe. In an embodiment, the dual chamber syringe comprises an outer barrel and an inner barrel. The inner barrel is adapted to slide inside the outer barrel. The inner barrel comprises a head member at a proximal end. Further, the head member comprises a frustum shaped conduit opening into the outer barrel.

BRIEF DESCRIPTION OF THE FIGURES

[0006] The detailed description is described with reference to the accompanying figures.

The use of the same reference number in different figures indicates similar or identical items. The features, aspects and advantages of the subject matter will be better understood with regard to the following description, and the accompanying drawings.

[0007] Fig. l a and Fig. l b illustrate various components of a dual chamber syringe, in accordance with an embodiment of the present subject matter.

[0008] Fig. l c illustrates a needle unit of the dual chamber syringe, in accordance to an embodiment of the present subject matter.

[0009] Fig. 2 illustrates an outer barrel of the dual chamber syringe, in accordance with an embodiment of the present subject matter.

[0010] Fig. 3 illustrates an inner barrel of the dual chamber syringe, in accordance with an embodiment of the present subject matter.

[0011] Fig. 4 illustrates a plunger of the dual chamber syringe, in accordance to an embodiment of the present subject matter.

DETAILED DESCRIPTION

[0012] The present subject matter describes a dual chamber syringe for providing a homogeneous mixture of two components, such as a product and a solvent, provided in the two chambers of the syringe. The dual chamber syringe may be used for a variety of applications, such as for dosage of parenteral drugs and for providing a solution to another object or device, for example, for lubricating mechanical devices. [0013] Typically, parenteral drugs, hereinafter referred to as drugs, are delivered in vials, and the drugs may be administered to patients through syringes. Further, for administration of lyophilized drugs, combination drugs or biological glues, the drugs may have to be combined with a corresponding solvent. For the ease of explanation, a lyophilized drug, one of the components of a combination drug, may be referred to as product. Likewise, a solvent for the lyophilized drug, the combination component of the drug, hereinafter, may be referred to as solvent. The product and the solvent may be provided in two separate vials. A syringe may be used to draw the solvent from a solvent vial and inject the solvent into a product vial. Once the solvent is filled into the product vial, the product vial is gently shaken to ensure uniform/homogenous mixing of the product and the solvent.

[0014] However, usage of vials could sometimes lead to inaccurate drug dosage or product amount. For example, while mixing, the product may be spilled and a correct amount of the product, which needs to be administered, may not be available for administration. At times, the administration of the drug may involve multiple stages in mixing the product with the solvent which accounts to substantial time. In such a scenario, self administering of the drugs becomes a challenge. Also during the drawing and mixing, microbial contamination may occur and hence the administration through vials may not be desirable.

[0015] In order to avoid the usage of vials, dual chamber pre-filled syringes are used conventionally. The dual chamber pre-filled syringe is known to have a single barrel which is bifurcated by a middle member into chambers. The middle member could be in the form of stopper(s). Either sides of the stopper form two chambers. A chamber ahead of the stopper, referred to as a first chamber, is filled with the product and has a needle hub thereon. A chamber below the stopper, referred to as a second chamber, is filled with a corresponding solvent. The middle member is capable of moving along the longitudinal axis of the barrel when actuated through a plunger. When pressure is applied on the plunger, the plunger is pushed towards the second chamber, which causes the middle member to tear and the solvent to enter the first chamber. In such cases, the pressure applied may cause the solvent to splash in the first chamber. Because of the splash created, part of the solvent may leak out through the needle hub. Further, such a splash may not allow a homogenous mixing of the product with the solvent. [0016] The present subject matter describes a dual chamber (DC) syringe. According to an embodiment of the present subject matter, the DC syringe includes an outer barrel to receive a product, an inner barrel to receive a solvent, and a plunger. The inner barrel may be slidably disposed inside the outer barrel. The inner barrel at one end has a head member and the other end is open to accommodate the plunger. Further, the outer barrel at one end includes a needle hub, adapted to seat the needle unit, while the other end is open to accommodate the inner barrel.

[0017] The needle unit may be fitted at the needle hub for the purpose of administering a mixture of the product and the solvent. Further, a frustum shaped conduit is provided in the head member of the inner barrel to form a nozzle therein. The aperture at the tapered end may be facing towards the product and may be sealed by a membrane. In one implementation, the membrane may be a thin membrane made of a polymer, including an elastomer, which may be punctured upon application of predetermined pressure.

[0018] In operation, the outer barrel is filled with the product, and the inner barrel is filled with the corresponding solvent. At the time of delivery, pressure may be applied on the plunger causing the solvent to advance towards the frustum shaped conduit. Due to the tapering portion of the frustum shaped conduit, the pressure of the solvent increases and may tear open the membrane. In an example, the membrane is made of an elastomer and the torn part of the membrane may stick to the rest of the membrane instead fragmenting into tiny pieces, thus preventing contamination in the product-solvent solution. Further, the solvent emerges out of the frustum shaped conduit as a thin stream with high pressure and mixes with the product. The high pressure of stream of the solvent results in homogeneous mixing and a precise amount of product-solvent mixture for administration. Also, the nozzle effect, owing to the frustum shaped conduit, adds pressure on the thin membrane and thereby enables it to tear easily as compared to a case where the conduit was of uniform diameter. The nozzle effect may help overcome the resistance offered by the torn membrane from allowing the solvent to enter the outer chamber. Further, due to the elastic property of the elastomer membrane and due to small diameter of the aperture, the membrane may act as a sealing member and regurgitation may be prevented. Furthermore, fewer manual steps may be necessary for administration of drugs and contaminations may be prevented. [0019] Although present subject matter has been explained in considerable detail with respect to dosage of drugs; however it will be understood that other dual chamber syringe may have applications as well. These and other aspects of the present subject matter would be described in a greater detail in conjunction with the following figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter.

[0020] Fig. l a and Fig. l b illustrate various components of a dual chamber (DC) syringe

100, according to an embodiment of the present subject matter. The DC syringe 100, as shown in Fig. 1 (a), includes an outer barrel 102 and an inner barrel 104 that coaxially slides inside the outer barrel 102, and a plunger 1 10 slidably disposed inside the inner barrel 104. The inner barrel 102 includes a head member 106 having a frustum shaped conduit 108 to connect the inner barrel 104 with the outer barrel 102. Further, the outer barrel 102 may include an outer barrel finger rest 1 12, and likewise the inner barrel 104 may include an inner barrel finger rest 1 14. In an example, the outer barrel 102 may be filled with a product, which may be in a powder form or in liquid form. The product may be a lyophilized drug or any of the components of a combination drug. Further, the inner barrel 104 may include a solvent to be mixed with the product. In an implementation, the DC syringe 100 may be made of polycarbonate, medical grade plastic or glass. It will be understood that in addition to elastomers, any other polymer may also be used to make various components of the DC syringe 100.

[0021] To administer the solution of the product and the solvent, a needle hub 1 16 of the outer barrel 102 may be adapted to receive a needle unit 1 18 illustrated in Fig. 1 (c). The needle unit 1 18 includes a needle adapter 120, which houses a needle 122. The needle unit 1 18 may be locked to the needle hub 1 16 by a locking mechanism, such as a press fit, a luer lock, or a thread lock, and may include a constriction that will restrict easy detaching of the needle unit 1 18 from the needle hub 1 16. The needle hub 1 16 may also have threading to accommodate the needle unit 1 18. The outer barrel 102 may include the needle hub 1 16 at a proximal end, with respect to the needle unit 1 18. In an implementation, the needle hub 1 16 may be a cylindrical shaped projection having apertures of equal diameter at both ends of the cylinder.

[0022] A distal end of the outer barrel 102 may be provided with the outer barrel finger rest 1 12. Further, the distal end may also include an opening to receive the inner barrel 104. The inner barrel 104, at its proximal end, includes the head member 106 and the solvent may traverse from the inner barrel 104 to the outer barrel 102 through the frustum shaped conduit 108. The broad end of the frustum shaped conduit 108 may be at the solvent receiving end and the narrow end of the frustum shaped conduit 108 may be at solvent delivering end.

[0023] In an initial position of the DC syringe 100, the inner barrel 104 is placed with the head member 106 close to the product. To first form the solution, the plunger 110 may be moved inside the inner barrel 104. Further, to aid the movement of the plunger 110, a user may rest fingers on the outer inner finger rest 1 14 and the thumb may be rested on the thumb rest 124. The forward motion of the plunger 110 may tear open a membrane (not shown in figures) provided on the head member 106 to allow the solvent from the inner barrel 104 to the outer barrel 102. Further, the varying diameter at the inlet and the outlet of the frustum shaped conduit 108 results in nozzle effect, where the solvent emerges out of the inner barrel 104 to form a homogeneous solution with the product. The homogenous solution ensures that an accurate formulation to be dosed is formed.

[0024] As the solution is formed inside the outer barrel 102, the solution replaces the amount of air present in the outer barrel 102 causing the inner barrel 104 to be pushed backwards. The backward movement of the inner barrel 104 and the forward movement of the plunger 110 takes place simultaneously. The movement of the plunger 1 10 is restricted by a bottom surface 126 of the head member 106. Since, the solution is formed inside the syringe itself, the chances of solution being contaminated or inappropriate amount of solvent being mixed with the product are minimized.

[0025] Once the plunger 110 reaches the bottom surface 126, a mechanical lock, such as a press fit lock or a notch provided at the inner surface of the inner barrel 104 locks the plunger 1 10. At this stage, complete amount of solvent is delivered into the outer barrel 102, and the plunger 110 and the inner barrel 104 may function as single plunging unit to administer the solution to a patient. For administering the solution, the needle unit 118 may be seated on the needle hub 1 16. Further, the user may rest the . fingers on the outer barrel finger rest 1 12 and the thumb on the thumb rest 124 to move the plunging unit, including the inner barrel 104 and the plunger 110, inside the outer barrel 102. The forward movement of the plunging unit may push the solution into the needle 122 via the needle hub 116. Accordingly, a precise dosage may be administered to the patient. [0026] Fig. 2 illustrates the outer barrel 102 of the dual chamber syringe 100, in accordance with an embodiment of the present subject matter. A distal end, with respect to the needle hub 1 16, of the outer barrel 102 may be provided with the outer barrel finger rest 1 12 and a proximal end may be provided with the needle hub 1 16. Further, the distal end may also include an opening to receive the inner barrel 104. The needle hub 1 16 may be coaxial to the outer barrel 102. In an implementation, the needle hub 1 16 may be a cylindrical shaped projection having apertures of equal diameter at both ends of the cylinder. In an example, the aperture at the tip of the needle hub 1 16, with respect to the needle unit 1 18, may be sealed with a rubber seal or an air-tight seal to prevent exposure of the product to moisture. The seal may be easily punctured with the help of a needle. Alternately, the rubber seal may be a thin seal, which maybe punctured on application of pressure through the product-solvent solution.

[0027] In another example, the needle hub 1 16 may be fitted with a cap (not shown). The cap may be fitted to provide a seal at the opening end of the needle hub 1 16. Further, the cap may prevent the product in the outer barrel 102 from being exposed to moisture and microbial contaminants. While administering the solution, the cap provided on the needle hub 1 16 may be removed and the needle unit 1 18 may be seated on the needle hub 1 16.

[0028] Fig. 3 illustrates the inner barrel 104, in accordance with an embodiment of the present subject matter. As mentioned earlier, the inner barrel 104 is adapted to include the solvent. The inner barrel 104 includes the head member 106 at its proximal end, with respect to the product contained in the outer barrel 102; and the inner barrel finger rest 1 14 and the opening for receiving the plunger 1 10 at its distal end. In an implementation, the distal end of the inner barrel 104 may include a notch (not shown). The notch prevents any accidental engagement of the plunger 1 10 with the inner barrel 104, which may cause the solvent to traverse into the outer barrel 102. Similarly, the outer barrel 102, at the distal end, may include a notch which prevents any accidental engagement of the inner barrel 104 with the outer barrel 102. In such a case, the plunger 1 10 may be adapted to slide in the inner barrel 104 upon application of a pre-determined pressure, which causes the plunger 1 10 slides over the notch. In another implementation, the inner barrel 104 may include a seal which needs to be punctured by the plunger 1 10 prior to engaging with the inner barrel 104. [0029] The head member 106 includes a first aperture 302 at solvent delivery end and a second aperture 304 at solvent receiving end. The diameter of the first aperture 302 is smaller as compared to the second aperture 304, thereby forming the frustum shaped conduit 108. In an example, the first aperture 302 may have cross-section, which is small enough to prevent non- usage of the solvent.

(0030] In one implementation, the first aperture 302 may be covered or sealed by a membrane. The membrane may be a thin membrane and be made of a material, such as silicon rubber or a polymer, including an elastomer, which has a probability of tearing under stress. Further, the membr ane may be of the same material as that of the surrounding elastomer. However, the membrane may be made thinner at the first aperture 302 area thereby allowing it to tear easily.

[0031] Further, in an example, the inner barrel 104 may include a gasket (not shown in the figures), such as an O-ring, to prevent seepage of the product and the solution into the inner barrel 104. It will be understood that the gasket may shaped so as to accommodate varying diameter of the frustum shaped conduit 108 at the first aperture 302.

[0032] While administering the solution, due to the applied pressure, the plunger 1 10 slides in the inner barrel 104 and causes the solvent to advance towards the frustum shaped conduit 108. Since the frustum shaped conduit 108, from the second aperture 304 to the first aperture 302, functions as a nozzle, the pressure of the solvent entering at the second aperture 304 is increased gradually as it proceeds towards the first aperture 302, causing an increase in stress on the membrane. The increase in stress may cause the membrane to tear open when the stress exceeds threshold stress of the material of the membrane. As a result, a thin stream of the solvent emerges out of the first aperture 302 with substantial high pressure into the outer barrel 102 containing the product. The thin stream of the solvent dissolves the product, thus forming a homogeneous solution. Further, the pressure may be applied at the thumb rest 124 until the plunger head 402 reaches the second aperture 304, thus causing complete amount of solvent to be delivered into the outer barrel 102.

[0033] In an embodiment, the outer chamber 102 may be vaccumized. The outer barrel

102 may be sealed with membrane to form an air-tight or vacuum chamber containing the product instead of a seal being provided at the head member of the inner barrel 104. At an initial position, the inner barrel 104 may be positioned close to the seal. As explained earlier, a notch may be provided to prevent accidental engagement of the inner barrel 104 with the seal. Further, pressure may be applied at the thumb rest 124 to engage the plunger 1 10 with the inner barrel 104. The movement of the plunger 1 10 causes the solvent to advance towards the seal. Once the pressure builds up at interface of the seal, the seal breaks open causing the solvent to mix with the product. The product-solvent solution is administered to a patient in the manner as described • earlier.

[0034] Fig. 4 illustrates the plunger 1 10, in accordance to an embodiment of the present subject matter. The plunger 1 10 includes a plunger head 402, a plunger rod 404. and the thumb rest 124. In an example, the plunger head 402 may be made of nitryl rubber or medical grade silicon. The plunger head 402 is provided at the proximal end, with respect to the head member 106, of the plunger 1 10 and the thumb rest 124 is at the distal end of the plunger 1 10. As mentioned earlier, the plunger 1 10 is inserted into the inner barrel 104 and is adapted to move coaxially inside the inner barrel 104. The plunger 1 10 may move freely in the inner barrel 104 until the plunger head 402 comes in contact with the bottom surface 126.

[0035] In an implementation, the plunger head 402 may be adapted to fit snuggly inside the inner barrel 104. In said implementation, the plunger head 402 acts as a sealing membrane and prevents any seepage of the solution from the inner barrel 104. Alternately, the plunger head 402 may also include a gasket, such as an O-ring, which functions as a sealing member. The gasket prevents seepage of the solvent from the head member 402. Thus, the gaskets sealing the outer barrel 102 and the inner barrel 104 not only ensure that the solution is protected from contaminants but also ensures that the solution has the product and the solvent in correct ratio.

[0036] Although the disclosed subject matter has been described with reference to particular means, materials, and embodiments, the disclosed subject matter is not intended to be limited to the particulars disclosed; rather, the subject matter extends to all functionally equivalent structures, methods, and uses, such as are within the scope of the appended claims.

Claims

I/We claim:

1 . A dual chamber syringe (100) comprising:

an outer barrel (102); and

an inner barrel ( 104) adapted to slide inside the outer barrel ( 102), wherein the inner barrel (104) comprises a head member ( 106) at a proximal end, and wherein the head member (106) comprises a frustum shaped conduit (108) opening into the outer barrel ( 102).

2. The dual chamber syringe (100) as claimed in claim 1 further comprising a plunger ( 1 10) adapted to slide inside the inner barrel (104).

3. The dual chamber syringe (100) as claimed in claim 2, wherein the plunger ( 1 10) comprises a gasket provided on a plunger head (402) of the plunger ( 1 10).

4. The dual chamber syringe (100) as claimed in claim 2, wherein the plunger (1 10) and the inner barrel (104) are adapted to form a single plunging unit, when the plunger ( 1 10) reaches a bottom surface ( 126) of the head member ( 106).

5. The dual chamber syringe (100) as claimed in claim 4, wherein the inner barrel ( 104) includes a mechanical lock to lock the plunger ( 1 10).

6. The dual chamber syringe ( 100) as claimed in claim 2, wherein the plunger ( 1 10) comprises a non return valve provided at a distal end.

7. The dual chamber syringe (100) as claimed in claim 1 , wherein the frustum shaped conduit ( 108) comprises a first aperture (302) having a cross section narrower than a second aperture (304), and wherein the first aperture (302) opens into the outer barrel ( 102).

8. The dual chamber syringe (100) as claimed in claim 7, wherein the first aperture (302) is sealed by a membrane.

9. The dual chamber syringe ( 100) as claimed in one of claim 1 or claim 8, wherein the head member ( 106) and the membrane are made of one of a polymer and silicon rubber.

10. The dual chamber syringe (100) as claimed in claim 1 , wherein the outer barrel ( 102) comprises a needle hub ( 1 16) including a locking mechanism to couple to a needle unit ( 1 18).

1 1. The dual chamber syringe ( 100) as claimed in claim 1 , wherein the dual chamber syringe ( 100) is composed of one of a polycarbonate, a medical grade plastic, and glass. The dual chamber syringe (100) as claimed in claim 1, wherein the outer barrel (102) comprises a seal to form an air-tight chamber.

The dual chamber syringe (100) as claimed in claim 1, wherein at least one of the outer barrel (102) and the inner barrel (104) comprises a notch provided at a corresponding distal end.