WO2014190225A1

WO2014190225A1 - Syringe assembly and barrel for use in such an assembly

Info

Publication number: WO2014190225A1
Application number: PCT/US2014/039267
Authority: WO
Inventors: Robert S. Abrams; Peter J. Sagona; Joseph A. Jones; Joseph W. Rogers; Jean-Pierre Giraud
Original assignee: Sio2 Medical Products, Inc
Priority date: 2013-05-24
Filing date: 2014-05-23
Publication date: 2014-11-27

Abstract

A syringe barrel includes a tubular wall having an inner surface, a front end configured for attachment of a needle, and a tail end having an opening configured to receive a plunger. The opening leads to an interior of the syringe barrel and traverses the barrel to the front end thereof. The tubular wall has a first zone located longitudinally toward the tail end and having a first inner diameter, and a second zone located longitudinally towards the front end and having a second inner diameter that is greater than the first inner diameter.

Description

SYRINGE ASSEMBLY AND BARREL FOR USE IN SUCH AN ASSEMBLY

FIELD OF INVENTION

[0001] The invention pertains to a syringe assembly and a barrel for use in such an assembly.

In particular, the invention pertains to an assembly or barrel used therein having at least two zones of different internal diameters. The invention further pertains to a method of molding such a syringe barrel.

BACKGROUND

[0002] Traditional syringes have barrels with constant inner diameters, or slightly varying inner diameters due to draft angles used in molding. The inner diameter of a conventional syringe barrel is designed to compress a rubber plunger when advanced through the barrel interior. This compression forms a seal to create and maintain container closure integrity, but can disadvantageously resist sliding of the plunger through the syringe barrel, Container closure integrity is the ability of a container closure system to provide protection and maintain efficacy and sterility during the shelf life of a sterile drug product. The ability of rubber components to prevent microbial ingress of parenteral containers can be measured by seal integrity. The established methods for assessing container closure integrity include: (1) submerging the sealed container into a microbial solution and confirm that sterility is maintained, (2) dye ingress method, (2) vacuum decay method and (3) helium leak method. A lubricant is typically applied uniformly on the interior surface of the syringe barrel to lower the plunger force required to advance the plunger. Many such lubricants come in direct contact with the drug product injected via the syringe, and in the case of pre-filled syringes, remain in contact therewith during shelf life. Such lubricants can generate particles and extractables that can degrade the injectable drug or otherwise affect drug activity and efficacy.

[0003] A need exists for a syringe barrel that permits plunger advancement with low plunger force, while in the case of a pre-filled syringe assembly, maintaining container closure integrity during shelf life and substantially eliminating contact between the lubricant and the drug to minimize the negative effects of such contact, such as particulates and extractables. [0004] The present invention pertains to a syringe assembly or barrel used therein having at least two zones of different inner diameters . A mold core for molding such a syringe barrel may have at least two zones of different outer diameters, in order to create the at least two zones of different inner diameters of the barrel. Molding of such an assembly presents a challenge with respect to extraction of the mold core having varying outer diameters. A need therefore exists for a molding method that permits extraction of a mold core for molding a syringe barrel having at least two zones of different inner diameters.

SUMMARY

[0005] The invention relates to a syringe barrel that includes a tubular wall having an inner surface, a front end configured for attachment of a needle, and a tail end having an opening configured to receive a plunger. The opening leads to an interior of the syringe barrel and traverses the barrel to the front end thereof. The tubular wall has a first zone located longitudinally toward the tail end and having a first inner diameter, and a second zone located longitudinally towards the front end and having a second inner diameter that is greater than the first inner diameter.

[0006] The invention further relates to a syringe assembly including a syringe barrel as described above, a needle attached to the front end of the tubular wall, and a plunger received within the opening of the tail end.

[0007] The invention further relates to a method of molding a syringe barrel as described above, including providing a molding assembly having a molding cavity and a core. The core fits within the molding cavity to define a molding space shaped to form the syringe barrel and includes a first core zone having a first outer diameter substantially equal to the first inner diameter of the tubular wall, and a second core zone having a second outer diameter substantially equal to the second inner diameter of the tubular wall. The method further includes injecting a molten molding material within the molding cavity, cooling the molding material to solidify, collapsing the core, and removing the core from the molding space.

[0008] The invention further relates to a method of forming a syringe barrel as described above, including providing a molding assembly including a molding cavity and a core. The core fits within the molding cavity to define a molding space shaped to form the syringe barrel. The core includes a first core zone having a first outer diameter substantially equal to the first inner diameter of the tubular wall, and a second core zone having a second outer diameter substantially equal to the second inner diameter of the tubular wall. The method further includes injecting a molten molding material within the molding cavity, cooling the molding material to solidify and form the syringe barrel, removing the syringe barrel from the molding cavity, and removing the core from the interior of the syringe barrel by drawing outward through the opening of the tail end.

[0009] The invention further relates to a method of molding a syringe barrel as described above, including molding a first piece including the first zone and the tail end, molding a second piece including the second zone and the front end, and attaching the first piece and the second piece such that the first zone connects with the second zone.

[0010] The invention further relates to a method of molding a syringe barrel as described above, including molding a first piece including the first zone, the second zone and the tail end, molding a second piece including the front end, and attaching the first piece and the second piece such that the second zone connects with the front end.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a partially exploded perspective view of an exemplary syringe according to the invention;

[0012] FIG. 2 is a partial longitudinal cross section of a first embodiment of a syringe barrel according to the invention, with the plunger in the retracted position;

[0013] FIG. 3 is partial a longitudinal cross section of the syringe barrel of FIG. 2, with the plunger in the partially advanced position;

[0014] FIG. 4 is a partial longitudinal cross section of the syringe barrel of FIG. 2, with the plunger in the fully advanced position;

[0015] FIG. 5 is partial a longitudinal cross section of a second embodiment of a syringe barrel according to the invention, with the plunger in the retracted position;

[0016] FIG. 6 is partial a longitudinal cross section of the syringe barrel of FIG. 5, with the plunger in the partially advanced position; [0017] FIG. 7 is a longitudinal cross section of the syringe barrel of FIG. 5, with the plunger in the fully advanced position;

[0018] FIG. 8 is a table that illustrates the relationship between inner barrel diameter and plunger force;

[0019] FIG. 9 is a cross sectional view of a first embodiment of a mold assembly for molding a syringe barrel according to the invention;

[0020] FIG. 10 is a cross sectional view of a second embodiment of a mold assembly for molding a syringe barrel according to the invention;

[0021] FIG. 11 is a cross sectional view of a first embodiment of a partially assembled syringe barrel according to the invention; and

[0022] FIG. 12 is a cross sectional view of a second embodiment of a partially assembled syringe barrel according to the invention.

DETAILED DESCRPTION OF THE PREFERRED EMBODIMENTS

[0023] Detailed embodiments of the present invention are disclosed herein, but it should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The figures are not necessarily to scale; some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0024] Certain terminology is used in the foregoing description for convenience and is not intended to be limiting. Words such as "front," "back," "top," and "bottom" designate directions in the drawings to which reference is made. This terminology includes the words specifically noted above, derivatives thereof, and words of similar import. Additionally, the words "a" and "one" are defined as including one or more of the referenced item unless specifically noted. The phrase "at least one of followed by a list of two or more items, such as "A, B or C," means any individual one of A, B or C, as well as any combination thereof.

[0025] An exemplary syringe assembly 10 according to the invention is shown in FIG. 1. As shown, the syringe 10 includes the barrel 50, a needle 20, and a plunger 30. The barrel 50 is formed as a substantially tubular wall 52 with an opened tail end 54 leading to an interior 56. The plunger 30 is slidably housed within the interior 56 and partially protrudes outward from the opened tail end 54. A collar 58 may extend radially outwardly from the tubular wall 52 at the first end 54 thereof, to facilitate gripping by a user when advancing the plunger 30 within the barrel 50. A needle receiving hub 60 protrudes from the front end 62 of the barrel 50, located opposite the tail end 54. The needle 20 includes a hub 22 that attaches to the receiving hub 60 of the barrel 50. A through passage 24 passes through the entire length of the needle 20 and joins with the open front end 62 of the barrel 50, to permit passage of injectable medication through the assembly 10. The plunger 30 includes a plunger rod 32 that is slidably received within the interior 56 of the barrel 50. An end face 34 of the plunger 30 is disposed at the end located within the interior 56, in contact with the injectable medication 12 stored therein, and a radially outwardly extending collar 36 is disposed at the opposite end, outside of the barrel 50. A plunger head 40 is formed as plurality of ribs 38 protruding from an outer surface of a region of the plunger rod 32 disposed within the barrel interior 56. The outer edges of each of the ribs 38 contact the inner surface 64 of the barrel tubular wall 52 to form a seal therebetween. An injectable medication 12 is disposed in front region 66 of the barrel, between the plunger face 34 and the front end 62. In use, the collars 36, 58 of the plunger 30 and barrel 50 are gripped between the thumb and forefinger of a user, and forced towards each other, to initiate sliding of the plunger 30 within the barrel 50, forcing medication 12 disposed within the assembly 10 outward through the needle passage 24.

[0026] FIGS . 2-4 show partial cross sectional views of a first embodiment of a syringe barrel

50 and plunger 30 assembly according to the invention. As shown, the tubular wall 52 of the barrel 50 is divided into a first zone 70 having a first, smaller inner diameter DI1, and a second zone 72 having a second, larger inner diameter DI2. The first zone 70 occupies a longitudinal region of the barrel 50 extending inward from the tail end 54, and the second zone 72 occupies a longitudinal region of the barrel 50 extending inward from the front end 62.

[0027] FIG. 2 shows the barrel 50 and plunger 30 assembly in a retracted position. As shown, in this position the plunger 30 is disposed within the first zone 70 of the barrel 50. The plunger face 34 faces the second zone 72, which houses an injectable medication 12. The plunger ribs 35 are compressed within the tubular wall 52 in the second zone 72, creating a seal that retains the medication 12 between the plunger face 50 and the front end 62 of the barrel 50.

[0028] As shown, a lubricity coating 74 is applied to the inner surface 64 of the tubular wall

54 in the first zone 70. Any type of lubricity coating known in the art may be used, such as silicone oil, a perfluoropolyether coating such as TRIBOGLIDE®, produced by IVEK corporation, I- COATING, produced by TERUMO, or a plasma lubricity such as that disclosed in US Patent No. 7,985,188, which is incorporated herein by reference as if fully set forth.

[0029] FIG. 3 shows the plunger 30 in a partially advanced position within the barrel 50. In this position, the plunger 30 has been pressed in direction P and is now located partially in the first zone 70 and partially in the second zone 72. As shown, a frontward one of the ribs 38A is positioned in the second zone 72, and has expanded due to the increased inner diameter DI2. The outer edge of the rib 38 A remains in contact with the inner surface 64 of the tubular wall 52 after transitioning into the second zone 72, retaining the seal to continue to retain the medication 12 between the plunger face 34 and front end 62 of the barrel 50. Rib 38A is now subject to a lower degree of compression due to the larger inner diameter DI2, to permit easier sliding of the plunger 30 in direction P to eject the medication 12 through the needle opening 24.

[0030] Still referring to FIG. 3 the lubricity coating 72 now extends into the portion of the second zone 72 that has been crossed by plunger rib 38A. As the plunger 30 moves in direction P, the lubricity coating is dispersed on the inner surface 64 of the tubular wall 52 as the ribs 38 in contact therewith slide within the barrel 50.

[0031] FIG. 4 shows the plunger 30 in an advanced position within the barrel 50. In this position, the plunger 30 has been further pressed in direction P and is now located fully in the second zone 72. As shown, all of the ribs 38 are now positioned in the second zone 72 and have expanded due to the increased diameter DI2. The outer edges of all ribs 38 remain in contact with the inner surface 64 of the tubular wall 52 after transitioning into the second zone 72, retaining the seal to continue to retain the medication 12 between the plunger face 34 and front end 62 of the barrel 50. The ribs 38 are however now subject to a lower degree of compression due to the larger inner diameter DI2, to permit easier sliding of the plunger 30 in direction P to eject the medication 12 through the needle opening 24. While the seal is intended to be maintained between the front rib 38A and inner surface 64, the other, rearward ribs 38 serve to form additional seals and catch any medication 12 that penetrates the seal between rib 38 A and inner surface 64, to prevent leakage of the medication 12 from the tail end 54 of the barrel.

[0032] Still referring to FIG. 4, the lubricity coating 72 now extends further into the second zone 72, into the portion thereof that has been crossed by plunger rib 38A. The additional, rearward located plunger ribs 38 further distribute the lubricity coating 74 along the inner surface 64 of the tubular wall 52.

[0033] According to the invention, as described above, the lubricity coating 74 maintains contact with outer edges of the plunger ribs 38 as they traverse the inner surface of the barrel tubular all 52, to minimize friction and force required to advance the plunger 30 in direction P. The lubricity coating 74 at the same time remains out of contact with the medication 12 stored within the syringe assembly 12, so that contamination, for example by way of the lubricity coating 74 leaching into the medication 12, can be avoided.

[0034] In another embodiment, the syringe barrel tubular wall 52 has the configuration shown in FIGS. 2-4, but the lubricity coating 74 is distributed in both the first zone 70 and second zone 72 when the plunger 30 is in the retracted position.

[0035] FIGS. 5-7 show partial cross sectional views of a second embodiment of a syringe barrel 50 and plunger 30 assembly according to the invention. This embodiment is similar to that show in FIGS. 2-4, with the exception of the fact that a transitional zone 76 is disposed between the first zone 70 and the second zone 72. The transitional zone 76 has a varying inner diameter that transitions from the inner diameter DI1 of the first zone 70 to the inner diameter DI2 of the second zone 72. In the embodiment shown, this transition takes places linearly, i.e., the inner surface 64 of the barrel tubular wall 52 takes on frusto-conical shape within the transitional zone 76, with a first end 78 thereof joining the transitional zone 76 with the first zone 70 and having a diameter of DI1, and a second end 80 thereof joining the transitional zone 76 with the second zone 72 and having a diameter of DI2.

[0036] FIG. 5 shows the barrel 50 and plunger 30 assembly in a retracted position. As shown, in this position the plunger 30 is disposed within the first zone 70 of the barrel 50. The plunger face 34 faces the second zone 72, which houses an injectable medication 12. The plunger ribs 35 are compressed within the tubular wall 52 in the second zone, creating a seal that retains the medication 12 between the plunger face 50 and the front end 62 of the barrel 50.

[0037] As shown, a lubricity coating 74 is applied to the inner surface 64 of the tubular wall

[0038] FIG. 6 shows the plunger 30 in a partially advanced position within the barrel 50. In this position, the plunger 30 has been pressed in direction P and is now located in the transition zone 76. As shown, the ribs 38 expand while advancing within the transition zone 76, from the smaller diameter DI1 to the larger diameter DI2. The outer edges of the ribs 38 remain in contact with the inner surface 64 of the tubular wall 52 while advancing through the transition zone 76 and after transitioning into the second zone 72, retaining the seal to continue to retain the medication 12 between the plunger face 34 and front end 62 of the barrel 50. The ribs 38, when in the transition zone 76 and even more so when in the second zone 72, are subject to a lower degree of compression due to the increasing inner diameter, to permit easier sliding of the plunger 30 in direction P to eject the medication 12 through the needle opening 24.

[0039] Still referring to FIG. 6 the lubricity coating 72 now extends into the portion of the transition zone 76 that has been crossed by plunger rib 38A. As the plunger 30 moves in direction P, the lubricity coating is dispersed on the inner surface 64 of the tubular wall 52 as the ribs 38 in contact therewith slide within the barrel 50.

[0040] FIG. 7 shows the plunger 30 in an advanced position within the barrel 50. In this position, the plunger 30 has been further pressed in direction P and is now located fully in the second zone 72. As shown, all of the ribs 38 are now positioned in the second zone 72 and have expanded due to the increased diameter DI2. The outer edges of all ribs 38 remain in contact with the inner surface 64 of the tubular wall 52 after transitioning into the second zone 72, retaining the seal to continue to retain the medication 12 between the plunger face 34 and front end 62 of the barrel 50. The ribs 38 are however now subject to a lower degree of compression due to the larger inner diameter DI2, to permit easier sliding of the plunger 30 in direction P to eject the medication 12 through the needle opening 24. While the seal is intended to be maintained between the front rib 38A and inner surface 64, the other, rearward ribs 38 serve to form additional seals and catch any medication 12 that penetrates the seal between rib 38 A and inner surface 64, to prevent leakage of the medication 12 from the tail end 54 of the barrel.

[0041] Still referring to FIG. 7, the lubricity coating 72 now extends into the second zone 72, into the portion thereof that has been crossed by plunger rib 38A. The additional, rearward located plunger ribs 38 further distribute the lubricity coating 74 along the inner surface 64 of the tubular wall 52.

[0042] According to the invention, as described above, the lubricity coating 74 maintains contact with outer edges of the plunger ribs 38 as they traverse the inner surface of the barrel tubular all 52, to minimize friction and force required to advance the plunger 30 in direction P. The lubricity coating 74 at the same time remains out of contact with the medication 12 stored within the syringe assembly 12, so that contamination, for example by way of the lubricity coating leaching into the medication 12, can be avoided.

[0043] In another embodiment, the syringe barrel tubular wall 52 has the configuration shown in FIGS. 5-7, but the lubricity coating 74 is distributed in both the first zone 70 and second zone 72 when the plunger 30 is in the retracted position.

[0044] In some embodiments of the invention, the syringe assembly 10 is a prefilled syringe, which is stored in a sealed condition with the medication stored therein. In such an embodiment, the assembly maybe stored in either of the retracted positions of FIGS. 2 and 5, with the plunger housed within the first zone 70.

[0045] In some embodiments of the invention, either or both of the first zone 70 and the second zone 72 can be formed with little or no draft angles, for example, using the process described in WO2012/009653, which is incorporated herein by reference as if fully set forth. In embodiments in which the second zone 72 is formed with little or no draft angles, the lubricity coating may be applied to the inner surface 64 of the first zone only, as little or no lubricity coating is needed where the inner surface 64 has little or no draft angles, due to the constant or nearly constant inner diameter. Alternatively, the barrel 50 can be formed with no lubricity coating at all, such that a small amount of excess force is required to advance the plunger 30 out from the first zone 70, and then a lower, constant amount of force is required to advance the plunger 30 within the second zone, due to the constant inner diameter.

[0046] FIG. 8 shows the relationship between the inner diameter of the syringe barrel tubular wall 52 and force required to advance the plunger 30. As shown, the force required to advance the plunger 30 decreases as the inner diameter of the barrel tubular wall 52 increases. Accordingly, the force needed to advance the plunger 30 within the second zone 72 of each of the embodiments described above should be less than that needed to advance the plunger within the first zone 70, such that less lubricity coating is needed in the second zone. In some such embodiments, no lubricity coating may need be directly applied in the second zone 72 at all, such as an embodiment in which the second zone 72 is formed with little or no draft angles, as described above, or in embodiments in which lubricity coating 74 is applied to the inner surface 64 of the first zone 70 and transferred to the second zone by the plunger 30 during advancement.

[0047] In one embodiment, the second inner diameter DI2 is at least 1.00 mm greater than the first inner diameter Dll. In another embodiment the second inner diameter DI2 is at least 0.95 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.90 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.85 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.80 mm greater than the first inner diameter Dll. In another embodiment the second inner diameter DI2 is at least 0.75 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.70 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.65 mm greater than the first inner diameter Dll. In another embodiment the second inner diameter DI2 is at least 0.60 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.55 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.50 mm greater than the first inner diameter Dll. In another embodiment the second inner diameter DI2 is at least 0.45 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.40 mm greater than the first inner diameter Dll . In another embodiment the second inner diameter DI2 is at least 0.35 mm greater than the first inner diameter Dll. In another embodiment the second inner diameter DI2 is at least 0.30 mm greater than the first inner diameter DIl . In another embodiment the second inner diameter DI2 is at least 0.25 mm greater than the first inner diameter DIl . In another embodiment the second inner diameter DI2 is at least 0.20 mm greater than the first inner diameter DIl. In another embodiment the second inner diameter DI2 is at least 0.15 mm greater than the first inner diameter DIl . In another embodiment the second inner diameter DI2 is at least 0.10 mm greater than the first inner diameter DIl . In another embodiment the second inner diameter DI2 is at least 0.05 mm greater than the first inner diameter DIl.

[0048] For a 1.0 ml long syringe, the inner diameter DIl of the first zone 70 is preferably between 6.10 and 7.00 mm, more preferably between 6.25 and 6.75 mm, and even more preferably between 6.35 and 6.55 mm. For a 1.0 ml long syringe, the inner diameter DI2 of the second zone 72 is preferably between 6.30 and 7.50 mm, more preferably between 6.35 and7.00 mm, andevenmore preferably between 6.45 and 6.65 mm. For a 1.0 ml long syringe, the first inner diameter DIl is preferably between 0.05 mm and 1.00 mm less than the second inner diameter DI2, more preferably between 0.15 mm and 0.75 mm, even more preferably between 0.25 and 0.60 mm.

[0049] The differing dimensions of the first inner diameter DIl and second inner diameter

DI2 result in different levels of compression of the plunger head 40 within the first zone 70 and the second zone 72. For example, in an embodiment in which the plunger head 40 has a diameter of 6.6 mm and the barrel second inner diameter DI2 is 6.35 mm, the plunger head 40 is subject to 4% compression in the second zone 72. If the barrel first inner diameter DIl is 6.25, the plunger head 40 is subject to 5.6% compression in the first zone 70, such that the difference in compression is 1.6%.

[0050] In one embodiment, the difference in such compression is at least 0.5%. In another embodiment, the difference in compression is at least 1.0%. In another embodiment, the difference in compression is at least 1.5%. In another embodiment, the difference in compression is at least 2.0%. In another embodiment, the difference in compression is at least 2.5%. In another embodiment, the difference in compression is at least 3.0% . In another embodiment, the difference in compression is at least 3.5%. In another embodiment, the difference in compression is at least 4.0%. In another embodiment, the difference in compression is at least 4.5%. In another embodiment, the difference in compression is at least 5.0%. In another embodiment, the difference in compression is at least 5.0%. In another embodiment, the difference in compression is at least 5.5%. another embodiment, the difference in compression is at least 6.0% . In another embodiment, the difference in compression is at least 6.5%. In another embodiment, the difference in compression is at least 7.0%. In another embodiment, the difference in compression is at least 7.5%. In another embodiment, the difference in compression is at least 8.0%. In another embodiment, the difference in compression is at least 8.5%. In another embodiment, the difference in compression is at least 9.0%. In another embodiment, the difference in compression is at least 9.5%. In another embodiment, the difference in compression is at least 10.0%. In another embodiment, the difference in compression is at least 10.5%. In another embodiment, the difference in compression is at least 11.0%. In another embodiment, the difference in compression is at least 11.5%. In another embodiment, the difference in compression is at least 12.0%. In another embodiment, the difference in compression is at least 12.5%. In another embodiment, the difference in compression is at least 13.0%. In another embodiment, the difference in compression is at least 13.5%. In another embodiment, the difference in compression is at least 14.0%. In another embodiment, the difference in compression is at least 14.5%. In another embodiment, the difference in compression is at least 15.0%.

[0051 ] In one exemplary embodiment of the invention, a barrel 50 used in a 1 ml long staked needle syringe assembly 10 includes a first zone 70 having a first inner diameter DIl of 6.35 mm, a transitional zone 76, and a second zone 72 having a second inner diameter DI2 of 6.65 mm.

[0052] In another exemplary embodiment of the invention, a barrel 50 used in a 1 ml long staked needle syringe assembly 10 includes a first zone 70 having a first inner diameter DIl of 6.35 mm, a transitional zone 76, and a second zone 72 having a second inner diameter DI2 of 7.00 mm.

[0053] In another exemplary embodiment of the invention, a barrel 50 used in a 1 ml long staked needle syringe assembly 10 includes a first zone 70 having a first inner diameter DIl of 6.45 mm, a transitional zone, and a second zone 72 having a second inner diameter DI2 of 6.65 mm.

[0054] In another exemplary embodiment of the invention, a barrel 50 used in a 1 ml long staked needle syringe assembly 10 includes a first zone 70 having a first inner diameter DIl of 6.45 mm, a transitional zone 76, and a second zone 72 having a second inner diameter DI2 of 7.00 mm.

[0055] In yet another exemplary embodiment of the invention, a barrel 50 used in a 1 ml long staked needle syringe assembly 10 includes a first zone 70 having a first inner diameter DIl of 6.45 mm, a transitional zone 76, and a second zone 72 having a second inner diameter DI2 of between 6.50 and 6.55 mm.

[0056] A syringe barrel 50 according to the invention can be formed of various materials known in the art, such as glass and polymeric materials. In embodiments in which the barrel 50 is formed of glass, any technique known in the art could be used to form the barrel 50, such as by using glass tubing or drawing a molten layer of glass over a mandrel. In embodiments in which the barrel 50 is formed of a polymeric material, the barrel may be formed by injection molding.

[0057] FIGS. 9 and 10 illustrate exemplary molding assemblies 90 for molding a syringe barrel 50 according to the invention. The assembly 90 of FIG. 9 could be used to mold a syringe barrel 50 such as that shown in FIGS. 2-4. The assembly 90 of FIG. 10 could be used to mold a syringe barrel 50 such as that shown in FIGS. 5-7. Each of the assemblies 90 of FIGS. 9 and 10 includes an upper plate 92, a lower plate 94 defining a mold cavity 96, and a core 98 that fits within the molding cavity 96 to define a molding space between the outer surface of the core 98 and the inner surface of the molding cavity 96.

[0058] In the embodiment of FIG. 9, the core 98 includes a first zone 100 having a first outer diameter DOl and a second zone 102 having a second outer diameter D02, which is greater than the first outer diameter DOl. The first zone 100 of the mold core 98 together with the inner surface of the molding cavity 96 forms a molding space that forms the first zone 70 of the syringe barrel 50. The second zone 102 of the mold core 98 together with the inner surface of the molding cavity 96 forms a molding space that forms the second zone 72 of the syringe barrel.

[0059] In the embodiment of FIG. 10, the core 98 includes a first zone 100 having a first outer diameter DOl, a second zone 102 having a second outer diameter D02, which is greater than the first outer diameter DOl, and a transitional zone 104 having a varying outer diameter that transitions from the outer diameter DOl of the first zone to the outer diameter D02 of the second zone. In the embodiment shown, this transition takes place linearly, i.e., the outer surface of the transitional zone 104 has a frusto-conical shape, with a first end 106 thereof joining with the first zone 100 and a second end 108 thereof joining with the second zone 102. The first zone 100 of the mold core 98 together with the inner surface of the molding cavity 96 forms a molding space that forms the first zone 70 of the syringe barrel 50. The second zone 102 of the mold core together with the inner surface of the molding cavity 96 forms a molding space that forms the second zone 72 of the syringe barrel. The transitional zone 104 of the mold core together with the inner surface of the molding cavity 96 forms a molding space that forms the transitional zone 76 of the syringe barrel.

[0060] In some embodiments, the mold core 96 can be collapsible. For example, the core 96 could be collapsed by mechanical means known in the art. In one embodiment, the core 96 is initially expanded by application of hydraulic pressure, and then collapsed by releasing such pressure. Varying wall thicknesses of the mold core would expand differently under hydraulic pressure. Such a collapsible core 96 could be collapsed after cooling of the polymeric molding material, so as to permit removal of the core 96 from the barrel interior 56.

[0061] In other embodiments in which a mold assembly 90 such as that shown in FIGS. 9 or

10 is used to form the syringe, the molding material is injected into the molding space 110, and cooled to solidify. The lower plate 94 and upper plate 94 are then removed from the molded barrel 50, leaving only the core 94 remaining within the interior 56 of the barrel. The core 94 is removed from the interior 56 by drawing upwards in direction Dl shown in FIGS. 9 and 10, which causes outward deformation of the barrel 50 in direction D2, until the inner diameter DI1 of the first zone 70 of the barrel 50 is greater than the outer diameter D02 of the second zone 102 of the core 98, allowing the second zone 102 of the core 98 to clear the inner surface 64 of the first zone 70 tubular wall 52 of the barrel 50 and be removed therefrom. Such a molding method may be useful with embodiments of the molding assembly 90 such as that shown in FIG. 10, where the core 98 includes a transitional zone 104, to facilitate upward sliding of the core in direction Dl and gradual expansion of the first zone 100 of the barrel tubular wall 52.

[0062] In another embodiment, the syringe barrel 50 is molded as multiple pieces. FIG. 11 shows one example in which a first piece 82 of the barrel 50 includes the transitional zone 76, first zone 70, tail end 54, and collar 58, and a second piece 84 of the barrel 50 includes the second zone 72, front end 62, and needle hub. The first piece 82 and second piece 84 are molded separately and joined by, for example sonic welding, spin welding, or adhesives. FIG. 12 shows another example in which the first piece 82 includes the first zone 70, transitional zone 76, second zone 72, tail end 58, and collar 58, and the second piece 84 includes the needle hub 60 and front end 62. The first piece 82 and second piece are molded individually and then joined after molding, for example by sonic welding, spin welding, adhesives, an injection molding of polymer material.

[0063] Any suitable glass or polymeric material known in the art could be used to form the syringe barrel, such as Type 1 borosilicate glass, a cyclic olefin polymer (COP) or cyclic olefin copolymer (COC). The syringe plunger 30 may be formed at least partially of an elastomeric material, such as a butyl rubber. Preferably, at least the ribs 38 are formed of an elastomeric material, so as to permit sufficient deformation and elasticity to create as seal between the plunger 30 and the barrel tubular wall 52. Suitable plungers include those manufactured by STEMLI, BD FLOROTEC, manufactured by WEST®, BD NOVA PURE, manufactured by WEST®, and DATWYLER.

[0064] While the preferred embodiments of the invention have been described in detail above, the invention is not limited to the specific embodiments described, which should be considered as merely exemplary.

* * *

Claims

CLAIMS What is claimed is:

1. A syringe barrel, comprising:

a tubular wall having an inner surface, a front end configured for attachment of a needle, and a tail end having an opening configured to receive a plunger, the opening leading to an interior of the syringe barrel and traversing through the barrel to the front end thereof;

wherein the tubular wall has a first zone located longitudinally toward the tail end and having a first inner diameter, and a second zone located longitudinally towards the front end and having a second inner diameter that is greater than the first inner diameter.

2. The syringe barrel of claim 1 , further comprising a collar extending radially outward from the tubular wall about the tail end and a hub configured for attachment of a needle at the front end.

3. The syringe barrel of any previous claim, further comprising a transitional zone located longitudinally between the first zone and the second zone.

4. The syringe barrel of claim 3, wherein the transitional zone has a varying inner diameter that transitions between the first inner diameter and the second inner diameter.

5. The syringe barrel of claim 4, wherein the transitional zone has a first end that joins with the first zone and has the first inner diameter, and a second end that joins with the second end and has the second inner diameter.

6. The syringe barrel of any one of claims 3-5, wherein the inner surface of the tubular wall has a frusto-conical shape within the transitional zone.

7. The syringe barrel of any previous claim, wherein the second inner diameter is at least 1.00 mm greater than the first inner diameter, alternatively at least 0.95 mm greater than the first inner diameter, alternatively at least 0.90 mm greater than the first inner diameter, alternatively at least 0.85 mm greater than the first inner diameter, alternatively at least 0.80 mm greater than the first inner diameter, alternatively at least 0.75 mm greater than the first inner diameter, alternatively at least 0.70 mm greater than the first inner diameter, alternatively at least 0.65 mm greater than the first inner diameter, alternatively at least 0.60 mm greater than the first inner diameter, alternatively at least 0.55 mm greater than the first inner diameter, alternatively at least 0.50 mm greater than the first inner diameter, alternatively at least 0.45 mm greater than the first inner diameter, alternatively at least 0.40 mm greater than the first inner diameter, alternatively at least 0.35 mm greater than the first inner diameter, alternatively at least 0.30 mm greater than the first inner diameter, alternatively at least 0.25 mm greater than the first inner diameter, alternatively at least 0.20 mm greater than the first inner diameter, alternatively at least 0.15 mm greater than the first inner diameter, alternatively at least 0.10 mm greater than the first inner diameter, alternatively at least 0.05 mm greater than the first inner diameter.

8. The syringe barrel of any one of claims 1-7, wherein the first inner diameter is 6.35 mm and the second inner diameter is 6.65 mm, alternatively wherein the first inner diameter is 6.35 mm and the second inner diameter is 7.00 mm, alternatively wherein the first inner diameter is 6.45 mm and the second inner diameter is 6.65 mm, alternatively wherein the first inner diameter is 6.45 mm and the second inner diameter is 7.00 mm, wherein the first inner diameter is 6.45 mm and the second inner diameter is between 6.50 and 6.55 mm.

9. The syringe barrel of any one of claims 1-8, wherein the first inner diameter is between 0.05 and 1.00 mm less than the second inner diameter, optionally wherein the first inner diameter is between 0.15 and 0.75 mm less than the second inner diameter, optionally wherein the first inner diameter is between 0.25 and 0.60 mm less than the second inner diameter.

10. The syringe barrel of any previous claim, wherein the syringe barrel is formed of glass.

11. The syringe barrel of any one of claims 1-9 wherein the syringe barrel is formed of a polymeric material.

12. The syringe barrel of claim 11, wherein the polymeric material is a cyclic olefin polymer or a cyclic olefin copolymer.

13. A syringe assembly comprising:

the syringe barrel of any previous claim;

a needle attached to the front end of the tubular wall; and

a plunger received within the opening of the tail end.

14. The syringe assembly of claim 13, wherein the plunger comprises a plunger rod slidably disposed within the interior and a plunger head formed of an elastomeric material located at an end of the plunger rod disposed within the interior of the barrel, wherein the plunger head slidably contacts the inner surface of the tubular wall, the plunger head comprising a plurality of radially outwardly protruding ribs, each rib having an edge that contacts the inner surface of the tubular wall, the ribs being compressed within the tubular wall to create a seal between the plunger head and the tubular wall, wherein the plunger slides between a retracted position, in which the plunger head is located within the first zone, and an advanced position, in which the plunger head is located within the second zone.

15. The syringe assembly of claim 14, further comprising a lubricity coating applied to a portion of the inner surface of the tubular wall, wherein the plunger head distributes the lubricity coating on the inner surface during sliding, wherein the lubricity coating is applied to the inner surface in the first zone when the assembly is in the retracted position, and the plunger head distributes the lubricity coating on the inner surface of the second zone during sliding from the retracted position to the advanced position.

16. The syringe assembly of any one of claims 13-15, wherein the plunger undergoes compression within the barrel, and the difference in compression between the first zone and the second zone is at least 0.5%, optionally at least 1.0%, optionally at least 1.5%, optionally at least 2.0%, optionally at least 2.5%, optionally at least 3.0%, optionally at least 3.5%, optionally at least 4.0%, optionally at least 4.5%, optionally at least 5.0%, optionally at least 5.5%, optionally at least 6.0%, optionally at least 6.5%, optionally at least 7.0%, optionally at least 7.5%, optionally at least

8.0%, optionally at least 8.5%, optionally at least 9.0%, optionally at least 9.5%, optionally at least 10.0%, optionally at least 10.5%, optionally at least 11.0%, optionally at least 11.5%, optionally at least 12.0%, optionally at least 12.5%, optionally at least 13.0%, optionally at least 13.5%, optionally at least 14.0%, optionally at least 14.5%, optionally at least 15.0%.

17. A method of molding a syringe barrel according to any one of claims 1-16, comprising:

providing a molding assembly including a molding cavity and a core, wherein the core fits within the molding cavity to define a molding space shaped to form the syringe barrel, the core comprising a first core zone having a first outer diameter substantially equal to the first inner diameter of the tubular wall, and a second core zone having a second outer diameter substantially equal to the second inner diameter of the tubular wall;

injecting a molten molding material within the molding cavity;

cooling the molding material to solidify;

collapsing the core; and

removing the core from the molding space.

18. A method of molding a syringe barrel according to any one of claims 1-16, comprising:

injecting a molten molding material within the molding cavity;

cooling the molding material to solidify and form the syringe barrel; removing the syringe barrel from the molding cavity; and

removing the core from the interior of the syringe barrel by drawing outward through the opening of the tail end.

19. The method of claim 18, wherein drawing the core outward through the opening of the tail end causes the tubular wall to deform in a radially outward direction, such that the first inner diameter increases until greater than the outer diameter of the second core zone, permitting the second core zone to clear the first zone of the barrel to be removed therefrom.