A syringe containing a high water content product and for use in a drug infusion system is provided. The syringe includes a plunger carrying front and rear o-rings made of a diene rubber compound such as chlorobutyl rubber or bromobutyl rubber to impart very low gas permeability characteristics to t
A syringe containing a high water content product and for use in a drug infusion system is provided. The syringe includes a plunger carrying front and rear o-rings made of a diene rubber compound such as chlorobutyl rubber or bromobutyl rubber to impart very low gas permeability characteristics to the o-rings. The plunger may be molded as a single part or in two parts. If molded as one part with radially-engaging mold portions, the seal glands in the plunger may include parting lines from the mold. If molded as two parts with axially-engaging mold portions, the front seal gland may include a sealing surface and under cut that has no parting line. The o-rings may be surface treated with a lubricant to improve sealing where the molding process gives rise to parting lines in the seal glands.
대표청구항▼
1. A syringe for use in a drug infusion system, the syringe comprising: a barrel having a tapered front end, a rear end, and a cylindrical wall defining an outer surface and an inner surface, the rear end of the barrel being open, and the front end of the barrel including an orifice;a plunger within
1. A syringe for use in a drug infusion system, the syringe comprising: a barrel having a tapered front end, a rear end, and a cylindrical wall defining an outer surface and an inner surface, the rear end of the barrel being open, and the front end of the barrel including an orifice;a plunger within the barrel, the plunger including a continuous contact surface at a front end of the plunger, a rear end of the plunger having an outer cylindrical surface including a tapered outer surface at the rear end of the plunger, a blind bore having an inner cylindrical wall portion defining a continuous even cylindrical surface extending from an entrance of the blind bore to a plunger seat, and a front seal gland extending circumferentially around the plunger between the front end of the plunger and the rear end of the plunger, a rear seal gland extending circumferentially around the plunger between the front seal gland and the rear end of the plunger, the tapered outer surface increasing in diameter from a surface of the rear seal gland to the rear end of the plunger;a front o-ring positioned in the front seal gland, and creating a gas-tight seal between the inner surface of the barrel and the plunger; andwherein the front o-ring is sized to maintain the gas tight seal through a temperature change within a temperature range of −25° C. to 40° C. 2. The syringe of claim 1 wherein the front o-ring is surface treated with a lubricant to ensure a gas-tight seal between the front o-ring and the front seal gland. 3. The syringe of claim 1, further comprising: a rear o-ring made of a rubber compound;wherein the rear o-ring is positioned in the rear seal gland; andwherein the rear o-ring creates a gas-tight seal between the inner surface of the barrel and the plunger. 4. The syringe of claim 1, wherein the front end of the plunger defines a head that includes the contact surface; wherein an outer diameter of the head is slightly smaller than an inner diameter of the barrel such that the head fits within the barrel with close tolerances;wherein the rear end of the plunger includes an integrally-formed molded ring having a maximum outer diameter that is slightly less than the inner diameter of the barrel such that the integrally-formed molded ring fits within the barrel; andwherein the head and the integrally-formed molded ring resist tipping of the plunger. 5. The syringe of claim 1, wherein the front o-ring is sized to maintain the gas tight seal through a temperature range of −20° C. to 40° C. 6. The syringe of claim 1, wherein the plunger is molded in a molding process as a single piece; wherein the front seal gland includes a parting line arising from the molding process; wherein a seal between the front o-ring and the front seal gland includes a leak path arising from the parting line; and wherein the front o-ring is surface treated with a lubricant to gas-tightly seal the leak path. 7. The syringe of claim 1, wherein the plunger is molded as a front portion and a rear portion; wherein the front portion is molded with axially-engaging mold portions to form a portion of the front seal gland with no parting lines; and wherein the rear portion is molded with radially-engaging mold portions to form a portion of the front seal gland with parting lines; and wherein the front o-ring is received within the front seal gland with no leak paths between the o-ring and the portion of the front seal gland having no parting lines. 8. The syringe of claim 1, wherein the front seal gland includes a rear-facing undercut surface in front of the o-ring; wherein a pocket is defined between the o-ring and the rear-facing undercut surface of the front seal gland; and wherein the plunger includes a venting slot in the rear-facing undercut surface, the venting slot communicating between the pocket and a product chamber such that air in the pocket is evacuated through the venting slot when a vacuum is applied to the product chamber, wherein the product chamber has a volume defined by the inner surface of the barrel, the front o-ring, and the contact surface. 9. The syringe of claim 8, wherein the pocket is an annular pocket extending around an entire circumference of the front seal gland; wherein the venting slot includes two diametrically opposed venting slots communicating with the annular pocket. 10. The syringe of claim 1, wherein the front o-ring is sized to maintain the gas-tight seal as a product inside a product chamber undergoes a phase change, wherein the product chamber having a volume defined between the inner surface of the barrel, the front o-ring, and the contact surface. 11. The syringe of claim 10, wherein the front o-ring is sized to maintain the gas-tight seal as a product inside the chamber changes volume as it undergoes the phase change. 12. The syringe of claim 1, wherein the contact surface of the plunger is configured to contact the orifice. 13. The syringe of claim 12, wherein an inner diameter of the barrel changes as a result of thermal contraction or thermal expansion. 14. The syringe of claim 1, wherein the plunger seat comprises a step shaped seat. 15. The syringe of claim 1, wherein the inner cylindrical wall portion allows removal of a pushrod upon completion of injection. 16. The syringe of claim 1, wherein the plunger is configured to move rearwardly in response to application of a force to the continuous contact surface while maintaining the gas-tight seal.
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이 특허에 인용된 특허 (19)
Haller Irene (7981 Stonehurst Ct. Pleasanton CA 94566), Disposable syringe with retractable cannula.
Bassarab, Stefan; Bauer, Alexander; Denkinger, Nicole; Garidel, Patrick; Hemminger, Markus; Kern, Hans-Joachim; Langer, Andreas; Presser, Ingo, Dual chamber container for lyophilization, process for the filling up and use thereof.
LeVeen Harry H. (800 Poly Pl. Brooklyn NY 11220) LeVeen Robert F. (122 S. 51st St. Omaha NE 68132), Molded hypodermic plunger with integral shaft and elastomeric head.
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