Patent Application
20090105684
The present disclosure generally relates to a medication port, an apparatus and a method for using a medication port for injecting or withdrawing a liquid from a container. More specifically, the present disclosure relates to improved materials and material designs for the medication port. Additionally, the present disclosure provides an apparatus and a method that may be used for the parenteral administration of a medical solution while providing for injection of an additional component, for example a drug, into the solution.
It is generally known that an individual may require a form of medication. Often, the medication must be administered to the patient parenterally, for example intravenously. For example, it may be impractical or impossible to administer medication orally to the patient, for example when the patient is unconscious or when a large volume of medication is to be delivered. Further, the patient may require prolonged, constant and/or immediate medication that may only be administered parenterally. Of course, numerous other reasons exist for parenterally medicating a patient.
Medical infusion solutions are typically stored in containers constructed from, for example, flexible plastic or glass. An administration port on the container is adapted to connect to an administration set (i.e., IV tubing) that is connected to a patient's vein. The mixed solution then flows from the administration port, through the IV, and into the patient's bloodstream. Other parenteral administration routes may also be used to deliver medication or other therapeutic fluid treatment to a patient. For example, medications and hydration fluids may be administered subcutaneously. As a further example, patients suffering from end stage renal disease may receive a fluid based therapy such as peritoneal dialysis.
Further, it is generally known to provide a medication port on the medical solution container through which drugs and/or other solutions may be administered. The medication port typically includes a resilient septum or membrane that may be pierced by a needle or cannula to provide sterile transfer of fluid into or out of the container. For example, hospital patients are often given an IV solution such as dextrose or saline to ensure that an administration route is already available if medication is required. Such medications are frequently delivered by injecting them into an access port on the IV solution container. As a further example, a diabetic patient receiving an infusion of a glucose-based peritoneal dialysis solution may need to add insulin to the solution to avoid a dangerous increase in blood sugar. Additionally, dialysis patients occasionally need to add other medications such as heparin or antibiotics to their dialysis solution to address acute conditions that have developed during their therapy.
Known medication ports are often constructed as one-way valves which allow the addition of a medication to a container. However, known medication ports may be difficult to maintain in a sterile condition once used. Bacteria, viruses, dirt, and other potentially harmful substances may be present on the surface of the septum, membrane or container. As a result, such substances may be inadvertently introduced into the solution.
Typically, a medication port is constructed or attached to a container either as an up-port or as a side-port. The up-port is generally located at a distal end of the container while the side port is located on a sidewall of the container. It is also generally known to provide a septum, also referred to as a bung, within an opening or port of the container. The septum, which is typically constructed of a resilient material such as an elastomer, prevents liquid inside the container from leaving the container. Additionally, the septum reduces the risk of foreign substances from entering the container. Further, known septa often may be pierced by a needle, cannula, tube or other object to establish fluid communication with the liquid in the container. Insertion of the fluid conduit may be facilitated by providing a pre-cut slit in the septum, which may extend all or part of the way through the thickness of the septum. Preferably the septum can be repeatedly pierced without compromising the integrity or sterility of the container.
A cap is often incorporated with the medication port to enclose and protect the septum. However, caps often completely surround the entire opening to the container. As a result, known caps are often bulky, expensive and inefficient. For instance, larger caps require more material to produce and add weight and/or complexity to the entire apparatus. In addition, personnel handling a cap may contaminate the cap while removing it. A need therefore exists for a medication port as well as an apparatus and a method for injecting or withdrawing a liquid from a container to overcome deficiencies of known ports and apparatus and methods using such a port. Additionally, a need exists for a medication port that allows a liquid to be introduced to a container in a sterile environment.
U.S. Pat. No. 6,994,699, assigned to the assignees of the present application, discloses a medication port assembly that includes a housing with a removable cover, a septum mounted within the housing, and a locking ring holding the septum in place. It is desirable to provide a medication port that performs comparably to this medication port while simplifying assembly. The present disclosure provides medication ports satisfying this need.
A first embodiment disclosed herein is a medication port for a medical container. The port includes a housing having a peripheral wall defining an interior, said housing made from a medical grade plastic or elastomeric material, the housing further including a surface for sealing against the container, and a septum made from a medical grade plastic or elastomeric material, the septum integrally attached to the housing, wherein the port is suitable for sterilizing by known wet and/or dry sterilization methods.
Another embodiment includes a medication port for a medical container. The port includes a housing made from a medical grade plastic or elastomeric material, the housing further including a surface for sealing against the container, and a septum made from the same material and integrally attached to the housing.
Another embodiment is a medical fluid container assembly. The medical fluid container includes a flexible film sheet having at least an inner film layer and an outer film layer, the film sheet formed into a medical fluid container sealed or folded closed on four edges. The medical fluid container assembly also includes an administration port attached near one end of the medical fluid container, and a medication port attached to one side of the medical fluid container, the medication port including a housing made from a medical grade plastic or elastomeric material, the housing further including a surface for sealing against the medical fluid container and a septum made from a medical grade plastic or elastomeric material, the septum integrally attached to the housing, wherein the medication port is suitable for sterilization by one or more known sterilization methods, by at least steam and gamma-irradtion methods.
Another embodiment includes a method of making a medication port for a medical container. The method includes steps of forming a housing from a medical grade plastic or elastomeric material, forming a septum from a medical grade plastic or elastomeric material, and integrally joining the housing and septum wherein at least the housing and the septum are suitable for sterilizing by at least one of steam and gamma-irradiation methods.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
The present invention generally relates to a port, a container and a method for accessing a container for injecting or withdrawing a liquid from the container. Additionally, the present invention relates to a container having a port. More specifically, the present invention relates to a port, a container and a method for accessing a container to introduce a drug into the port. Referring now to the drawings,
Container 10 has a medication port 12 having an inner portion 13 adjacent the container at interface 17 and an outer portion 14, the outer portion being the portion of the port that is most distal from the inner portion 13. Medication port 12 of the present invention may be a side port as shown or could also be an up-port, located at a distal end of container 10. Container 10 is illustrated in a position as is common in actual use, positioned up-right with medication port 12 elevated above an administration port 15 in actual use. Additionally, container 10 may also include a hanger 16 for use with a hook to hang the container in an elevated position at or near a patient. When the container 10 is positioned at or near the patient, gravity may force the liquid 11 inside the container through the administration port 15 to the patient. Preferably, the administration port 15 may be located remotely from the medication port 12 as illustrated in the embodiment shown in
The medication port is affixed to the container as shown in
A first embodiment of a port is depicted in
In the embodiment of
In some embodiments, two materials may be used, one for the septum and one for the housing. In other embodiments, a single material may be used for both the housing and the septum. In embodiments using two materials, the housing is preferably made from a medical grade plastic that is suitable for sterilization, such as polypropylene. The polypropylene may also be blended with polymers such as ultra low density polyethylene, linear low density polyethylene, or thermoplastic elastomers such as SEBS (styrene-ethylene/butene-styrene block copolymer) or SEPS (styrene-ethylene/propylene-styrene block copolymer). Suitable thermoplastic elastomers include the Kraton® G series from Kraton Polymers and the Cawiton Med series available from Wittenburg B.V. Other plastic and elastomeric materials suitable for the housing include polypropylene modified with EVA (such as Escorene®); EPDM (such as Santoprene™ TPV); or silicone rubber (such as TPSiV™). Usually, about 15-30% modifier is sufficient. Many other medically acceptable materials may also be used. In an embodiment, the housing is made of a blend of approximately 55-60% polypropylene impact copolymer, 10-20% EVA and 15-25% SEBS; for example, the housing may have the following composition (identified in the data below as PL18016):
The inclusion of a colorant in the housing composition creates a strong visual contrast between the housing and the septum, which helps certain visually impaired patients to locate and use the medication port.
The septum is typically made from a softer, elastomeric material. Examples of materials suitable for the septum include thermoplastic elastomers such as SEBS (styrene-ethylene/butene-styrene) or SEPS (styrene-ethylene/propylene-styrene), examples of which include the Kratone® G series. Other suitable elastomeric materials include polypropylene/EPDM blends, such as Santoprene™ TPV; silicone rubber, such as TPSiV™; and alpha-olefin elastomers, such as VISTAMAXX™. VISTAMAXX™ is ExxonMobil's trademark for a family of polyethylene and polypropylene elastomers with a degree of crystallinity. Any of these polymers may be used alone or may be blended with polyisoprene (PI), styrene-isoprene-styrene block copolymer (SIS), or other polymers. Typically, the PI or SIS materials are about 0-30% of the total polymer. This softness or flexibility helps the septum to reseal after it is punctured by a needle to inject the medication into the container. In an embodiment, the septum is a food/medical grade thermoplastic elastomer such as THERMOLAST® K TF3STE available from Kraiburg TPE, or MARFRAN® M1/55, a SEBS thermoplastic elastomer available from VTC Franceschetti Elastomeri, Corte Franca, Italy.
Where the septum and housing are made of different materials, it is desirable that both parts contain at least one common or similar material to facilitate adhesion of the septum to the housing. For example, both components may contain a material that begins to melt close to the injection molding temperature or the sterilization temperature. This allows an adhesive bond to form between the components. In an embodiment, both the housing and the septum contain a styrene-hydrocarbon block thermoplastic elastomer. Other bonding methods may also be used, such as by ultrasonic welding, i.e., holding the two parts adjacent each other and vibrating them very rapidly with a horn that transmits the ultrasonic energy. The two parts may also be joined integrally by plastic welding, that is, a process in which a narrow bead of material of one of the parts, or a bead of a third material, is melted to form a “weld” between the parts. The term integral is thus used in the sense that the septum and the housing may only be separated from each other by destroying the assembled port.
Experimental results for a number of medication ports are tabulated in Table 1 below.
Another embodiment of a port is depicted in
In another embodiment, depicted in
The housing and septum embodiments of
The materials preferred for the single-material embodiments include thermoplastic elastomers based on styrene block copolymers with polybutadiene, polyisoprene, and poly-isoprene/butadiene. Examples include THERMOLAST® K TF3STE and TF4STA thermoplastic elastomers available from Kraiburg TPE. The inventors have found that single-material medication ports work well when the material has a Shore A hardness from about 35 to 65, preferably about 35 to 50, and most preferably about 45 Shore A. Materials with this hardness, or rather softness, are easily flexed and have no trouble admitting a needle to deliver a medication. These materials typically also have sufficient strength to resist normal handling and use. Typical tensile strengths range from about 1.6 ksi (6.5 N/mm2) to about 2.7 ksi (11.0 N/mm2), preferably about 1.6 ksi (6.5 N/mm2) to about 2.45 ksi (10 N/mm2), and most preferably about 2.2 ksi (9.0 N/mm2). Other materials may be used and elastomers or plastics with other strengths may also be used.
Following the assembly of the port onto the container as described above, the container may be filled with a medical solution and terminally sterilized by methods known in the art, such as dry or moist heat sterilization.
Thus, the medication port provides a convenient means for delivering an additional medication, such as heparin, insulin, an anesthetic, an antibiotic, and so forth into the medical solution without compromising the sterility of the solution in the container. The port also allows medical personnel to withdraw a sample of the liquid in the container, before or after a medication is added to the container.
A flowchart for a method of manufacturing a medication port according to the above teachings is presented in
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
