Patent Description:
Syringes and other medical containers have been in use for many years. However, such containers were typically made of glass. Gradually with the discovery of plastic materials, some containers, including syringes, began to be offered in plastic. In recent history, a number of plastic syringe manufacturers, medical device manufacturers and/or drug companies began offering prefilled plastic containers, including vials and syringes, with fluid material, such as saline, heparinized saline or lidocaine. However, as discovered by such manufacturers these materials are sensitive to certain sterilization techniques. For example, IV flush solutions, drugs, vaccines or other fluid materials that contain saline solution may experience a change in their respective composition or properties, such as an undesirable pH shift of the saline solution, when saline contents in the plastic container is exposed to ethylene oxide ("EtO") gas sterilization. Further, the potency of heparinized saline and/or lidocaine may be adversely affected, and EtO gas residual, and/or residual toxic byproducts may be created when the solution is exposed to certain sterilization techniques after filling is accomplished.

Thus, pre-filled syringes and other containers manufactured from plastic materials, such as polypropylene have been found to lead to various complications. For example, the United States Pharmacopeia ("USP") guidelines require that normal saline solution (i.e., <NUM>% NaCl) in prefilled syringes may only possess a pH between <NUM> and <NUM> to be suitable for human use. It has been determined that one complication that frequently occurs with known prefilled containers is an undesired shift in pH following ethylene oxide gas (EtO) sterilization. PH has been identified as an indicator of EO ingress, such that if the pH of the fluid within the syringe had shifted (usually +, or higher) outside of accepted USP standards limits, one or more of the other parameters indicative of suitable for human use (as discussed in further detail below), were also exceeded.

Commercially available prior art prefilled saline and heparinized saline syringes and a vial for IV flushes were obtained for a testing regimen performed and designed for assess state of the art for prefilled plastic containers, such as syringes and vials. Tests were performed on control samples that had not be subjected to EtO sterilization, as well as on <NUM> groups of EtO sterilized samples. Upon completion of the EtO sterilization process, the pH level of all of the samples were tested. The tests revealed that the commercially available samples demonstrated an undesirable pH shift, such that the pH of the saline exceeds the range permitted by the USP after being subjected to EtO sterilization. Each of the test groups subjected <NUM> samples from different prior art manufacturers. The average amount of pH shift from the control samples indicated unacceptable pH shifts, which resulted in the pH of the saline falling outside of the mandated pH range of <NUM> to <NUM>:.

This undesirable shift is determinative of EO ingress into the syringe/container, during the EtO sterilization process.

However, it is desirable to package prefilled syringes or other containers containing sterilization-sensitive fluid material with other medical procedural tools and/or equipment requiring sterilization in a medical procedural tray, kit, pouch or other packaging. For example, collectively packaged convenience kits such as surgical or procedural kits may include prefilled syringes, as well as surgical instruments, gloves, dressings, aseptic wipes, etc. - all requiring EtO sterilization, which are necessary to perform a given medical procedure. In such instances where prefilled syringes that include sterilization-sensitive fluid material are incorporated in such convenience kits, one known way to avoid the problems created by the use of plastic pre-filled syringes or other prefilled containers is to utilize glass containers and glass syringes due to the barrier properties of glass, as glass effectively prevents the above identified undesirable effects of EtO ingress to the fluid material.

However, while glass containers have proven to be a suitable barrier for enabling EtO sterilization, glass containers have certain limitations that leave this choice of material undesirable. As one example, glass containers are fragile. As a result, there is a danger of the sterilization-sensitive material attacking the surface of the glass material, or that the glass may sliver and contaminate the material therein. As another example, microcracks in the glass may permit penetration of EO and/or the glass container may explode during deep sterilization cycle vacuums. Other issues caused by the fragility of the glass include breakage of the syringe if the syringe is dropped. While broken glass may be cleaned up, if the syringe is dropped during a procedure in the operating room, such cleanup might require shutting the operating room down (at significant financial cost to the facility) to recreate a sterile field, as well as delaying patient care. Further, glass is much more costly to manufacture as compared to plastic, and has inherent limitations relating to geometry, size and intricacy of the container. Transporting glass, including with sterilization sensitive material therein and transporting used glass syringes after use, is much more expensive than plastic due to the weight of the material, in addition to the extra care that must be taken to avoid breakage. Finally, glass syringes have additional issues, in that an integrated medical industry standard luer tip cannot be created for a glass syringe. Instead, an adapter must also be provided to incorporate a luer fitting, thereby increasing costs.

One method of addressing the known EtO sterilization limits inherent to plastic containers is to sterilize an empty plastic syringe or other empty plastic container and then fill the plastic container with sterile fluid (introducing the sterile fluid in a clean room or aseptic environment). The filled syringe is then packaged in a non-sterile pouch. This method provides a "sterile fluid pathway" but the syringe exterior itself is not sterile. More specifically, the outside of the syringe/container is not sterile. As a result, the syringe/container must be separately packaged from the rest of the procedure kit, thereby creating two different SKU numbers, which may complicate inventory tracking and create end clinical user inconvenience and inefficiency. In one example, the non-sterile, prefilled container is attached to the exterior of a sterile kit post-sterilization of the kit, sometimes referred to as a "sidecar" package, thereby creating a secondary non-sterile kit comprised of a non-sterile prefilled container and a sterile kit. While this combination kit may reduce inventory tracking, the added step of separately packaging plastic containers and attaching them to sterilized kits makes manufacturing and assembly more time consuming and expensive. In addition, there is a danger that the sidecar package may become detached and lost in the medical facility, which then may result in unnecessary waste, as well as delaying the procedure while new material is located.

In addition, for a fully wrapped "liftout" surgical kit of components inside of a sterile tray, the syringe/container components are not inside the wrapped assemblies. Instead, these syringe/container components must be separately unpackaged and loaded onto the surgical wrap/drape, after the wrap/drape is opened within the sterile field.

Another known method to address known EtO sterilization limits inherent to plastic containers is to fill an empty plastic syringe/container with fluid material, which may be introduced as sterile fluid in a clean room or aseptic environment, as discussed above. The filled plastic syringe/container may then be autoclaved, which will ensure that a sterile fluid and fluid pathway results. However, the outside of the syringe/container still remains non-sterile and may be packaged as described above.

Moreover, maintaining sterile technique during a clinical procedure becomes more challenging when a separately packaged, non-sterile component must be handled. This may affect the sequence of actions required to complete a given procedure; or, in some cases, the number of physicians needed to complete a procedure. For example, during a procedure, a nurse must open the non-sterile package outside of the sterile field and once the doctor touches the syringe and/or container, the procedure must be adjusted to maintain the sterile technique.

As another solution, a filled "sterile fluid path" syringe/container may be steam sterilized. Upon steam sterilization, the syringe/container is then placed in an EtO gas impermeable foil package, which is then introduced into a procedural kit, with the kit and foil package being EtO sterilized together. The foil package prevents the EtO gas inside the procedural kit from getting through the foil package, and thus prevents EtO gas from interacting with the fluid material within the syringe/container. However, this process is also time consuming and expensive, as it requires two separate sterilization processes. Moreover, in use, it then requires a clinician to open multiple packages during a procedure and move it to the appropriate location in the sterile field, as well as requiring proper disposal of the packaging components without compromising the integrity of the sterile field.

In another solution, the prefilled syringes/containers containing sterile solution (though the exterior of the syringe was not sterile), is packaged in a sleeve that may be attached to lidding or a pouch of the kit. Once packaged, the sleeve may be autoclaved so that the packaged syringe/container is sterile field ready. However, this arrangement then requires an extra person to open the packaging to drop the syringe/container within the sterile field. This arrangement does not permit having the syringe/container in an EtO sterilizable procedure kit.

It is desired to address one or more such limitations experienced with known glass containers, plastic containers, packaged kits, and/or methods disclosed herein. The document <CIT> describes a housing assembly provided to define a locally controlled environment to maintain a localized clean work area without the need to maintain cleanliness levels in an entire room as in conventional clean rooms. Filled in advance medical containers, such as syringe barrels and syringe tip closures, are introduced into the housing assembly where the syringe barrels and tip closures are cleaned with filtered ionized air and the tip closures are coupled to the barrels. The syringe barrels either filled or packaged in the array can be sterilized. The document <CIT> describes a prefilled syringe assembly produced from materials that do not interfere with the substance contained in the syringe and enable long term storage. A tip cap is made from a blend of a cyclic olefin polymer or copolymer and a thermoplastic elastomer. The thermoplastic elastomer is blended with the cyclic olefin copolymer. The document <CIT> describes a pre-filled syringe. The syringe comprises a glass body, a stopper and a plunger. The syringe is filled with a dosage volume of about <NUM>-<NUM> and a syringe barrel comprises less than about 500µg silicon oil. The document <CIT> describes a pre-filled syringe-needle assembly. Said shield-closure unit comprises a tube which covers the needle and a plug.

<CIT> discloses the sterilization of pre-filled non-glass syringe assembly using ethylene oxide and comprising filling and assembling a syringe, performing a conditioning stage and an ethylene oxide sterilization stage.

Referring now to the drawings, illustrative examples are shown in detail. Although the drawings represent certain examples, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain an innovative aspect of an example. Further, the examples described herein are not intended to be exhaustive or otherwise limiting to the precise form and configuration shown in the drawings and disclosed herein.

The present invention relates to a method of employing ethylene oxide (EtO) to sterilize a prefilled syringe as decribed in the appended claims. In one exemplary arrangement, a prefilled container system may be embodied as a syringe assembly having a barrel, plunger and tip cap. A chamber may be formed within the barrel between the plunger and tip cap and may be configured to hold sterilization sensitive materials such as saline or heparinized saline. The syringe assembly may be formed of various materials and/or solutions that permit the syringe assembly to be packaged with a surgical kit containing other items necessary to perform a medical procedure and sterilized together. For example, as determined by medical professionals such as nurses, surgeons and other operating room staff, such kits may be tailored to particular procedures and may include items such as instruments, drugs, antiseptics, dressings that are appropriate and needed for the particular procedure. For convenience, as well as to reduce inventory burden (such as tracking) it is preferred that individual items not be separately packaged. In another exemplary arrangement, a container having a chamber therein may be formed of various materials and/or solutions that permit the container to be packaged with a surgical kit containing other items necessary to perform a medical procedure and sterilized together.

As another key advantage, providing a sterile convenience kit permits operating room staff to maintain established sterile techniques in performing surgical operations, such that there is no need to separately remove the syringe from separate packaging and locate the syringe/container in the sterile field.

For health and sanitary purposes, it may be desired and necessary that all items within the kit be sterilized and ready for use by the medical professionals. During manufacturing, the items within the kit may be sterilized to eliminate live bacteria or other microorganisms present on the inside or outside of the kit, and inside and outside of any component item within the sterile kit. Known sterilization methods may include EtO sterilization, autoclaving, or other methods such as irradiation. In one embodiment, terminal sterilization is used as the sole sterilization step in the assembling and manufacturing of the packaged kits. However, as explained above, the EtO gases used during terminal sterilization may alter the composition of sterilization sensitive material within a syringe and/or container.

Accordingly, in one exemplary arrangement, a syringe assembly <NUM>, as shown in <FIG>, may include a barrel <NUM>, a plunger <NUM> and a tip cap <NUM> (shown in <FIG>). The interior of the barrel <NUM> may cooperate with a distal end <NUM> of the plunger <NUM> and the tip cap <NUM>, when assembled to the barrel <NUM>, to define a chamber <NUM> (best seen in <FIG>). Any saline solutions (i.e., material) may be included in the chamber <NUM>. Examples of preferred solutions include, but are not limited to, sodium chloride (such as <NUM>% NaCl saline), heparinized saline (various amounts of heparin content), lidocaine. The solution may also include active ingredients such as vaccines, drugs, probiotics, diagnostic compositions, etc. Typically, the chamber contents are a liquid solution that is sterile; either by an aseptic filling process or post filling terminal sterilization that provides a sterile fluid path. These solutions, when included in a procedural kit, may be adversely affected by the terminal kit sterilization process, such as EtO sterilization as explained above. However, the kit sterilization is necessary to ensure all the contents of the finished procedural kit are sterile.

The contents of plastic containers, as described above, may be compromised during the kit sterilization process and, therefore, the solution contained therein may be affected and considered "sterilization sensitive. " For example, EtO sterilization may include subjecting the filled syringe assembly <NUM> to EtO gas. The use of EtO gas is effective and an accepted procedure to kill any micro-organisms and ensure that the assembly <NUM> is sterilized prior to use. However, as recognized by Federal Drug Administration (FDA), the EtO gases may alter the composition of the sterilization sensitive solution. Thus, as set out in the notice of rulemaking published by the FDA in the Federal Drug Administration, <NUM> Fed. <NUM> at <NUM>-<NUM> (proposed June <NUM>, <NUM>) (to be codified at <NUM> C. § <NUM> and § <NUM>) ("Ethylene Oxide, Ethylene Chlorohydrin, and Ethylene Glycol - Proposed Maximum Residue Limits and Maximum Levels of Exposure") the amount of residual Ethylene Oxide (EO) gas, Ethylene Chlorohydrin (ECH) and Ethylene Glycol (EG) toxic by-products present in an injectable drug must be tightly controlled. For injectable drugs, the FDA guidance document suggests that the residual EO and ECH shall not exceed <NUM> ppm and the residual EG shall not exceed <NUM> ppm. In addition, the FDA guidelines also set maximum daily exposure level requirements. More specifically, for EO, the maximum daily exposure level is <NUM>µg/kg/day up to <NUM> days. For ECH, the maximum daily exposure level is <NUM>µg/kg/day up to <NUM> days. And for EG, the maximum daily exposure level is <NUM>/kg/day up to <NUM> days. While the above proposed limits for residual EO, ECH and EG were never published as a final rule, these limits have been used and accepted by both industry and government as a de facto regulation for more almost <NUM> years.

With specific reference to sodium chloride injections, the U. Pharmacopeia (USP) - National Formulary has provided a test standard for an acceptable pH in such solutions. More specifically, the pH should be in the range of <NUM>-<NUM> (test no. The inventors of the present application have determined that a pH shift outside of this range is an indicator for undesirable EO ingress in a chamber <NUM> of a syringe or in a container holding sterilization sensitive material. For example, as set forth in the background, testing of samples prior to undergoing a EtO sterilization process, yielded a baseline pH, well within the USP range of <NUM>-<NUM>. However, once those prior art samples were subjected to prior art EtO sterilization techniques, the pH shifted outside the UPS range, thereby revealing that the solution within the containers had been altered.

The USP also sets forth an acceptable pH range for other injectable solutions that are contemplated by this disclosure, such as lidocaine hydrochloride and epinephrine injections (pH in the range of <NUM>-<NUM>), lidocaine hydrochloride injections (pH in the range of <NUM>-<NUM>), and heparin lock flush solutions (pH in the range of <NUM>-<NUM>).

While the above USP standard is directed to the material within the chamber <NUM>, the syringe assembly <NUM> itself also is subject to maximum residue limits. More specifically, the syringe is classified as a medical device and is subject to ANSI/AAMI/ISO <NUM>-<NUM>:<NUM> "Biological Evaluation of Medical Devices- Part <NUM>: ETO Sterilization Residuals. For those medical devices subject to EtO Sterilization techniques, the residual EO gas in the device must be less than or equal to <NUM> per device, while the residual ECH toxic by product must be less than or equal to <NUM>/device. Currently there is no standard for residual EG toxic byproduct.

To provide a syringe assembly <NUM> that conforms to the above FDA requirements, as well as the relevant ISO standards, as explained in further detail below, the syringe assembly <NUM> provides that the chamber <NUM> is capable of creating an effective barrier between sterilization gases and the solution so that the solution remains substantially unchanged within the chamber <NUM> during and after sterilization. The pH of the solution stays with the range of about <NUM>-<NUM>. The inventors have discovered these unexpected results after numerous experiments with different plastic material for assembly <NUM>, in combination with variations of sterilization cycle parameters, which will be discussed below in further detail. As another example, if the solution remains substantially unchanged after exposure to sterilization, then the device and solution still meets the regulatory requirements for the manufacture, sale, and use of that drug, i.e., is also has residual EO gas and ECH toxic byproduct that does not exceed <NUM> ppm and the residual EG toxic byproduct that does not exceed <NUM> ppm.

In an exemplary configuration of the syringe assembly <NUM>, the plunger <NUM>, as shown in <FIG>, may include a plunger body <NUM> extending along an axis A and having a base <NUM> at one end and a stopper mount <NUM> disposed at the opposite end of the plunger body <NUM>. The stopper mount <NUM> is configured to receive a plunger stopper <NUM>. The plunger body <NUM> may be made of a light-weight material. As explained in further detail below, because the plunger body <NUM> does not come into contact with the solution disposed in barrel <NUM>, there are several options for the material for the plunger body <NUM>. In one exemplary arrangement, the plunger body <NUM> may be fabricated from polypropylene, which is low in cost, as well as being lightweight.

In one exemplary configuration, the stopper mount <NUM> comprises an extension element <NUM> that extends distally from the plunger body <NUM>. Extension element <NUM> has a diameter that is slightly smaller than the diameter of the plunger body <NUM>. A mounting flange <NUM> is secured to the distal end of the extension element <NUM>. This configuration provides a mounting channel <NUM> between the mounting flange <NUM> and the distal end of the plunger body <NUM>. Mounting channel <NUM> is configured to receive an annular retainer <NUM> of the stopper <NUM>, as shown in <FIG>, for example.

As shown best in <FIG>, the stopper <NUM> may include a cylindrical portion <NUM> and an end portion <NUM>, which may have a conical shape. The cylindrical portion <NUM> may also include at least one wiper <NUM> extending radially around the cylindrical portion <NUM>. As discussed above, in one exemplary arrangement, the stopper <NUM> may be connected to the extension element <NUM> of the plunger body <NUM> via a retainer <NUM>. In one exemplary arrangement, the attachment mechanism <NUM>, as shown in <FIG>, includes an annular retainer <NUM> that extends inwardly from an outside surface and is configured to be frictionally engaged within the mounting channel <NUM> of the extension element <NUM>. However, it is understood that other connection arrangements are contemplated. For example, a suitable attachment member may include a male and female connection mechanism, whereby the stopper <NUM> may define an opening (not shown) configured to receive a post (not shown) extending outwardly along the axis A of the plunger body <NUM> so as to frictionally engage the stopper <NUM>. Further, a suitable attachment mechanism <NUM> may also include an adhesive such as glue may be used. Additionally or alternatively other mechanisms may be used such as a screw mechanism, hook and eye mechanism, etc..

The stopper <NUM> may have relatively a stiff elastic modulus and be formed from one or more materials, including high barrier thermoplastic elastomers. Exemplary elastomers may include, but are not limited to, butyl rubber or bromobutyl rubber. The stopper <NUM> may also be coated for increased barrier properties to EO ingress, such as, for example, with silicone lubricant of appropriately selected centistokes viscosity. In addition, a suitable coating may provide smooth operating/slide friction, with no unintended plunger movement during the many environmental pressure changes imparted on the assembly <NUM> during the various EtO sterilization cycle parameters.

The base <NUM> of the plunger <NUM> may be formed so as to be co-extensive with the plunger body <NUM> and thus include similar materials. In one exemplary arrangement, the plunger body <NUM> is configured to angle inwardly from a first diameter D<NUM> to a second D<NUM> to a second diameter at the proximal end <NUM> of the plunger body <NUM>. This configuration serves to limit movement of the plunger body <NUM> within the barrel <NUM>. The base <NUM> is sized to be greater than the first diameter D<NUM> so as to provide a land area for activating movement of the plunger <NUM> within the barrel <NUM> during use. As explained above, during sterilization, the base <NUM>, and at least a portion of the plunger body <NUM> may be exposed to EtO gases. However, the plunger body <NUM> and base <NUM> does not come into contact with the sterilization sensitive material within the chamber <NUM>. Thus, at least one of the base <NUM> and plunger body <NUM> may be formed of less expensive plastics such as polypropylene or polycarbonate.

The barrel <NUM>, as shown in <FIG> and <FIG>, includes a first end <NUM>, a second end <NUM> and a barrel body <NUM> extending therebetween. The barrel body <NUM> may form a cylindrical shape extending along the axis A. The first end <NUM> may be an open end configured to receive the plunger <NUM> so as to provide a fluid tight seal. The second end <NUM> may include a barrel neck <NUM>. In one exemplary arrangement, the neck <NUM> may include a male luer <NUM> defining an opening <NUM>.

The barrel <NUM> may also include a mechanical engagement system, or barrel flange <NUM>, extending radially inwardly of an inner surface of the barrel <NUM> adjacent the first end <NUM>. More specifically, as shown in <FIG>, the inner surface of the barrel <NUM> adjacent the first end <NUM> of the barrel <NUM> may have a cross-sectional thickness that is greater to as to extend toward a central axis extending through the barrel <NUM>. With this arrangement, a barrel flange <NUM> is formed. During EtO sterilization, a positive pressure differential may be created within the barrel <NUM> (relative to the pressure outside the barrel, which may be negative). This differential may apply a force against the plunger <NUM>, attempting to force the plunger <NUM> out of the barrel <NUM>, and leaking fluid from the barrel <NUM>. The barrel flange <NUM> may be configured to engage the outer periphery of a plunger flange <NUM> and/or the wipers <NUM> of the stopper <NUM> to prevent the plunger <NUM> from complete expulsion from the barrel <NUM>. Other exemplary mechanical engagements may include one or more protrusions on an inner surface of the barrel <NUM> that are sufficient to prevent expulsion of the plunger <NUM>. For example, as shown in <FIG>, in one arrangement, the interior surface of barrel <NUM> may further include an inwardly extending annular detent <NUM>'.

The stopper <NUM> has an outer diameter that is slightly larger than the interior diameter of the barrel <NUM>. While stopper <NUM> will compress when introduced into the barrel <NUM>, the barrel flange <NUM> or annular detent <NUM>' will prevent stopper <NUM> from being extracted from the barrel <NUM>, as portion of the annular retainer <NUM> will come into contact with the barrel flange <NUM> and annular detent <NUM>'.

In one exemplary method, an air bubble is intentionally left within the barrel after filling the chamber <NUM> with solution. The air bubble facilitates a large pressure differential and outward force of the plunger <NUM> during sterilization as an EtO sterilization cycle uses a deep draw vacuum. In another exemplary method, the chamber <NUM> is free of air bubbles. As described above, choice of silicone lubricant parameters may also affect plunger motion.

Disposed on the first end exterior of the barrel <NUM> is a gripping flange <NUM>. The gripping flange <NUM> extends radially outwardly around the open first end <NUM> so as to be sized to be greater than a diameter of the barrel <NUM>. In one exemplary arrangement, the gripping flange <NUM> extends all the way around the open first end <NUM>. In another exemplary arrangement, the gripping flange <NUM> is configured with gaps between land areas. Both configurations allow a user to grip the barrel <NUM> while the plunger <NUM> is being moved inwardly within the chamber <NUM>.

The barrel <NUM> may be manufactured with one or more plastic materials. However, in one exemplary arrangement, barrel <NUM> is formed of cyclic olefin polymer (COP) and/or cyclic olefin copolymer (COC) materials. These polymers are similar to glass in that they have high gas impermeability, high moisture barrier and low absorption rate properties. However, unlike glass, COC and COP materials are not fragile and do not have the weight and transport issues associated with glass. The barrel <NUM> may be coated with materials for increased barrier properties, such as silicone dioxide or aluminum dioxide. In another embodiment, the barrel <NUM> may be uncoated. Additionally or alternatively, the barrel <NUM> may be formed from materials having high clarity so that contents of the barrel may be visibly inspected. The barrel <NUM> may also be formed from materials having at least one of low water vapor permeability (in one example, less than about <NUM>/m<NUM>per day per <NUM> micron thickness at atm to minimize moisture transmission across walls of the container), low oxygen permeability (in one example, less than about <NUM><NUM>/m<NUM> per day per <NUM> micron thickness at atm to minimize gas transmission across walls of the container), high heat resistance to withstand temperatures of autoclaving (in one example, the heat resistance is effective to standard autoclaving temperatures), and minimal leaching, elution, extraction, absorption or adsorption.

The barrel <NUM> may be configured to receive the plunger <NUM> at the barrel first end <NUM>. The stopper <NUM> of the plunger <NUM> may be inserted at the first end <NUM>. The stopper <NUM>, along with the tip cap <NUM>, may be configured to create the chamber <NUM> within the barrel <NUM>. As explained above, the stopper <NUM> may have a relatively stiff elastic modulus and the wipers <NUM> may create a mating surface with the inside of the barrel <NUM>. Thus, the stopper <NUM> may permit the plunger <NUM> to move along axis A within the barrel <NUM> and also create a seal within the barrel <NUM> to prevent any material from leaving the chamber <NUM>. Moreover, the mating conical surfaces between the barrel <NUM> and the stopper <NUM> may also serve to prevent blood uptake after the prefilled syringe has been administered to a patient by preventing the plunger assembly <NUM> from recoiling upward after administration.

Referring to <FIG>, in one exemplary arrangement, the tip cap <NUM> may be configured as a female luer <NUM> configured to receive the mating male luer <NUM> extending from the barrel <NUM>. The tip cap <NUM> may be configured to seal the syringe assembly <NUM> to assist in creating the chamber <NUM> within the barrel <NUM>. In one exemplary arrangement, the tip cap <NUM> includes an insert <NUM> that is disposed in a housing member <NUM>. The housing member <NUM> may be constructed of a substantially rigid material, such as polycarbonate or other suitable plastic, as the housing member <NUM> does not contact the material disposed within the chamber <NUM>. The insert <NUM> includes a base member <NUM> and a neck <NUM>. The base member <NUM> is disposed within a cavity <NUM> formed by inner flanges <NUM> that extend inwardly from an inner surface <NUM> of the housing member <NUM>. In one exemplary arrangement, the inner flange <NUM> has an upwardly extending lip <NUM> that extends annularly around the insert <NUM> so as to lock the insert <NUM> into the housing member <NUM>. The inner flanges <NUM> are separated from one another such that a void area <NUM> is created between adjacent flanges <NUM>. While not shown, in one exemplary arrangement inner surface <NUM> may include threads.

The insert <NUM> is manipulated such that the base member <NUM> is disposed within the cavity <NUM> and retained within the housing member <NUM> by the inner flanges <NUM>. With the insert <NUM> mechanically fixed to the housing member <NUM>, the housing is disposed over the barrel neck <NUM>, such that the insert <NUM> is inserted into the barrel neck <NUM> with the male luer <NUM> being received within a channel <NUM> of the insert with an interference fit. A locating member <NUM> is disposed within an opening formed within the male luer <NUM>. The base member <NUM> fits against and seals a top surface of the barrel neck <NUM>. In one exemplary arrangement, the inner surface <NUM> may include threads that cooperate with corresponding threads disposed on an exterior surface of the barrel neck <NUM> to lock the tip cap <NUM> onto the barrel <NUM>.

As explained, the chamber <NUM> may be configured to hold the sterilization-sensitive material. Thus, a portion of the tip cap <NUM> may come in contact with the material during sterilization, shipping and storage of the syringe. In instances where a syringe assembly <NUM> is included in a package such as a surgical kit, a needle for insertion into the barrel neck <NUM> may also be included in the kit.

The tip cap <NUM> may be made of any number of materials. Exemplary materials may include polycarbonates that possess adequate barrier properties. For example, plastics such as polypropylene coated with a high-barrier material (e.g., butyl rubber) on at least a portion of the tip cap <NUM> may be used. The surface area of the tip cap <NUM> exposed to the material in the chamber <NUM> is relatively small compared to that of the barrel <NUM> and stopper <NUM>. Thus, the portion exposed to the material may be coated, while the remaining portions of the tip cap <NUM> may not.

In another exemplary arrangement (not shown), the tip cap may be constructed entirely of butyl rubber and include a neck and a base member. The base member is configured with an outer diameter that is larger than an outer diameter of the neck area. Disposed within the neck area is a channel, similar to channel <NUM>. The channel is also defined by an open end and a closed end. A locating element, similar to locating member <NUM> and may be fixedly disposed on the closed end of the channel.

In operation, the neck area is inserted into the barrel neck with the male luer being received within the channel with an interference fit. The locating member is disposed within an opening formed within the male luer <NUM>. The base member fits against and seals a top surface of the barrel neck <NUM>.

Referring to <FIG> is another exemplary arrangement; the tip cap <NUM>" includes a butyl rubber insert <NUM> that is disposed in a housing member <NUM>. The housing member <NUM> may be constructed of a substantially rigid material, such as polycarbonate or other suitable plastic, as the housing member <NUM> does not contact the material disposed within the chamber <NUM>. The insert <NUM> includes a base member <NUM> and a neck <NUM>. The base member <NUM> is disposed within a cavity <NUM> formed by inner flanges <NUM> that extend inwardly from an inner surface <NUM> of the housing member <NUM>. In one exemplary arrangement, the inner flange <NUM> has an upwardly extending lip <NUM> that extends annularly around the insert <NUM> so as to lock the insert <NUM> into the housing member <NUM>. The inner flanges <NUM> are separated from one another such that a void area <NUM> is created between adjacent flanges <NUM>. While not shown, in one exemplary arrangement inner surface <NUM> may include threads.

<FIG> shows an exemplary vial <NUM> including a stopper <NUM> and a cap <NUM>. The vial <NUM> may be formed from COC or COP (much like the barrel <NUM>) and the stopper <NUM> may include a region formed of a thermoplastic elastomer such as a butyl rubber. The stopper <NUM> may be fitted within a neck of the vial <NUM>. The cap <NUM> may surround the top of the vial <NUM>. The vial <NUM> may include sterilization sensitive material, similar to the syringe assembly <NUM> above. During sterilization, pressure may build within the vial and the cap <NUM> may be configured to abut at least a portion of the stopper <NUM> at the top of the vial to prevent the stopper <NUM> from being ejected from the vial <NUM> during pressure increases.

As explained above, the outside of the syringe assembly <NUM> and/or the vial <NUM> (or other container) may be sterilized along with the other items within a surgical kit via a variety of sterilization techniques such as EtO sterilization and/or autoclaving. Prior to sterilization, the separate components of the syringe assembly <NUM> and the vial <NUM> (e.g., the barrel <NUM>, plunger <NUM>, tip cap <NUM>, etc.) may be manufactured in a clean room environment. Additionally or alternatively, each component may be sterilized prior to assembly. Upon partial assembly of the components, the chamber <NUM> may be filled with the material. In one example, the stopper <NUM> of the plunger <NUM> may be inserted at the first end <NUM> of the barrel <NUM> and prior to attaching the tip cap <NUM> to the barrel neck <NUM>, the material may be filled at the opening <NUM>. The tip cap <NUM> may then be attached to the barrel <NUM> at the barrel neck <NUM>, thus sealing the material within the chamber <NUM>. In another example, the tip cap <NUM> may first be connected to the barrel neck <NUM> via the luer fitting and the material may be filled at the first end <NUM> prior to the plunger <NUM> being inserted into the barrel <NUM>. Once the chamber <NUM> has been filled, and the plunger <NUM> inserted, the syringe assembly <NUM> may be sterilized.

For example, the assembly <NUM>/vial <NUM> or other container may be placed in an autoclave. By subjecting the syringe assembly <NUM>/vial <NUM> or other container to highly saturated steam, the exterior of the assembly may be sterilized. Further, the interior of the components, which will not be exposed to the steam, will also be sterilized due to high temperature of the container's solution therein. Once the syringe assembly <NUM>/vial <NUM> or other container is removed from the autoclave, the outside of the assembly <NUM>/vial <NUM> or other container may become non-sterile; however, the fluid and fluid path remain sterile. The syringe assembly <NUM>/vial <NUM> or other container may be individually packaged (as single dose syringes/containers or multiple syringes/containers in a single package) or be combined with the remaining kit contents. The individual packages or the entire kit may then be sterilized via EtO sterilization. Thus, the outside of the assembly <NUM>/vial <NUM> or other container is sterilized. For those arrangements that include packaging the syringe assembly <NUM>/vial <NUM> or other container with the rest of the kit items, the outside of the assembly <NUM>/vial <NUM> or other container may be sterilized simultaneously with the other kit components. Due to the specific properties of the barrel <NUM>, plunger <NUM>, stopper <NUM>, and tip cap <NUM>, the material within the chamber <NUM> is not altered or affected by the sterilization process.

In another alternative arrangement, once the syringe assembly <NUM> is removed from the autoclave, the syringe assemblies <NUM> (with or without sterilization sensitive material being disposed therein) may be placed in its own pouch with one or more vials <NUM>/containers containing sterilization sensitive material. The packaged combination syringe assembly <NUM> and vial <NUM>/containers may then be subjected to an EtO sterilization procedure. Finally, it is understood that the present disclosure also contemplates that vials and/or containers, such as vial <NUM>, that are constructed of COP or COC material with a suitable butyl rubber boundary, may be individually packaged (or included in a surgical kit) and subjected to an EtO sterilization process without adversely affecting sterilization sensititve material.

Advantageously, prefilled container systems may be packaged together with other materials requiring terminal sterilization as part of the manufacturing process and need not be separately packaged with materials having high barrier properties such as sealed, foil wrapping.

The inventors have found that by using COP or COC for the barrel of the syringe (and/or vials <NUM> or other containers) and employing a suitable sterilization protocol, no undesirable pH shift of the solution disposed within the chamber <NUM> after undergoing a suitable terminal sterilization procedure was experienced. More specifically, the inventors have developed a series of sterilization protocols that were tested on an exemplary arrangement of prototypes manufactured with a COP barrel and a tip cap manufactured from polypropylene with a chlorobutyl rubber insert.

One exemplary EtO sterilization cycle that the inventors have developed for successfully EtO sterilizing prefilled syringes (which would also be applicable to other containers/vials, including single dose applicator delivery devices) has many processes, but generally can be classified into four basic groups of processes and/or parameters: <NUM>) preprocessing or preconditioning; <NUM>) chamber washes and conditioning; <NUM>) sterilization and <NUM>) evacuation. Such sterilization is disclosed in the appended claims and is set forth in Table <NUM> below:.

The preprocessing group of processes is designed to precondition the syringes/vials/containers to get any bacteria "active" or "excited" so as to make any bacteria/microorganisms grow and be more susceptible to EtO gas. To do this, the preprocessing group of processes seeks to raise the temperature and humidity to precondition the syringes/vials/containers and their contents. In one embodiment, the preprocessing group of processes starts by placing the syringes/vials/containers in a preconditioning area, such as, for example, a room or chamber, which is set at a minimum temperature. Alternatively, the preprocessing step may also be done in a sterilization chamber, which is used for other of the parameters of the sterilization cycles, as will be explained in further detail below. In one exemplary arrangement, the minimum initial starting temperature may be within the range of <NUM>-<NUM> °F. In one particular example, the initial starting temperature may be room temperature, i.e., approximately <NUM> °F.

From the initial starting temperature, the temperature in the preprocessing area is then raised to a preconditioning temperature. In one exemplary arrangement, the range of temperatures is within about <NUM>-<NUM> °F.

The humidity is also raised in the preprocessing group of processes. More specifically, the preconditioning humidity in the preprocessing area is raised to be in the range of <NUM>-<NUM>% relative humidity.

To appropriately grow any bacteria/microorganisms, the syringes/containers remain in the preprocessing area/chamber for a preprocessing time period. The time period is dependent upon the temperature of the product and the humidity of the product reaching the approximate temperature and humidity of the room/chamber. In one exemplary arrangement, the range of time for the syringes/containers to remain in the preprocessing room/chamber is between <NUM> hours and <NUM> hours. In another exemplary arrangement, the range of time for the syringes/containers to remain in the preprocessing room/chamber is between <NUM>-<NUM> hours.

Once the preprocessing group of processes/parameters is complete, if necessary, the syringes/containers are then exposed or subjected to chamber washes and conditioning. A first embodiment of chamber washes and conditioning group of processes/parameters for an EtO sterilization cycle is set forth in Table <NUM> below:.

The washing/conditioning group of processes/parameters is performed to remove most (in one exemplary arrangement ><NUM>%) of the air from the chamber so the EO gas/air mixture is not explosive. In addition, the washing/conditioning group of processes/parameters is performed to add both moisture and heat to the area/chamber so when EO gas is injected into the chamber, the bacteria/microorganisms exposed in the preprocessing step above will be eradicated. Once the syringes/containers are properly sealed in a suitable area, the temperature with the area/chamber is raised to a sterilization temperature. In one exemplary arrangement, the sterilization temperature is raised within the range of <NUM>-<NUM> °F.

Simultaneous with raising the temperature to a sterilization temperature, the sterilization area is subjected to an evacuation process to remove air from the syringes/containers. In one exemplary arrangement, the evacuation process applies vacuum pressure within a range of <NUM>-<NUM> inHgA. In another exemplary arrangement, the initial evacuation process applies vacuum pressure of approximately <NUM> inHgA. In yet another exemplary arrangement, the initial evacuation process applies vacuum pressure of approximately <NUM> inHgA. An acceptable tolerance for vacuum pressure is <NUM> inHgA.

Once the evacuation process reaches a desirable set point, for example <NUM> inHgA, the vacuum may be turned off and a leak test is performed to verify that the that the sterilization area is properly sealed. If the evacuation pressure remains at the set point, within an acceptable tolerance for the duration of the leak test, then the washing/conditioning process proceeds to a pressure injection step. However, if the leak test fails, the sterilization area must be inspected for any failed seals and preprocessing procedure must be repeated for the syringes/containers. In one exemplary arrangement, the leak test is performed within the range of <NUM>-<NUM> minutes. In one particular example, the leak test is performed for <NUM> minutes.

If the leak test is satisfactory, in one exemplary optional embodiment, moisture may be introduced into the syringes/containers, such as by raising the relative humidity of the sterilization area until pressure within the sterilization area is raised to a predetermined pressure limit or the desired relative humidity set point is reached from direct measure (i.e., if the sterilization area includes one or more sensors to indicate the relative humidity). If the pressure injection step is omitted, the next step in the process is injecting Nitrogen gas into the sterilization area, discussed below.

For the humidity injection, in one example, the sterilization area (including the syringes) is injected with moisture to a target range of relative humidity of <NUM>-<NUM> inHgA to achieve a predetermined dwell pressure. In one exemplary arrangement, the dwell pressure may be within the range of <NUM>-<NUM> inHgA. Once the desired dwell pressure is reached, the relative humidity level is maintained for a predetermined dwell time. In one exemplary arrangement, the dwell time is within the range of <NUM>-<NUM> minutes. Once the dwell time has expired, the relative humidity of the sterilization area is confirmed. A relative humidity within the range of <NUM>-<NUM>% has been determined by the inventors to be acceptable. If pressure injection fails, the cycle will be aborted.

After the humidity injection (or after the leak test if the humidity injection is omitted), next, Nitrogen gas is injected into the sterilization area under pressure. In one exemplary arrangement, Nitrogen gas is injected up to <NUM> inHgA. In another exemplary arrangement, Nitrogen gas is injected at approximately <NUM> inHgA. In another exemplary arrangement Nitrogen gas is injected with a range of <NUM>-<NUM> inHgA.

Next, the sterilization area undergoes another evacuation process. In one exemplary arrangement, the sterilization area is subjected to vacuum pressure within the range of <NUM>-<NUM> inHgA. In another exemplary arrangement, the sterilization chamber is subjected to a vacuum pressure set point of approximately <NUM> inHgA. In another exemplary arrangement, the sterilization area is subjected to a vacuum pressure set point of approximately <NUM> inHgA. The inventors have determined that a tolerance of <NUM> inHgA is acceptable for the second evacuation process.

After the Nitrogen evacuation process, the Nitrogen pressure/evacuation process outlined above may be repeated, though not required. For example, in one exemplary arrangement the Nitrogen pressure/evacuation process is repeated within the range of <NUM>-<NUM> times. In another exemplary arrangement, the Nitrogen pressure/evacuation process is repeated approximately <NUM> times. In another exemplary arrangement the Nitrogen pressure/evacuation process is repeated <NUM> times.

After the Nitrogen evacuation process, more water vapor may be introduced into the sterilization area to raise the relative humidity level. In one exemplary arrangement, the sterilization area (including the syringes/containers) is injected with moisture to a target range of relative humidity of <NUM>-<NUM> inHgA. In another example, the sterilization area is injected with moisture to a target humidity of <NUM> inHgA, to achieve a predetermined dwell pressure. In one exemplary arrangement, the dwell pressure may be within the range of <NUM>-<NUM> inHgA. In another exemplary arrangement, a target dwell pressure may be within the range of <NUM>-<NUM> inHgA. In yet other exemplary arrangements, a target dwell pressure may be <NUM> or <NUM>. Once the desired dwell pressure is reached, the relative humidity level is maintained for a predetermined dwell time. In one exemplary arrangement, the dwell time is within the range of <NUM>-<NUM> minutes. In another exemplary arrangement, a dwell time of <NUM> minutes has been found to be acceptable.

Once the chamber washes and conditioning group of processes is complete, the syringes/containers are then subjected to an EtO sterilization process. The EtO sterilization group of processes and parameters for an EtO sterilization cycle is set forth in Table <NUM> below:.

The EtO sterilization group of processes begins by introduction of EtO gas into the sterilization area until reaching a predetermined pressure level. In one exemplary arrangement, the pressure level is within the range of approximately <NUM>-<NUM> inHgA.

Next, the EtO concentration within the sterilization area is verified to be with a preset target level after EtO injection. In one exemplary arrangement, a suitable target range is <NUM>-<NUM>/L. In another exemplary arrangement, a target range of approximately <NUM>-<NUM>/L. In one exemplary arrangement, a set target of <NUM>/L is desirable. Alternatively, a biologic indicator may be used to verify the EtO concentration within the sterilization chamber.

Once the EtO concentration has been reached, a nitrogen blanket may be introduced. In one exemplary arrangement the nitrogen blanket target range is up to <NUM> inHgA. In another exemplar arrangement, a suitable target range may be between <NUM>-<NUM> inHgA.

The EtO concentration within the sterilization area is maintained at a set temperature for a suitable dwell time. In one exemplary arrangement, the dwell temperature is within the range <NUM>-<NUM> °F. Alternatively, the dwell temperature may be within the range of <NUM>-<NUM> °F. The dwell time may be within the range of <NUM>-<NUM> hours. In another example, the dwell time may be within the range of <NUM>-<NUM> hours. In yet another exemplary arrangement, a dwell time of <NUM> hours is utilized.

During the dwell time, if the EtO concentration falls below a predetermined set point, additional EtO supplements may be injected until the EtO concentration can be maintained above the set point for a minimum dwell time. EtO injections may be employed up to <NUM> times during an EtO sterilization procedure.

Once the EtO sterilization group of processes is complete, the syringes/containers are then subjected to a wash and post exposure process. A first embodiment of the wash and post exposure group of processes/parameters for an EtO sterilization cycle is set forth in Table <NUM> below:.

The wash/exposure group of processes/parameters begins by evacuating EtO gas and Nitrogen from the sterilization area to remove EtO gas from the sterilization area. In one exemplary arrangement a vacuum pressure is applied to the sterilization area within the range of <NUM>-<NUM> inHgA. A vacuum pressure of <NUM> inHgA has been found to be a suitable vacuum level by the inventors of the present application. The evacuation pressure is applied between <NUM> and <NUM> minutes.

Next, Nitrogen gas is injected into the sterilization chamber under pressure. In one exemplary arrangement, Nitrogen gas is injected up to <NUM> inHgA. In another exemplary arrangement, Nitrogen gas is injected at approximately <NUM> inHgA. In another exemplary arrangement Nitrogen gas is injected with a range of <NUM>-<NUM> inHgA. The nitrogen gas injection is performed for <NUM> to <NUM> minutes. This process may be repeated up to <NUM> times. In one exemplary arrangement, the Nitrogen gas injection is repeated three times.

After completing the Nitrogen gas injections, the sterilization area is evacuated to an evacuation pressure. In one exemplary arrangement, a vacuum pressure of approximately <NUM>-<NUM> inHgA is applied. In another exemplary arrangement, a vacuum pressure of <NUM> inHgA has been found to be acceptable. In yet another example, a vacuum pressure of <NUM> inHgA has been found to be acceptable.

Next, the sterilization area undergoes an air wash step. Air is injected under pressure between up to <NUM> inHgA. In one exemplary arrangement, the pressure range for the air wash is between <NUM>-<NUM> inHgA. The sterilization area is subjected to the air wash for <NUM> to <NUM> minutes. The air washes may be repeated up to <NUM> times. In one exemplary arrangement, the air wash may be repeated <NUM> times. In another exemplary arrangement, the air wash process may be repeated <NUM> times.

After the air washes are completed, the sterilization area is opened to the atmosphere and product pallets containing the prefilled syringes may be removed and taken to an aeration facility within the manufacturing facility, as well be explained in further detail below. Alternatively, the product pallets may remain the sterilization area. In one exemplary arrangement, the aeration temperature within the aeration area of the facility may be within the range of <NUM>-<NUM> °F. The product pallets may be aerated within the range of <NUM>-<NUM> hours.

Referring to <FIG>, configurations of the sterilization protocols will now be discussed. More specifically, the flow chart in <FIG> represents alternative product flow (i.e., syringes, vials or other items) for sterilization protocols discussed herein. For ease of explanation, the product flow will be described in the context of EtO sterilization of a syringe, although it is understood that the below described protocols may be applied to other containers containing sterilization sensitive material therein.

In a first arrangement, represented by solid arrow lines A, the preprocessing/preconditioning group of processes begins with the syringe (or group of syringes) being placed in a preconditioning area within a facility. The preprocessing/preconditioning group of processes are then all performed in the preconditioning area. Once the preprocessing/preconditioning group of processes are completed, the syringes are then moved to a sterilization chamber/area. Once in the sterilization chamber/area, in product flow A, the syringes are subjected to the chamber washes/conditioning, sterilization and evacuation group of processes. Finally, the syringes may then be moved to an aeration area to aerate the syringes.

In another alternative arrangement, all of the group of processes (i.e., preprocessing/preconditioning, chamber washes/conditioning, sterilization and evacuation, (including aeration) may be done as an "all-in-one" process in a single area or chamber. This product flow is represented by element B in <FIG>.

As a further alternative arrangement, represented by dashed line C, the product flow comprises the preprocess/preconditioning group of processes being performed in a preprocessing area/chamber. Once completed, the syringes are moved to a sterilization chamber/area, where the remaining groups of processes are conducted (i.e., the chamber washes/conditioning, sterilization and evacuation, including aeration).

In the product flow arrangement represented by small dashed line D, the syringes undergo the preprocessing/preconditioning group of processes and the chamber washes/conditioning and sterilization group of processes in the same location, such as in a sterilization chamber/area. Once evacuation of the chamber/area is completed, the syringes are then moved to an aeration area in a facility.

Product flow arrangements represented by product flow paths E-H, involves repeating certain aspects of the groups of processes. More specifically, product flow path represented by a dot alternating with a dash line E involves, first subjecting the syringes to the preprocessing group of steps in the preconditioning area. Next, the syringes are moved to sterilization chamber where the preconditioning group of processes are repeated and the chamber washes/conditioning, sterilization and evacuation (including aeration) group of processes are completed. The syringes are then moved to the aeration area in the facility and may be aerated again.

In the product flow arrangement represented by the small dotted line F, the syringes are first subjected to the preprocessing group of steps in a preconditioning area. Next, the syringes are moved to a sterilization chamber where chamber washes/conditioning, sterilization and evacuation groups of processes are conducted. The syringes are then moved to the aeration area in the facility and may be aerated again.

The product flow arrangement represented by long dashed lines G involves first subjecting the syringes to the preprocessing group of steps in a preconditioning area. Next, the syringes are moved to a sterilization chamber/area, where the preprocessing group of steps of repeated, and where the chamber washes/conditioning, sterilization and evacuation groups of processes are conducted. The syringes are then moved to the aeration facility and may be aerated.

An additional alternative product flow arrangement is represented by double dot dashed line H. In this arrangement, the syringes are subjected to the preprocessing group of steps in a preconditioning area. Next, the syringes are moved to a sterilization chamber whereby the syringes then undergo another preprocessing/preconditioning step, as well as subjecting the syringes to the chamber washes/conditioning, sterilization and evacuation group of steps, including aeration.

A series of test samples were prepared for verifying the effectiveness of the sterilization procedures described above. The sample size for testing included <NUM> total prefilled syringe assemblies <NUM>, divided into six groups of <NUM> syringe assemblies <NUM>. Each chamber <NUM> of the respective syringe assemblies <NUM> includes a chamber <NUM> of the barrel <NUM> filed with <NUM> of saline and the tip cap <NUM> is secured at the end of the barrel <NUM>. One set of <NUM> syringe assemblies <NUM> was selected as being the Control Samples (identified as Group <NUM>) and set aside, without performing any sterilization procedure.

A second set of <NUM> syringe assemblies <NUM> was designated as Group <NUM>. The Group <NUM> syringes were exposed to two EtO sterilization cycles (as discussed in further detail below).

A third set of <NUM> syringe assemblies <NUM> was designated as Group <NUM>. The Group <NUM> syringe assemblies <NUM> were exposed to steam sterilization only.

A fourth set of <NUM> syringe assemblies <NUM> was designated as Group <NUM>. The Group <NUM> syringe assemblies <NUM> were exposed to steam sterilization and two EtO sterilization cycles (set forth below).

A fifth set of <NUM> syringe assemblies <NUM> was designated as Group <NUM>. The Group <NUM> syringe assemblies <NUM> were exposed to one EtO sterilization cycle (set forth below).

A final set of <NUM> syringe assemblies <NUM> was designated as Group <NUM>. The Group <NUM> was exposed to steam sterilization and one EtO sterilization cycle (set forth below).

The NaCl saline solution from each syringe in Groups <NUM>-<NUM> were tested for pH using an acceptable testing protocol for determining pH readings with an accuracy level of ±<NUM> pH. The NaCl saline solution from each syringe in the Control Group (Group <NUM>) and Groups <NUM>, <NUM>, and <NUM> were tested for EO and ECH residuals using an acceptable testing protocol, such as one using gas chromatography with a flame ionization detector. The average results of the testing for each group are set forth in Table <NUM> table below:.

As can be seen from the table above, the pH shift is within acceptable ranges resulting pH levels well within the USP requirements. More specifically, the pH for the solution in Groups <NUM>-<NUM> all fall within the range of <NUM>-<NUM>. Moreover, the residual EO and ECH are also well within the FDA requirements. More specifically, the EO residual results are below the limit of <NUM>/device and the ECH residual results are below the limit of <NUM>/device.

The present disclosure provides a manufacturing methods, EtO sterilization processes and cycles, parameters, and ranges, for regulatory compliant production and EtO gas sterilization (post filling and autoclaving) of polymer prefilled containers, such as syringes, as well as vials. Suitable materials for such prefilled containers include <NUM>% NaCl normal saline, heparinized saline, or other liquids. Correct application of the above complex methods create resultant sterile prefilled container without EtO gas ingress to EtO sensitive fluid within the container. The methods disclosed herein do not create the many possible unacceptable side effects of EtO gas ingress, such as pH shift outside the range of <NUM> to <NUM>; toxic byproducts like EO-EC-EG residuals; <NUM>% NaCl potency shift more than ±<NUM>%; alteration of contents (mL) due to plunger motion and leakage caused by an inappropriate selection of the nominal value of one or more of <NUM>+ EtO sterilization process cycle parameters. The discovery of these disclosed methods has resulted in the ability to include non-glass pre-filled containers, such as syringes and vials, that can safely be put unpackaged (i.e., without additional user, inconvenient protective ETO barrier over-packaging-foil, etc.) into a standard breathable medical procedure sterile tray (i.e., convenience tray), kit pouch, or package with other components, or individually package the containers and be subjected to EtO sterilization and directly ready for infusion when it is extracted from its packaging or lifted out of the sterile procedure tray by the operating technician.

With regard to the processes, systems, methods, heuristics, etc. described herein, it should be understood that, although the steps of such processes, etc. have been described as occurring according to a certain ordered sequence, such processes could be practiced with the described steps performed in an order other than the order described herein. It further should be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps described herein could be omitted. In other words, the descriptions of processes herein are provided for the purpose of illustrating certain embodiments, and should in no way be construed so as to limit the claimed invention.

Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.

All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary in made herein. In particular, use of the singular articles such as "a," "the," "said," etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. For simplicity, the aforementioned temperature values in °F correspond in SI unit °C to:.

Moreover, the aforementioned pressure values in "inHgA" correspond in SI unit kPa to:.

Claim 1:
A method of employing ethylene oxide (EtO) to sterilize a prefilled syringe assembly (<NUM>) without adversely affecting the contents of the prefilled syringe assembly (<NUM>), comprising:
assembling a syringe assembly (<NUM>) that comprises a plunger (<NUM>) and a non-glass barrel (<NUM>), the method including:
inserting the plunger (<NUM>) into the barrel (<NUM>) at a second end of the non-glass barrel (<NUM>) to define a chamber (<NUM>) therein;
filling the non-glass barrel (<NUM>) with sterilization sensitive material at a first end of the non-glass barrel (<NUM>), the sterilization sensitive material one of saline, heparinized saline, and lidocaine;
inserting a tip cap (<NUM>) at the first end of the barrel (<NUM>) to seal the sterilization sensitive material within the barrel (<NUM>);
performing at least one ethylene oxide (EtO) sterilization procedure cycle of the assembled syringe assembly (<NUM>), wherein the sterilization procedure cycle comprises undergoing a preprocessing stage including raising the temperature and humidity of a preconditioning area into which the syringe assembly (<NUM>) is located to a predetermined level to initiate growth of microorganisms and where the temperature is within the range of <NUM> - <NUM> (<NUM>-<NUM> °F), and where the humidity is within the range of <NUM>-<NUM>%, a wash and conditioning stage after the preprocessing stage including moving the syringe assembly (<NUM>) to the sterilization chamber, sealing the sterilization chamber and raising the temperature to a conditioning temperature within a range of <NUM> - <NUM> (<NUM>-<NUM> °F), and an EtO sterilization stage after the wash and conditioning stage,
wherein the EtO sterilization stage comprises introducing EtO gas into a sterilization chamber containing the prefilled syringe assembly (<NUM>) until reaching a predetermined pressure level within the range of <NUM>,<NUM> kPa - <NUM>,<NUM> kPa (<NUM>-<NUM> inHgA);
evacuating the EtO gas by applying a vacuum pressure of approximately <NUM>,<NUM> kPa (<NUM> in HgA); and
wherein upon completing the EtO sterilization procedure cycle, a resultant pH of the sterilization-sensitive material is between <NUM>-<NUM>.