Patent Description:
Prolonged storage of RBCs can (negatively) affect RBC function. In order for the RBCs to be suitable for transfusion to the recipient, RBCs must maintain adequate cell function and metabolism. For example, RBCs must maintain an adequate concentration of adenosine triphosphate (ATP) and <NUM>,<NUM>-DPG. In addition, the presence of lactate must not be too high in the stored RBCs. Still further, stored RBCs must have acceptably low levels of hemolysis. Typically, an acceptable level of hemolysis is below <NUM>% (in, for example, the U. ) and <NUM>% (in Europe) after <NUM> day storage.

Media for providing a storage environment for RBCs that will allow cell function and cell metabolism to be preserved and maintained have been developed and are commonly used. The media developed for RBCs can prolong the storage life of RBCs for up to <NUM> days. Such media (or "storage solutions") often include a nutrient for the RBCs, a buffer to help maintain the pH of the RBCs, electrolytes, a RBC membrane-protecting compound and other additives to enhance and extend the life of the RBCs. Examples of widely used and accepted storage media are Adsol and SAG-M, available from Fenwal, Inc. , of Lake Zurich, Illinois. Adsol and SAG-M include sodium chloride, glucose, mannitol, and adenine. Both Adsol and SAG-M have a pH of about <NUM> (referred to herein as "low pH") and are substantially isotonic.

Other additive solutions are disclosed in <CIT> and <CIT>. The additive solutions disclosed therein are, hypotonic, synthetic aqueous storage solutions for the prolonged storage of RBCs. The storage media disclosed therein typically include adenine, mannitol, sodium citrate, sodium phosphate, and glucose as the nutrient. These hypotonic aqueous additive solutions have a "high" pH of at least about <NUM>.

During storage, concentrated RBCs and the additive solutions in which they are stored are typically kept in a sealed container, usually made of a plastic material. Most typically, the containers approved for the collection of whole blood and the storage of RBCs are made of a polyvinyl chloride (PVC). Inasmuch as polyvinyl chloride can be somewhat rigid or brittle, a plasticizer is typically incorporated into the PVC. Examples of currently known and used plasticizers for medical grade PVC are DEHP, TEHTM, and the family of citrate esters described in <CIT>.

As reported in <CIT> and other literature, such as <NPL>; <NPL>, certain plasticizers may have a beneficial effect on the storage life of RBCs. More particularly, plasticizers such as DEHP and the family of citrate esters have been found to suppress hemolysis of RBCs stored in containers that include such leachable plasticizers. RBCs stored in containers made of plasticized PVC or a non-PVC container with plasticizer added (as described in <CIT>) have traditionally been combined with an isotonic, low pH storage solution (such as Adsol). While DEHP plasticized containers have worked well for the storage of red cells, the use of other container materials and additive solutions to provide a suitable storage environment for red blood cells remains a topic of keen interest.

<NPL>", Indian Patent Application <CIT>, pages <NUM>-<NUM>, India, discloses a composition comprising polyvinyl chloride, BTHC and DINCH, an epoxidized vegetable oil, calcium and zinc salts of fatty acids, a fatty acid ester and saturated aliphatic hydrocarbon. The composition may be used to prepare containers for the storage of red blood cells.

It would be desirable to provide a storage environment for RBCs wherein (<NUM>) the container is made of a PVC material plasticized with a non-phthalate plasticizer and (<NUM>) a suitable storage media. As used herein, the term "storage environment" refers to the materials and solutions that contact the RBCs during storage.

The claimed invention is directed to a container for storing red blood cell compositions and to a use of such a container. RBC products and compositions or methods providing such products or compositions are not part of the claimed invention but are only disclosed for explanation of the use of the claimed container. In one aspect, not claimed, the present disclosure is directed to RBC products. The products include a container in which the wall of the container defines an interior chamber. At least a portion of the wall is made of a plastic combined with at least one non-phthalate plasticizer or other extractable agent. In another aspect, not claimed, the product further includes a suspension of RBCs contained within the chamber. The suspension includes concentrated RBCs in a hypotonic solution. The hypotonic, chloride-free solution includes at least a nutrient, a buffer, and has a pH of greater than approximately <NUM>. The plastic is a PVC composition.

In another aspect, not claimed, the present disclosure is directed to a transfusible RBC composition. The composition includes a suspension of RBCs that includes concentrated RBCs substantially free of a phthalate plasticizer and having a hemolysis level of below at least <NUM>% for its storage life.

In another aspect, not claimed, the present disclosure is directed to a method for providing a transfusible red blood cell product. The method includes deriving red blood cell concentrate from whole blood, combining the concentrate with a hypotonic solution and storing the combination of concentrate and solution in a container that includes a polymeric material that is substantially free of phthalate.

In a further aspect, the present disclosure is directed to a container for storing red blood cell compositions in accordance with claim <NUM>. The container includes one or more container walls defining an interior chamber. The container wall(s) is made of a polymeric material that is free of phthalate and comprises at least a first extractable agent which is BTHC and a second extractable agent which is DINCH, wherein each of the at least first and second extractable agents is effective in suppressing hemolysis in red blood cells. The polymeric material includes polyvinyl chloride (PVC).

In another aspect, the present disclosure is directed to a red blood cell product that includes the container having one or more container wall(s) defining an interior chamber. A suspension of red blood cells is contained within the interior chamber and includes concentrated red blood cells and an additive solution that includes a nutrient.

The invention is defined by the claims and is directed to a container for storing red blood cell compositions as defined in claim <NUM> and to a use of such a container as defined in claim <NUM>. Further disclosed aspects, such as RBC products and compositions, methods of preparing such products and compositions, or additive solutions, illustrate the claimed invention but do not form part of it.

Disclosed herein are RBC products that include (a) a RBC composition, and (b) a container for holding the composition during a period of storage. The RBC composition itself includes concentrated RBCs that have been combined with an additive solution selected to maintain cell function and metabolism of the RBCs during prolonged storage (e.g., at least about <NUM> days and possibly even up to at least <NUM> and/or <NUM> days). The container is made of a plastic material that does not include a phthalate plasticizer but otherwise includes non-phthalate plasticizers. The polymeric material further comprises extractable agents. The RBCs of the RBC product are suitable for transfusion to a patient.

As noted above, RBC compositions include RBC concentrate and an additive solution. Concentrated RBCs are derived from whole blood either by manual or automated separation collection techniques which will be known to those skilled in the art. RBC concentrates may include some residual amount of plasma. The RBC concentrate may have most of its plasma removed as described, for example, in International Application Publication <CIT>.

Regardless of how much plasma remains with the RBCs, the additive solution is one that allows for the extended storage of RBCs (in the containers described herein) for over <NUM> days, over <NUM> days, up to at least <NUM> days, and even up to at least <NUM> and/or <NUM> days. Suitable additive solutions include at least sodium chloride, glucose (nutrient), mannitol and adenine. In a specific example, the additive solution includes approximately <NUM> glucose (dextrose), <NUM> sodium chloride, <NUM> mannitol and <NUM> adenine. The solutions may have a pH of about <NUM> and are substantially isotonic. Such solution is commonly known as Adsol and is available from Fenwal, Inc. , of Lake Zurich, Illinois. In another example, additive solutions suitable for the storage of RBCs in accordance with the present disclosure are generally hypotonic and typically (but not necessarily) do not include sodium chloride. Such storage solutions also include a nutrient, a buffer, other additives such as sodium citrate, and typically have a pH of about <NUM> or higher.

More specific examples of hypotonic, high pH additive solutions are described in U. Patent Publication Nos. <CIT> and <CIT>. In a specific example, the additive solutions include between about <NUM> to <NUM> of adenine; about <NUM> to about <NUM> of mannitol; about <NUM> to about <NUM> sodium citrate; about <NUM> to about <NUM> sodium phosphate dibasic and about <NUM> to about <NUM> of glucose. The pH of the additive solution is above about <NUM>.

In a more specific example, the additive solution useful in the storage of concentrated RBCs in accordance with the present disclosure includes about <NUM> of adenine; about <NUM> of mannitol; or about <NUM> of sodium citrate; about <NUM> of sodium phosphate dibasic and about <NUM> of glucose. The solution described above is referred to herein as "E-Sol <NUM>.

Thus, concentrated RBCs with some or most of the plasma removed are combined with additive solutions of the type described above to provide the RBC composition. In one example, the RBC composition includes between about <NUM> to <NUM> of the additive solution combined with about <NUM> to <NUM> of the concentrated RBCs. More preferably, the volume of additive solution may be about <NUM>-<NUM>.

In the collection of RBCs, it is typical to remove leukocytes from, or at least reduce the number of leukocytes in, the RBCs prior to their storage and transfusion. RBCs suspended in an additive solution are often subjected to a leuko-reduction step which commonly includes filtration of the RBC/additive solution.

In accordance with the methods and systems disclosed herein, RBCs are subjected to a filtration step or other treatment whereby one or both of leukocytes and prions are substantially removed (or the populations of leukocytes and/or prions are substantially reduced) from the RBCs. Concentrated RBCs may be combined with an additive solution of the type described above and the combined concentrated RBC/additive solution composition may be subjected to the leukocyte and/or prion removal (e.g., filtration) step.

The RBC concentrate may be "leuko-reduced" and/or "prion-reduced" prior to combination with the additive solution. Thus, RBC concentrate separated from whole blood may be filtered by passing the RBC concentrate through a leuko-reduction filter. Alternatively, the whole blood may be subjected to leuko-reduction (i.e., leuko-filtration) and/or prion reduction/removal prior to separation of the RBCs from the whole blood. In any event, the RBCs are "leuko-reduced and/or "prion-reduced. " Filters suitable for removing leukocytes (and/or prions) from whole blood or RBC concentrate (prior to the addition of the additive solution) include, but are not limited to, the Sepacell R-<NUM> II, RZ-<NUM>, RS-<NUM>, Flex-Excel, Pure-RC, RZ-<NUM> and R-<NUM>. (Of course, other means for removing and/or reducing the number of leukocytes may also be used. ) The (now) leuko-reduced RBC concentrate may be combined with the hypotonic additive solution of the type described above. The hypotonic additive solution may be added after introduction of the RBC concentrate into the container, or may already be present in the container at the time of RBC concentrate introduction.

Leuko-reduced (and/or prion-reduced) RBC concentrate (either with or without additive solution) is then introduced into a container which is made of a container made of PVC that is at least substantially free of phthalate plasticizer but is plasticized with or otherwise includes non-phthalate plasticizers or extractable agents. Containers for storing the RBC compositions disclosed herein may be permeable to oxygen or at least semi-permeable to oxygen. As shown in <FIG>, container <NUM> may include one or more container walls <NUM> which define an interior chamber <NUM> for receiving the RBC composition <NUM>. In one example, two sheets made of a plastic material are brought together and sealed along their peripheries <NUM> to form container <NUM>. Other ways of making container <NUM> will be known to those of skill in the art and are part of the present disclosure. As shown in <FIG>, container wall <NUM> includes an inner surface <NUM> which contacts the RBCs and an outer surface <NUM>. In one embodiment, the container wall is made of a single layer of a PVC polymer material. In another embodiment, container wall <NUM> is made of a multiple sheet laminate wherein inner surface <NUM> is made of one material and outer surface <NUM> is made of a different material. Container <NUM> may include one or more access ports <NUM> for connection with tubing <NUM>, docking devices and the like to establish flow into and out from the interior chamber <NUM> of container <NUM>.

In one embodiment, containers useful in the storage of RBCs as described above include container walls that are made in whole or at least in part of a plastic material that includes at least one or more polymeric compounds. The one or more plastic and/or polymeric compounds may be blended together and formed into flat sheets that are sealed together in the manner described above. The polymeric material may be made from or otherwise include polyvinyl chloride (PVC) or one or more non-PVC polyolefin homopolymers, copolymers or blends thereof. Examples of suitable non-PVC polyolefins include polypropylene, polyethylene, including ultra low density polyethylene (ULDPE) and very low density polyethylene (VLDPE). Other suitable compounds that may be used in the plastic materials of the containers or as part of the blend for making the plastic materials include ethylene vinyl acetate (EVA) and block copolymers such as Kraton®. Exemplary formulations and/or the polyolefins, polyolefin blends or other polymeric compounds which are useful, either alone or in combination, in the manufacture of containers suitable for use in the RBC products of the present disclosure are described in <CIT>, <CIT>, <CIT>, and <CIT>. According to the invention the polymer material comprises <NUM>-<NUM> wt. -% PVC resin.

As indicated above, the structure of the container or container wall may include one, two or more layers. The layer formulations may include one, two, three or more components. These structures should be suitable for sterilization by appropriate means, such as steam, ionizing radiation or ethylene oxide. Structures suitable for steam sterilization should resist distortions to high temperatures up to <NUM>. This typically requires incorporation of materials with a melting peak of greater than <NUM>. The preferred structure of autoclavable material suitable for the invention will incorporate polypropylene homopolymer or copolymer at a level of <NUM>% or more in at least one of the layers to provide thermal resistance. A suitable polypropylene copolymer is supplied by Total Petrochemicals (random copolymer <NUM>). However, thermal resistance can also be obtained by crosslinking a lower melting material. For example, a <NUM>% vinyl acetate EVA can be crosslinked by ionizing radiation sufficiently to withstand autoclave temperatures even though it has a melting point of <NUM>. Suitable materials include Arkema Evatane® <NUM>-<NUM> and Celanese Ateva® <NUM>. The preferred structure is highly flexible, having a composite modulus of not more than <NUM>,<NUM> psi.

In some cases, it may be desirable for the structure to have radio frequency (RF) response to enable heat sealing. This can be accomplished by incorporating an RF responsive material such as described in <CIT>.

Preferred structures for radiation sterilized applications will incorporate at least <NUM>% of an ethylene based polymer (LDPE, LLDPE, ULDPE, VLDPE, EVA) in at least one of the layers. Structures of polypropylene copolymers and polypropylene polymers blended with elastomers such as Kraton® or ULDPE are also suitable for radiation sterilized applications. The preferred structure incorporates lower modulus components in at least one of the layers to enhance flexibility and toughness. These lower modulus components can be ultra low density polyethylene (ULDPE - typical density less than <NUM>/L), very low density polyethylene (VLDPE -typically density less than <NUM>/L), ethylene vinyl acetate copolymers (EVA) with greater than <NUM>% vinyl acetate content, styrene butadiene terpolymers such as Kraton®. ULDPE materials are commercially available as Mitsui TAFMER®, Exxon Mobil Exact® and Dow Affinity®. EVA materials are available as Arkema Evatane® and Celanese Ateva®. These materials are incorporated at levels sufficient to obtain a composite modulus of less than <NUM>,<NUM> psi while maintaining resistance to distortion at temperatures greater than <NUM> for autoclaved applications. The disclosure of suitable non-PVC plastics set forth above is not meant to be exhaustive and it will be appreciated that other non-PVC plastics, polymers and blends thereof may also be used in the products and compositions of the present disclosure.

Containers of the type described herein may have a container sheet (wall) thickness of between approximately <NUM> to <NUM> inches. They may include a non-smooth or any surface finish that minimizes sheet sticking. Typically, containers of the type described herein may have a container volume (i.e., interior chamber volume) of approximately <NUM> to <NUM>.

Containers suitable for use in the products, systems and methods of the present disclosure are at least substantially free of phthalate plasticizer, such as DEHP. Since the container includes PVC, such container material will have to be plasticized due to the brittle nature of PVC. As noted above, the plasticizer is a non-phthalate plasticizer. Non-phthalate plasticizers that may be suitable for use in the PVC containers described above include, for example, triethylhexyltrimellitate (TEHTM) and the family of citrate esters, as described in <CIT>. According to the invention, the PVC is plasticized with <NUM>,<NUM>-cyclohexane dicarboxylic acid diisononyl ester, known by its trade name, DINCH and with n-butyryltri-n-hexyl citrate (BTHC). DINCH is available from, for example, BASF of Ludwigshafen, Germany.

The PVC container (or more specifically, the container wall) is at least substantially free of a phthalate plasticizer but includes a non-phthalate plasticizer or extractable agent. Accordingly, such non-phthalate plasticizer(s) will be present in and part of the RBC storage environment. As the containers disclosed herein are often part of a larger processing set that includes tubing, ports, membranes and connectors in addition to being part of the storage environment, non-PVC and non-phthalate materials of the type described herein may also be used in the manufacture of such other processing set components.

RBC compositions (which include RBC concentrates and hypotonic, high pH additive solutions) may be stored in the substantially phthalate-free containers. The RBC compositions stored in such containers may be stored for more than <NUM> days, more than <NUM> days and up to at least <NUM> days or even up to at least <NUM> days and/or <NUM> days, while maintaining acceptable storage cell function parameters (i.e., a level of ATP, <NUM>,<NUM>-DPG, lactate). In particular, RBC compositions stored in the containers described above and that are substantially phthalate-free maintain hemolysis levels below <NUM>% and even below <NUM>% at, for example, <NUM> days of storage. Similarly, the RBC compositions stored for at least about <NUM> days also include ATP, <NUM>,<NUM>-DPG, lactate, potassium, phosphate levels that are comparable to RBC compositions stored in plasticized PVC containers, as shown in the Studies reported herein.

The plastic composition in accordance with the claimed invention includes two or more plasticizers or extractable agents. The structure of the container may also be as described above (single layer or multiple layers). The plastic composition includes a first extractable agent and a second extractable agent. At least the first and second extractable agents or plasticizers are extractable agents or plasticizers, each effective in suppressing hemolysis in RBCs. One of such extractable hemolysis-suppressing agents is the citrate ester n-butyryl-n-hexyl citrate (BTHC), and the other of the at least first and second extractable agents or plasticizers is the non-phthalate plasticizer DINCH, which also is effective in suppressing hemolysis.

The plastic composition thus includes a first and second extractable agent/plasticizer (wherein one of the first or second agents/plasticizers is BTHC and the other is DINCH) and a further or third agent or plasticizer. According to the invention, the third plasticizer is epoxidized oil, which is a plasticizer that is not readily extractable or marginally extractable and which also acts as a stabilizer. Additional agents or plasticizers may further be included in the formulation of the containers described herein. Another example of a third plasticizer that may be used is TEHTM, which is a plasticizer that is not readily extractable or marginally extractable.

The containers according to the invention include <NUM>-<NUM>%, by weight, PVC resin, <NUM>-<NUM>% DINCH plasticizer, <NUM>-<NUM>% BTHC, <NUM>-<NUM>% epoxidized oil and <NUM>-<NUM>% of additional co-stabilizers and lubricants. DINCH is available from, for example, BASF of Ludwigshafen, Germany.

The compositions of the present disclosure may also include other additives such as anti-blocking and slip agents. Examples of such anti-blocking and slip agents include derivatives of fatty acid and ethylenediamine. More specifically, the agents may be longer chain fatty acids, containing <NUM> or longer hydrocarbon chains with or without mono-unsaturated carbon-carbon bonds, based daiamide with ethylendiamine, such as n,n'-ethylene bissteararamide and n,n'-dioleoyl ethylenediamine. Commercially available compounds of the type described above and which may be used in non-PVC, non-plasticized compositions include Acrawax and Glycolube, both available from Lonza of Basel, Switzerland. The anti-blocking and/or slip agents may be coated onto the interior surface of the containers or otherwise incorporated therein.

The compositions that include two or more non-phthalate plasticizers or extractable agents are suitable for storing concentrated RBCs with an additive solution. In such applications, any additive solution may be used. In one embodiment, the additive solutions may be any known additive solution, such as SAG-M or Adsol (AS-<NUM>) available from Fenwal, Inc. , of Lake Zurich, Illinois. Alternatively, the additive solution may be the generally hypotonic additive solution described above.

Although the container walls (or at least the inner surface(s) <NUM> of the walls) are made of a material completely free of phthalate, some small trace amounts of phthalate may be present in the container walls as a result of migration from adjoining or adjacent containers, from PVC tubing and/or the surrounding environment generally. In addition, as described above, ports <NUM> may likewise include PVC and as a result may include some plasticizer (including DEHP). Nonetheless, the presence of some trace amounts of plasticizer attributable to migration from other containers or tubing, or present in the plastic ports <NUM>, is negligible and such containers are referred to herein as "substantially phthalate-free" or "substantially free of phthalate.

The below studies <NUM> to <NUM> are not according to the invention and are present for illustration purposes only.

Whole blood units were collected in CPD anticoagulant in commercially available blood pack units. Within <NUM> minutes of collection, the units were transferred to non-PVC, non-DEHP polyolefin based containers for pooling. Three units of ABO matched whole blood were pooled together and split back into non-DEHP, non-PVC, polyolefin-based containers. The units were leukofiltered, centrifuged, and processed into plasma and concentrated red cells. Approximately <NUM> of E-Sol <NUM> was added to each RBC concentrate. The RBC concentrates were then transferred to: (<NUM>) a container made of a standard PVC, plasticized with a DEHP (referenced in the Figures as <NUM> DEHP, PVC); (<NUM>) a container made of a non-PVC, oxygen semi-permeable material that is a steam sterilizable, multi-component blend that includes a copolymer of polypropylene as its major component with <NUM>% less of the DEHP-plasticizer than the container in subsection (<NUM>) above (referenced in the Figures as <NUM> DEHP, non-PVC A), and (<NUM>) a container made of a non-PVC plasticizer-free material that is a radiation sterilizable, multi-component blend including primarily ethylene vinyl acetate (referenced in the Figures as <NUM> DEHP, non-PVC B).

Units were stored upright for <NUM> days at <NUM>, with weekly sampling for in vitro parameters. On Day <NUM> DEHP content in the RBC concentrate was also measured after thorough mixing of each unit.

In a further study, whole blood units were collected into CPD anticoagulant in commercially available PVC, plasticizer blood pack units. Within <NUM> minutes of collection, whole blood units were leukofiltered, centrifuged, and processed into plasma and concentrated RBC component. Approximately <NUM> of E-Sol <NUM> was added to each red cell concentrate, which was transferred to a container made of a semi gas-permeable, non-PVC material of the type used in the container of subsection (<NUM>) in Study <NUM> described above but substantially free of any plasticizer (referenced in the Figures as <NUM> DEHP, non-PVC A).

Units were stored upright for <NUM> days at <NUM>, with weekly sampling for in vitro parameters. On Day <NUM> of storage, DEHP content in the RBC concentrate was also measured after thorough mixing of each unit.

Whole blood units were collected in CPD anticoagulant in commercially available PVC, plasticizer blood pack units. Within <NUM> minutes of collection, the units were transferred to non-PVC, non-DEHP polyolefin based containers for pooling. Two units of ABO matched whole blood were pooled together and split back into the original collection containers. The units were leukofiltered, centrifuged, and processed into plasma and concentrated red cells. Approximately <NUM> of Adsol was added to each RBC concentrate which was then stored in a container identical to the container used to store red cell concentrate in E-Sol, as described above in Study <NUM> (i.e., referenced in the Figures as <NUM> DEHP, Non PVC A, Adsol and no plasticizer).

Paired units were stored upright for <NUM> days at <NUM>, with weekly sampling for in vitro parameters in one unit from each pair (data shown in <FIG>) and Day <NUM> and Day <NUM> sampling only in the other unit from each pair (data not shown). On Day <NUM> of storage, DEHP content in the RBC concentrate was also measured after thorough mixing of each unit.

No major differences were observed in hematocrit, pH, glucose, lactate, phosphate, potassium, <NUM>,<NUM>-DPG, and red cell micro particles among the three arms of Study <NUM> and the single arm of Study <NUM> described above. As shown in <FIG>, all E-Sol <NUM> units passed accepted criteria for hemolysis (below <NUM>% and <NUM>%, respectively) at Day <NUM>. The Adsol units described in Study <NUM> had <NUM>% hemolysis on average on Day <NUM>. ATP, <NUM>,<NUM>-DPG and lactate levels were also comparable in the E-Sol stored units, as also shown in <FIG>. With reference to Table <NUM> below, DEHP levels in the non-PVC, non-plasticized containers from Studies <NUM> and <NUM> showed negligible DEHP levels of <NUM> ± <NUM> and <NUM> + <NUM> and <NUM> and + <NUM> ppm, respectively in the RBC compositions, thereby indicating that the RBC compositions that are "substantially plasticizer-free" and stored in E-Sol <NUM> maintained acceptable hemolysis levels.

Paired, ABO matched WB units in CPD were collected into DEHP-PVC bags and pooled into non-DEHP bags within <NUM> minutes of collection. Pooled WB units were split into <NUM> non-DEHP containers and each unit was leukofiltered and processed into plasma and a red cell concentrate (RCC). In Study <NUM>, one RCC was stored in a standard DEHP-PVC bag with <NUM> Adsol (control) and the other RCC in a DINCH-PVC bag with <NUM> Adsol (test). In Study <NUM>, one RCC was stored in a standard DEHP-PVC bag with <NUM> Adsol (control) and the other RCC in a DINCH-PVC bag with <NUM> E-Sol <NUM> (test). Units were stored upright at <NUM> for <NUM> days with weekly sampling. On Day <NUM>, DEHP content was quantified for test and control units in Study <NUM> to ensure there was minimal DEHP exposure during processing and storage of test units. In vitro storage parameter results are summarized in Tables <NUM> and <NUM> below.

Claim 1:
A container for storing red blood cell compositions comprising:
one or more container walls defining an interior chamber, said container wall(s) comprising a polymeric material that is:
(a) free of phthalate; and
(b) comprises at least a first extractable agent and a second extractable agent,
wherein each of said at least first and second extractable agents is effective in suppressing hemolysis in red blood cells, wherein the first extractable agent is n-butyryltri-n-hexyl citrate (BTHC) and the second extractable agent is <NUM>,<NUM>-cyclohexane dicarboxylic acid diisononyl ester (DINCH), and wherein the polymer material comprises <NUM>-<NUM>%, by weight, PVC resin, <NUM>-<NUM>% BTHC, <NUM>-<NUM>% epoxidized oil and <NUM>-<NUM>% DINCH, with <NUM>-<NUM>% of additional co-stabilizers and lubricants.