Title of Invention	"BLOOD COMPONENT PRESERVATION CONTAINER FOR PRESERVING A LIQUID CONTAINING AT LEAST A BLOOD COMPONENT"
Abstract	A blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing 5 to 40% by weight of a first plasticizer as herein described and 5 to 45% by weight of a second plasticizer as herein described; wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C).

Title of Invention

"BLOOD COMPONENT PRESERVATION CONTAINER FOR PRESERVING A LIQUID CONTAINING AT LEAST A BLOOD COMPONENT"

Abstract

A blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing 5 to 40% by weight of a first plasticizer as herein described and 5 to 45% by weight of a second plasticizer as herein described; wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C).

Full Text	This invention relates to a blood component preservation container which is suited for preserving blood, a blood component, in particular an erythrocyte-containing solution, and also to a multi-linkage container. In recent years, a blood component preservation container of bag-like structure which is formed of superimposed thermoplastic resin sheets whobe peripheries are fusion-bonded with each other has been extensively utilized as a container for collecting, separating or preserving blood. This blood component preservation container (a blood bag) is required to have various properties, such as a sufficient transparency for enabling the condition of blood or blood components contained therein to be observed from outside; a sufficient flexibility (pliability) for easily enabling various operations such as blood collection, blood transfusion or separation of blood components; a sufficient strength for withstanding these operations; an excellent sanitariness; and an excellent safety. Since soft polyvinyl chloride meets roost of these requirements, it is predominantly utilized as a material for the blood bag at present. Meanwhile, as far as the preservation of erythrocyte component is concerned, there has been an advancement in the development of a preservation solution for exclusive use therefor, i.e., a preservation solution (such as M.A.P. solution) which is capable of effectively preserving erythrocyte component for 42 days has been developed and is actually put into use now. However, in spite of the availability of such a preservation solution to preserve erythrocyte component for a long period of time, there has been raised another problem that a big agglomerate or a so-called macroaggregate (hereinafter referred to as HA) is quite frequently generated during the storage of erythrocyte. No measures have been developed as yet to prevent the generation of this MA. It is also important to prevent the hemolysis (the destruction of blood cell) of erythrocyte being preserved. Namely, if the hemolysis degree of erythrocyte is increased, the quality of erythrocyte preparation would be deteriorated. Although various methods have been developed to prevent the heroolysis, all of these methods are only aimed at preventing the hemolysis, and a method for suppressing not only the hemolysis but also the generation of MA has not been developed as yet. Accordingly, an object of the present invention is to provide a blood component preservation container which is excellent in blood component preservation property and capable of suppressing not only the hemoiysis of erythrocyte but also the generation of macroaggregate (MA). Another object of the present invention is to provide a multi-linkage container system comprising such a blood component preservation container as mentioned above. These objects have been accomplished according to the present invention by a blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing a first plasticizer and a second plasticizer, wherein the first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predeter¬mined amount of a blood component is preserved at a temperature of 4tJ for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppra by weight or more of the added first plasticizer is eluted into the blood component, and the second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when the second plasticizer is singly mixed in the polyvinyl chloride sheet at a ratio of 32% by weight, the oxygen gas permeability of the resulting polyvinyl chloride sheet is not less than 4,0 L/m2 -mm -day -atm (30t;). To meet the aforementioned objectives, the invention provides for a blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing 5 to 40% by weight of a first plasticizer as herein described and 5 to 45% by weight of a second plasticizer as herein described; wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C). This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a plan view showing one example of a multi-linkage container system according to the present invention; FIG. 2 is a graph showing the relationship between an amount of a plasticizer (OEHP) added and an amount of the plasticizer eluted; and FIG. 3 is a graph showing the relationship between the amount of a plasticizer (DEHP) added and the rate of hemolysis. A blood component preservation container and a multi-linkage container system according to the present invention will be explained in detail with reference to a preferred embodiment shown in the drawings. FIG. 1 shows a plan view illustrating one example of a multi-linkage container system 1 according to the present invention. Referring to FIG. 1, this multi-linkage container system 1 is formed of quadruple containers including a blood collection bag (a first bag) 10, a blood plasma bag (a second bag) 20, a buffy coat bag (a third bag) 30 and a chemicals storage bag (a fourth bag) 40, all of these bags being connected with each other via prescribed tubes. Specifically, the blood collection bag 10 disposed leftmost side in FIG. 1 constitutes a blood component preservation container and includes a main bag portion 11 comprising two pliable polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or high-frequency bonding) or adhered, thereby forming a sealed portion 12. The inner portion surrounded by the scaled portion 12 of the main bag portion 11 serves as a blood storage space 13 for storing a collected blood. Further, since the blood collection bag 10 can be utilized also as an erythrocyte bag for preserving erythrocyte therein, the blood storage space 13 may be used for ultimately storing and preserving a concentrated erythrocyte. The main bag portion 11 is provided at its upper portion with a couple of sealed opening ports 14 each provided with a peeling tab for opening the opening ports 14. The main bag portion 11 is also provided, beside.the opening ports 14, with an outlet port 18 for communicating the blood storage space 13 with other bags 30, 20 and 40. To this outlet port 18 is connected one end of a tube 61 via a connector member 17. Preferably, the connector member 17 is constructed in such a manner that the passage thereof is closed before the connector member 17 is fractured, but can be opened once the connector member 17 is fractured. To the other end of the tube 61 is connected a Y-shaped branch connector 64, to the branched ends of which each end of tubes 62 and 63 is connected respectively. The other end of the tube 62 is attached with a branch connector 19 of the same construction ao that of the branch connector 64. The branched ends of the branch connector 19 are connected to each end of tubes 25 and 46 respectively. A pliable tube 15 is attached via one »nd thereof to the upper portion of the main bag portion 11 so as to communicated with the interior of the blood storage space 13. The other end of the pliable tube 15 is attached via a hub 151 with a blood collecting needle 152. The hub 151 is adapted to be mounted with a cap 153 for encasing the blood collecting needle 152. The blood plasma bag 20 includes a main bag portion 21 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or high-frequency bonding) or adhered thereby forming a sealed portion 22. The inner portion surrounded by the sealed portion 22 of this main bag portion 21 is used as a plasma storage space 23 for storing plasma separated from the blood in the blood collecting bag 10. The main bag portion 21 is provided at its upper portion with a couple of sealed outlet ports 24 for blood transfusion each provided with a peeling tab for opening the outlet ports 24. The main bag portion 21 is connected, beside the outlet ports 24, with the other end portion of the tube 25 communicating with the plasma storage space 23. Therefore, when the passage of the connector member 17 is opened, the blood storage space 13 of the blood collection bag 10 is allowed to communicate, via the connector member 17, the tubes 61, 62 and 25 and the branch connectors 64 and 19, with the blood plasma storage space 23 of the blood plasma bag 20. The buffy coat bag 30 includes a main bag portion 31 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or" high-frequency bonding) or adhered thereby forming a sealed portion 32. The inner portion surrounded by the sealed portion 32 of this main bag portion 31 is used as a buffy coat storage space 33 for storing buffy coat separated from the blood in the blood collecting bag 10. The main bag portion 31 is connected via its upper portion with the other end of the tube 63 communicating with the buffy coat storage space 33. The chemicals storage bag 40 includes a main bag portion 41 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or high-frequency bonding) or adhered, thereby forming a sealed portion 42, The inner portion surrounded by the sealed portion 42 of this main bag portion 41 is used as a chemicals storage space 43 for storing chemicals. In this embodiment, a predetermined volume of an erythrocyte preservation solution 47 is stored in the chemicals storage space 43. This erythrocyte preservation solution may be a M.A.P. solution, a S.A.G.M. solution, an OPTISOL solution or an ADSOL solution. The main bag portion 41 is provided at its upper portion with a couple of sealed 'outlet ports 44 each provided with a peeling tab for opening the outlet ports 44. The main bag portion 41 is provided, beside the outlet ports 44, with a connector member 45 of the same construction as that of the connector member 17 for communicating with the chemicals storage space 43. To this connector member 45 is connected the other end of tube 46. Therefore, when the passages of the connector members 17 and 45 are opened, all of the bags, i.e. the blood storage space 13 of the blood collection bag 10, the chemicals storage space 43 of the chemicals storage bag 40, the blood plasma storage space 23 of the blood plasma bag 20 and the buffy coat storage space 33 of the buffy coat bag 30 are allowed to communicate with each other, via the connector members 17 and 45, the tubes 61, 62, 63, 25 and 46 and the branch connectors 64 and 19. It is preferable to preliminarily introduce an anti-coagulant in the blood collection bag 10. This anti-coagulant is liquid in general and may be, for example, an ACD-A solution, a CPD solution, a CPDA-1 . solution or heparin sodium solution. The volume of these anti-coagulants may be suitably determined in advance depending on the volume of blood to be collected. The buffy coat bag 30 may be the one which contains in advance a platelet preservation solution. Examples of such a platelet preservation solution are a physiological saline solution, a GAC solution, a 1?AS solution, a PSM-1 solution and a synthetic storage medium solution. Next, the conditions for the materials that can be employed for the bags 10, 20, 30 and 40 will be explained. (1) The blood collection bag 10: The blood collection bag 10 constituting a blood component preservation container of the invention is formed of a soft polyvinyl chloride sheet containing a first plasticizer and a second plasticizer, wherein the hemolysis depression effect (an effect to minimize the amount of hemoglobin to be eluted into a liquid to be preserved) is attained by the first plasticizer which is aluted from the soft polyvinyl chloride sheet into a liquid to be preserved (hereinafter referred to as a preservation liquid or solution) and the second plasticizer which is eluted from the soft polyvinyl chloride sheet into a preservation liquid or solution in a very small amount. In addition, the MA generation suppression effect is attained by a high gas per¬meability of the soft polyvinyl chloride sheet that is provided by the second plasticizer. Due to a balanced combination of these hemolysis depression effect and MA generation suppression effect, it is possible to obtain a blood collection bag, which is excellent in blood cell preservation property. The resin constituting the soft polyvinyl chloride sheet may be selected from polyvinyl chloride and polymeric materials mainly comprising polyvinyl chloride (such as a copolymer, a polymer blend and a polymer alloy, each containing a small amount of other polymer materials). The first plasticizer should be exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component. This limitation of the elution level on the first plasticizer is based on the results obtained from the relationship between an amount of plasticizer added to the sheet and the amount of the plasticizer eluted (FIG. 2), and on the results obtained front the relationship between the amount of the plasticizer eluted and the rate of hemolysis (FIG. 3), with di-2-ethylhexyl phthalate (DEHP) used as the plasticizer. The first plasticizer should preferably be an aliphatic or aromatic acid ester containing at least two ester linkages and containing an aliphatic hydrocarbon group having 4 to 12 carbon atoms in its hydrocarbon chain. Among them/ dialkyl phthalate and dialkyl adipate are preferable in particular. Specific examples of the first plasticizer are dioctyl phthalate, dioctyl adipate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, di-2-ethylhexyl maleate, dibutyl phthalate and dihexyl phthalate. These esters may be employed singly or in combination of two or more of these. Among them, di-2-ethylhexyl phthalate (DEHP) or a composition mainly comprising DEHP is most preferable, because of the stability in the amount of elution and an excellent hemolysis depression effect that may be obtained therefrom. The content of the first plasticizer in the polyvinyl chloride sheet should preferably be 5 to 40% by weight, more preferably 10 to 30% by weight, and most preferably 10 to 25% by weight. If the content of the first plasticizer is less than 5% by weight, the amount of elution of the first plasticizer becomes too small to obtain a sufficient hemolysis depression effect. On the other hand, if the content of the first plasticizer exceeds 40% by weight, the amount of elution of the first plasticizer becomes excessive so that the physiological activity of blood cell may be adversely affected by the first plasticizer, and at the same time, the inclusion of such a large amount of the first plasticizer may deteriorate the mechanical strength of the bag so that the bag may be fractured during the centrifugation, for instance. The second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when the second plasticizer is singly mixed in the polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 l>/ar -mm-day -atm (30^), more preferably not less than 4.2 L/m2-mm-day-atm (30T:), and preferably also the carbon dioxide gas permeability of the resultant polyvinyl chloride sheet becomes not less than 23.0 L/ra2 -mm -day -atm (301C). In particular, the second plasticizer should preferably be the one, which is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predeter¬mined amount of a blood component is preserved at a temperature of 4"C for 35 days in a blood component preservation container formed of the resultant polyvinyl chloride, 2 ppm by weight or more of the added second plasticizer is eluted into the blood component, but the elution amount of the second plasticizer is smaller than that of the first plasticizer. Namely, the second plasticizer should be slightly exudative to the blood component. Preferable examples of the second plasticizer are phthalic diester, dialkyl phthalate, adipic ester and dialkyl adipate, each having two or more aliphatic hydrocarbon groups each containing 4 to 12 carbon atoms. In this case, the phthalic diester should preferably be di-n-decyl phthalate, and the dialkyl adipate should preferably be di-octyl adipate. In particular, a diester which can be derived from phthalic acid and an alcohol or aliphatic hydrocarbon group having 8 to 12 carbon atoms is preferable. Among them, di-n-decyl phthalate (DnDF) or a composition mainly comprising DnDP is more preferable. Of the dioctyl adipate, di-2-ethylhexyl .adipate (DEHA) is more preferable. The content of the second plasticizer in the polyvinyl chloride sheet should preferably be 5 to 45% by weight, more preferably 10 to 30% by weight, and most preferably 12 to 30% by weight. If the content of the second plasticizer is less than 5% by weight, the gas permeability of the resultant polyvinyl chloride sheet becomes too low and the MA generation suppressing effect of the sheet would be deteriorated. On the other hand, if the content of the second plasticizer exceeds 45% by weight, the content of the first plasticizer would inevitably become very little due to the limitation on the total amount of the first and second piasticizers (the total amount of the first and second plasticizers is confined to a certain level with a view to maintain the mechanical strength of the resultant sheet), so that the hemolysis depression effect to be derived from the first plasticizer would be deteriorated. Since the second plasticizer of the present invention is slightly exudative to blood plasma, the following advantages will be obtained. If the second plasticizer not exudative at all, only the first plasticizer would elute, so that a fairly large amount of the first plasticizer is required to be added in order to sufficiently suppress the hemolysis. However, since there is a limitation (for example, 50% by weight) on the total amount of the first and second plasticizers in order to maintain the mechanical strength of the resultant sheet as explained below, each amount of the first plasticizer and the second plasticizer is also restricted to a certain level. By contrast, when the second plasticizer is slightly exudative, both first plasticizer and second plasticizer would elute, so that a sufficient hemolysis depression effect can be attained with a relatively smaller amount of the first plasticizer as compared with the case where the second plasticizer is not exudative at all. As a result, the amount of the second plasticizer to be added can be correspondingly increased, thus making it possible to obtain a polyvinyl chloride sheet excellent in gas permeability. Namely, it is possible according to the present invention to obtain a polyvinyl chloride sheet improved in both plasticizer elution property and gas per¬meability, thereby achieving an effective and balanced suppression of the hemolysis and the MA generation, while maintaining a predetermined mechanical strength of the polyvinyl chloride sheet. The total content of the first plasticizer and the second plasticizer should preferably be in the range of 20 to 50% by weight, more preferably 25 to 40% by weight. If this total content is less than 25% by weight, at least one of the hemolysis depression effect and the MA generation-suppressing effect may become insufficient. On the other hand, if this total content exceeds 50% by weight, the mechanical strength (such as tensile strength) of the resultant polyvinyl chloride sheet would be deteriorated, and hence a bag formed of such a polyvinyl chloride sheet may be fractured if it is exposed to a severe condition such as a centri fugation. The polyvinyl chloride sheet may contain, if desired, various additives such as a stabilizer, in addition to the first and second plasticizers. As the stabilizer, various kinds of epoxy compounds, compounds of zinc, calcium, barium or magnesium may be added in the polyvinyl chloride sheet at a ratio of 0.1 to 15% by weight, for instance. The thickness of the polyvinyl chloride sheet may be suitably determined taking into consideration the balance between the mechanical strength and the gas permeability required for the polyvinyl chloride sheet. However, in general, the thickness of the polyvinyl chloride sheet should preferably be in the range of 0.2 to 0.5 mm, more preferably 0.25 to 0.4 mm. The polyvinyl chloride sheet having the aforementioned features may be manufactured, for instance, by the following method. A soft polyvinyl chloride, the first plasticizer and the second plasticizer are sufficiently kneaded by a kneader to obtain a kneaded product, which is then extruded via a T-die or a circular die to obtain a flat sheet. The sheet is then subjected to a sequence of manufacturing steps including a thermoforroing step, a blowing step, a stretching step, a cutting step and a step of sealing (fusion bonding) the end portion to obtain a product of predetermined shape and structure. The surface of the sheet (raw material) may be roughened (or embossed), or coated or applied with an anti-blocking agent or a slip agent for preventing the blocking of the interface between the sheets - (2) The platelet bag: The chemicals storage bag 40 may be utilized as a platelet bag for preserving platelet after the erythrocyte preservation solution 47 is transferred to the blood storage space 13 of the blood collection bag 10. There is not any particular limitation regarding the composition and property of the sheet material for constituting the chemicals storage bag 40. For example, the same materials as employed for the blood collection bag 10 may be employed. If the same materials as employed for the blood collection bag 10 are employed in the manufacture of the chemicals storage bag 40, the manufacture of the bag may be simplified because of the decrease in kinds of sheet materials to be prepared, and at the same time, the preservation of platelet will be improved due to the elution of the plasticizers and also to the excellent gas permeability of the bag (for example, the effective preservation period will be extended to 3 to 5 days). (3) The blood plasma bag 20: There is not any particular limitation regarding the composition and property of the sheet meterial for constituting the plasma bag 20. For example, the same materials as employed for the blood collection bag 10 may be employed. If the same materials as employed for the blood collection bag 10 are employed in the manufacture of this plasma bag 20, the manufacture of the bag may be simplified because of the decrease in kinds of sheet materials to be prepared. (4) The tubes 15, 61, 62, 63, 25 and 46: As for the materials for the tubes 15, 61, 62, 63, 25 and 46, polyvinyl chloride, polyethylene, polypropylene, polyester (such as PET, PBT), ethylene-vinyl acetate copolymer, polyurethane, a thermoplastic elastomer (such as polyester elastomer, styrene-butadiene-styrene copolymer) or a material mainly comprised of any of these polymers may be employed. Among them, polyvinyl chloride and a material mainly comprising polyvinyl chloride are preferable for use. If each-of these tubes is formed of polyvinyl chloride, they may be excellent in pliability and flexibility, thereby making it easy to handle them, and at the same time they may be easily closed with a clamp and the like. Moreover, since a polyvinyl chloride tube is excellent in compatibility with the sheet material forming the bags and made of the same kind of material as that of the tube, a bonding or adhesion which is high in bonding strength and excellent in gas-tightness will be effected between the tubes and the bags, which is preferable in view of assuring the invulnerability to the centrifugation and retaining the sterilized condition of the bags. There is not any particular limitation with respect to the kind and content of plasticizer to be employed for these tubes. As for the multi-linkage container system of the present invention, it is not limited to the construction shown in the drawing, but may be of any construction as far as it includes a blood component preservation container for preserving a liquid containing a blood component, i.e., a blood cell preservation bag such as a blood collection bag or an erythrocyte preservation bag as explained above. For example, the multi-linkage container system of the present invention may be a double bag comprising a blood collection bag and a platelet bag; a triple-linkage bag comprising a blood collection bag, a blood plasma bag and a platelet bag; a quadruple-linkage bag comprising a blood collection bag, a platelet bag, a blood plasma bag and an erythrocyte bag for exclusive use therefor; a quadruple-linkage bag comprising a blood collection bag which may be used also as an erythrocyte bag, a platelet bag, a plasma bag and a buffy coat bag (a small bag for relay); or any other multi-linkage bags where any additional bag for additional end-use is attached to any of the aforementioned bags. The container to be connected with the blood component preservation container may be formed of a bag made of the same material as used for forming the tubes or formed of a container of any other shape and construction. This invention will be further explained with reference to the following specific examples. Examples 1-2, and Comparative Examples 1 to 4 A. Method of experiment: (1) Manufacture of a multi-linkage bag system Various kinds of sheets having compositions and properties as shown in Table 1 below were employed and formed into a 2-ply structure, which was then cut and the periphery thereof was heat-sealed thereby to form a blood collection bag. Likewise, a platelet bag (chemicals storage bag), a blood plasma bag and a buffy coat bag were prepared. 95 ml of an erythrocyte preservation liquid (an aqueous solution containing M-A.P. solution/sodium chloride: 5.52 g/1; adenine: 0.16 g/1; glucose: 8.01 g/1; mannitol: 16.19 g/1; citric acid: 0-22 g/1; sodium citrate: 1.67 g/1; sodium phosphate: 1.04 g/1) was introduced via the tube into the platelet bag (chemicals storage bag). Then, all of the bags were connected via pliable tubes, and at the same time, a blood collecting tube was connected to the blood collection bag. Thereafter, 60 ml of an anticoagulant (an aqueous solution containing ACD-A solution/sodium citrate: 22.0 g/1; citric acid: 8.0 g/1; and glucose: 22.0 g/1) was introduced via the tube into the blood collection bag, thereby preparing a quadruple-linkage bag system comprising four bags connected with each other. This quadruple-linkage bag system was then subjected to a high pressure steam sterilization (121t:, 30 minutes). The construction of each bag in this quadruple-linkage bag system is shown in Table 2 below. The tubes and the blood collecting tube employed herein were made of a soft polyvinyl chloride containing 36.7% by weight of di-2-ethylhexyl phthalate. (Table Removed) PVC: Polyvinyl chloride PO : A mixture of poly (ethylenebutylene) polystyrene block copolymer, polypropylene and polyethylene vinyl acetate An apparatus for measuring 02 gas permeability: L-100, Dr. Lysssy, Zollikon, Switzerland (Table Removed) (2) Heavy metals and eluate test Tests on heavy metals and eluate were performed according the specification prescribed in Japanese Pharmaceutical Codex, General Testing Method, RPlastic container for Transfusion Testing Methods. (3) Separation of blood components About 400 ml of whole blood was introduced into the blood collection bag, and then the multi-linkage bag system was subjected to a centrifugation by a centrifugal separator, thereby separating the whole blood into three phases, i.e., a platelet-poor plasma, a buffy coat and a concentrated erythrocyte. Then, the platelet-poor plasma in the blood collection bag was transferred via the tube to the blood plasma bag. Thereafter, the buffy coat was transferred via the tube to the buffy coat bag, leaving the concentrated erythrocyte in the blood collection bag. Then, the erythrocyte preservation solution which had been charged in advance in the platelet bag was transferred via the tube to the blood collection bag, and after a predetermined portions of the tubes were heat-sealed, the tubes were cut off to separate the multi-linkage bag system into a blood collection bag (erythrocyte bag) filled with the concentrated erythrocyte mixed with an erythrocyte preservation solution, a platelet bag filled with platelet poor plasma, and a double-linkage bag system consisting of the buffy coat bag filled with buffy coat and the platelet bag. The double-linkage bag system was then subjected to a slight centrifugation to separate the buffy coat in the buffy coat bag into two layers, i.e., an upper layer comprising a concentrated platelet and a lower layer comprising leukocyte. Then, the concentrated platelet was transferred via the tube to the platelet bag. Finally, the tube linking the platelet bag and the buffy coat bag was cut off to separate these bags from each other. (4) Confirmation of HA generation The blood collection bag which was obtained in-the aforementioned procedure (3) and filled with the concentrated erythrocyte mixed with a erythrocyte preservation solution was preserved for 35 days at a temperature of 41C, and then the generation of MA was observed for each of the samples according to Example 1 and Comparative Examples 1 to 3. The results are shown in Table 3 below. (5) Confirmation of hemolysis level The blood collection bag which was obtained in the aforementioned procedure (3) and filled with the concentrated erythrocyte mixed with a erythrocyte preservation solution was preserved for 35 days at a temperature of 4t, and then 1 ml of sample solution after the preservation was aseptically taken out from each of the bags according to Example 1 and Comparative Examples 1 to 3 to measure the hemoglobin concontraLion and the hematocrit value by using an automatic blood cell counter (Sysmex CC-180 available from Toa lyo Densi Co. Ltd., Japan). Furthermore, a portion of the sample solution taken out was subjected to a centrifugation for 15 minutes under the condition of 1,500 G by using a centrifugal separator (KR-702 available from Kubota Seisakusho Co. Ltd., Japan) to take out the upper layer constituted by blood plasma. Thereafter, the hemoglobin concentration in the blood plasma was measured by means of Leuco-crystal violet method JLCV method). The values obtained in this manner were put into the following equation to calculate the degree of hemolysis, the results being shown in Table 3. Hemolysis degree (%) = {[hemoglobin concentration (mg/dl) in plasma x (1 - hematocrit/100)] / [hemoglobin concentration (g/dl) in M.A.P.-added concentrated erythrocyte x 1,000]} x 100 (6) Confirmation of preservation state of platelet The platelet bag which was obtained in the aforementioned procedure (3) and filled with a concentrated platelet was preserved with stirring at a temperature of 22X:/ and then 1 ml of sample solution was aseptically taken out from the bag on Oth day, 3rd day and 5th day to measure the number of platelets in the sample solution.by using the aforementioned automatic blood cell counter, the results baing shown in Table 4. Furthermore, the pH value (at 37X1) of the sample solution taken out as mentioned above was measured by using a blood gas/pH measuring apparatus (IL 1304 available from Instrumentation Lab.), the results being shown in Table 5. (7) Centrifugation The blood collection bag filled with a predetermined volume of distilled water was subjected to a centrifugation under the following conditions. Centrifugal separator: Himac CR7B3, Hitachi Seisakusho, Japan Conditions : 1.80 x 10® gasec., 4,000 rpm (4,670 G), 22t:. After the centrifugation, the blood collection bag was taken out of the auxiliary cup and examined to see if any damage was caused thereto, the results being shown in Table 6. B. Results of the experiment (1) Preparation of sheet and bag The preparation of sheets could be smoothly performed, obtaining sheets excellent in uniformity. The preparation of each bag was also smoothly performed. (2) Results of the heavy metals and eluate test It was confirmed that all of the samples satisfied, in terms of heavy metals and eluate, the conditions prescribed in the specification of Japanese Pharmaceutical Codex, General Testing Method, RPlastic container for Transfusion Testing Methods. (3) Evaluation on the preservation of erythrocyte Table 3 shows findings on the generation of macroaggregate (MA) and hemolysis level. As seen from Table 3, the blood collection bags according to Examples 1 and 2 indicated no generation of MA, and at the same time it was confirmed that the level of hemolysis in the blood collection bags according to Examples 1 and 2 was very low. (Table Removed) (4) Evaluation on the preservation of platelet Table 4 shows the change with time in the number of platelets, and Table 5 shows the change with time of pH value. As shown in Table 4, any substantial change in the number of platelets was recognized in any of the samples. As shown in Table 5, Comparative Example 2 indicated the lowering of pH value or the deterioration in quality of platelets under the aforementioned condition that the number of platelets was almost the same in all of the samples, which was assumed to be caused by the low gas permeability of sample according to Comparative Example 2. However, with respect to other samples, it was confirmed that they could be preserved in a stable condition up to 5th days of storage. (Table Removed) (5) Evaluation on the strength of bag by making use of centrifugation test Table 6 shows the number of fractured blood collection bags which were subjected to a centrifugation test. As seen from Table 6, the blood collection bags according to Examples 1 and 2 were not fractured at all, indicating a sufficient degree of strength of the bag to withstand the operation of centrifugation. (Table Removed) As explained above, it is possible, according to the blood component preservation container and the multi-linkage container system of the present invention, to attain a suitable degree of elution of plasticizer and a high gas permeability so as to concurrently achieve an excellent hemolysis depression effect and an excellent macroaggregate (MA) suppression effect as a blood component is preserved therein. These effects will be further promoted, while assuring a sufficient mechanical strength of the blood component preservation container, in particular a mechanical strength sufficient to withstand the operation of centrifugation, if a plasticizer of slightly exudative is employed as the second plasticizer; if a preferable composition is employed for the first plasticizer and for the second plasticizer; if each content of the first plasticizer and the second plasticizer are suitably selected and at the same time the total content of the first and second plasticizers is selected within the aforementioned predetermined range. Due to the aforementioned features of the blood component preservation container and the multi-linkage container of the present invention/ it is possible to preserve erythrocyte and other blood components for a long period of time, while maintaining the quality of the erythrocyte, etc., in an excellent condition. Furthermore, the blood component preservation container and the multi-linkage container system pf the present invention are easy in handling and manufacture, and excellent in safety. We Claim : 1. A blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing 5 to 40% by weight of a first plasticizer as herein described and 5 to 45% by weight of a second plasticizer as herein described; wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C). 2. The container as claimed in claim 1, wherein said second plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4°C for 35 days in a blood component preservation container formed of the resultant polyvinyl chloride, 2 ppm by weight or more of the added second plasticizer is eluted into the blood component, but the elution amount of the second plasticizer is smaller than that of the first plasticizer. 3. The container as claimed in claim 1 or 2, wherein said second plasticizer is an aliphatic or aromatic ester having at least two ester linkages and containing an aliphatic hydrocarbon group having at least four carbon atoms in its hydrocarbon chain. 4. The container as claimed in claim 3, wherein said second plasticizer is selected from the group consisting of phthalic diester, dialkyl phthalate, adipic ester and dialkyl adipate, each having two or more aliphatic hydrocarbon groups each containing 4 to 12 carbon atoms. 5. The container as claimed in claim 4, wherein said phthalic diester is di- n-decyl phthalate, and said dialkyl adipate is di-octyl adipate. 6. The container as claimed in claims 1 to 5, wherein said first plasticizer is an aliphatic or aromatic ester having at least two ester linkages and containing an aliphatic hydrocarbon group having 4 to 12 carbon atoms in its hydrocarbon chain. 7. The container as claimed in claim 6, wherein said first plasticizer is dialkyl phthalate or dialkyl adipate. 8. The container as claimed in any one of claims 1 to 5, wherein said first plasticizer is dioctyl phthalate. 9. The container as claimed in any one of claims 1 to 8, wherein the total content of said first plasticizer and said second plasticizer is 20 to 50% by weight. 10. A multi-linkage container system comprising a plurality of containers connected together via tubes, said containers including at least one blood component preservation container as claimed in any one of claims 1 to 9. 11. A blood component preservation container and multi-linkage container system, substantially as hereinbefore described with reference to the accompanying drawings.

Full Text

This invention relates to a blood component preservation container which is suited for preserving blood, a blood component, in particular an erythrocyte-containing solution, and also to a multi-linkage container.
In recent years, a blood component preservation container of bag-like structure which is formed of superimposed thermoplastic resin sheets whobe peripheries are fusion-bonded with each other has been extensively utilized as a container for collecting, separating or preserving blood.
This blood component preservation container (a blood bag) is required to have various properties, such as a sufficient transparency for enabling the condition of blood or blood components contained therein to be observed from outside; a sufficient flexibility (pliability) for easily enabling various operations such as blood collection, blood transfusion or separation of blood components; a sufficient strength for withstanding these operations; an excellent sanitariness; and an excellent safety.
Since soft polyvinyl chloride meets roost of these requirements, it is predominantly utilized as a material for the blood bag at present.
Meanwhile, as far as the preservation of erythrocyte component is concerned, there has been an advancement in the development of a preservation
solution for exclusive use therefor, i.e., a preservation solution (such as M.A.P. solution) which is capable of effectively preserving erythrocyte component for 42 days has been developed and is actually put into use now.
However, in spite of the availability of such a preservation solution to preserve erythrocyte component for a long period of time, there has been raised another problem that a big agglomerate or a so-called macroaggregate (hereinafter referred to as HA) is quite frequently generated during the storage of erythrocyte. No measures have been developed as yet to prevent the generation of this MA.
It is also important to prevent the hemolysis (the destruction of blood cell) of erythrocyte being preserved. Namely, if the hemolysis degree of erythrocyte is increased, the quality of erythrocyte preparation would be deteriorated.
Although various methods have been developed to prevent the heroolysis, all of these methods are only aimed at preventing the hemolysis, and a method for suppressing not only the hemolysis but also the generation of MA has not been developed as yet.
Accordingly, an object of the present invention is to provide a blood component preservation container which is excellent in blood component preservation property and capable of suppressing not only the
hemoiysis of erythrocyte but also the generation of macroaggregate (MA).
Another object of the present invention is to provide a multi-linkage container system comprising such a blood component preservation container as mentioned above.
These objects have been accomplished according to the present invention by a blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing a first plasticizer and a second plasticizer, wherein the first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predeter¬mined amount of a blood component is preserved at a temperature of 4tJ for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppra by weight or more of the added first plasticizer is eluted into the blood component, and the second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when the second plasticizer is singly mixed in the polyvinyl chloride sheet at a ratio of 32% by weight, the oxygen gas permeability of the resulting polyvinyl chloride sheet is not less than 4,0 L/m2 -mm -day -atm (30t;).
To meet the aforementioned objectives, the invention provides for a blood component preservation container for preserving a liquid containing at least a blood component, which is formed of a soft polyvinyl chloride sheet containing 5 to 40% by weight of a first plasticizer as herein described and 5 to 45% by weight of a second plasticizer as herein described;
wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C).
This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a plan view showing one example of a multi-linkage container system according to the present invention;
FIG. 2 is a graph showing the relationship between an amount of a plasticizer (OEHP) added and an amount of the plasticizer eluted; and
FIG. 3 is a graph showing the relationship between the amount of a plasticizer (DEHP) added and the rate of hemolysis.
A blood component preservation container and a multi-linkage container system according to the present invention will be explained in detail with reference to a preferred embodiment shown in the drawings.
FIG. 1 shows a plan view illustrating one example of a multi-linkage container system 1 according to the present invention. Referring to FIG. 1, this multi-linkage container system 1 is formed of quadruple containers including a blood collection bag (a first bag) 10, a blood plasma bag (a second bag) 20, a buffy coat bag (a third bag) 30 and a chemicals storage bag (a fourth bag) 40, all of these bags being connected with each other via prescribed tubes.
Specifically, the blood collection bag 10 disposed leftmost side in FIG. 1 constitutes a blood component
preservation container and includes a main bag portion
11 comprising two pliable polyvinyl chloride sheets
which are superimposed one upon another and the
peripheries of which are fusion-bonded (through heat
bonding or high-frequency bonding) or adhered, thereby
forming a sealed portion 12.
The inner portion surrounded by the scaled portion
12 of the main bag portion 11 serves as a blood storage
space 13 for storing a collected blood. Further, since
the blood collection bag 10 can be utilized also as an
erythrocyte bag for preserving erythrocyte therein,
the blood storage space 13 may be used for ultimately
storing and preserving a concentrated erythrocyte.
The main bag portion 11 is provided at its upper portion with a couple of sealed opening ports 14 each provided with a peeling tab for opening the opening ports 14. The main bag portion 11 is also provided, beside.the opening ports 14, with an outlet port 18 for communicating the blood storage space 13 with other bags 30, 20 and 40. To this outlet port 18 is connected one end of a tube 61 via a connector member 17. Preferably, the connector member 17 is constructed in such a manner that the passage thereof is closed before the connector member 17 is fractured, but can be opened once the connector member 17 is fractured.
To the other end of the tube 61 is connected a Y-shaped branch connector 64, to the branched ends
of which each end of tubes 62 and 63 is connected respectively. The other end of the tube 62 is attached with a branch connector 19 of the same construction ao that of the branch connector 64. The branched ends of the branch connector 19 are connected to each end of tubes 25 and 46 respectively.
A pliable tube 15 is attached via one *»nd thereof to the upper portion of the main bag portion 11 so as to communicated with the interior of the blood storage space 13. The other end of the pliable tube 15 is attached via a hub 151 with a blood collecting needle 152. The hub 151 is adapted to be mounted with a cap 153 for encasing the blood collecting needle 152.
The blood plasma bag 20 includes a main bag portion 21 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or high-frequency bonding) or adhered thereby forming a sealed portion 22.
The inner portion surrounded by the sealed portion 22 of this main bag portion 21 is used as a plasma storage space 23 for storing plasma separated from the blood in the blood collecting bag 10.
The main bag portion 21 is provided at its upper portion with a couple of sealed outlet ports 24 for blood transfusion each provided with a peeling tab for
opening the outlet ports 24. The main bag portion 21 is connected, beside the outlet ports 24, with the other end portion of the tube 25 communicating with the plasma storage space 23. Therefore, when the passage of the connector member 17 is opened, the blood storage space 13 of the blood collection bag 10 is allowed to communicate, via the connector member 17, the tubes 61, 62 and 25 and the branch connectors 64 and 19, with the blood plasma storage space 23 of the blood plasma bag 20.
The buffy coat bag 30 includes a main bag portion 31 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or" high-frequency bonding) or adhered thereby forming a sealed portion 32.
The inner portion surrounded by the sealed portion 32 of this main bag portion 31 is used as a buffy coat storage space 33 for storing buffy coat separated from the blood in the blood collecting bag 10.
The main bag portion 31 is connected via its upper portion with the other end of the tube 63 communicating with the buffy coat storage space 33.
The chemicals storage bag 40 includes a main bag portion 41 comprising two pliable soft resin sheets such as soft polyvinyl chloride sheets which are
superimposed one upon another and the peripheries of which are fusion-bonded (through heat bonding or high-frequency bonding) or adhered, thereby forming a sealed portion 42,
The inner portion surrounded by the sealed portion 42 of this main bag portion 41 is used as a chemicals storage space 43 for storing chemicals. In this embodiment, a predetermined volume of an erythrocyte preservation solution 47 is stored in the chemicals storage space 43. This erythrocyte preservation solution may be a M.A.P. solution, a S.A.G.M. solution, an OPTISOL solution or an ADSOL solution.
The main bag portion 41 is provided at its upper portion with a couple of sealed 'outlet ports 44 each provided with a peeling tab for opening the outlet ports 44. The main bag portion 41 is provided, beside the outlet ports 44, with a connector member 45 of the same construction as that of the connector member 17 for communicating with the chemicals storage space 43. To this connector member 45 is connected the other end of tube 46. Therefore, when the passages of the connector members 17 and 45 are opened, all of the bags, i.e. the blood storage space 13 of the blood collection bag 10, the chemicals storage space 43 of the chemicals storage bag 40, the blood plasma storage space 23 of the blood plasma bag 20 and the buffy coat storage space 33 of the buffy coat bag 30 are allowed to communicate with each other, via the connector members 17 and 45, the tubes 61, 62, 63, 25 and 46 and the branch connectors 64 and 19.
It is preferable to preliminarily introduce an anti-coagulant in the blood collection bag 10. This anti-coagulant is liquid in general and may be, for example, an ACD-A solution, a CPD solution, a CPDA-1 . solution or heparin sodium solution. The volume of these anti-coagulants may be suitably determined in advance depending on the volume of blood to be collected.
The buffy coat bag 30 may be the one which contains in advance a platelet preservation solution. Examples of such a platelet preservation solution are a physiological saline solution, a GAC solution, a 1?AS solution, a PSM-1 solution and a synthetic storage medium solution.
Next, the conditions for the materials that can be employed for the bags 10, 20, 30 and 40 will be explained.
(1) The blood collection bag 10:
The blood collection bag 10 constituting a blood component preservation container of the invention is formed of a soft polyvinyl chloride sheet containing a first plasticizer and a second plasticizer, wherein the hemolysis depression effect (an effect to minimize the amount of hemoglobin to be eluted into a liquid to be preserved) is attained by the first plasticizer which is aluted from the soft polyvinyl chloride sheet into a liquid to be preserved (hereinafter referred to as a preservation liquid or solution) and the second plasticizer which is eluted from the soft polyvinyl chloride sheet into a preservation liquid or solution in a very small amount. In addition, the MA generation suppression effect is attained by a high gas per¬meability of the soft polyvinyl chloride sheet that is provided by the second plasticizer. Due to a balanced combination of these hemolysis depression effect and MA generation suppression effect, it is possible to obtain a blood collection bag, which is excellent in blood cell preservation property.
The resin constituting the soft polyvinyl chloride sheet may be selected from polyvinyl chloride and polymeric materials mainly comprising polyvinyl chloride (such as a copolymer, a polymer blend and a polymer alloy, each containing a small amount of other polymer materials).
The first plasticizer should be exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4*C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet,
15 ppm by weight or more of the added first plasticizer is eluted into the blood component.
This limitation of the elution level on the first plasticizer is based on the results obtained from the relationship between an amount of plasticizer added to the sheet and the amount of the plasticizer eluted (FIG. 2), and on the results obtained front the relationship between the amount of the plasticizer eluted and the rate of hemolysis (FIG. 3), with di-2-ethylhexyl phthalate (DEHP) used as the plasticizer.
The first plasticizer should preferably be an aliphatic or aromatic acid ester containing at least two ester linkages and containing an aliphatic hydrocarbon group having 4 to 12 carbon atoms in its hydrocarbon chain. Among them/ dialkyl phthalate and dialkyl adipate are preferable in particular.
Specific examples of the first plasticizer are dioctyl phthalate, dioctyl adipate, di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, di-2-ethylhexyl maleate, dibutyl phthalate and dihexyl phthalate. These esters may be employed singly or in combination of two or more of these. Among them, di-2-ethylhexyl phthalate (DEHP) or a composition mainly comprising DEHP is most preferable, because of the stability in the amount of elution and an excellent hemolysis depression effect that may be obtained therefrom.
The content of the first plasticizer in the polyvinyl chloride sheet should preferably be 5 to 40% by weight, more preferably 10 to 30% by weight, and most preferably 10 to 25% by weight. If the content of the first plasticizer is less than 5% by weight, the amount of elution of the first plasticizer becomes too small to obtain a sufficient hemolysis depression effect. On the other hand, if the content of the first plasticizer exceeds 40% by weight, the amount of elution of the first plasticizer becomes excessive so that the physiological activity of blood cell may be adversely affected by the first plasticizer, and at the same time, the inclusion of such a large amount of the first plasticizer may deteriorate the mechanical strength of the bag so that the bag may be fractured during the centrifugation, for instance.
The second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when the second plasticizer is singly mixed in the polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 l>/ar -mm-day -atm (30^), more preferably not less than 4.2 L/m2-mm-day-atm (30T:), and preferably also the carbon dioxide gas permeability of the resultant polyvinyl chloride sheet becomes not less than 23.0 L/ra2 -mm -day -atm (301C). In particular, the second plasticizer should preferably be the one, which is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predeter¬mined amount of a blood component is preserved at a temperature of 4"C for 35 days in a blood component preservation container formed of the resultant polyvinyl chloride, 2 ppm by weight or more of the added second plasticizer is eluted into the blood component, but the elution amount of the second plasticizer is smaller than that of the first plasticizer. Namely, the second plasticizer should be slightly exudative to the blood component.
Preferable examples of the second plasticizer are phthalic diester, dialkyl phthalate, adipic ester and dialkyl adipate, each having two or more aliphatic hydrocarbon groups each containing 4 to 12 carbon atoms. In this case, the phthalic diester should preferably be di-n-decyl phthalate, and the dialkyl adipate should preferably be di-octyl adipate.
In particular, a diester which can be derived from phthalic acid and an alcohol or aliphatic hydrocarbon group having 8 to 12 carbon atoms is preferable. Among them, di-n-decyl phthalate (DnDF) or a composition mainly comprising DnDP is more preferable. Of the dioctyl adipate, di-2-ethylhexyl .adipate (DEHA) is more preferable.
The content of the second plasticizer in the polyvinyl chloride sheet should preferably be 5 to 45% by weight, more preferably 10 to 30% by weight, and most preferably 12 to 30% by weight. If the content of the second plasticizer is less than 5% by weight, the gas permeability of the resultant polyvinyl chloride sheet becomes too low and the MA generation suppressing effect of the sheet would be deteriorated. On the other hand, if the content of the second plasticizer exceeds 45% by weight, the content of the first plasticizer would inevitably become very little due to the limitation on the total amount of the first and second piasticizers (the total amount of the first and second plasticizers is confined to a certain level with a view to maintain the mechanical strength of the resultant sheet), so that the hemolysis depression effect to be derived from the first plasticizer would be deteriorated.
Since the second plasticizer of the present invention is slightly exudative to blood plasma, the following advantages will be obtained.
If the second plasticizer not exudative at all, only the first plasticizer would elute, so that a fairly large amount of the first plasticizer is required to be added in order to sufficiently suppress the hemolysis. However, since there is a limitation (for example, 50% by weight) on the total amount of the
first and second plasticizers in order to maintain the mechanical strength of the resultant sheet as explained below, each amount of the first plasticizer and the second plasticizer is also restricted to a certain level.
By contrast, when the second plasticizer is slightly exudative, both first plasticizer and second plasticizer would elute, so that a sufficient hemolysis depression effect can be attained with a relatively smaller amount of the first plasticizer as compared with the case where the second plasticizer is not exudative at all. As a result, the amount of the second plasticizer to be added can be correspondingly increased, thus making it possible to obtain a polyvinyl chloride sheet excellent in gas permeability. Namely, it is possible according to the present invention to obtain a polyvinyl chloride sheet improved in both plasticizer elution property and gas per¬meability, thereby achieving an effective and balanced suppression of the hemolysis and the MA generation, while maintaining a predetermined mechanical strength of the polyvinyl chloride sheet.
The total content of the first plasticizer and the second plasticizer should preferably be in the range of 20 to 50% by weight, more preferably 25 to 40% by weight. If this total content is less than 25% by weight, at least one of the hemolysis depression effect
and the MA generation-suppressing effect may become insufficient. On the other hand, if this total content exceeds 50% by weight, the mechanical strength (such as tensile strength) of the resultant polyvinyl chloride sheet would be deteriorated, and hence a bag formed of such a polyvinyl chloride sheet may be fractured if it is exposed to a severe condition such as a centri fugation.
The polyvinyl chloride sheet may contain, if desired, various additives such as a stabilizer, in addition to the first and second plasticizers. As the stabilizer, various kinds of epoxy compounds, compounds of zinc, calcium, barium or magnesium may be added in the polyvinyl chloride sheet at a ratio of 0.1 to 15% by weight, for instance.
The thickness of the polyvinyl chloride sheet may be suitably determined taking into consideration the balance between the mechanical strength and the gas permeability required for the polyvinyl chloride sheet. However, in general, the thickness of the polyvinyl chloride sheet should preferably be in the range of 0.2 to 0.5 mm, more preferably 0.25 to 0.4 mm.
The polyvinyl chloride sheet having the aforementioned features may be manufactured, for instance, by the following method.
A soft polyvinyl chloride, the first plasticizer and the second plasticizer are sufficiently kneaded by
a kneader to obtain a kneaded product, which is then extruded via a T-die or a circular die to obtain a flat sheet. The sheet is then subjected to a sequence of manufacturing steps including a thermoforroing step, a blowing step, a stretching step, a cutting step and a step of sealing (fusion bonding) the end portion to obtain a product of predetermined shape and structure.
The surface of the sheet (raw material) may be roughened (or embossed), or coated or applied with an anti-blocking agent or a slip agent for preventing the blocking of the interface between the sheets -
(2) The platelet bag:
The chemicals storage bag 40 may be utilized as a platelet bag for preserving platelet after the erythrocyte preservation solution 47 is transferred to the blood storage space 13 of the blood collection bag 10.
There is not any particular limitation regarding the composition and property of the sheet material for constituting the chemicals storage bag 40. For example, the same materials as employed for the blood collection bag 10 may be employed. If the same materials as employed for the blood collection bag 10 are employed in the manufacture of the chemicals storage bag 40, the manufacture of the bag may be simplified because of the decrease in kinds of sheet materials to be prepared, and at the same time, the
preservation of platelet will be improved due to the elution of the plasticizers and also to the excellent gas permeability of the bag (for example, the effective preservation period will be extended to 3 to 5 days).
(3) The blood plasma bag 20:
There is not any particular limitation regarding the composition and property of the sheet meterial for constituting the plasma bag 20. For example, the same materials as employed for the blood collection bag 10 may be employed. If the same materials as employed for the blood collection bag 10 are employed in the manufacture of this plasma bag 20, the manufacture of the bag may be simplified because of the decrease in kinds of sheet materials to be prepared.
(4) The tubes 15, 61, 62, 63, 25 and 46:
As for the materials for the tubes 15, 61, 62, 63, 25 and 46, polyvinyl chloride, polyethylene, polypropylene, polyester (such as PET, PBT), ethylene-vinyl acetate copolymer, polyurethane, a thermoplastic elastomer (such as polyester elastomer, styrene-butadiene-styrene copolymer) or a material mainly comprised of any of these polymers may be employed. Among them, polyvinyl chloride and a material mainly comprising polyvinyl chloride are preferable for use.
If each-of these tubes is formed of polyvinyl chloride, they may be excellent in pliability and flexibility, thereby making it easy to handle them, and
at the same time they may be easily closed with a clamp and the like. Moreover, since a polyvinyl chloride tube is excellent in compatibility with the sheet material forming the bags and made of the same kind of material as that of the tube, a bonding or adhesion which is high in bonding strength and excellent in gas-tightness will be effected between the tubes and the bags, which is preferable in view of assuring the invulnerability to the centrifugation and retaining the sterilized condition of the bags. There is not any particular limitation with respect to the kind and content of plasticizer to be employed for these tubes.
As for the multi-linkage container system of the present invention, it is not limited to the construction shown in the drawing, but may be of any construction as far as it includes a blood component preservation container for preserving a liquid containing a blood component, i.e., a blood cell preservation bag such as a blood collection bag or an erythrocyte preservation bag as explained above. For example, the multi-linkage container system of the present invention may be a double bag comprising a blood collection bag and a platelet bag; a triple-linkage bag comprising a blood collection bag, a blood plasma bag and a platelet bag; a quadruple-linkage bag comprising a blood collection bag, a platelet bag, a blood plasma bag and an erythrocyte bag for exclusive use therefor; a quadruple-linkage bag comprising a blood collection bag which may be used also as an erythrocyte bag, a platelet bag, a plasma bag and a buffy coat bag (a small bag for relay); or any other multi-linkage bags where any additional bag for additional end-use is attached to any of the aforementioned bags.
The container to be connected with the blood component preservation container may be formed of a bag made of the same material as used for forming the tubes or formed of a container of any other shape and construction.
This invention will be further explained with reference to the following specific examples. Examples 1-2, and Comparative Examples 1 to 4
A. Method of experiment:
(1) Manufacture of a multi-linkage bag system
Various kinds of sheets having compositions and properties as shown in Table 1 below were employed and formed into a 2-ply structure, which was then cut and the periphery thereof was heat-sealed thereby to form a blood collection bag. Likewise, a platelet bag (chemicals storage bag), a blood plasma bag and a buffy coat bag were prepared.
95 ml of an erythrocyte preservation liquid (an aqueous solution containing M-A.P. solution/sodium chloride: 5.52 g/1; adenine: 0.16 g/1; glucose:
8.01 g/1; mannitol: 16.19 g/1; citric acid: 0-22 g/1; sodium citrate: 1.67 g/1; sodium phosphate: 1.04 g/1) was introduced via the tube into the platelet bag (chemicals storage bag). Then, all of the bags were connected via pliable tubes, and at the same time, a blood collecting tube was connected to the blood collection bag. Thereafter, 60 ml of an anticoagulant (an aqueous solution containing ACD-A solution/sodium citrate: 22.0 g/1; citric acid: 8.0 g/1; and glucose: 22.0 g/1) was introduced via the tube into the blood collection bag, thereby preparing a quadruple-linkage bag system comprising four bags connected with each other.
This quadruple-linkage bag system was then subjected to a high pressure steam sterilization (121t:, 30 minutes). The construction of each bag in this quadruple-linkage bag system is shown in Table 2 below.
The tubes and the blood collecting tube employed herein were made of a soft polyvinyl chloride containing 36.7% by weight of di-2-ethylhexyl phthalate.
(Table Removed)
PVC: Polyvinyl chloride
PO : A mixture of poly (ethylenebutylene) polystyrene block copolymer, polypropylene and
polyethylene vinyl acetate An apparatus for measuring 02 gas permeability: L-100, Dr. Lysssy, Zollikon, Switzerland
(Table Removed)
(2) Heavy metals and eluate test
Tests on heavy metals and eluate were performed according the specification prescribed in Japanese Pharmaceutical Codex, General Testing Method, RPlastic container for Transfusion Testing Methods.
(3) Separation of blood components
About 400 ml of whole blood was introduced into the blood collection bag, and then the multi-linkage bag system was subjected to a centrifugation by a centrifugal separator, thereby separating the whole blood into three phases, i.e., a platelet-poor plasma, a buffy coat and a concentrated erythrocyte.
Then, the platelet-poor plasma in the blood collection bag was transferred via the tube to the blood plasma bag. Thereafter, the buffy coat was transferred via the tube to the buffy coat bag, leaving the concentrated erythrocyte in the blood collection bag.
Then, the erythrocyte preservation solution which had been charged in advance in the platelet bag was transferred via the tube to the blood collection bag, and after a predetermined portions of the tubes were heat-sealed, the tubes were cut off to separate the multi-linkage bag system into a blood collection bag (erythrocyte bag) filled with the concentrated erythrocyte mixed with an erythrocyte preservation solution, a platelet bag filled with platelet poor
plasma, and a double-linkage bag system consisting of the buffy coat bag filled with buffy coat and the platelet bag.
The double-linkage bag system was then subjected to a slight centrifugation to separate the buffy coat in the buffy coat bag into two layers, i.e., an upper layer comprising a concentrated platelet and a lower layer comprising leukocyte. Then, the concentrated platelet was transferred via the tube to the platelet bag.
Finally, the tube linking the platelet bag and the buffy coat bag was cut off to separate these bags from each other.
(4) Confirmation of HA generation
The blood collection bag which was obtained in-the aforementioned procedure (3) and filled with the concentrated erythrocyte mixed with a erythrocyte preservation solution was preserved for 35 days at a temperature of 41C, and then the generation of MA was observed for each of the samples according to Example 1 and Comparative Examples 1 to 3. The results are shown in Table 3 below.
(5) Confirmation of hemolysis level
The blood collection bag which was obtained in the aforementioned procedure (3) and filled with the concentrated erythrocyte mixed with a erythrocyte preservation solution was preserved for 35 days at
a temperature of 4t, and then 1 ml of sample solution after the preservation was aseptically taken out from each of the bags according to Example 1 and Comparative Examples 1 to 3 to measure the hemoglobin concontraLion and the hematocrit value by using an automatic blood cell counter (Sysmex CC-180 available from Toa lyo Densi Co. Ltd., Japan).
Furthermore, a portion of the sample solution taken out was subjected to a centrifugation for 15 minutes under the condition of 1,500 G by using a centrifugal separator (KR-702 available from Kubota Seisakusho Co. Ltd., Japan) to take out the upper layer constituted by blood plasma. Thereafter, the hemoglobin concentration in the blood plasma was measured by means of Leuco-crystal violet method JLCV method).
The values obtained in this manner were put into the following equation to calculate the degree of hemolysis, the results being shown in Table 3.
Hemolysis degree (%) = {[hemoglobin concentration (mg/dl) in plasma x (1 - hematocrit/100)] / [hemoglobin concentration (g/dl) in M.A.P.-added concentrated erythrocyte x 1,000]} x 100 (6) Confirmation of preservation state of platelet
The platelet bag which was obtained in the aforementioned procedure (3) and filled with a concentrated platelet was preserved with stirring at
a temperature of 22X:/ and then 1 ml of sample solution was aseptically taken out from the bag on Oth day, 3rd day and 5th day to measure the number of platelets in the sample solution.by using the aforementioned automatic blood cell counter, the results baing shown in Table 4.
Furthermore, the pH value (at 37X1) of the sample solution taken out as mentioned above was measured by using a blood gas/pH measuring apparatus (IL 1304 available from Instrumentation Lab.), the results being shown in Table 5.
(7) Centrifugation
The blood collection bag filled with a predetermined volume of distilled water was subjected to a centrifugation under the following conditions.
Centrifugal separator: Himac CR7B3, Hitachi Seisakusho, Japan
Conditions : 1.80 x 10® gasec., 4,000 rpm
(4,670 G), 22t:.
After the centrifugation, the blood collection bag was taken out of the auxiliary cup and examined to see if any damage was caused thereto, the results being shown in Table 6.
B. Results of the experiment
(1) Preparation of sheet and bag
The preparation of sheets could be smoothly performed, obtaining sheets excellent in uniformity.
The preparation of each bag was also smoothly performed.
(2) Results of the heavy metals and eluate test
It was confirmed that all of the samples
satisfied, in terms of heavy metals and eluate, the conditions prescribed in the specification of Japanese Pharmaceutical Codex, General Testing Method, RPlastic container for Transfusion Testing Methods.
(3) Evaluation on the preservation of erythrocyte
Table 3 shows findings on the generation of
macroaggregate (MA) and hemolysis level. As seen from Table 3, the blood collection bags according to Examples 1 and 2 indicated no generation of MA, and at the same time it was confirmed that the level of hemolysis in the blood collection bags according to Examples 1 and 2 was very low.
(Table Removed)
(4) Evaluation on the preservation of platelet Table 4 shows the change with time in the number of platelets, and Table 5 shows the change with time of pH value. As shown in Table 4, any substantial change in the number of platelets was recognized in any of the samples. As shown in Table 5, Comparative Example 2 indicated the lowering of pH value or the deterioration in quality of platelets under the aforementioned condition that the number of platelets was almost the same in all of the samples, which was assumed to be caused by the low gas permeability of sample according to Comparative Example 2. However, with respect to other samples, it was confirmed that they could be preserved in a stable condition up to 5th days of storage.
(Table Removed)
(5) Evaluation on the strength of bag by making use of centrifugation test
Table 6 shows the number of fractured blood collection bags which were subjected to a centrifugation test. As seen from Table 6, the blood collection bags according to Examples 1 and 2 were not fractured at all, indicating a sufficient degree of strength of the bag to withstand the operation of centrifugation.

(Table Removed)
As explained above, it is possible, according to the blood component preservation container and the multi-linkage container system of the present invention, to attain a suitable degree of elution of plasticizer and a high gas permeability so as to concurrently achieve an excellent hemolysis depression effect and an excellent macroaggregate (MA) suppression effect as a blood component is preserved therein.
These effects will be further promoted, while assuring a sufficient mechanical strength of the blood component preservation container, in particular a mechanical strength sufficient to withstand the operation of centrifugation, if a plasticizer of slightly exudative is employed as the second
plasticizer; if a preferable composition is employed for the first plasticizer and for the second plasticizer; if each content of the first plasticizer and the second plasticizer are suitably selected and at the same time the total content of the first and second plasticizers is selected within the aforementioned predetermined range.
Due to the aforementioned features of the blood component preservation container and the multi-linkage container of the present invention/ it is possible to preserve erythrocyte and other blood components for a long period of time, while maintaining the quality of the erythrocyte, etc., in an excellent condition.
Furthermore, the blood component preservation container and the multi-linkage container system pf the present invention are easy in handling and manufacture, and excellent in safety.

We Claim :
1. A blood component preservation container for preserving a liquid
containing at least a blood component, which is formed of a soft
polyvinyl chloride sheet containing 5 to 40% by weight of a first
plasticizer as herein described and 5 to 45% by weight of a second
plasticizer as herein described;
wherein said first plasticizer is exudative to the blood component in such a degree that when it is singly mixed in an amount of 32% by weight in a polyvinyl chloride sheet, and a predetermined amount of a blood component is preserved at a temperature of 4 deg. C for 35 days in a blood component preservation container constituted by the resultant polyvinyl chloride sheet, 15 ppm by weight or more of the added first plasticizer is eluted into the blood component, and said second plasticizer is capable of giving an oxygen gas permeability to a polyvinyl chloride sheet in such a degree that when said second plasticizer is singly mixed in said polyvinyl chloride sheet in an amount of 32% by weight, the oxygen gas permeability of the resultant polyvinyl chloride sheet becomes not less than 4.0 L/m2 .mm.day.atm (30°C).
2. The container as claimed in claim 1, wherein said second plasticizer is
exudative to the blood component in such a degree that when it is
singly mixed in an amount of 32% by weight in a polyvinyl chloride
sheet, and a predetermined amount of a blood component is preserved
at a temperature of 4°C for 35 days in a blood component preservation
container formed of the resultant polyvinyl chloride, 2 ppm by weight or
more of the added second plasticizer is eluted into the blood
component, but the elution amount of the second plasticizer is smaller
than that of the first plasticizer.
3. The container as claimed in claim 1 or 2, wherein said second
plasticizer is an aliphatic or aromatic ester having at least two ester
linkages and containing an aliphatic hydrocarbon group having at least
four carbon atoms in its hydrocarbon chain.
4. The container as claimed in claim 3, wherein said second plasticizer is
selected from the group consisting of phthalic diester, dialkyl phthalate,
adipic ester and dialkyl adipate, each having two or more aliphatic
hydrocarbon groups each containing 4 to 12 carbon atoms.
5. The container as claimed in claim 4, wherein said phthalic diester is di-
n-decyl phthalate, and said dialkyl adipate is di-octyl adipate.
6. The container as claimed in claims 1 to 5, wherein said first plasticizer
is an aliphatic or aromatic ester having at least two ester linkages and
containing an aliphatic hydrocarbon group having 4 to 12 carbon atoms
in its hydrocarbon chain.
7. The container as claimed in claim 6, wherein said first plasticizer is
dialkyl phthalate or dialkyl adipate.
8. The container as claimed in any one of claims 1 to 5, wherein said first
plasticizer is dioctyl phthalate.
9. The container as claimed in any one of claims 1 to 8, wherein the total
content of said first plasticizer and said second plasticizer is 20 to 50%
by weight.
10. A multi-linkage container system comprising a plurality of containers
connected together via tubes, said containers including at least one
blood component preservation container as claimed in any one of
claims 1 to 9.
11. A blood component preservation container and multi-linkage container
system, substantially as hereinbefore described with reference to the
accompanying drawings.

Documents:

2167-del-1996-abstract.pdf

2167-del-1996-claims.pdf

2167-del-1996-correspondence-others.pdf

2167-del-1996-correspondence-po.pdf

2167-del-1996-description (complete).pdf

2167-del-1996-drawings.pdf

2167-del-1996-form-1.pdf

2167-del-1996-form-19.pdf

2167-del-1996-form-2.pdf

2167-del-1996-form-3.pdf

2167-del-1996-form-4.pdf

2167-del-1996-form-6.pdf

2167-del-1996-gpa.pdf

2167-del-1996-pa.pdf

2167-del-1996-petition-137.pdf

2167-del-1996-petition-others.pdf

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Patent Number

214786

Indian Patent Application Number

2167/DEL/1996

PG Journal Number

09/2008

Publication Date

29-Feb-2008

Grant Date

15-Feb-2008

Date of Filing

03-Oct-1996

Name of Patentee

TERUMO KABUSHIKI KAISHA

Applicant Address

44-1 HATAGAYA 2-CHOME, SHIBUYA-KU, TOKYO, JAPAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	NOBORU ISHIDA	C/O TERUMO KABUSHIKI KAISHA, 818, MISONODAIRA, FUJINOMIYA-SHI, SHIZUOKA-KEN, JAPAN.

PCT International Classification Number

A61L33/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	7-279730	1996-10-03	Japan