Abstract:
A biocontainer. The biocontainer includes a first flexible wall, a second flexible wall opposite the first flexible wall, a first end, a second end opposite the first end, a third end extending between the first and second ends, a fourth end extending between the first and second ends and opposite the third end, and a first relief section extending from the first end.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims priority on U.S. Provisional Application No. 61/449,027, filed on Mar. 3, 2011, the contents of which are fully incorporated herein by reference. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    Single-use biocontainers  10  as shown in  FIG. 1  are manufactured for use in conjunction with hardware designed around a platform  12  that oscillates in a rocking or seesaw motion, as for example described in U.S. Pat. Nos. 6,190,913, 6,544,788 and 7,195,394, the contents of which are fully incorporated herein by reference. This rocking motion, typically on the order of 12 to 20 degrees total sweep at a rate of 4-25 cycles per minute, is transferred to the biocontainer about an axis  14  which in turn imparts motion to a fluid and/or gas contained therein. For convenience the term “fluid” as used hereafter after refers to a fluid, or a gas, or to the combination of a fluid and, a gas. The imparted fluid motion is often used to accomplish unit processing steps within the biopharmaceutical industry, e.g. mixing or cell culture operations. The latter of these examples can require extended processing times on the order of one week to three months plus during which the oscillatory rocking motion is repeated constantly. These extended operating periods subject the biocontainer to high cyclical stress loads which can lead to breaches in the fluid containment area. 
         [0003]    The biocontainers manufactured for use in conjunction with the aforementioned rocking platforms are typically single-use bags of construction such as shown in  FIG. 2A . It should be noted that “bag(s),” “biocontainer(s)” and “biocontainer bag(s)” are used interchangeably herein. Representative biocontainers are two-dimensional in nature and are manufactured from two sheets (films)  16 A,  16 B of polymeric film  16  having dimensions (H 1 ×W 1 ) that are welded together along weld lines  18 ,  20 ,  22 ,  24 ,  26  and  28  to create a contained seal geometry. The welds along the weld lines form seams. Thus, the terms “weld lines” and “seams” are used interchangeably herein to refer to the area of bonding between the two sheets of polymeric film. These biocontainers contain porting  29 , for fluid ingress and egress as well as gas exchange, which are welded within a fluid containment area  16  (H 2 ×W 2 ) defined between weld lines  18 ,  20 ,  22  and  24 . The weld lines form seams. Additionally, the biocontainers include rigid support rods  32  at each end which are sealed into segregated areas  33  of the biocontainer (H 3 ×W 3 ) defined between weld lines  20 ,  26 ,  18  and  22 , and  24 ,  26 ,  18  and  22 , respectively. The support rods are used to help secure the biocontainer to the rocking platform. The rocking platform includes at least two clamps, such that each clamp clamps on the segregated areas and specifically the rod in such areas for securing each end of the biocontainer in place. 
         [0004]    When the biocontainers are deployed, i.e. secured to the rocking platform and filled to capacity with a fluid, three distinct zones  34 ,  36  and  38  form. A first zone  34  also referred to herein as “Zone  1 ” is a two-dimensional zone in that it remains relatively flat. This area of the flexible single-use biocontainer is constrained by the rocking platform clamp and thus retains it two-dimensional “flat” shape. A second zone  36  referred to herein as “Zone  2 ” is a transitional zone. In this area, the biocontainer shape transitions between a generally two-dimensional shape at one end and the fully developed three-dimensional shape at its other end. A third zone  38  also referred to herein as “Zone  3 ” is a three-dimensional zone. In this zone, the biocontainer has developed its three-dimensional shape and has a cross-sectional shape along its length which is oval as a result of the fluid fill volume. 
         [0005]    With the current biocontainers depicted in  FIG. 2A , folding, crumpling and/or other undesirable film shapes can occur in Zone  2 , i.e., in the transitional zone, due to geometry constraints associated with the transition between the two-dimensional end portion and the three-dimensional center portion. These undesirable film shapes create stress concentrations which when combined with the cyclical stress associated with the oscillatory motion of the fluid within the biocontainer, serve to decrease the service life of the biocontainer. Premature failures are believed to be due to either, a stress crack in the polymeric film material at a stress concentration point, or abrasion between the two films at a contact point. Both of these failure mechanisms manifest themselves in a repeatable nature in the four identified areas D in the transitional zones  36  of the current biocontainers and are directly attributable to the aforementioned undesirable film shapes in the transitional zones (Zones  2 ). 
       SUMMARY OF THE INVENTION 
       [0006]    In an exemplary embodiment a biocontainer is provided including a first flexible wall, a second flexible wall opposite the first flexible wall, a first end, a second end opposite the first end, a third end extending between the first and second ends, a fourth end extending between the first and second ends and opposite the third end, and a first relief section extending from the first end, wherein the first relief section is connects the first flexible wall to the second wall. In another exemplary embodiment, the first flexible wall is separate from the second flexible wall and is connected to the second flexible wall. In yet another exemplary embodiment, the first flexible wall is connected to the second flexible wall along at least one of the ends. In a further exemplary embodiment, the first relief section includes a separate member connected to the first flexible wall and to the second flexible wall. In yet a further exemplary embodiment, the first relief section is formed by connecting the first flexible wall directly to the second flexible wall. In one exemplary embodiment, the first relief section begins and ends at the first end. In another exemplary embodiment, the biocontainer also includes a second relief section, along which the first wall is connected to the second wall, proximate the fourth end beginning from and ending at the first end, a third relief section, along which the first wall is connected to the second wall, proximate the third end beginning from and ending at the second end, and a fourth relief section, along which the first wall is connected to the second wall, proximate the fourth end beginning from and ending at the second end. In yet another exemplary embodiment, each of the relief sections is semi-circular in plan view. In a further exemplary embodiment, when the bag is filled with a fluid, the biocontainer has a depth as measured between the first and second walls, wherein the depth increases from each of the third and fourth ends in a direction along each of the first and second ends transitioning between minimum or no depth at each of the third and fourth ends to an expanded depth at a distance from each of the third and fourth ends, wherein each of the first, second, third and fourth seams are located along a length within the distance. In one exemplary embodiment, the expanded depth is a maximum depth. In a further exemplary embodiment, each of the first, second, third and fourth relief sections are curved or define a geometric shape in plan view. In yet a further exemplary embodiment, each of the first, second, third and fourth relief sections intersects its corresponding first or second end at an external angle greater than 90°. In another exemplary embodiment, the biocontainer also includes a seam extending from the third to the fourth ends and being spaced apart from the first and second ends. In yet a further exemplary embodiment, the first relief section aids in the mixing of a fluid within the biocontainer. In one exemplary embodiment, a seam is defined along each of the ends connecting the first flexible wall to the second flexible wall. In another exemplary embodiment, a single piece of flexible material is bent over itself and connected along a seam to form the first flexible wall and the second flexible wall. 
         [0007]    In yet another exemplary embodiment, the first flexible wall is separate from the second flexible wall and the biocontainer further includes a first seam along the first end along which the first wall is connected to the second wall, a second seam along the second end along which the first wall is connected to the second wall opposite the first seam, a third seam along the third end along which the first wall is connected to the second wall and extending between the first and second seams, a fourth seam along the fourth end along which the first wall is connected to the second wall and extending between the first and second seams and being opposite the third seam, and a fifth seam defining the first relief section, along which the first wall is connected to the second wall, proximate the third seam beginning from and ending at the first seam, wherein the biocontainer has a length along the first seam and a width along the third seam as measured between the third and fourth seams, wherein each seam connects the first flexible wall to the second flexible wall. In a further exemplary embodiment, the biocontainer also includes a sixth seam, along which the first wall is connected to the second wall, proximate the fourth seam beginning from and ending at the first seam, a seventh seam, along which the first wall is connected to the second wall, proximate the third seam beginning from and ending at the second seam, and an eight seam, along which the first wall is connected to the second wall, proximate the fourth seam beginning from and ending at the second seam. In one exemplary embodiment, each of the seams is semi-circular in plan view. In another exemplary embodiment when the biocontainer is filled with a fluid, the biocontainer has a depth as measured between the first and second walls, wherein the depth increases from each of the third and fourth seams in a direction along each of the first and second seams transitioning between minimum or no depth at each of the third and fourth seams to an expanded depth at a distance from each of the third and fourth seams, wherein each of the fifth, sixth, seventh and eight seams are located along a length within the distance. In yet another exemplary embodiment, each of the fifth, sixth, seventh and eighth seams are curved or define a geometric shape in plan view. In one exemplary embodiment, each of the fifth, sixth, seventh and eighth seams intersects its corresponding first or second seam at an external angle greater than 90°. 
         [0008]    In any of the aforementioned exemplary embodiments, the biocontainer may include a rod proximate at least one of said third and fourth ends or seams. Furthermore any of the aforementioned exemplary embodiment biocontainers may be clamped proximate its third and fourth sides or seams to an oscillating platform. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematically depicted end view of a biocontainer mounted on a rocking platform. 
           [0010]      FIG. 2A  is a top view of a biocontainer of the present invention. 
           [0011]      FIG. 2B  is a cross-sectional view taken along arrow  2 B- 2 B in  FIG. 2A  of the biocontainer shown in  FIG. 2A  in an inflated state. 
           [0012]      FIGS. 3-11  are top views of an exemplary embodiment biocontainers of the present invention. 
           [0013]      FIG. 12  is a partial cross-sectional view of another exemplary embodiment biocontainer of the present invention. 
           [0014]      FIG. 13  is a top view of another exemplary embodiment biocontainer of the present invention. 
           [0015]      FIG. 14  is a cross-sectional view of another biocontainer. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Applicants have invented a biocontainer bag that overcomes the deficiencies of the current biocontainer bags. Applicants have been able to achieve this by including relief sections in the transitional zones (Zones  2 )  36 , as for example shown in  FIG. 3 . The locations of the transitional zones for a given biocontainer dimensions may be easily determined by filling the bag with a fluid. As discussed when the biocontainer bag  10  is filled, the transitional zones  36  is the zone between the generally two-dimensional flat end portions (Zone  1 )  34  of the bag to the full three-dimensional center portion (Zone  3 )  38  of the bag. In an exemplary embodiment, four relief sections  37  are provided, two extending from each of the weld lines  18  and  22 , respectively. First relief sections  42 ,  46  are formed at the transitional zone proximate one end of the biocontainer and second relief sections  44 ,  48  are formed at the transitional zone proximate the opposite end of the biocontainer. Each relief section is formed by welding the two film sheets together along the curve extending from its corresponding weld line  18 ,  22  (i.e., beginning from and ending at its corresponding weld line). Welding of such film sheets is accomplished by using welding methods known in the art. In an exemplary embodiment, each relief section has a semi-circular shape. In an exemplary embodiment, a semi-circular shape has a radius not greater than one half of the length  51  of the transitional zone  36  as measured along the weld lines  18  and  22 . In another exemplary embodiment, the bag may not be welded along any portion  51  of a section  50  between the beginning and end of each relief section along each of the weld lines  18  and  20 , as for example shown in  FIG. 4 . In other exemplary embodiments as for example shown in  FIG. 5 , the relief sections  37  may be formed by welding along a circular arc that is less than a semi-circle. In another exemplary embodiment, the relief sections  36  may be formed by welding along other geometric shapes, as for example an elliptical shape, or an angular shape so as to form a triangle, or a free-flowing shape, or a rectangular or square shape. In other exemplary embodiments as shown in  FIG. 6 , the interior of the defined shape of the relief section may also be welded to define a solid shape, as for example shape  37   a . It is also desirable that an external angle  41  between the weld lines  18  and  22 , and the relief section is 90 degrees or greater. It is believed that if the external angle is smaller than 90 degrees, as for example by forming a relief section by welding along a circular arc which is greater than a semi-circle, an area of intersection between the weld lines  18  and  22  and the relief section would create an area where fluid stagnation can occur. Such stagnation can be detrimental to the actual processing that the biocontainer needs to accomplish, such as mixing or cell culture operations. 
         [0017]    These relief sections in an exemplary embodiment provide for a biocontainer which does not form any, or which has a reduced number of folds or crumples or other undesirable film shapes when filled with a fluid. Applicants have discovered by eliminating or reducing these folds, crumples or undesirable film shapes, the life span of the biocontainer is increased. In addition, applicants believe that these relief sections cause a change of direction in the fluid during the rocking motion. In other words, as the fluid contacts these relief sections during the rocking motion, the fluid is caused to change its direction and thus, better mix. As such, use of the inventive biocontainers result in better processing of the fluid which is being processed within the biocontainer during mixing or cell culture operations. Thus, another advantage of the present invention is that the relief sections improve the mixing and processing accomplished by the biocontainers. In this regard, the processing time required for processing such fluid using the inventive biocontainers may be reduced. 
         [0018]    In the exemplary embodiments where the relief sections are semi-circular, such sections have a radius  56  that is proportional to the length (H 2 )  54  and the length  51  of the transitional zone  36 . However, applicants also believe that optimum length of the radius  56  may also be affected by the ratio of the width  52  to the length  54 . In an exemplary embodiment, the location of a center  58  of each semi-circular relief section is located at a distance  60  from an end  62  of the biocontainer bag from which end the length  54  is measured. This distance  60  is also proportional to the length  54  but it is believed that it is also affected by the ratio of the width  52  to the length  54 . In an exemplary embodiment, each relief section occupies at least a portion of the length of the transitional zone. In another exemplary embodiment, each relief section is confined within a transitional zone. Applicants believe that the distance  60  is at a maximum for square biocontainers, i.e., when biocontainers having a width  52  equal to the length  54 . 
         [0019]    In an exemplary embodiment relief sections, their dimensions and locations for a 22 L biocontainer, a 50 L biocontainer, and a 300 L biocontainer, are shown in  FIGS. 7 ,  8  and  9 , respectively. The dimensions of the biocontainer and relief sections are provided in inches, unless otherwise specified. 
         [0020]    In another exemplary embodiment, either of the aforementioned relief zones  37  is formed by welding or otherwise connecting the film sheets  16 A,  16 B together via another member  90  such as a gusset or other piece of plastic as shown in  FIG. 12 . The gusset or plastic may itself be a piece of film. This member is attached or welded to film sheets  16 A and  16 B forming seams  92  and  94 , respectively and limits the separation of the upper wall and lower walls when the bag is filled with a fluid. 
         [0021]    In another exemplary embodiment as for example shown in  FIG. 10 , applicants have developed dual bag containers  80 ,  82  which are connected together along one weld line  84 . In other words, both biocontainer bags  80 ,  82  share a common weld line  84 . With this invention, two different solutions may be oscillated using a single platform. As can be seen, the inventive multiple compartment bags also designed to be used in the existing platform, as for example by incorporating the rigid support rods  32  at each end which are sealed into segregated areas  33  defined between weld lines. In yet a further exemplary embodiment, any of the relief areas as described in relation with the exemplary embodiment as shown in  FIG. 3  may be incorporated in a multiple compartment biocontainer, as for example shown in  FIG. 11 . Although the bag is being shown with two compartments, the bag may be formed with more than two compartments where adjacent compartments sharing a common weld line. In yet another exemplary embodiment, the relief sections between each compartment can have different geometrical shapes depending on the type of mixing or processing that is required. 
         [0022]    Although the present invention has been described and illustrated with respect to exemplary embodiments, it is to be understood that it is not so limited, since changes and modification may be needed which are within the full scope of the invention. For example, the biocontainer bags may have only two seams, as for example 20 and 24 (or only seams  18  and  22  in another exemplary embodiment) plus the seams defining the relief sections  37  as for example shown in  FIG. 13 . With this embodiment there are no seams along the ends  96  and  98  of the biocontainer bag. In one embodiment the bag may be formed to have a seam  100  along one of the upper portion or lower portion of the film  16 , as shown in  FIG. 14  where the seam is formed on the lower portion. With this exemplary embodiment, one end of the film  16  is welded or otherwise attached to another end of the film  16  to form seam  100 . As can be seen with these embodiments, the biocontainers may be formed from a single film which is folded on to itself to form the upper and lower films (or walls, or layers) of the biocontainer.