Buffer management for bioprocessing system
A buffer management system includes a supply of concentrated buffer solution, an inline dilution skid having a manifold in fluid communication with the supply of concentrated buffer solution and a control unit configured to operate the dilution skid to selectively dilute the supply of concentrated buffer solution in the manifold with a source of water for injection (WFI), and a biocontainer assembly. The biocontainer assembly includes a biocontainer bag defining a storage volume and a fill level sensor configured to generate a fill level signal indicative of the amount of material within the storage volume of the biocontainer bag. The biocontainer bag is in fluid communication with the manifold of the dilution skid for storing diluted buffer solution therein. The fill level sensor communicates the fill level signal to the control unit of the dilution skis, which uses it to manage the operation of the dilution skid.
1 . A buffer management system comprising:
a supply of concentrated buffer solution;
a dilution skid, the dilution skid including a single use manifold and a control unit, the single use manifold in fluid communication with the supply of concentrated buffer solution, the manifold adapted to be placed in fluid communication with a source of water for injection (WFI), the control unit configured to operate the dilution skid to selectively mix the supply of concentrated buffer solution with an amount of WFI from the source of WFI in the single use manifold to produce a diluted buffer solution;
a biocontainer assembly, the biocontainer assembly including a biocontainer bag, a fill level sensor, and a shelf, the biocontainer bag defining a storage volume, the biocontainer bag in fluid communication with the manifold of the dilution skid for storing diluted buffer solution therein, the fill level sensor configured to generate a fill level signal indicative of a volume of material within the storage volume of the biocontainer bag, and the fill level sensor in communication with the control unit of the dilution skid to transmit the fill level signal thereto, wherein the shelf has a support surface configured to support the biocontainer bag and disposed at an oblique angle with respect to a horizontal axis, and wherein the fill level sensor comprises a capacitive fill level sensor mounted to the support surface;
wherein the control unit is configured to divert the diluted buffer solution away from the storage volume of the biocontainer bag if the buffer solution being produced is outside of a predetermined tolerance range of a given specification for a desired buffer, to fill the storage volume of the biocontainer with the diluted buffer solution when the buffer solution being produced is within the predetermined tolerance of the buffer recipe, to stop production of the diluted buffer solution once a predetermined fill volume of diluted buffer solution is in the storage volume of the biocontainer bag based upon the fill level signal received from the fill level sensor, and to maintain a predetermined minimum volume of diluted buffer solution in the storage volume of the biocontainer bag based upon the fill level signal received from the fill level sensor by operating, once the fill level signal indicates the minimum volume has been reached, the dilution skid to selectively mix the supply of concentrated buffer solution with an amount of WFI from the source of WFI in the single use manifold to produce an additional amount of diluted buffer solution to bring the diluted buffer solution in the storage volume of the biocontainer bag above a predetermined operational volume based upon the fill level signal received from the fill level sensor.
2 . The buffer management system according to claim 1 , wherein the oblique angle at which the support surface is disposed is in a range between five degrees and forty-five degrees.
3 . The buffer management system according to claim 1 , wherein the oblique angle at which the support surface is disposed is in a range between fifteen degrees and thirty-five degrees.
4 . The buffer management system according to claim 1 , wherein the shelf includes an upper end and a lower end, the lower end being disposed vertically below the upper end, and wherein the shelf includes a bag cradle mounted to the lower end, the bag cradle including an angled support surface configured to receive therein a bottom end of the biocontainer bag.
5 . The buffer management system according to claim 1 , wherein the shelf includes an underside surface, and wherein the capacitive fill level sensor is mounted to the underside surface.
6 . The buffer management system according to claim 5 , wherein the underside surface of the shelf defines a recess, the capacitive fill level sensor disposed within the recess, and wherein the shelf includes a cover plate, the cover plate mounted to the underside of the shelf such that the cover plate is over the recess.
7 . The buffer management system according to claim 1 , wherein the capacitive fill level sensor comprises a strip sensor configured to detect fill levels along the strip over a predetermined length.
8 . The buffer management system according to claim 1 , wherein the capacitive fill level sensor comprises a plurality of fill level sensors arranged in spaced relationship to each other, a first fill level sensor being disposed at a first position corresponding to a predetermined maximum fill volume, and a second fill level sensor being disposed at a second position corresponding to the predetermined minimum fill volume.
9 . The buffer management system according to claim 1 , wherein the single use manifold includes a buffer characteristic sensor, the buffer characteristic sensor configured to detect a value of a buffer characteristic of the diluted buffer solution in the single use manifold and to generate a buffer characteristic signal indicative of the sensed value for the buffer characteristic, the buffer characteristic sensor in electrical communication with the control unit to receive the buffer characteristic signal therefrom, wherein the control unit is configured to determine whether the diluted buffer solution is within the predetermined tolerance range of the given specification for the desired buffer based upon the buffer characteristic signal, and wherein the control unit is configured to selectively adjust a volumetric ratio of concentrated buffer solution to WFI flowing through the through the single use manifold based upon the buffer characteristic signal.
10 . The buffer management system according to claim 1 , wherein the operational volume is different from the fill volume.
11 . The buffer management system according to claim 1 , wherein the single use manifold includes a buffer inlet line, a water for injection (WFI) inlet line, and a discharge line in fluid communication with both the buffer inlet line and the WFI inlet line, the buffer inlet line in selective fluid communication with the supply of concentrated buffer solution, the WFI inlet line adapted to be placed in fluid communication with a source of WFI.
12 . The buffer management system according to claim 11 , wherein the buffer inlet line, the WFI inlet line, and the discharge line comprise tubing adapted to be selectively occluded by a pinch valve externally mounted thereto.
13 . The buffer management system according to claim 11 , wherein the single use manifold incudes a drain junction and a waste line, the drain junction in fluid communication with the discharge line, and the waste line being in fluid communication with the discharge line via the drain junction.
14 . The buffer management system according to claim 13 , wherein the control unit is configured to divert the diluted buffer solution to the waste line if the buffer solution being produced is outside of the predetermined tolerance range of the given specification for the desired buffer, and to fill the storage volume of the biocontainer with the diluted buffer solution via the discharge line when the buffer solution being produced is within the predetermined tolerance of the buffer recipe.
15 . The buffer management system according to claim 13 , wherein the drain junction comprises a first drain junction, the single use manifold further includes a second drain junction, the second drain junction in fluid communication with both the WFI line and the waste line such that the WFI line is in fluid communication with the waste line via the second drain junction.
16 . The buffer management system according to claim 15 , wherein the buffer inlet line is in fluid communication with the waste line.
17 . The buffer management system according to claim 15 wherein the single use manifold further includes a third drain junction, the third drain junction in fluid communication with, and interposed between, the buffer inlet line and the WFI inlet line, wherein the buffer inlet line is in fluid communication with the waste line via the third drain junction, the WFI line, and the second drain junction.