Monoclonal Antibody ProductionThis example analyzes the production of a therapeutic monoclonal antibody using animal cell culture. The recipe analyzed produces 19 kg of purified product per batch. Three SuperPro Designer files are included in this example:

Mab7_0a.spf: This is the simplest file of the three. It represents the core Mab process (buffer preparation & holding, delivery lines, transfer panels not included). For reference and guidelines on how to model a simple Mab production process the user should refer to section 5 of this file.

Mab7_0b.spf: This file is based on the previous file but it also includes modeling of buffer preparation and holding activities, transfer panels, and buffer delivery lines. It explains how to specify equipment sharing within these and provides tips on how to model single-cycle operations in multi-cycle unit procedures. For information on all the above the user should refer to section 6 of this file.

Mab7_0c.spf: The process of this file is the same as the previous one. The difference between the two files is in the number of upstream trains used. In this case a cycle time reduction exercise is performed by increasing the number of bioreactor trains. This is the implementation design and thus a full economic analysis is performed to evaluate profitability. For information on how to specify staggered equipment in order to reduce cycle times and how to perform cost of goods analysis, please refer to sections 7 & 8 in this file.

Section 1 below provides a brief description of the basic features of the monoclonal antibody process (Mab7_0a.spf). All files for this example can be found in the C:\Program Files\Intelligen\SuperPro Designer\EXAMPLES\MAB7_0 subdirectory.

1 Upstream ProcessingThe upstream section is split in two sub-sections, the Inoculum preparation section and the Bioreaction section. Flowsheet sections in SuperPro are simply set of related unit procedures (processing steps).

1.1 Inoculum preparation The inoculum is initially prepared in 225 ml T-flasks. The material is first moved to roller bottles (2.2 L), then to 20 L and subsequently to 100 L disposable bag bioreactors. Sterilized media is fed at the appropriate amount in all of these four initial steps (3.6, 11.4, 43.6, 175.4 kg/batch respectively). The broth is then moved to the first (1000 L) and second (4000 L) seed bioreactor. For the seed bioreactors the media powder is diluted using WFI in two prep tanks (MP-101 & MP-102) and then sterilized/fed to the reactors through 0.2 μm dead-end filters (DE-101 & DE-102).

1.2 Bioreaction section Serum-free low-protein media powder is dissolved in WFI in a stainless steel tank (MP-103). The solution is sterilized using a 0.2 m dead-end polishing filter (DE-103). A stirred-tank bioreactor (PBR1) is used to grow the cells, which produce the therapeutic monoclonal antibody (Mab). The production bioreactor operates under a fed batch mode. To edit the fed batch options the user should select the Fed Batch tab of the FERMENT-1 (Batch Stoich. Fermentation) operation dialog. High media concentrations are inhibitory to the cells so half of the media is added at the start of the process and the rest is fed at a constant rate during fermentation. The concentration of media powder in the initial feed solution is 17 g/L. The fermentation time is 12 days. The volume of broth generated per bioreactor batch is approximately 15,000 L, which contains roughly 30 kg of product (the product titer is approximately 2 g/L). The target product titer can be specified through the Reactions tab of the FERMENT-1 (Batch Stoich. Fermentation) operation

dialog; select the option Calculate to Achieve. The stoichiometry of the reaction is specified by clicking on the button that looks like a shake flask (in the Reaction Sequence box).

2 Downstream ProcessingBetween the downstream unit procedures there are 0.2 μm dead-end filters to ensure sterility.

The generated biomass and other suspended compounds are removed using a Disc-Stack centrifuge (DS-101). During this step, roughly 2% of Mab is lost in the solids waste stream resulting in a product yield of 98%. The bulk of the contaminant proteins are removed using a Protein-A affinity chromatography column (C-101). The yield on Mab for this step is 90%. The protein solution is then concentrated 5x and diafiltered 2x (in P-21 / DF-101). The yield on product is 97% and this is represented by the product denaturation feature of the Diafiltration operation. The concentrated protein solution is then chemically treated for 1.5 h with Polysorbate 80 to inactivate viruses (in P-22 / V-111). An Ion Exchange chromatography step follows (P-24 \ C-102) with a yield on Mab of 90%. Ammonium sulfate is then added to the IEX eluate (in P-25 \ V-109) to increase the ionic strength for the Hydrophobic Interaction Chromatography (P-26 \ C-103) that follows. 10% of Mab is lost during the HIC procedure. A viral exclusion step (DE-105) follows. It is a dead-end type of filter with a pore size of 0.02 μm. Finally the HIC elution buffer is exchanged for the product bulk (PBS) storage buffer and concentrated 1.5-fold (in DF-102). The approximately 800 L of final protein solution is stored in twenty 50 L disposable storage bags (DCS-101). 19 kg of Mab per batch are produced approximately. The overall yield of the downstream operations is approximately 63%.

NOTE: Numbers between the files may differ slightly due to modeling differences

3 General featuresIn all the unit procedures, excluding those utilizing disposable containers and columns, an SIP operation is scheduled before and a CIP after the main processing. WFI is used for the rinsing step of the CIP cycle while the CIP skids are dedicated either to upstream or downstream equipment (2 skids for the upstream section and 2 for the downstream). Finally, flush operations are performed prior to processing in the two diafiltration units (DF-101 and DF-102).

4 Material RequirementsThe table below displays the material requirements in kg/year, kg/batch and kg/kg MP (main product – purified Mab in this case). This plant produces approximately 19 kg of therapeutic Mab per batch. The table below was extracted from the RTF version of the Streams & Mat. Balance report of the Mab7_0a.spf file. The material results of the other two files (Mab7_0b.spf, Mab7_0c.spf) are different because they also include the cleaning of the buffer prep and holding vessels, which are missing from this file. Reports in SuperPro are generated through the Reports menu of the main menu bar. The format and contents of the reports can be customized by selecting Reports \ Options from the main menu bar.

BULK RAW MATERIALS (ENTIRE PROCESS)Raw Material kg/yr kg/batch kg/kg MPInoc Media Sltn 4,914 234.000 12.189WFI 1,061,122 50,529.621 2,632.031SerumFree Media 9,419 448.521 23.363Air 399,957 19,045.581 992.063H3PO4 (5% w/w) 238,471 11,355.738 591.508NaOH (0.5 M) 223,921 10,662.883 555.417Prot-A Reg Buff 120,628 5,744.183 299.208Protein A eluti 202,047 9,621.269 501.161Protein A Equil 439,376 20,922.660 1,089.838NaOH (0.1M) 135,799 6,466.600 336.838IEX-Eq-Buff 65,752 3,131.052 163.093IEX-Wash-Buff 65,818 3,134.170 163.255IEX-El-Buff 3,706 176.475 9.192NaCI (1 M) 40,473 1,927.281 100.390Amm. Sulfate 2,801 133.359 6.947HIC-Eq-Buff 24,991 1,190.049 61.988HIC-Wash-Buff 62,478 2,975.123 154.971HIC-El-Buff 60,415 2,876.887 149.854NaOH (1 M) 65,709 3,129.000 162.986PBS 32,307 1,538.439 80.136Polysorbate 80 2 0.077 0.004TOTAL 3,260,102 155,242.969 8,086.430

There are also resins, membranes and other consumables that are consumed in a Monoclonal antibody production process. For information on initialization of consumables, refer to section 9.

5 Analysis of the Base Case (Mab7_0a.spf)The equipment in Mab7_0a.spf is in Design Mode, which is the default option for newly created files. In Design Mode, SuperPro Designer sizes the equipment based on amounts of material processed per batch and operating time allocated to various activities. If you wish to specify the size of a specific equipment item, right-click on its procedure icon and select Equipment Data. Figure 1 (below) displays the equipment data dialog of a vessel. Select Set by User (Rating Mode) to specify the volume of the vessel.

Figure 1: The equipment data dialog box

The equipment occupancy chart for four consecutive batches is shown in Figure 2. The cycle time specified by the user is 14 days, which results in 21 batches per year (403 kg of product per year). To generate the chart of the figure below, select View \ Equipment Occupancy Chart \ Multiple Batches from the main menu of SuperPro. To change the number of displayed batches, right-click on the chart and select Set Number of Batches. To specify the recipe cycle time, select Tasks \ Recipe Scheduling Information. To copy the equipment occupancy chart, make it the top window and press “Alt + Prnt Scrn”. That generates a screen view in the clip board that can be pasted into other application, such as MS Word. Alternatively, you may right-click on the chart, select Copy and then move to the destination application and select Paste or Paste Special. The top lines of the chart represent the occupancy of CIP (cleaning-in-place) skids used to clean other equipment items. CIP operations determine the occupancy of CIP skids.

7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 112 119 126 133 14014day1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20wk

DCS-101DE-107DF-102DE-105

V-110DE-106

V-108C-103V-109

DE-110C-102V-111

DF-101DE-109

V-107C-101

DE-108DS-101

V-101V-103

DE-104V-105

DE-103V-106PBR1

DE-102V-104SBR2

DE-101V-102SBR1

BBS-102BBS-101RBR-101TFR-101

CIP-DSP-2CIP-DSP-1CIP-UPS-2CIP-UPS-1

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Figure 2: The equipment occupancy chart for four consecutive batches of the base case (Mab7_0a.spf)

The scheduling bottleneck identified is the production bioreactor PBR1, as it has the longest time occupancy. This information is provided on the Recipe Scheduling Information dialog. It can be noted that the downstream train has low time utilization. To increase column time utilization and consequently reduce the required size the user can specify more than one cycle for each column operation. To do this the user must right click on the procedure icon in question, select Procedure Data and specify the number of cycles per batch (Figure 3). The number of cycles specified for the Protein-A column is 4 and for the IEX and the HIC columns 3. One can specify more cycles and subsequently reduce the size of the column. Too many cycles, however, lead to increased labor cost.

Figure 3: The Procedure Data dialog box for the Protein-A column

In addition to the equipment occupancy chart, SuperPro generates Gantt charts for the various operations and their unit procedures (through Tasks \ Gantt Charts \ Operations GC). In the Operations Gantt chart that follows (Figure 4), the tan bar at the top represents the time required for one full batch. The duration of each section of the flowsheet is displayed with green bars. The dark blue bars represent the time required for each unit procedure, and the light blue bars represent individual operations. The Gantt chart is highly customizable. To modify the bar properties (such as their colors, labels for duration, etc.), right-click on the empty area of the chart and select Styles from the drop-down list. Then choose a bar type to edit.

Charts such as the Gantt chart and the Equipment Occupancy chart are powerful tools for cycle time analysis, debottlenecking, scheduling purposes, and technology transfer.

Gantt charts (for single or multiple batches) can be exported to MS Project (see Chapter 6 of the SuperPro manual for information on exporting to MS Project).

Figure 4: Operations Gantt chart (Mab7_0a.spf)

6 Advanced Modeling Features

6.1 Modeling Chromatography Steps The rest of this document focuses on advanced modeling features for biopharmaceutical applications utilized in files Mab7_0b.spf and Mab7_0c.spf.

In these two files each chromatography step is represented with three unit procedures. The reason for that is because when a unit procedure in SuperPro has multiple cycles, that applies to all operations of the procedure. If certain operations are done only once per batch (e.g., column storage), the only way to represent it is by using a separate unit procedure that utilizes the same equipment. The table below explains the way the processing is done in the columns:

Pre Processing

(Cycles/Batch)

Main Processing

(Cycles/Batch)

Post Processing

(Cycles/Batch)

Protein A 1 4 1

IEX 1 3 1

HIC 1 3 1

The pre- and post-processing activities do not follow a cycling pattern. Therefore, they must be represented with different procedures that have one cycle per batch and utilize the same column as the main chromatography activity. To specify that a pre- or post-processing unit procedure (e.g., P-66 or P-67 for Protein-A in Mab7_0b.spf) utilizes the same column as the main activity (e.g., P-18 in Mab7_0b.spf), right-click on its icon and select Equipment Data. Then, focus on the Selection box (upper left corner of the dialog) and select C-101 through the Select drop-down menu.

NOTE: The chromatography columns in these two files are in Rating Mode (i.e., their dimensions are specified). You may view their dimensions by right-clicking on their icons and selecting Equipment Data. Please note that if the columns are left in Design Mode, then SuperPro will force you to specify a fake Load operation for the pre- and post-processing unit procedures. That’s the case because all procedures that are in Design Mode must have an operation that can size their equipment. In chromatography procedures the Load operation is the only one that can size the column.

6.2 Modeling Buffer Preparation and Holding Biopharmaceutical processes are generally designed to be limited by bioreactor capacity. However when bioreactor capacity is increased with multiple bioreactor trains, constraints may arise in purification and supporting processes (e.g., buffer preparation & holding, cleaning, etc.). Such constraints limit plant throughput. Modeling the buffer preparation section of a process is therefore important. When developing such models two issues need to be taken into account; the material balances and the scheduling both have to be based on the main downstream processing (DSP) steps. The user is advised to follow the methodology described in this section when modeling such processes in SuperPro.

A typical buffer preparation step consists of a preparation vessel (PV) where the ingredients are charged and mixed and a holding vessel (HV) where the prepared buffer is transferred from the prep-vessel and stored until used by the DSP process. The buffer is filtered while transferred from the PV to the HV to ensure sterility. A similar installation is assumed in this example with 5 PV and 8 HV vessels. The filters in between are not included in this model for simplicity. Between the HV and PV there are two transfer panels that connect any of the HV with any of the PV. The generic boxes TP-101 and TP-102 represent the transfer panels. Finally, the buffer preparation equipment is installed in a separate room to the DSP suite. Therefore, 4 buffer delivery lines have been specified, BDL-101, BDL-102, BDL-103, BDL-104 (represented with generic boxes) that are dedicated to supplying buffers to the Protein A, IEX, HIC columns and the diafiltration skids (DF-101, DF-102) respectively. The way to simulate the occupancy of the transfer panels and the buffer delivery lines will be described later in this document.

The five buffer prep vessels are used to prepare more than five different buffers. For instance, PV-102 is used to prepare three different buffers. On the flowsheet each buffer preparation is represented with a different unit procedure. On the Equipment Occupancy chart those procedures are presented with a rectangle (one rectangle for each procedure) on the PV-102 line (since all three utilize the same equipment, but at different times). The red circles of Figure 5 shown below highlight the three different procedures handled by PV-102. As mentioned in the previous section, equipment sharing by multiple procedures is specified through the Selection box of a procedure’s Equipment Data dialog (upper left corner of the dialog).

Figure 5: Visualizing equipment sharing with the Equipment Occupancy chart.

6.3 Material balances Under regular operating conditions the user would specify the amount of material that needs to be charged into a prep tank before transferred into a holding tank and subsequently used by the DSP process. However, the operation that determines the amount of material that needs to be charged is the DSP operation, such as the Equilibration operation of a chromatography step. So what is needed is an operation in the holding tank that allows the column operation to draw the amount of material required. SuperPro has this ability through the Pull-Out operation.

A Pull-Out operation is similar, in concept, to a Transfer-Out operation but with one very important difference; the amount of material being transferred out is not known and therefore not set by the user but instead computed during simulation by the pulling (consuming) operation that utilizes its stream. If the amount of material available in an HV vessel is less than the amount required by the consuming operation and all the input streams of the charge operations in the PV procedures are in Auto-Adjust mode (specified by checking the corresponding check box), the Pull-Out operation will back-propagate the information for the greater demand and the simulation algorithm of SuperPro will attempt to adjust all inputs streams of that train so that the demand is fully met

The following table indicates the way the operations should be specified in the PV and HV tanks:

PV Tanks HV Tanks

SIP SIP

Charge Transfer-In

Agitate Pull-Out (Instead of Transfer Out)

Transfer-Out CIP

CIP

Multiple draws of material form the same HV vessel should be handled by multiple pull out operations in the same HV unit procedure (e.g., P-37 \ HV-101) with their duration and scheduling info arranged as described above.

That way and by setting the input stream(s) of the train to Auto-Adjust mode, the amount of material is automatically computed depending on the requirements of the downstream operation(s). The way to schedule the above operations will be dealt with in the following section. To locate the Auto-Adjust option in the stream dialog, refer to Figure 6.

NOTE: The PV tank procedures include a single charge operation that pumps the buffer into the tank. In reality the constituents are added one by one and consequently mixed. However, we recommend this approach (charging the buffer which is defined as a stock mixture instead of its constituents) because it enables you to track the demand of the various buffers (as stock mixtures) as well as the demand of the constituents of the buffers.

Figure 6: The auto-adjust option in an input stream

6.4 Scheduling Buffer Prep and Holding Operations The scheduling of buffer preparation and holding activities should be based on the main downstream operations; the pull out operations in the HV tanks should be synchronized with the relevant downstream operation (e.g., equilibration of a chromatography step). Thus the pull out operation is used as a scheduling basis for all the other operations in the HV and PV procedures. Operations that precede the pull out operation are scheduled relative to the start of the pull out using appropriate negative values for Start Time Shift (top of the Scheduling tap of an

operation’s dialog). A negative Start Time Shift is equivalent to a Lead Time. This is the only way to handle the equivalent of scheduling based on finish time, which is not available in the current version of SuperPro.

A description of the recommended approach follows:

HV:

A pull out in the HV is set to last as long as the buffer utilizing operation (using a master slave relationship) in the DSP process and scheduled to start at the same time. Please visit at this point the Oper.Cond’s tab of PULL-OUT-1 in P-43/HV-103 that feeds regeneration buffer to the Protein A column (C-101). You will notice that PULL-OUT-1 is a slave of the REGENERATE-1 operation in P-18 (the Protein A step). That makes the duration of PULL-OUT-1 the same as the duration of REGENERATE-1 (spanning all four cycles on REGENERATE-1 in P-18). Furthermore, if you visit the Scheduling tab of PULL-OUT-1, you will see that it is scheduled to start at the same time as REGENERATE-1 in P-18.

The TRANSFER-IN-1 operation in P-43 (duration 60 min) is scheduled to start based on the start of the PULL-OUT-1 with a Start Time Shift of -3 h (i.e., 3 h before the start of PULL-OUT-1). That way the buffer is in the HV tank 2 h prior to use (safety margin).

The SIP-1 operation P-43 (HV tank) which has a duration of 50 min is scheduled to start based on the start of TRANSFER-IN-1 with a shift of -50 min. That way, SIP will be finished by the time transfer-in starts.

The CIP is scheduled to start when the Pull out operation has finished.

PV:

Transfer out is set to last as long as the transfer in operation in the HV (using a master slave relationship) and scheduled to start at the same time as transfer-in in the HV.

The rest of the operations are scheduled based on the transfer out according to the way described for the HV (using negative Start Time Shifts)

Using this scheduling methodology, changes in the DSP schedule will automatically adjust the scheduling in the buffer prep operations since all HV and PV operations depend directly or indirectly on the time that the buffer is used by the main DSP process.

6.5 Modeling Delivery Lines and Transfer Panels As mentioned earlier in this document, the occupancy of transfer panels and buffer delivery lines has to be simulated to ensure that scheduling conflicts do not occur. This is done by representing such equipment items with generic boxes that include a Hold operation, which is synchronized with the operation in question (using the techniques described in the previous section).

For example, buffer delivery line one (BDL-101) is utilized during the operation of the first column i.e. it delivers the buffers from the buffer preparation area to the DSP area. To tackle this issue since buffer delivery line does not exist as a separate unit procedure, the user should use a batch generic box and name is appropriately (BDL-101 in this case). Generic boxes are selected from Units Procedures \ Generic Boxes \ Bulk Flow \ Batch {type}. Subsequently, the user should add three hold operations (in P-72) one for each of the protein A unit procedures. The first hold operation should be synchronized with the pre-processing activities of C-101 (represented by P-67) using a master slave relationship and the same start time. The second hold operation should be synchronized to all the processing operations in P-18. Finally the third hold operation should be synchronized to the post processing activities and skid storage represented by P-66. That way the buffer delivery line is occupied when a buffer from the Buffer preparation area is transferred to the DSP process. The other three delivery lines should be modeled in a similar way.

The user should model Transfer Panels in the same way. Use batch generic boxes with hold operations that are synchronized with the corresponding transfer operations that utilize the

transfer panels. This approach enables you to keep track of the use of simple transfer panels that can handle a single transfer at a time. Complex transfer panels that are equipped with multiple bridges and jumpers and can handle multiple simultaneous transfers can be modeled in detail using SchedulePro, the second member of the Intelligen Suite. Two transfer panels were used in this example, TP-101 or TP-102.

NOTE: The generic boxes utilized to represent delivery lines and transfer panels should be set under Rating mode since Hold is not an operation that can size equipment. Otherwise, those procedures will generate error messages during simulation. To choose between Rating and Design mode the user should visit the equipment data dialog box by right-clicking on a procedure icon and selecting Equipment Data (Figure 1).

6.6 Modeling Preparation of Excess Buffer for Safety In commercial buffer preparation activities the amount of buffer produced is slightly higher than the amount needed for safety reasons. This can be accounted for by adding a splitter between the HV and the DSP operation and specifying a certain amount of removed buffer (in this case 5%) in the upper stream. Since this splitting is a dummy operation that is only required for mass balancing calculations, the user can remove the procedure from the scheduling calculations by selecting the scheduling dialog box under procedure data (right click on the procedure icon and select Procedure Data) and checking the Omit from Scheduling box. Look at procedures P-38 and P-39 in the IEX buffer prep/holding area for more information.

7 Cycle Time ReductionThe Mab7_0b.spf file represents a process running in a plant with a single equipment line. Figure 7 displays the equipment occupancy chart for four consecutive batches of the process. The top eight lines correspond to the CIP skids.

The time between consecutive batches (process cycle time) is two weeks. The production bioreactor (PBR1) which has the longest cycle time determines the cycle time of the process. In other words, the production bioreactor is the time (or scheduling) bottleneck of the process.

It is obvious that under these conditions the purification line is underutilized. The cycle time of the process can be reduced (and its throughput increased) by adding another production bioreactor that operates in staggered mode (out of phase) compared to the original (PBR1). This is done through the Equipment Data dialog of the fermentation procedure (P-11). Check the Stagger Mode box (in the lower left corner) and set the number of extra pieces of equipment that operate out of phase with the main. The names of the extra equipment can be edited by clicking on the Names button in the same dialog. When debottlenecking a facility the extra pieces should be introduced to the equipment that is the scheduling bottleneck. Once the new bioreactor is specified (PBR1b), the new bottleneck is the tank used to store the media for the fed batch operation (MP-104). In the same manner a new tank is specified (MP-104b). Following the same method whereby a bottleneck is identified and removed one by one the cycle time of the process is reduced to 3.5 days (corresponding to file Mab7_0c.spf). Figure 8 below displays the Equipment Occupancy chart for 15 consecutive batches of Mab7_0c.spf. The first batch is handled by PBR1 (the original production bioreactor), the second by PBR1b, the third by PBR1c, and the fourth by PBR1d. The next four batches follow the same sequence. This availability of multiple bioreactors that operate out of phase reduces the cycle time of the process to 3.5 days even though each bioreactor continuous to have a cycle time of 14 days. All bioreactor batches are handled by the single purification line.

The following total upstream equipment is required for a process cycle time of 3.5 days.

Two inoculum preparation trains

Three seed bioreactor trains (SBR1,b,c and SBR2,b,c)

Four production bioreactors trains (PBR1, PBR1b, PBR1c, PBR1d)

Under these conditions the number of batches per year increases to 81 and the annual throughput to 1,555 kg of purified Mab.

7 14 21 28 35 42 49 56 63 70 77 84 91 98 10514day1 2 3 4 5 6 7 8 9 10 11 12 13 14 15wk

DCS-101DE-107DF-102DE-105

V-110DE-106

V-108C-103

BDL-103V-109

DE-110HV-105HV-107

C-102BDL-102

PV-105V-111

HV-108BDL-104

DF-101HV-106HV-104PV-104DE-109HV-102TP-102HV-103PV-102

V-107C-101

BDL-101PV-103TP-101HV-101PV-101DE-108DS-101

V-101V-103

DE-104MP-104DE-103MP-103

PBR1DE-102MP-102

SBR2DE-101MP-101

SBR1BBS-102BBS-101RBR-101TFR-101CIP-BP-4CIP-BP-2CIP-BP-3

CIP-DSP-2CIP-DSP-1

CIP-BP-1CIP-UPS-2CIP-UPS-1

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Figure 7: Four consecutive batches of scenario Mab7_0b.spf (one bioreactor train)

7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 112 119 126 133 14014day1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20wk

DCS-101DE-107DF-102DE-105

V-110DE-106

V-108C-103

BDL-103V-109

DE-110HV-105HV-107

C-102BDL-102

PV-105V-111

HV-108BDL-104

DF-101HV-106HV-104PV-104DE-109HV-102TP-102HV-103PV-102

V-107C-101

BDL-101PV-103TP-101HV-101PV-101DE-108DS-101

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DE-104dDE-104cDE-104b

DE-104MP-104dMP-104cMP-104b

MP-104DE-103MP-103PBR1dPBR1cPBR1bPBR1

DE-102MP-102SBR2cSBR2bSBR2

DE-101MP-101SBR1cSBR1bSBR1

BBS-102bBBS-102

BBS-101bBBS-101

RBR-101bRBR-101

TFR-101bTFR-101CIP-BP-4CIP-BP-2CIP-BP-3

CIP-DSP-2CIP-DSP-1

CIP-BP-1CIP-UPS-2CIP-UPS-1

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Figure 8: Fifteen consecutive batches of scenario Mab7_0c.spf (four bioreactor trains).

8 Cost AnalysisSuperPro Designer performs thorough cost analysis and generates three pertinent reports (through the Reports menu). The table below displays the key economic evaluation figures for the case of Mab7_0c.spf (four bioreactor trains). The table was extracted from the Economic Evaluation Report (generated in RTF format). For a plant of this capacity (60,000 L of production bioreactor volume) that produces 1,555 kg of purified Mab per year, the total capital investment is around $171.3 million (or $2.86 million per m3 of bioreactor capacity). The estimated manufacturing cost is $311 million per year, which translates to a unit cost of $65/g of purified Mab. The numbers for the calculation of the Return-On-Investment, Payback Time, etc. are based on a selling price of $200/g of purified Mab.

EXECUTIVE SUMMARY (2006 prices)Total Capital Investment 171,208,000 $Capital Investment Charged to This Project 171,208,000 $Operating Cost 93,911,000 $/yrProduction Rate 1,555.22 kg MP/yrUnit Production Cost 60,384.49 $/kg MPTotal Revenues 311,043,000 $/yrGross Margin 69.81 %Return On Investment 83.71 %Payback Time 1.19 yearsIRR (After Taxes) 72.58 %NPV (at 7.0% Interest) 916,936,000 $MP = Flow of Component Mab in Stream Final Product

Figure 9 below displays the annual operating cost breakdown. It is a chart that is automatically generated with the Economic Evaluation Report. To include such charts in the report, visit Reports \ Options and select Include Charts (lower left corner of the dialog). The facility-dependent overhead cost is the most important item accounting for 27% of the overall manufacturing cost. The cost of consumables is in the second position accounting for 24.2%.

Figure 9: Annual operating cost breakdown (Mab7_0c.spf)

The table below displays the operating cost breakdown per flowsheet section for the Mab7_0c.spf case. The table was copied from the Itemized Cost Report (RTF format) that can be generated by selecting Reports \ Itemized cost (ICR).

SUMMARY PER SECTIONSection $/kg MP $/batch $/year %Inoc Prep 15,670.057 300,868 24,370,324 25.95Bioreaction 16,407.276 315,023 25,516,857 27.17Prim Recov 2,054.678 39,450 3,195,469 3.40Protein-A 12,045.297 231,272 18,733,039 19.95IEX Chrom 2,386.569 45,823 3,711,630 3.95HIC Chrom 2,206.522 42,366 3,431,618 3.65Final Filtration 687.069 13,192 1,068,541 1.14Chemical Virus Inactivation 1,748.633 33,574 2,719,501 2.90Viral Exclusion 1,974.948 37,919 3,071,470 3.27Buffer Preparation 5,203.442 99,907 8,092,476 8.62TOTAL 60,384.491 1,159,394 93,910,924 100.00

The Bioreaction section has the highest contribution to the manufacturing cost (27.17% of total), followed by Inoculum Preparation (25.95%), and Protein-A (19.95%). Roughly 53% of the operating cost is associated with the upstream sections and 47% with the downstream sections.

NOTE: A section in SuperPro is simply a set of unit procedures. If a long process is divided into sections, the reports of SuperPro provide various breakdowns per section.

The table below provides a breakdown of the consumables costs (the second most important item of the operating cost). The Protein-A resin is the most important contributor to this cost (72% of total).

CONSUMABLES COST (2006 prices) - PROCESS SUMMARY

ConsumableUnits Cost

($)Annual

Amount UOMAnnual Cost

($) %2.2 L Roller Bottle 6 648 item 3,888 0.02Dft DEF Cartridge 1,000 729 item 729,000 3.20225 mL T-Flask 2 1,458 item 2,916 0.01Dft Membrane 400 126 m2 50,226 0.2250 L Bag 5 1,620 item 8,100 0.04100 L Cell Bag 300 405 item 121,500 0.53Viral Exclusion Membrane 13,356 162 item 2,163,672 9.5120 L Cell Bag 100 486 item 48,600 0.21Protein A 6,000 2,714 L 16,286,016 71.57HIC Butyl Sepharose HP 2,050 954 L 1,956,230 8.60SP-Sepharose HP 1,200 1,155 L 1,385,584 6.09TOTAL 22,756,000 100.00

The table below provides a breakdown of the raw materials costs. Serum Free Media is the most expensive raw material. A purchasing price of $300/kg was assumed for Serum Free Media (in powder form).

RAW MATERIALS COST - PROCESS SUMMARY

Bulk Raw Material

Unit Cost ($/kg)

Annual Amount

(kg)

Annual Cost ($)

%

Inoc Media Sltn 6.147 18,959 116,539 0.71H3PO4 (5% w/w) 0.143 2,419,199 344,736 2.09NaOH (0.5 M) 0.245 2,163,923 530,291 3.21WFI 0.150 8,733,654 1,310,048 7.93SerumFree Media 300.000 36,339 10,901,767 65.97NaOH (0.1M) 0.243 7,912,570 1,923,704 11.64Amm. Sulfate 8.000 12,314 98,510 0.60Polysorbate 80 1.833 7 12 0.00Protein A Equil 0.153 1,991,715 304,633 1.84Protein A eluti 0.153 810,196 124,349 0.75Prot-A Reg Buff 0.168 486,392 81,583 0.49NaCI (1 M) 0.368 186,484 68,681 0.42IEX-El-Buff 0.347 16,335 5,674 0.03IEX-Eq-Buff 0.186 673,218 125,309 0.76HIC-El-Buff 0.305 242,190 73,779 0.45HIC-Eq-Buff 0.909 455,253 413,727 2.50PBS 0.182 129,302 23,570 0.14EtOH (10% w/w) 0.210 367,536 77,182 0.47TOTAL 28,199,045 16,524,095 100.00

NOTE: The estimation of the Facility-Dependent overhead cost is based on a variety of multipliers that are process and region specific. The default multipliers typically underestimate the Facility-Dependent overhead cost for biopharmaceuticals. For information on how to access and modify those multipliers, please consult the Economic Evaluation chapter of the manual and the corresponding topic in the Help Facility of SuperPro.

NOTE: Most of the multipliers used in cost analysis can be stored into the User Database of SuperPro and retrieved for future pertinent work. That facilitates standardization and improves the accuracy of cost estimation. For information on how to take advantage of the database capabilities of SuperPro, please consult the SynPharmDB document in the …EXAMPLES \ SYNPHARM subdirectory of the SuperPro installation.

9 Initialization of ConsumablesBiopharmaceutical processes tend to use large amounts of consumables such as filter cartridges, chromatographic resins, and disposable bag bioreactors. The cost of consumables is often the most important item of the manufacturing cost. Consumables in SuperPro are associated with equipment and can be specified through the Consumables tab of the Equipment Data dialog (Figure 10). Certain equipment types, such a chromatography columns and membrane filters, have equipment-specific consumables (e.g., chromatography resins and filter cartridges) specified through the top box of the Consumables tab (e.g., Membrane box of Figure 10). All equipment types can utilize other (non-equipment specific) consumables specified through the Other Consumables table.

Figure 10: The Consumables dialog box

SuperPro is equipped with a consumables database that can be accessed by selecting Databanks \ Consumables. That brings up the dialog of Figure 11. The types of available consumables are listed on the left-hand-side of the window. The user can add a new type of consumable by right-clicking on All Consumable Types and selecting Add Consumable Type. When a consumable type is selected on the left, SuperPro displays the available instances of that type on the right. The user may add a new instance (e.g., a new filter cartridge) by right-clicking on the name of the type (on the right) and selecting Add Consumable. Consumables that are part of the Designer database of SuperPro are displayed in red color and cannot be modified by the user. Those that are displayed in green are part of the user database and can be modified by the user.

During selection of a consumable through the Consumables tab of the Equipment Data dialog, the user has access to all compatible consumables that are already registered in the file and to those that are available in the database. When a user selects a consumable from the database, the program makes a copy of that consumable into the SuperPro file (this is called consumable registration). In other words, SuperPro does not maintain a live link to the objects in the Consumables database, but it simply copies the information from the database. The same logic applies to all other objects stored in the SuperPro databases.

Figure 11: The consumables databank

NOTE: Since SuperPro does not maintain a live link with the consumables databank, any changes in the databank do not automatically propagate to the SuperPro files. The synchronization of values is done by selecting Tasks \ Edit Other Resources \ Consumables that brings up the dialog of Figure 12.To update the values of a specific consumable (e.g., 100 L Cell Bag), select it by clicking on its line number and click the Update Consumable’s Properties from DB record button (the button in the red circle). If you change the same consumable in the design case file and you wish to update the contents of the User Database, select the consumable and click on the Deposit/Update Consumable into DB Record (the button in the blue circle).

Figure 12: Updating Consumable properties from the DB record

10 Resource Tracking and Sizing of WFI SystemsSuperPro has the ability to calculate and display demand for resources (e.g., materials, utilities, and labor) as a function of time. For instance, Figure 13 displays the demand for WFI over a period of fifteen consecutive batches (for Mab7_0c.spf). To generate this chart, select View \ Resource Consumption Tracking Chart \ Ingredient \ Multiple Batches from the main menu bar of SuperPro and then select the raw material of interest in the dialog that appears (WFI in this case). To change the number of batches, right-click on the chart and select Set Number of Batches. The red and blue lines of the graph correspond to the LHS y-axis and represent instantaneous and averaged (for 24-h intervals) WFI demand, respectively. The green line corresponds to the RHS y-axis and represents cumulative demand (for 24-h intervals).

This chart provides useful information for sizing WFI systems. Specifically, the tallest red peak (highest instantaneous demand) is useful information for sizing the pipe diameter of the circulation loop and its pumping capacity since the loop and the pump must be able to accommodate the highest instantaneous demand. The tallest green peak provides useful information for sizing the surge tank of the WFI system. It corresponds to the working volume of the surge tank if a 24-h buffer capacity is required (i.e., a 24-h supply even if the still is not operational during that period). The blue line for the green peak interval (which is also the blue peak) provides useful information for sizing the still. The averaging interval can be adjusted by the user. The larger the averaging interval, the greater the size of the surge tank and the smaller the size of the still. In other words, there is a trade off between still size and tank size in the sizing of WFI systems. Based on the values of Figure 13, for a 24-h WFI capacity, we need a tank that has a storage capacity of around 130,000 kg and a still that has a rate of slightly above 5,000 kg/h.

Figure 13: WFI consumption chart (Mab7_0a.spf) for 15 consecutive batches

SuperPro also can calculate and display inventory information for material resources and utilities. Suppose the storage capacity of the WFI tank is 100,000 kg. Suppose further that the WFI still has a rate of 8,000 kg/h and it is turned on when the level in the tank drops below 40% and off when it reaches 100%. To visualize the liquid level in the tank and the operation of the still, do the following. Select View \ Resource Inventory Chart \ Ingredient \ Multiple Batches. Select ‘WFI’ and then click on the Supply Info button to specify the size of the tank, the rate of the still, the initial contents, and the on/off criteria (the values provided above). Then click OK and on the next dialog click OK again. That will bring up the graph of Figure 14. The green line (that corresponds to the y-axis on the RHS) represents the WFI level in the tank. The blue line (that corresponds to the y-axis on the LHS) represents the operation of the still.

Obviously, there is an infinite number of combinations of tank size and still rate that constitute a solution. The larger the still rate, the smaller the required tank size. If the still rate is equal to the tallest instantaneous demand, then, no surge tank is practically required.

Figure 14: WFI inventory (green lines) and still operation (blue lines).