Figure 3. Cost comparison of options 1 and 2 under scenario 2
Scenario 2: Scenario 2 is similar to scenario 1 except that it explores the use of disposable technology. The use of disposable diafiltration
pods, instead of depth filters and housings, and buffer bags, instead of tanks, resulted in lower costs for equipment cleaning,
commissioning, and validation. Figure 3 shows a comparison of the different cost components for the two options. The total
cost for both options is approximately 10% lower than those in scenario 1. The raw material costs for option 2 are ~70% higher
because of the use of disposable consumables, which is similar to what has been reported in the literature.7 However, the reduction in capital cost (~25%) more than makes up for this increase for this application. Disposables are
an economically attractive alternative, particularly when a company wants to limit its capital investment.
Figure 4. Cost comparison of options 1 and 2 under scenario 3
Scenario 3: This scenario depicts a medium or large biopharmaceutical company that has several products in the pipeline and thus, the
equipment cost in this scenario can be discounted for depreciation. Figure 4 shows a comparison of the different cost components
for the two options. The capital cost for scenario 3 is drastically lower versus scenarios 1 and 2, because of the equipment
costs discounted for depreciation. Further, option 1 (centrifuge + depth filtration) appears to be a more desirable option,
with a 20% lower cost in comparison to option 2 (microfiltration), primarily because of the larger amount of purified water
required for the microfiltration step.
Figure 5. Cost comparison of options 1 and 2 under scenario 4
Scenario 4: This scenario also assumes discounting of equipment costs for depreciation and models the cost for a high volume product
(50 lots per year). Figure 5 shows that, like scenario 3, the total cost for option 1 is about 25% lower than that for option
2. The cost of raw materials and the capital cost are an insignificant portion of the total cost.
Anurag S. Rathore, PhD, is a consultant, Biotech CMC Issues, and a member of the faculty in the department of chemical engineering at the Indian Institute of Technology. Rathore is also a member of BioPharm International's Editorial Advisory Board.
Articles by Anurag S. Rathore, PhD