The Future of Downstream Processing - Pharmaceutical Technology

Latest Issue
PharmTech

Latest Issue
PharmTech Europe

The Future of Downstream Processing
The author reviews the state of downstream processing and considers potential solutions, including the streamlining of full processes and borrowed technologies.


Pharmaceutical Technology
Volume 35, pp. s36-s41

Streamlining and redesigning existing manufacturing processes

Many processes for biopharmaceutical manufacturing were designed at a time where process efficiency was considered unimportant (3). More recently, manufacturers have sought to increase the efficiency of each unit operation, but they are only now starting to consider redesigning the entire process train to see whether cost savings can be made. The trend toward process streamlining owes a lot to FDA's quality-by-design (QbD) principles, which are derived from the design-of-experiments (DOE) concept. The design space of a manufacturing process is littered with efficiency peaks and troughs, but there is not always a simple path leading to the most efficient process. Therefore, process design incorporating efficiency and quality from first principles involves going back to the drawing board and evaluating the critical attributes that contribute to an efficient process.

Most companies are applying these principles and actively streamlining their processing strategies wherever possible. Antibodies take center stage because they represent more than half of all biopharmaceutical products in development, and their common properties make it possible for companies to share process efficiency data that are applicable across platforms (10, 11). It is for this reason that antibody manufacturing has benefitted from the development of so-called generic platform processes, which are broadly similar for all antibodies but can be tweaked to match the specific properties of individual products (12).

Antibody manufacturing provides an excellent example of the application of process redesign and streamlining principles to increase productivity, cut costs, and maintain product quality. Most manufacturers use three chromatography steps for antibody purification, starting with a very expensive Protein A capture step that is placed immediately after clarification, followed by anion exchange (AEX) chromatography in flow-through mode to extract negatively charged contaminants, such as host-cell protein (HCP), endotoxins, host DNA, and leached Protein A. Then, either cation exchange (CEX) chromatography or hydrophobic interaction chromatography (HIC) in retention mode is used to remove positively charged residual contaminants and product related impurities, such as aggregates and degradation products (13). Modern platform processes also serve as orthogonal strategies for virus removal.

Realizing that no further cost savings could be gained by scaling up the above process, Pfizer explored the design space around the standard process and found that certain modifications could reduce costs considerably without affecting the quality of the antibody (14). The company introduced two types of process modifications, one in which the order of the polishing steps was reversed and another in which different separation technologies were used to increase process capacity (i.e., using membrane absorbers for the flow-through chromatography step and replacing the depth filtration step with continuous centrifugation) (15). These changes increased the efficiency of purification to such an extent that, for some antibody products, the cation-exchange step became unnecessary reducing the process from three columns to two columns or even a single column. Not only did this save the direct costs of column resin and buffers, but also reduced the process time by >45% which doubled the productivity in terms of batch processing (14).


ADVERTISEMENT

blog comments powered by Disqus
LCGC E-mail Newsletters

Subscribe: Click to learn more about the newsletter
| Weekly
| Monthly
|Monthly
| Weekly

Survey
What role should the US government play in the current Ebola outbreak?
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Finance development of drugs to treat/prevent disease.
23%
Oversee medical treatment of patients in the US.
14%
Provide treatment for patients globally.
7%
All of the above.
47%
No government involvement in patient treatment or drug development.
9%
Jim Miller Outsourcing Outlook Jim MillerOutside Looking In
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerAdvances in Large-Scale Heterocyclic Synthesis
Jill Wechsler Regulatory Watch Jill Wechsler New Era for Generic Drugs
Sean Milmo European Regulatory WatchSean MilmoTackling Drug Shortages
New Congress to Tackle Health Reform, Biomedical Innovation, Tax Policy
Combination Products Challenge Biopharma Manufacturers
Seven Steps to Solving Tabletting and Tooling ProblemsStep 1: Clean
Legislators Urge Added Incentives for Ebola Drug Development
FDA Reorganization to Promote Drug Quality
Source: Pharmaceutical Technology,
Click here