Tag: biochemical engineering

Downstream Processing: Introduction

Now you know what upstream processing is, what happens once you’ve expanded the cell culture and product formation? Is that it? The short answer is NO! You can’t just give the cell broth to someone! The cell broth produced after upstream processing contains cells, product impurities (improperly folded product, product that has been modified in some way), media components, cell debris, etc. This stuff is potentially dangerous to the end user, and is also likely to cause the product to degrade quicker, leading to crappy storage.

In order to create a pure, consistent, safe and defined product, we must isolate it from the rest of the cell broth. This is called downstream processing. Downstream processing consists of various unit-operations in which the product is isolated and purified, producing a bulk drug substance (where the majority of the mass is the product). Fill/finishing (where more impurities are removed and excipients are added to improve long-term stability / change the state of the product to allow storage and transport) then produces the drug product from the bulk drug substance.

*In most cases, for FDA / regulatory body approval, the product needs to be at 95% purity, and majority of impurities must be less than 1 part per million in the final drug product.

Downstream processing unit operations can be split into 4 categories based on their purpose:

  1. Recovery: Initial isolation of the product from other components of the cell broth. Unit operation examples: centrifugation, filtration.
  2. Isolation: Further isolation of the product from cell broth components. Unit operation examples: precipitation, capture chromatography, liquid-liquid extraction.
  3. Purification: Removal of impurities/ other remaining non-product components. Unit operation examples: Crystallisation, Polishing chromatography.
  4. Fill/Finish: Removal of remaining impurities + preparing drug product for storage and transport. Examples: Ultrafiltration, nanofiltration, freeze-drying.

After downstream processing and fill/finish, the product can now be used!

If you have any questions, please leave a comment below and I will get back to you ASAP

Definitions of biotech-specific words

In your exams/quizzes you might come across questions that ask you to define certain terms, so I’ve included a list of textbook definitions for each term that you might need to define.

Biotechnology-related terms

  • Bioprocessing: The cultivation and use of living cells to for biological material or processes for medical or commercial purposes. A branch of biotechnology, often used for development of manufacturing processes.
  • Biotechnology: Commercial techniques that use living organisms, or substances derived from living organisms, to make/ modify a product. This does not include agricultural/ranching unless genetic engineering has been used.
  • –Industrial biotechnology: The use of living cells/and or their enzymes to produce or process commercial and industrial products. Usually it is cheaper than using traditional methods (i.e. extraction or catalysis).
  • Bioengineering/ Biomedical Engineering: The application of engineering principles to biological or biomedical products.

  • Medical Biotechnology: Medicine derived from the use of genetics, cell biology and other sciences.
  • Bio-pharmaceuticals: Biologically significant compounds that are used to treat human disorders. This is different from pharmaceuticals because they are not chemically synthesised i.e insulin. Does not include compounds directly extracted from tissue.
  • Regenerative Medicine: Any therapy that induces regeneration of an organ or tissue in the case of disease, injury or developmental defects.
  • Tissue Engineering: The use of engineering and biological principles to create a viable substitute for an organ, with the aim of restoring, maintaining or improving the function or an organ or tissue.
  • Biochemical Engineering: The use of bio-catalysts to produce a desired chemical transformation. Extends off chemical engineering.

Bioprocessing-specific terms

  • Upstream Processing: The mass manufacture of a desired product using cell cultivation processes.
  • Downstream Processing: The isolation, purification and formulation of a product from cell broth to form the final product format.
  • Formulation: Techniques used to generate the final product form from the bulk product. The final product form is ready to be used commercially/ medicinally, or to be stored and transported.
  • Quality control: Ensuring the product quality, safety, and efficacy are maintained within a certain range that meet the Good Manufacturing Practice standards set by the FDA.
  • Unit operations: Individual steps in a process that change or separate components of the cell broth. For example: centrifugation, filtration.

I will go over the bioprocessing terms in more detail, in their own sections as they are topics of their own, but I hope this is useful for you guys when you are cramming/ need a reminder!

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