Exploring Biological Buffers and Their Uses in the Pharmaceutical Industry
Biological buffers play an essential role in a wide range of applications used in the biopharmaceutical manufacturing processes.
The characteristics of biological buffers, the adjustment of the pH value, and the stabilization of the biological systems are essential when performing biological experiments, because proteins and enzymes are sensitive to changes and therefore biological buffers are vital to maintain a healthy biological system and ensure consistent results in the experiment or during the manufacturing process.
We examine the importance of biological buffers and the process of choosing the correct buffer for current upstream and downstream experiments.
Essential Properties of Biological Buffers
In the past, different inorganic substances, such as phosphate, cacodylate, borate, and bicarbonate, were used as buffers, with organic acids being added to the list to conduct biological experiments. However, the disadvantage of these buffers was that they were not inert, because these substances were enzymes substrates or enzyme inhibitors and could react with metabolites or other components.
For a buffer to be effective it should not be subject to either enzymatic or non-enzymatic changes and therefore be inert.
The right buffering system can protect the integrity of biomolecules and reagents and provide solution stability and pH control without interfering with biological processes. Buffer systems also need to supply critical salts and nutrients for cells and tissues to thrive. The right system can bring stability to cell culture, polymerase chain reaction (PCR), drug screening, bioprocessing, purification, and final formulation applications.
Essential properties of an effective buffer:
- - Solubility
- - Permeability through biological membranes is an important requirement
- - pKa value at the mid-point of the range of the test system
- - Change in pKa value should be dependent on temperature
- - Change in pKa value should also be dependent on dilution
- - Interaction with other components (e.g. metal ions, enzymes)
- - UV absorption
- - Non-toxic
Choosing the Right Buffer
When choosing a buffer, while considering its advantages and disadvantages, it is important to ensure that the pH range of the agents you plan to use in an experiment coincides with the pH range of your chosen buffer. Another consideration is that the pKa value should be within one unit of your desired pH.
The other elements to focus on are the concentration, buffer toxicity, temperature, and reactivity:
The concentration of your buffer must be sufficient to account for the amount of acid or base you plan to use in your experiment. The more the pH-altering component you plan to use, the higher the buffer concentration you will need.
- Buffer Toxicity
Buffer toxicity is highly important because some buffers can be toxic to the cells you are working with. If unsure about the toxicity, you can test the buffer on the cells before using it in the experiment.
As temperature can alter the buffering capacity of your buffer, checking the temperature for your experiment is essential.
Finally, ensuring that your chosen buffer does not produce unwanted reactions in your experiment is important to conduct a reactivity test.
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Christoph Zahner is based in Zurich, Switzerland. He is currently Senior Manager, Global Business Development, Pharmaceutical Industry at DKSH.