The Purification Insights Blog

Changing from purification products based on synthetic polymers to agarose-based chromatography will increase the purity of the target virus.

Just before the Christmas break, Lars, Haneskog, Bio-Works R&D Director, presented a new and proven strategy for downstream processing at the New Horizons in Biologics and Bioprocessing conference. It was met with great interest and several enquiries and, for those that missed it, we asked Dr. Haneskog to give us a brief summary of what was discussed.

Improving downstream bioprocess economy depends on fine-tuning an enormous range of parameters, from culture and harvesting to purification and final polishing. Success depends on the ability to troubleshoot difficulties and identify novel approaches that will boost process efficiency in a cost-effective manner. This is particularly true when high-value chromatography columns are used in the process. Bioburden and cleaning-in-place procedures can reduce column lifetime and capacity, and threaten product quality and yield. An alternative approach that protects these valuable columns is to reverse the first two steps to remove the potentially damaging components of a feedstock before proceeding with highly selective capture followed by polishing. We call this ECP... 

A critical and fundamental factor in both analytical and preparative chromatography is the use of true buffers. In other words, mobile phases with buffering capacity. For example, in peptide purification, there are concentrated bands of various components of the sample, including the target peptide, moving through the column and you need to have control over their tendency to dissociate...

Filtering is crucial in order to protect the packed column from all solid particles in feeds or eluents. Clogging of the column will increase back-pressure and disturb the feed loading zone causing reduced resolution and it is a common problem...

Peptide therapeutic agents are enjoying increasing success but they are challenging to produce and, not least, to purify. Purity requirements are, in fact, approaching those for small molecules. Synthesis generates a crude mixture containing failed sequences and chemical variants. 

Immobilized Metal Ion Affinity Chromatography (IMAC) is used for purification of His-tagged proteins. Ni-NTA based resins are the most commonly used as the Ni²⁺ ion is considered to have the strongest affinity to histidine-tagged proteins but stringent requirements on the yield of target protein can make it well worth the extra effort of trying another metal ion to optimize the purification process...

The environmental impact of pharmaceutical R&D and production is considerable. Although the industry is rather conservative and also constrained by regulatory guidelines, there is increasing interest in the implementation of sustainable practices that not only improve corporate social responsibility (CSR) performance but also reduce costs and increase efficiency. This effort is embodied in the concept of Green Chemistry and includes reducing the use of toxic solvents in production and purification, which is a considerable problem. Solutions include recycling and the use of upstream protective columns that remove bioburden to increase the life-cycle of columns used downstream, or even make certain solvent-consuming steps redundant altogether.

Designing an optimized purification process means maximizing yield and purity, and at the same time controlling costs. So, you remove a lot of bulk impurities during the first steps, and focus on high yield steps at the end, when every gram is precious. If you’re purifying mAbs, it would also be good to remove impurities before affinity chromatography to protect the protein A column and reduce the need for cleaning in place (CIP).

When it comes to many serious and challenging diseases, healthcare has reached a point of unsustainability, due to drug costs. For example, sustained therapy for an autoimmune disease or cancer, involving large amounts of monoclonal antibodies (mAbs), might not be a viable option for simple economic reasons. As a consequence, healthcare authorities want to reduce the cost of drugs by encouraging the development of biosimilars. When biological drugs are off-patent they can be copied – which is cheaper than developing the novel drug, but still challenging because of the need to demonstrate the same efficacy and safety. Drug purification, a key to successful manufacture of biologicals, must also adapt by exploiting products and technologies that lower the overall cost of production.