Pall filter 'a leap forward' in bioprocessing

The company launched the new product - the Supor UEVA 0.2 micron filer - at the Biophex meeting in San Francisco, US, last week.

Ian Sellick, Pall's director of marketing, told In-Pharmatechnologist.com​ that there are three new elements incorporated into the filter that improve its performance compared to existing technologies.

The first is a large increase in the surface area of the filter, achieved whilst retaining the standard size of the filter casing. Each filter has a surface area of more than 1 square metre per 10 inch module - up to twice that of rival products - achieved by a proprietary way of folding the membrane known as Ultipleat.

The product has also been able to 'hijack' some of the space ordinarily used to collect filtrate in a filter, known as the core collecting chamber, to increase the surface area of the filter.

Secondly, the layout of the filter, using a helical formation rather than the more usual star pattern - makes all the surface area available for filtration and makes it easier for fluid to pass through it, with a uniform flow across the device.

Finally, the third pillar of the new filter is a new type of membrane construction. Most filter membranes are uniform and symmetrical in structure, like a honeycomb. Pall's product has an asymmetric structure with a range of pore sizes from 3 to 0.2 microns. This provides graded retention of particulate matter - with solids trapped across the entire membrane structure - that improves the capacity of the filter to reduce bioburden.

The net result of these innovations is a filter that cuts bioburden more effectively - with an improvement in flow rate - and this can have economic benefits. For example, Pall presented data at Biophex suggesting that using Supor UAEV in processing could enhance the lifespan of sterile filters for fermentation and cell culture harvest and remove the need to use them entirely in some applications.

It can also protect other sensitive downstream processing equipment, such as tangential flow filtration (TFF) and chromatography systems.

As an example, Sellick noted that the components of a chromatography column can carry a significant value - in the hundreds of thousands of dollars in some instances. Pall's product can reduce the risk of such a column being wasted through contamination, he said.

One other cost saving comes from the fact that Pall's filter is smaller than rival products and has a smaller filling volume. At the end of a production process some filtrate will be retained - and lost - within the filter, and for some products this wastage is not insignificant in commercial terms.

For example, recombinant Factor VIII carries a price of several hundred thousand dollars per gramme, so saving even a few milligrammes of material is desirable. The Supor UAEV's small size reduces this wastage, said Sellick.

Bioburden reducing filters - i.e. used ahead of the final sterilising filtration step, are the workhorse of the bioprocessing industry, with applications across the remainder of the production process. Pall's new product works with a diverse range of biopharmaceutical fluids, including buffers, biologicals, tissue culture media, ophthalmics and cell culture supernatants.

While it is hard to ascribe a figure to this portion of the market, it is thought to represent a significant chunk of the $800 million (€650m)-plus spent each year by the biopharma industry on filtration, according to a report​ published last year by D&MD.

Sellick noted that the broad applicability of the new filter - with uses spanning biotechnology, blood products and vaccines production etc - also ties in with the preferred buying patterns of companies. They now want to buy products from as few providers as possible, and particularly like items flexible enough to have multiple uses.