Ask the Expert: Boosting Profits with Single-Use Powder Transfer

with Chris Rombach

Open-suite biomanufacturing is gaining popularity. But it leaves surfaces open to contamination, workers at risk for exposure to airborne particulates, and processes more exposed to product loss due to waste or spillage. Liquid-handling systems are often adapted for dry-powder applications, but flow rates, handling characteristics, and dispensing volumes differ dramatically. ILC Dover’s purpose-built, single-use EZ BioPac system is designed specifically to contain and release dry powders. With single-use bags engineered for the task, it can deliver several advantages: reducing spillage, waste, and processing time by filling quickly and precisely, sealing completely and dispensing swiftly and cleanly, leaving no residue inside, and eliminating unwieldy barrels and containers.

In an “Ask the Expert” webinar on 31 August 2016, Chris Rombach (ILC Dover’s director of global strategic accounts) described how the system works and how its critical components are designed. He supported its specific performance characteristics with data from a series of comparative tests.

Rombach’s Presentation
A powder-transfer system needs a large-diameter top opening to facilitate filling and adjust final weights. It should work for a broad range of filling and dispensing volumes, flow rates, and product weights. It should be rugged and disposable, with antistatic properties. And it should discharge quickly and cleanly into process vessels.

The EZ BioPac system was designed specifically for powder containment and transfer. It offers distinct advantages over liquid-derived systems (e.g., those listed above). It has a large fill opening that allows for fast and consistent filling and easy fine-tuning with a large scoop.

To measure specific performance, we tested our EZ BioPac system against a typical 2D transfer bag, filling bags to ~5.25 kg and then adjusting them down to a final weight of exactly 5.0 kg in three independent trials. The new system was consistently faster by as much as 71%.

For contamination prevention, a protective outer skirt folds down to completely cover the frame and the outside of the bag. This is turned up to seal the bag after filling, locking powder residues into the interior surface. Simple sealing options include a proprietary crimping system and simple Z-folding by hand (then clamping with attached cable ties that come prewelded to the bag). Filled bags can be transported with integral hand straps or by using a hoist.

A separate discharge outlet ensures that the discharge path remains clear and clean and emptying is complete. We compared our bags to competitive 2D transfer bags in a process of removing the clamp, installing the bag, opening the closure, discharging it, and then fastening it and disconnecting it. In three independent trials, the EZ BioPac system discharged 18.6% faster and retained 33.3% less material. Its proprietary ArmorFlex 114 film has a permanent static-dissipative property to prevent product from clinging inside the bag during dispensing.

The system uses a strong and lightweight, stand-alone, self-supporting frame for bag support and protection. Frames accommodate 1-L to 100-L bag volumes. The EZ BioPac system comes in a wide range of volumes and flange sizes, different bag weights and connection sizes. The product is certified for GMP use and has a five-year shelf life.

Questions and Answers
Can a dry powder supplier order these bags as a standard offering? Are the bags easy to implement in an existing, semiautomated filling set-up? Millipore Sigma provides them prefilled with its powders for automated or semiautomated filling.

Can you talk about the difference between 2D and 3D bags? A 3D bag fills out into a full three dimensions. Our bags are circular with a proprietary lap-welding design. A 2D bag is much like a pillow case, with a single opening and seams that can create small gaps and crevices, making it hard to discharge powder.

Can EZ BioPac bags work for closed-powder changing? Yes. Different types of connections are readily available to facilitate higher levels of containment. For the highest level, we recommend a split-butterfly design. We work closely with ChargePoint, which might help with highly active pharmaceuticals.

Does the bag (or can it) include a feature to minimize water absorption for hygroscopic materials? That depends on how the system is configured and working. For example, our partner Millipore Sigma has developed designs that include desiccant inside the transportation drum. We could certainly work with customers using some of our other films and overwraps, such as our high-barrier, aluminum-based foil films.

What is the minimum powder quantity for high powder recovery? That depends on the powder itself. Typically we see retention of about 2 g. It’s not a function of how much was in the bag, but rather of its surface area. We have smaller bags, as well. For very small volumes, we would be happy to collaborate with any customer on stability testing.

What is the maximum weight rating for the bags? It is 100 kg for the largest design (100 L).

More Online
The full presentation of this August “Ask the Expert” webcast can be found on the BioProcess International website at www.bioprocessintl.com/webinars/how-to-boost-profits-with-single-use-powder-transfer.