Smooth vaccine production

The global vaccination campaign against COVID-19 is steadily progressing. In October 2021, more than 20 million people worldwide received a vaccination. The need  or vaccination serums is accordingly high. To serve this demand even better in the future, the vaccine manufacturer BioNTech has expanded its strategic partnership  with the German pharmaceutical and chemical company Merck. Merck is one of the leading manufacturers of lipids, which are urgently needed for the vaccine production. Product safety, trouble-free operation, and the resulting reliable and quick delivery of the important vaccine components are of key importance. To  ensure this, Merck relies on a long-standing and reliable cooperation with EagleBurgmann and trusts in their gas-lubricated agitator seals from the AGSZ series.

mRNA vaccines – there’s no way around lipids

BioNTech/Pfizer’s Comirnaty® (BNT162b2) was the first vaccine to receive global approval as a protective vaccination against COVID-19 . It is a so-called mRNA vaccine (mRNA = messenger ribonucleic acid). The vaccination serum transports the mRNA into the body. It acts as a blueprint of a special characteristic of the SARS-CoV-2- Virus (spike protein) and provides the cell machinery with the information it needs to produce the corresponding antigen. As a consequence, the immune system  triggers an immune response.

But the vaccine consists of more than just its active ingredient. It is also made up of numerous excipients essential for the serum’s effectiveness. Among these, lipids are especially important. The mRNA molecule is rather instable – it has to be shielded in a protective shell so that it does not become ineffective before  arriving in the body cells. This shell is made up of lipids. 

Lipid production at Merck

As a strategic partner of BioNTech, Merck is heavily involved in numerous process steps of the vaccine production. For example, they develop and produce the lipids urgently needed for production of the mRNA vaccines. BioNTech/Pfizer for instance uses four different lipids in its vaccine. 

As one of only a few companies worldwide, Merck is able to produce the lipids in the required quantities while meeting the quality standards for mRNA vaccines. In  the first quarter of 2021, Merck announced that they would expand the strategic partnership with BioNTech and increase their lipid production capacities in several locations around the world until the end of the year. This will significantly speed up the supply of lipids and increase their available quantities to keep up with the currently high demand.

For the lipid production, Merck uses agitators with top entry drives, which had previously been used to process other products. When it comes to agitator seals,  they have put their trust in EagleBurgmann’s competence and quality for more than 30 years. This is why the choice was made for gas-lubricated agitator seals from the AGSZ series when they expanded their production capacities. “We were privileged to supply Merck with four glass-lined double-acting gas seals with bearings and rinsing flanges as well as the corresponding supply systems to be used in the lipid production in the converted agitators. The seals have a diameter of 100 millimeters and 80 millimeters respectively,” explains Markus Schmidt, Product Manager Mechanical Seals for Agitators, Mixers & Kneaders at EagleBurgmann. “Especially in a case like this that requires highest product purity, our FDA- and ATEX-compliant gas-lubricated AGSZ seals offer a variety of advantages.”

Constantly high product quality and trouble-free processes are essential to ensure quick and reliable lipid production. With gas-lubricated agitator seals from the  GSZ
series, both prerequisites are met to the fullest extent.

The AGSZ seals run contact-free. Thanks to precisely machined gas grooves, the seal face and seat achieve static lift-off at differential pressures as low as 3 bar. This allows a stable gas film with high stiffness to be created even without dynamic movement. “The contact-free operation reliably prevents abrasion. As a result, there is basically no chance of product contamination,” explains Schmidt.

In its new application in the converted agitators, the gas-lubricated mechanical seal offers another decisive advantage. “With the product change in the agitators, stricter purity requirements are needed,” notes Schmidt. “This also means that the product cannot be contaminated with buffer fluid. Gas-lubricated seals are ideally suited for quality and purity specifications like these.” At Merck, nitrogen (N2) is used as barrier gas, which is supplied via suitable supply systems from  EagleBurgmann. The process in the agitator vessel is not affected by the inert gas. Thus, high product purity and quality can be ensured at any time.

Trouble-free processes

Not only do the contact-free sliding-surfaces reliably avoid contamination of the product through abrasion. The wear-free operation also significantly increases the seals’ longevity. Additional factors, which contribute to their long service life, are their hard/hard material combination as well as the seal faces’ “diamond-like  carbon” coating, which also lends them their outstanding emergency running properties. The special seal design with a reduced number of parts also benefits Merck in the form of lowers maintenance requirements. Schmidt summarizes: “All of these factors contribute to a reliable, trouble-free operation in the lipid production at our client. Operating reliability is always important. This is all the more true in the current pandemic situation, where vaccines are so urgently  needed.”

Swift order implementation

EagleBurgmann answered the urgency of the project with a short delivery time and to Merck’s fullest satisfaction. The seals were supplied within a very short time and commissioned by trained personnel from Merck. “Our AGSZ seals are ready-to-fit cartridge units,” explains Schmidt. “This sped up and simplified their  installation and commissioning in the new production capacities at Merck. We are proud that this project allowed us to contribute to the progress of the global vaccination campaign.”

• Quick, simple installation and operating reliability through ready-to-fit cartridge unit
• Highest possible product purity due to contact surfaces running without friction and abrasion
• Minimum friction heat due to low start-up torque 
• Process safety through use of an inert barrier gas (N2)
• Longevity and cost-effectiveness through wear-free operation on the sliding surfaces

AGSZ seals from EagleBurgmann are ideal for applications in the pharmaceutical industry, chemical, as well as food industry – where highest product purity is essential.

• Shaft diameters: d1 = 40 … 220 mm
• Pressure: p1 = vacuum … 6 bar (87 PSI), Δp = min. 3 bar (44 PSI), p3 = 9 bar (131 PSI)
• Temperature: t1 = -20 °C ... +200 °C (+250 °C witch cooling flange)
• Sliding velocity: vg = 0 … 5 m/s (0 … 16 ft/s)