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Unveiled at Pharmapack, the no-added silicone sealing solution mitigates contamination threats.

To help pharmaceutical and biotech developers better protect the integrity of injectable formulations and optimize the functionality of prefilled syringes and cartridges, Datwyler launched its NeoFlex™ plungers. Announced at Pharmapack, Datwyler’s NeoFlex™ plungers are equipped with the highest quality elastomer compound and a proprietary, inert fluoropolymer spray coating to ensure excellent extractable and leachable profiles. The spray coating is a no-added silicone solution to help mitigate the risk of drug contamination.

“Amid the rise of therapeutic biologics as well as auto-injectors and wearables that facilitate self-administration, there are more drug delivery challenges than ever before,” said Carina Van Eester, Platform Leader, Prefilled Syringes and Cartridges at Datwyler. “This makes optimizing function and performance critical. NeoFlex™ plungers guarantee a low and consistent break loose and gliding force while preventing leakage and ensuring limited plunger movement during air transport.”

NeoFlex™ plungers guarantee container closure integrity and are compatible with gamma and steam sterilization. Due to the performant washing programs, the plungers have low visible and subvisible particulate levels, low bioburden and low endotoxins. All plungers are camera inspected after washing to further enhance the quality, ensuring elimination of visible particulates and plunger defects.

Contamination is a significant concern among drug manufacturers. In a recent poll of more than 200 biopharmaceutical professionals by Datwyler, 63 percent of respondents cited some form of particle or leachable contamination among their greatest concerns. Twenty-five percent specifically cited particles as their topic of most concern while about 21 percent pointed to extractables and 17 percent specified silicone. 

“No one who heads up project development, engineering or R&D for biopharmaceuticals ever wants their company to undergo a recall—especially if the contamination could have been prevented,” said Carina Van Eester. “The gravity of this scenario demands every measure to protect the integrity of drug formulations and prevent production delays and shortages of important medicines.”

Unlike plungers made from co-molded components that contain areas of naked rubber and pose the risk of residue transfer, Datwyler’s NeoFlex™ plungers are fully coated using Datwyler’s proprietary spray coating technology. This efficient method provides a robust barrier between drug and rubber to minimize extractables and leachables, and speed time to market.

NeoFlex™ plungers can be offered ready-to-use, minimizing human intervention as another step towards reducing contaminants. The RTU packaging uses double vacuum sealed bags. If ever a puncture in the packaging were to compromise the sterilized plungers, the bag would lose its vacuum seal, enabling customers to easily identify and divert the plungers out of their supply chains.

Datwyler manufactures all of its NeoFlex™ plungers to FirstLine™ production standards. The company’s network of FirstLine™ facilities marry best-in-class production technologies with fully integrated cleanroom environments. Multiple FirstLine™ plant locations around the world ensure multinational options for sourcing.

NeoFlex™ plungers are available in 0.5 ml, 1.0 ml and 2.25 ml sizes for prefilled syringes and in 3 ml for cartridges. NeoFlex™ is the preferred option for proteins prone to degradation and denaturation in the presence of metal ions, silicone oil, oil-based formulations, and other compatibility challenges. Application areas include prefilled syringes for manual application, prefilled syringes in auto-injectors, cartridges in pen-injectors, and siliconized glass and polymer syringes.


Datwyler is focusing on high-quality, system-critical elastomer components and has leading positions in attractive global markets such as healthcare, mobility, oil & gas, and food & beverage. With its recognized core competencies and technological leadership, the company delivers added value to customers in the markets served. With more than 20 operating companies, sales in over 100 countries and more than 7,000 employees Datwyler generates annual sales of more than CHF 1’000 million. Within the healthcare solutions business area, Datwyler develops, designs, and manufactures solutions for injectable packaging and drug delivery systems to facilitate customers to create a safer medical environment of tomorrow. Looking back onto more than 100 years of history, Datwyler is a reliable partner, now and in the future!