Eliminate silicone in both barrel and plunger to protect sensitive biologics in glass pre-filled syringes (PFS)
Today’s complex biologics, such as monoclonal antibodies and conjugate vaccines, can be vulnerable to silicone-induced protein aggregation and particle formation. In addition, over time, silicone migration can impact consistency of delivery, as it may change break loose and glide force (BLGF) and injection time. As a result, many biopharmaceutical manufacturers are actively seeking ways to address these silicone-related issues.

For the first time, GORE™ ImproJect™ Plungers enable manufacturers to completely eliminate silicone from both plunger and barrel in their PFS.
New GORE™ ImproJect™ Plungers for pre-filled syringes protect complex and sensitive biologics from silicone-induced protein aggregation and particulation. They do so by completely eliminating the need for silicone in both the plunger and the glass barrel.
- The plungers are silicone-free: Silicone is not a raw material and is not used in the manufacture of the plungers.
- The plungers, designed for use in bare-glass (non-siliconized) barrels, provide excellent container closure integrity (CCI) and maintain consistent injection performance over time.
GORE™ ImproJect™ Plungers effectively protect many of the more complex biologics that are silicone-sensitive. Testing demonstrates that GORE™ ImproJect™ Plungers provide:
- Orders of magnitude reduction in sub-visible particles, compared to siliconized syringes.
- Excellent biocompatibility: 21 CFR Part 4 and ISO 10993-1.
- No significant extractable compounds, due to our plunger’s proprietary PTFE-based fluoropolymer barrier.

The only plunger that enables low particulates and consistent delivery over time in bare glass (non-siliconized) barrels.
Due to its proprietary plunger design and fluoropolymer barrier, the GORE™ ImproJect ™ Plunger ensures:
- Excellent CCI, to protect against drug loss, leakage and microbial ingress.
- Consistent delivery including auto-injector applications – even after accelerated aging conditions.
- No significant extractable compounds.
GORE™ ImproJect™ Plungers provide the only option for a silicone-free PFS (plunger with glass barrel), which protects sensitive biologics from potential interactions with silicone. To explore this new option in drug delivery, connect with your local Gore representative, or contact us.
Compliance & Quality
GORE™ ImproJect™ Plungers are manufactured in accordance with appropriate material and regulatory requirements, including USP <381>, EP 3.2.9 ad JP7.03, and in adherence to relevant Good Manufacturing Processes (cGMP) as defined in the Gore PharmBIO quality system, which is certified to ISO 13485, and ISO 15378.
To read our most current compliance statements, please contact us.
Product Information
For additional product information, please review our Data Sheet. To request a technical consultation, product samples, or a Validation Guide, please contact us.
Pharmaceutical - Drug Delivery and Packaging - ImproJect Plungers - Data Sheet - US
Pharmaceutical - Drug Delivery and Packaging - ImproJect Plungers - US
GORE™ ImproJect™ Plungers eliminate the need for silicone as a lubricant in pre-filled syringes. Used with bare-glass (non-siliconized) barrels, these plungers protect complex or sensitive biologics from silicone-induced aggregation and particulation while maintaining consistent injection performance over time.

Pharmaceutical - Contact Group - Americas, Europe, All Other - US
Pharmaceutical - Contact - All Other - US
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Gore has built a worldwide reputation for ethics and integrity in its dealings with customers, suppliers and employees.
Pharmaceutical - Drug Delivery and Packaging - ImproJect Plungers - Validation Guide - US
Pharmaceutical - Drug Delivery and Packaging - ImproJect Plungers - US
A comprehensive guide for validating these plungers for use in bare-glass (non-siliconized) pre-filled syringe barrels. GORE™ ImproJect™ plungers can help to protect the stability of complex, silicone-sensitive biologics, while providing consistent delivery performance over time. This document is available upon request.

Pharmaceutical - Contact Group - Americas, Europe, All Other - US
Pharmaceutical - Contact - All Other - US
Enterprise - Contact - Product Contact Form - US
Gore has built a worldwide reputation for ethics and integrity in its dealings with customers, suppliers and employees.

Pharmaceutical - Drug Delivery and Packaging - ImproJect Plungers - Data Sheet - US


Pharmaceutical - Contact Group - Americas, Europe, All Other - US
Pharmaceutical - Contact - All Other - US
Enterprise - Contact - Product Contact Form - US
Gore has built a worldwide reputation for ethics and integrity in its dealings with customers, suppliers and employees.