GORE™ ImproJect™ Plungers

Eliminate silicone in both barrel and plunger to protect sensitive biologics in glass pre-filled syringes (PFS)

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Data Sheet: GORE™ ImproJect™ Plungers

Drug Delivery and Packaging

GORE™ ImproJect™ Plungers eliminate the need for silicone as a lubricant in pre-filled syringes. Used with bare-glass (non-siliconized) barrels, these silicone-free plungers provide consistent delivery performance over time, and can protect complex or sensitive biologics from silicone-induced aggregation and particulation.

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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.

Now, GORE™ ImproJect™ Plungers Offer A New Solution
Silicone-free plunger with PTFE-based fluoropolymer barrer, non-siliconized glass syringe barrel

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.

Exceptionally Low Particles

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.

Functional Performance

ImproJect Syringe Plungers

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.



A New Option for Drug Delivery

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.


Recent News

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Gore Attending Two Upcoming Biopharmaceutical Conferences in April

Posted March 22, 2019

Visit Booth 70 at BPI Europe in Vienna and Booth 3737 at Interphex in New York City to learn how Gore's innovative technologies help biopharmaceutical manufacturers achieve efficiency and operate reliably.


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Posted October 12, 2018

Gore plans to commercially launch the GORE™ ImproJectTM Plunger for Pre-Filled Syringes at the 2018 PDA’s Universe of Pre-Filled Syringe and Injection Device meeting in Orlando, FL on October 8th.

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Gore Strengthens Collaborative Relationship with ViaCyte by Investing Additional $10 Million

Posted September 25, 2018

ViaCyte, Inc. and W. L. Gore & Associates, Inc. today announced a $10 million investment by Gore into ViaCyte in the form of a convertible promissory note. This new investment by Gore into ViaCyte follows a similar multimillion‐dollar investment by Gore in May 2017.

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