Enhancing Patient Safety: Addressing Vial Coring Risks in Injectable Medications

As drug manufacturers aim for higher safety standards and enhanced patient care, controlling the drug product at the point-of-use in a hospital or clinical environment remains a significant challenge. The method of vial access often varies, increasing the risk of adverse patient outcomes, such as stopper cores or fragments entering the drug product. If injected, these fragments can lead to cardiovascular events and other complications. Several factors contribute to stopper coring and fragmentation in the field, primarily influenced by the technique of the practitioner and the properties of the elastomeric closure.

Recently, the Anesthesia Patient Safety Foundation (APSF) and the Institute for Safe Medication Practices (ISMP), along with Emergency Care Research Institute (ECRI), issued an urgent alert regarding increased reports of medication vial coring incidents. The alert emphasizes the critical need for awareness of the potential risks associated with vial coring, especially when using blunt needles.^1,2

Current Causes of Coring or Fragmentation

Technique and Design Related Factors:

• Needle Type: Blunt needle tips have a higher tendency to produce fragmentation compared to sharp beveled needles. Recent reports highlight the critical importance of avoiding blunt needles when accessing vials.
• Needle Gauge: Needles larger than 21-gauge are more likely to contribute to fragmentation. Interim guidance suggests using smaller gauge needles. 
• Needle Siliconization: Enhanced uniformity in needle siliconization helps reduce coring and fragmentation.
• Needle Reuse: The practice of needle reuse is strongly discouraged to prevent dulling of needles and silicone removal, which increases coring risk. 
• Force of Puncture: Controlled force application during puncture aids in minimizing coring.
• Angle of Puncture: Entering the vial at an angle that creates the least resistance to puncture is recommended when using sharp beveled needles.
• Number of Punctures: Puncturing the vial stopper only once is advised to limit coring risk.
• Incorrect Use: Clear labeling and device compatibility guidelines help avoid the use of spikes on stoppers not designed for them.

Closure Properties:

• Elastomer Formulation: Formulations with strong functional properties offer enhanced tensile strength and reduced coring.
• Configuration: Stopper diaphragm thickness and design optimizations help reduce coring. 
• Siliconization of the Closure: Modern siliconization techniques provide improved performance by creating a more durable silicone layer on closures.
• Closure Processing: Controlled sterilization techniques maintain elastomer integrity to minimize degradation.

Clinical Risks to Patients Across Various Routes of Drug Administration

Coring during injectable medication administration can pose several significant clinical risks to patients across various routes of administration, including:

Intravenous (IV) Administration:

• Embolism Risk: Stopper fragments can enter the bloodstream, causing embolism and potentially blocking critical blood vessels, resulting in conditions such as stroke or myocardial infarction.
• Infection Risk: The introduction of contaminated material into the bloodstream can lead to infections, particularly if aseptic techniques are compromised.
• Inflammatory Response: The body may react to stopper particles as foreign invaders, leading to systemic inflammatory responses or localized issues such as phlebitis.

Subcutaneous Administration:

•  Local Inflammatory Reaction: The presence of stopper fragments under the skin can lead to localized inflammation, pain, or swelling.
• Delayed Absorption: Fragments may interfere with the medication's absorption, leading to reduced efficacy and delayed onset of therapeutic effects.
• Granuloma Formation: The immune system may form granulomas around stopper fragments, resulting in persistent nodules or lumps under the skin.

Intramuscular Administration:

• Muscle Damage: Injection of fragments into muscle tissue may cause trauma, inflammation, or abscess formation, leading to pain and impaired muscle function. 
• Local Infection: The presence of foreign particles can introduce infection at the injection site, necessitating medical intervention.
• Granuloma Formation: Stopper fragments can lead to granuloma formation within the muscle, causing nodules that may require medical evaluation and management.

Intra-articular Administration:

•  Joint Damage: Injections into joints containing stopper fragments can lead to synovitis, joint inflammation, or cartilage damage, causing pain and decreased mobility.

Recommendations for Reducing Coring Risk

To further reduce the risk of coring, West suggests expanding field education on proper needle/spike usage and selection. Drug manufacturers can significantly influence coring prevention through appropriate elastomer formulation and design decisions tailored for the intended end-use. For applications requiring multiple doses, advanced synthetic isoprene and low-coring stopper designs are commercially available. The integration of vial adapters offers a standardized approach to vial access, allowing for multiple dose withdrawals using a single stopper puncture.

APSF and ECRI/ISMP’s interim practice recommendations emphasize consulting the manufacturer's package insert for specific directions on accessing vials and avoiding blunt needles whenever possible. Practitioners should inspect vials for macroscopic coring and refrain from administering medications if coring is suspected or visible, ensuring affected vials and medications are secured and reported appropriately.

By integrating recent advancements in needle and elastomer technology and emphasizing best practices and educational outreach, the pharmaceutical industry can more effectively manage and mitigate the risks associated with coring and fragmentation, ultimately safeguarding patient health. West conducts extensive coring and fragmentation testing on its components, ensuring that rigorous standards of quality and safety are met. The results of these tests are compiled into comprehensive reports that are made available for both internal stakeholders and external clients. Furthermore, West Services and Solutions, LLC offers coring and fragmentation studies as part of its suite of services, emphasizing its profound knowledge and experience in this domain. This commitment to quality and safety underscores West's dedication to delivering reliable and effective solutions in the pharmaceutical and biotechnology industries. Reach out to your West Technical Account Specialist to explore new-generation low-coring stopper options and solutions tailored to your needs.

¹ Patient Safety Alert: Urgent Alert Regarding Medication Vial Coring and Fragmentation Risks. Anesthesia Patient Safety Foundation. March 30, 2025.
² Taylor A. ALERT: Medication Vial Coring Poses Potential Fragmentation Risks. Outpatient Surgery Magazine. April 10, 2025.