Pharmaceutical cap liners are chosen based on their compatibility with the contents and the necessary seal integrity to prevent contamination of a sample within its lab storage container. The most common varieties of cap liners are silicone, butyl rubber, PTFE, polyethylene, and foil liners. Each type of cap liner has unique advantages specific to the requirements of the pharmaceutical product. The selection process is influenced by factors such as the chemical composition of the contents, sensitivity to temperature changes, and susceptibility to external elements. Pharmaceutical companies carefully consider these factors to achieve chemical resistance, flexibility, cushioning, or a hermetic seal in order to comply with regulatory standards and guarantee the delivery of products that uphold the highest quality and safety benchmarks within the pharmaceutical industry.
Silicone Septa for Pharmaceuticals
One of the most popular choices for pharmaceutical cap liners, silicone septa are primarily used for their remarkable resealability and thermal stability. These properties make them ideal for applications involving multiple punctures, such as repetitive sample withdrawals or injections in gas chromatography (GC) and high-performance liquid chromatography (HPLC). The resilience of silicone allows the septa to maintain a secure seal, preventing sample evaporation or contamination even after repeated needle penetrations. Silicone’s suitability comes from its stability and compatibility with a wide range of chemicals, shrinking the risk of sample contamination or interaction. Its temperature resistance is advantageous for processes requiring exposure to varying temperatures, ensuring the integrity of the septa under different experimental conditions.
ILT currently offers a range of silicone septa, find them here.
Pharmaceutical Butyl Rubber Liners
Butyl rubber liners are utilized in pharmaceutical labs mainly for their outstanding impermeability to gases, making them excellent for long-term storage of air-sensitive compounds. Their low permeability to air, oxygen, and other gases ensures the integrity of the contents, especially critical in the stability of pharmaceutical products. The material’s high resilience and flexibility also contribute to a tight seal, further preserving the contents against external contamination. The appeal of butyl rubber lies in its resistance to a broad range of temperatures, which allows for its use in both high and low-temperature environments. This versatility is beneficial in various laboratory processes, including those requiring refrigeration or heating. Butyl rubber’s moderate resistance to chemicals also makes it appropriate for a range of applications, especially where minimal interaction with the liner is needed.
PTFE Liners for Pharmaceutical Chromatography
PTFE (Polytetrafluoroethylene) backed silicone liners are frequently used in pharmaceutical labs for applications that demand high chemical resistance. They are compatible with many chemicals, including aggressive solvents, acids, and bases, making them ideal for storing highly reactive or corrosive substances. PTFE’s inert nature ensures that it does not react with the contents, maintaining the purity and integrity of the stored materials. This property is especially valuable in analytical testing and sample preparation, where any interaction with the container can compromise the results. PTFE is also able to withstand a wide range of temperatures, from very low to very high, without degradation. This makes it suitable for processes that involve temperature extremes, such as autoclaving or cryogenic storage.
Read more about the pharmaceutical industry and the seals and septa industry on our blog page or learn more about ILT, the world leader in manufacturing seals and septa here.
