Helium leak testing is defined as the act of finding leaks in different types of enclosed or sealed systems using helium as a “tracer” gas and its concentration is measured as it escapes due to leakage. A vial, consisting of a container and elastomeric closure, is a good example of a package system. A vial is helium-filled & is subjected to vacuum. The amount of helium escaping that package is quantitatively measured and stated as a leak rate. Other examples include a prefilled syringe, a foil pouch or a cold form blister card. Each of these package types is designed and intended to keep the drug product contained while keeping out any detrimental environmental contaminants, such as debris, microorganisms, or even gases. The helium leak detection method has the sensitivity to evaluate each of them.
Helium Leak Detection Technology
Helium gas has certain key qualities that make it ideal for package leak testing:
- Helium gas is one of the smallest molecules, allowing it to breach pathways reliably and quickly.
- It is an inert gas & it will not interact with the components being tested, thus making it is safe to use
- The instrument noise due to environmental helium is inherently low because of its limited presence in the atmosphere at less than 5ppm and thus gives incredibly accurate reports
Benefits of Using Helium Based Testing Methods:
- Helium is a highly sensitive leak test technology, equipped with the detection of extremely small leaks which is not possible with other leak testing methods.
- Using a high vacuum technique, the leak test thresholds to be set down as low as 1×10-12l.sec-1, a sensitivity level allowing unique comparisons between package components, for example.
The world’s regulatory agencies have placed more focus on container closure integrity issues during the past 20 years. More emphasis has been laid on improved technology that enables the use of more effective test methods in place of sterility testing.. The objective is to ensure that contaminants cannot penetrate the intended barrier that a closed system is designed to maintain. Example of such contaminants include gases (especially reactive ones), any type of microorganism or any other foreign substance that can compromise or react with the enclosed drug product or compromise the sterility of the system.
The PTI/Leak Detection Associates (LDA) team brings a level of experience and knowledge to the Container Closure Integrity testing market that is unmatched. They are committed to assisting and ensuring that you understand and meet the strict regulatory requirements when it comes to your container and package system testing needs.
Seal Integrity Monitoring System
The most current model, the Seal Integrity Monitoring System (SIMS) 1915+, is the ideal choice for your helium-based leak detection system. Compared to conventional vacuum bubble and dye penetration test methods, packages can be quantitatively tested using helium as the tracer gas that ensures higher levels of accuracy. Such an approach allows a comparison between multiple packaging materials and forms production line settings and stability storage conditions, supporting the entire lifecycle.
The LDA SIMS 1915+ has an array of applications which ranges from package design, tooling qualification, production line setup and on-going product quality monitoring. It is also effective in accommodating a variety of package types including cold form blister cards, foil pouches, parenteral vials, syringes, pre-filled syringes and unique medical devices.
Depending on the client’s specific requirement, each SIMS 1915+ Helium Leak Testing instrument is customized. Instrument build specifications are determined based on the following key factors.
- Identifying what type of package(s) you will be testing with this instrument – Vials, Blister Cards, Syringes, Cartridge System or Medical Device. Determine size and closure type and whenever possible a schematic of the package or device can be helpful in optimizing the test system.
- Country where the instrument will be installed
Specifically designed for the needs of pharmaceutical and medical device industries, the Seal Integrity Monitoring System (SIMS) Model 1915+ is a helium-based leak testing system that features an oil-free pump, detector and integrated power system. It enables quantitative analysis of package systems at sensitivity levels as low as 1 x 10 -10 cc/s at room temperature. The most critical component, the Helium Leak Detector Module (HLDM), is engineered into a Console Frame Assembly that features a stainless-steel working surface and optional Dual Test Port Manifold. The consoles are fitted with a locking wheel and articulating arm system for mounting of the computer and peripherals, making the freestanding unit easy to use and maneuver.
In addition to instrumentation and accessories, we also offer complete sets of calibrated helium leak standards to support routine use, daily performance verification or system suitability checks, and scheduled qualifications.
Internal Leak Standards: Each SIMS 1915+ contains an internal helium leak standard. Corresponding to a known leak rate, this tool is calibrated to release a specific concentration of helium. It is used automatically by the instrument on each day of use, or on demand for a point-of use autocalibration prior to analysis.
Low Temperature/Cold Storage Package Test Systems
Complex drug and biologic formulations have resulted in a continuous drive toward deeper cold storage in an effort to maintain product quality attributes, requiring life science companies to drive toward deeper cold storage. Since these products are often cell or gene or proteinaceous in nature, they are required to be stored at below -20°C, and also needs storage and distribution environment that include dry ice (~-78.5°C), or even liquid nitrogen (~-200°C).
While the products demanding such intense cold storage may be complex, oftentimes, the package systems in which the products are placed are rather traditional in nature, such as a screw or crimp top vial. However, at these temperatures, many of the materials used in these package systems and responsible for maintaining package integrity are not typically assessed at these temperatures. When such packages are exposed to deep-cold or ultra-cold temperatures, materials reach or exceed their glass transition state. This particularly causes physical changes to elastomeric components and creates leaks at low temperatures that would otherwise not be observed while at room temperature. Common areas where such type of leakages are observed include primary seal areas, t primarily between an elastomeric closure and glass vial being used below -60C.If manufacturers are able to test container closure integrity while at these low temperatures, they gain a number of benefits with regard to optimal package choice and design, assembly parameters, minimizing leakages as well as have a clear understanding of a package system’s performance in accordance with USP 1207.
PTI/LDA offers a line of low temperature add-on options that enable helium leak testing to as low as -140C for individual package samples. When using helium as a tracer gas, packages can be quantitatively tested to levels far exceeding bubble and dye penetration tests, pressure decay, mass extraction, and high voltage leak detection. The LDA systems follow the guidelines set forth by the USP 1207 general chapter test requirement and more specifically by ASTM F2391-05, a method that was authored by LDA’s original founder
Dr. Darrell Morrow.