In simple terms, helium leak testing is the act of finding leaks in some type of enclosed or sealed system using helium as a “tracer” gas, and measuring its concentration as it escapes due to leakage. A package system such as a vial, consisting of a container and elastomeric closure, is a good example. A helium-filled vial is subjected to vacuum, and the amount of helium escaping that package is quantitatively measured and reported 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. Helium leak detection has the sensitivity to evaluate each of them.
Helium possesses a few key qualities that make its use ideal for this type of testing:
- Helium gas is one of the smallest molecules, allowing it to breach pathways reliably and quickly
- It is inert, making it safe to use and it will not interact with the components being tested
- Its limited presence in the atmosphere at less than 5ppm means instrument noise due to environmental helium is inherently low and thus incredibly accurate
Benefits of Using Helium Based Testing Methods:
- Enable the discovery of extremely small leaks that other leak testing methods cannot detect
- Using via 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.
Over the past 20 years, the world’s regulatory agencies have placed more significance on container closure integrity issues. Much of this focus is attributable to improved technology that enables the use of more effective test methods in place of sterility testing. The objective is to insure 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.
As referenced on 21 CFR 211.94, the goal of an effective container and package system leak testing program is the receipt of an FDA generated warning letter that opens with the following sentence:
“Your firm failed to ensure your container closure system provided adequate protection against foreseeable factors in storage and use that can cause deterioration or contamination of the drug product”
The Leak Detection Associates team brings a level of experience and knowledge to the Container Closure Integrity testing market that 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.