By Oliver Stauffer
This study shows that PTI’s HVLDmc can in fact detect leaks down to the Maximum Allowable Leakage Limit (MALL) and arguably makes it one of the most sensitive leak test methods in the market. The Kirsch et al study that is often cited in papers laying out what the critical leak size is for parenteral products, dictates that there is still a potential for microbial ingress at the 1 micron level. Many clients may be concerned with that high a level of sensitivity, potentially detecting defects that were otherwise not detectable before. However, if a defect is not detected and the product is put up for stability, it will undoubtedly cause much greater trouble that can lead to stability failure and major recalls.
Fundamentally MicroCurrent HVLD is a reliable test method, and as long as a method detects good samples as good and identifies defects as defects, the client should only have confidence in the methods impact on their testing regime. Along with its sensitivity and reliability, PTI’s MicroCurrent HVLD is capable of testing a wide range of product conductivities. This study places HVLDmc at the forefront in the field of parenteral CCIT.
PTI recently performed a feasibility study with a client in which naturally occurring cracks were created as positive controls. The cracks were created using PTI’s thermal method, and many of the cracks were undetectable using vacuum decay. MicroCurrent HVLD (HVLDmc) was the only suitable technology to detect the defects. The cracks were later verified using the Helium leak test method. All the cracks produced were detected using HVLDmc. Several cracks were below 1 micron and barely detectable using the Helium leak test method.