Validation of a semi automated sterility test system for fast sterility testing of PET products

Objectives Typically, PET products are sent off for sterility testing following complete radioactive decay and are tested using validated methods according to e.g. EP 2.6.1. The time between product creation and final confirmation of sterility is relatively long with a minimal turnaround time in the case of a positive finding of 2-3 weeks, limiting the ability to take swift remedial action. The BacT/ALERT® 3D system uses colormetric sensor-and-detection technology to track microbial metabolic CO2 levels and is commonly used for Clinical blood cultures. The aim of this work was to evaluate the system as a platform for assessing PET product sterility.

Methods The approach taken for the validation of the sterility testing unit involved assessing the system’s ability to detect a range of microbial flora (The sterility test EP 2.6.1 strains, selected NCTC strains and wild type strains common to the production facility) at low levels and in the presence of a simulated PET product. Each validation stage was carried out in triplicate, using different batches of media, and each test repeated 5 times against negative controls.

Results In all cases, the system detected the microorganisms before the EP direct inoculation method. In the majority of cases, the system was able to detect growth within 2 days of inoculation with all strains giving an average detection time of less than 5 days. The system demonstrated an ability to quickly detect even very low levels of inoculation (<10 cfu).

Conclusions The semi automated sterility testing system provides a fast means to detect microbiological contamination in PET products. By performing the test in-house using this system, we will be able to take swift remedial action, within 5 days in the case of suspected microbiological contamination of production systems or starting materials. In addition, a significant saving will be possible by using this method to perform the testing in-house