Valencian Institute of Microbiology
(I V A M I)

ISO 15747 describes the biological requirements for plastic containers for intravenous injections. One of the requirements is that the infusion container must be impermeable to microorganisms. To demonstrate this, the impermeability test described in section C.2 of the standard is performed, as detailed below.

To perform the impermeability test, empty containers are filled to their nominal capacity with a culture medium under sterile conditions and sealed. Subsequently, the containers, or appropriate parts thereof, are immersed in a suspension of challenge microorganism (Bacillus atrophaeus ATCC 9372, formerly Bacillus subtilis) for at least 30 minutes. The containers are then removed from the inoculation suspension and incubated for at least 7 days at 30°C (the appropriate temperature for the growth of the inoculated microorganism). The test must be performed with 5 replicates and in parallel with a negative control (containers not submerged in the bacterial suspension) and two positive controls (one container prepared in the same way, but inoculating the culture medium with 1 mL of a microorganism culture, and another container prepared in the same way as the test samples but manipulated by perforating an area). After 7 days of incubation, the contents of the test container are examined for any microbial growth. The positive control should exhibit turbidity, while the negative control and the samples from the test container should not exhibit any turbidity.

ISO 15747 only specifies performing the test directly after inoculation of the test sample. However, if the client wishes to validate different timeframes, the samples can be stored at room temperature after inoculation for the time specified by the client and then incubated for one week, followed by observation of turbidity as an indicator of growth. In this case, a negative control, a positive control, and 5 replicates of the test product should be analyzed for each requested test period.