As GfPS mbH, we offer our customers a complete service package for radiation sterility validation.
This first includes validation to determine the microbial load (bioburden) using representative test samples. This is then used to determine the verification dose with which the radiation sterilization is carried out. Our cooperation partners are available to us as certified partner laboratories with first-class expertise. Finally, a sterility test is carried out in accordance with DIN EN ISO 11737-2 to verify the success of the radiation sterilization, and a final report is prepared.

We offer you the following procedures for microbiological validation:

Procedure 1
Validation in accordance with DIN EN ISO 11137, Part 2

In procedure 1, it must be estimated whether the microbial population on the product is normally resistant (according to the standard distribution of resistances) or more resistant to irradiation.
This relationship is shown in the tables of the DIN EN ISO 11137-2 standard.

This validation consists of:

  • Validation of the bioburden: Determination of the product-specific recovery rate. (required once per product or product group)
  • Determination of the average microbial load (bioburden) across three independent production batches.
  • Determination of the verification dose based on the determined average microbial load of the product.
  • Irradiation of 100 test samples from any batch with the determined verification dose.
  • Sterility test of the 100 irradiated test samples according to DIN EN ISO 11737-2.
  • Validation of the sterility test in accordance with DIN EN ISO 11737-2 (test for unhindered growth of microorganisms in the presence of the product).
  • Final evaluation

VDmax25/ VDmax15 method
Validation in accordance with DIN EN ISO 11137, Part 2

Similar to method 1, it is necessary to estimate whether the microbial population on the product is normally resistant (according to the standard distribution of resistances) or more resistant to irradiation.
This relationship is also specified in the tables of the DIN EN ISO 11137-2 standard.

If validation is passed in accordance with:

  • VDmax25 25 kGy is sufficient
  • VDmax1515 kGy is sufficient

The VDmax25 method may only be applied to medical devices that do not exceed a corrected average bioburden of 1000 colony-forming units (CFU) per product unit.

The VDmax15 method may only be applied to medical devices that do not exceed a corrected average bioburden of 1.5 colony-forming units (CFU) per product unit.

The validation consists of:

  • Validation of the bioburden: Determination of the product-specific recovery rate. (required once)
  • Determination of the average microbial load (bioburden) across three independent production batches.
  • Determination of the verification dose (VDmax25/ VDmax15) based on the determined average microbial load of the product.
  • Irradiation of 10 non-sterile samples from any batch with the determined verification dose.
  • Sterility test of the 10 irradiated samples according to DIN EN ISO 11737-2
  • Validation of the sterility test in accordance with DIN EN ISO 11737-2 (test for unhindered growth of microorganisms in the presence of the product).
  • Final evaluation

Procedure 1
For repeated verification of the verification dose, in accordance with DIN EN ISO 11137, Part 2

In accordance with DIN EN ISO 11137-1, the sterilization dose must be checked at fixed intervals to confirm its continued suitability. An interval of three months between sterilization dose checks is generally selected for this purpose.

The review consists of:

  • Determination of the microbial load (bioburden) of non-sterile samples from a production batch
  • Irradiation of 100 non-sterile samples from the same production batch with the verification dose determined in the validation.
  • Sterility test of 100 irradiated samples according to DIN EN ISO 11737-2.
  • Final evaluation

Procedure 2
Repeated verification of the verification dose, in accordance with DIN EN ISO 11137, Part 2

VDmax25/ VDmax15 procedure
The sterilization dose for the VDmax25 or VDmax15 procedure must also be checked at regular intervals in the same way as the repeated checks for procedure 1.

A time interval of three months between sterilization dose checks is also generally selected for this purpose (in accordance with DIN EN ISO 11137-1).

The review consists of:

  • Determination of the microbial load (bioburden) of non-sterile samples from a production batch.
  • Irradiation of 10 non-sterile samples from the same production batch with the verification dose determined in the validation.
  • Sterility test of the 10 irradiated samples according to DIN EN ISO 11737-2.
  • Final evaluation

VDmaxSD
Radiation sterilization validation in accordance with DIN EN ISO 13004 comprises various steps, from defining the sterilization objectives to documenting the results.

A key aspect of validation is checking material compatibility and precise dosimetry. This ensures that the product undergoes sterilization without impairment and that the radiation dose is correctly controlled.

Continuous quality control is critical to ensure that the sterilization process remains consistent and reliable

Guidelines:

  • Validations according to DIN EN ISO 11137- 2
  • VDmax 25
  • VDmax 15
  • VDmax SD DIN CEN ISO/TS 13004

We are happy to support you with your questions about radiation sterilization validation at
freigabe@gfps.de
.