Radiation Tissue Dose Audits
Radiation Sterilization determines the appropriate radiation sterilization dose for a product that requires a sterile label claim. It incorporates bioburden testing, a bioburden recovery efficiency test, a sub-lethal radiation dose (verification dose), test of sterility and bacteriostasis/fungistasis testing.
If a sterile label claim is required and the sterilization method will be radiation, a validation is required to determine the appropriate sterilization dose. Nelson Laboratories has vast experience providing validations for complex or unique products, or products which cannot handle large doses of radiation. The testing complies with the Radiation Sterilization standard ANSI/AAMI/ISO 11137 and AAMI TIR 33 (soon to be ISO 13004).
- ISO 11137
- AAMI TIR33
Standard turn around times (TAT) are listed below. Ask an expert for a specific consultation on your product. If you are ready to submit your samples for testing, click here to fill out the Sample Submission Form.
|Code||Test||TAT (days)||Request Quote|
|SVR130||Radiation Sterilization: AAMI VDmax Dose Audit - <1L||39||Add|
|SVR135||Radiation Sterilization: AAMI VDmax Dose Audit - >1L||39||Add|
|SVR220||Radiation Sterilization: AAMI Method 1 Dose Audit - <1L||45||Add|
|SVR225||Radiation Sterilization: AAMI Method 1 Dose Audit - >1L||45||Add|
|SVR320||Radiation Sterilization: AAMI Method 2 Dose Audit <1L||45||Add|
SVR130 - Radiation Sterilization: AAMI VDmax Dose Audit - <1L
TAT: 39 days
SVR135 - Radiation Sterilization: AAMI VDmax Dose Audit - >1L
TAT: 39 days
SVR220 - Radiation Sterilization: AAMI Method 1 Dose Audit - <1L
TAT: 45 days
SVR225 - Radiation Sterilization: AAMI Method 1 Dose Audit - >1L
TAT: 45 days
SVR320 - Radiation Sterilization: AAMI Method 2 Dose Audit <1L
TAT: 45 days
SVR130: 20 samples
SVR135: 20 samples
SVR220: 110 samples
SVR225: 110 samples
Study OutlineRadiation Sterilization is used to determine the appropriate sterilization dose for a product. Usually the sterilization dose must represent a sterility assurance level (SAL) of 10-6, which is a one in one million probability of a non-sterile product. The most common validation methods are VDmax (short for Verification Dose Maximum) and Method 1.
VDmax and Method 1
Both of these methods are available in a single batch validation format (for clinical trials) or a full 3-batch validation. These radiation validations consist of three main phases:
- Bioburden test: This test determines the quantity of viable microorganisms on or in the product. This test is performed prior to any sterilization but after all other manufacturing steps, including packaging. Critical to this test is the performance of a recovery efficiency test to determine the effectiveness of the bioburden extraction method at removing microorganisms from the product. Other options for performing bioburden are available and may be more appropriate for certain product types.
- Application of verification dose: The bioburden results are taken to a table from the standard to determine the proper verification dose. The verification dose is then applied to the required number of products.
Sterility test: The irradiated products undergo a test of sterility. The acceptance criteria for each method are detailed in ANSI/AAMI/ISO 11137-2. Critical to this test is the performance of a bacteriostasis/fungistasis test to demonstrate the lack of inhibition in the sterility test system and is required to validate the test of sterility.
If the number of non-sterile samples in the test of sterility meets the acceptance criteria, the radiation sterilization dose is validated. Additional testing should be performed on a quarterly basis (called a quarterly dose audit) to demonstrate that the sterilization dose continues to be appropriate for the product. The quarterly dose audits follow the same flow as described above, but only involve samples from a single batch, and include use of the verification dose determined in the validation rather than setting a new one.
A less frequently used validation method is Method 2 (available as either Method 2A or 2B). This method is used when it is critical to validate the lowest sterilization dose possible for a product, usually because the product is sensitive to radiation.
Requirements of radiation validations and quarterly dose audits are provided in the ANSI/AAMI/ISO 11137 standard series (currently under revision).