Sterility Test

What is a Sterility Test?

A sterility test is a microbiological analysis performed to ensure that medical devices, pharmaceutical products, and biological materials do not contain any living microorganisms. This test demonstrates that the product is safe for human health and that the sterilization process has been effectively carried out.

Sterility tests not only demonstrate product quality but also ensure its regulatory compliance.

International Standards for Sterility Testing

Sterility tests must be conducted in accordance with the following globally recognized standards:

• ISO 11737-2: Specifies sterility test procedures and sampling plans for medical devices after sterilization.
• European Pharmacopoeia 2.6.1 (EP 2.6.1): Specifies sterility testing procedures for pharmaceutical products and medical devices.
• USP 71: Describes sterility test procedures and criteria within the framework of the United States Pharmacopeia.

These standards ensure the reliability of the tests and the international recognition of the results.

How is a sterility test performed?

The following methods are generally applied in sterility testing:

1. Membrane Filtration Method: Applied to liquid or soluble products. The product is passed through a special filter that retains microorganisms. The filter is then placed into a culture medium and examined for microbial growth in an incubation chamber.
2. Direct Inoculation Method: A sample of the solid or liquid product is directly added to a sterile culture medium. The product is incubated for a specified period at an appropriate temperature and examined for microbial growth.

During the testing procedure, both aerobic (growing in an oxygen-rich environment) and anaerobic (growing in an oxygen-free environment) microorganisms are detected.

For which products is sterility testing required?

Sterility testing is legally mandated for the following product groups:

• Sterile disposable medical devices
• Surgical instruments
• Implants and orthopedic aids
• Parenteral pharmaceuticals (injectable products)
• Ophthalmic products (eye drops, contact lenses)
• Biological materials
• Dialysis and intravenous solutions

Sterility Test: ISO 11737-2, European Pharmacopoeia 2.6.1, USP 71