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Product Sterility – Isolator

The Product Sterility – Isolator test protects test articles from contamination by eliminating direct contact between the analyst and the test articles. This test is required on medical devices, pharmaceuticals, preparations, tissue materials, and any other materials that claim to be sterile or free from viable microorganisms.

Testing is done in conformance with criteria from USP General Chapter 71, ANSI/AAMI/ISO 11737-2, EP 2.6.1, JP and 21 CFR 610.12. To optimize aseptic transfer of samples into test material, sterility testing is performed in an isolator. Vaporized hydrogen peroxide is used to sterilize the contents of the isolator and the inside of the enclosure prior to testing. Isolator sterility tests must be validated by performing a Method Suitability study (Bacteriostasis/Fungistasis (B/F), Sterility and MPN Method Suitability) test. Isolator sterility tests must also have isolator package validation testing performed.

Applicable Standards

  • USP 71
  • USP 161
  • USP 797
  • EP 2.6.1
  • JP 14 54
  • ANSI/AAMI/ISO 11737
  • AAMI TIR33

Testing Locations

Study Outline

The Product Sterility – Isolator test evaluates samples for sterility by placing them in growth media, incubating them for a minimum of 14 days, and then checking for evidence of microbial contamination. This sterility test is performed in an isolator that has been sterilized with vaporized hydrogen peroxide.

Samples may be tested using either direct transfer or membrane filtration, and using a soybean casein digest broth (soy) or fluid thioglycollate (thio) media, as follows:

USP Method: Samples tested by direct transfer are aseptically immersed in the test media. Samples tested by membrane filtration (liquids, filterable solids, soluble ointments [oils] and sterile-pathway-only devices) are passed through a 0.45µm filter, and the filter is immersed in the test media. A soybean casein digest broth (soy) media is used for aerobic and fungal growth at incubation temperatures of 20 – 25°C. A fluid thioglycollate (thio) media is used for anaerobic growth at an incubation temperature of 30 – 35°C. Sample size is determined both by batch size and individual container fill volumes.

AAMI Method: Samples tested by direct transfer are aseptically immersed in the test media. Soy is used for aerobic and fungal growth at incubation temperatures 28 – 32°C. Sample size depends on lot size, method used, and bioburden levels.

After a 14-day incubation, samples are evaluated for the presence of turbidity and/or growth. A media transfer and/or confirmation test may be performed. A failure investigation is performed as necessary. Recovered organisms are identified and compared to the organisms that may have been recovered on monitors performed by the test analyst during applicable test sessions. It is determined whether any anomalies occurred on the day of testing, with media sterilization, during sample processing, and/or during shipping.

If you have additional questions about Product Sterility – Isolator test services, or would like to consult with the experts at Nelson Labs, just send us a request or call us at +1 (801) 290-7500.