Cleanliness and Microbiological Testing

Element's testing capabilities cover the full spectrum of medical devices and components throughout their lifecycle. We specialize in: 

• Finished medical devices and their components
• Orthopedic implants and surgical instruments
• Raw materials and manufacturing process materials
• Water systems and cleaning agents
• Reusable medical devices requiring reprocessing validation

We deliver comprehensive microbiological analysis tailored to your regulatory and quality requirements. Our testing suite includes: 

• Bioburden testing - Before final sterilization and packaging, medical devices and pharmaceuticals often need to undergo bioburden testing. This process involves determining the population of viable microorganisms on or inside the product. Bioburden testing applies to non-sterile medical products as well as pre-sterilization evaluations. The results help determine the appropriate sterilization levels and procedures.
• Bacterial endotoxin testing (BET) - BET is essential for the lot release of medical devices and injectable pharmaceutical products. It helps ensure that these products are safe for human use by detecting endotoxins. BET is also part of routine monitoring for water systems and incoming materials, ensuring that production processes do not contribute to contamination.
• Cytotoxicity testing - Cytotoxicity testing is used to assess the toxicity of medical devices and materials. This testing is required for all medical devices before they can receive regulatory approval. It is a quick and standardized process that identifies potentially harmful substances in biomedical materials or devices. The results help screen materials and serve as an initial step in confirming biocompatibility.
• Total Organic Carbon (TOC) testing - TOC testing helps medical device manufacturers monitor water quality to ensure compliance with USP and EP standards. It is also used to validate the cleanliness of both single-use and reusable medical devices. This testing ensures that water systems maintain safe levels of organic compounds and checks for the presence of contaminants or residues from cleaning agents or manufacturing fluids.
• Gravimetric residue analysis - This evaluates the amount of residue extracted from medical device metal components.

We employ validated techniques aligned with ISO and USP standards to meet your specific testing needs. Our validated methods include: 

Bioburden Testing: 

• Microbial Characterization (ISO 11737-1)
  Bioburden testing according to ISO 11737 may include testing for aerobic bacteria, spores, fungi, anaerobes, or combinations of these. Typically, the process involves extracting microorganisms from the product, followed by membrane filtration, microbial growth on medium, and counting visible colonies. Alternatively, a plate-count method may be used depending on the product. 
• Bioburden Recovery Validation (ISO 11135) – Repetitive or Inoculation Method
  Bioburden recovery validation is used to develop and validate a product-specific testing procedure. It helps assess the effectiveness of the procedure, evaluate the product’s antimicrobial properties, and establish a recovery factor. 
  The repetitive (exhaustive) recovery method uses the naturally occurring bioburden to determine how efficiently it can be recovered from the test article.  
  Whereas the spore inoculation method creates an artificial bioburden to test recovery efficiency. 

Bacterial Endotoxin Testing (BET): 

• Kinetic Chromogenic & Turbidimetric Methods (USP 85)
  This in-vitro quantitative assay detects endotoxins from gram-negative bacteria using Limulus Amebocyte Lysate (LAL) and photometric analysis. It is widely used for medical devices, sterile and non-pyrogenic assemblies, parenteral drugs, and other biological products to predict potential pyrogenic responses. 
  Validation is required for each device or any changes to processes or materials. Element’s Kinetic Chromogenic method has a detection limit of 0.005 EU/ml, while the Kinetic Turbidimetric method has a detection limit of 0.010 EU/ml. 

Cytotoxicity Testing: 

• Cytotoxicity (ISO 10993-5, USP 87)
  ISO 10993-5 and USP 87 are in-vitro qualitative assays that detect toxins in medical devices, their components, or raw materials, based on their effect on mammalian cell viability. 
  Testing is done on the final product, representative samples, or materials processed the same way as the final product (see ISO 10993-1). Specimens are prepared according to ISO 10993-12. 
  If a device or implant is sterilized before use, it should be sterilized according to the manufacturer’s recommendations prior to testing. If non-sterile test samples are used, they must be checked for bacterial contamination to prevent false cytotoxicity results. Testing is performed in triplicate with L929 cells. 
• Common Testing Methods
  The most common cytotoxicity testing method is the MEM Elution method, which simulates actual conditions in which medical devices would be used, often exaggerating these conditions. Other methods used include the Agarose Overlay Method and Direct Contact Method. We also offer cytotoxicity testing for raw materials to help screen your options early in the development process.

Gravimetric residue analysis: 
This is conducted using aqueous or organic solvents. While gravimetry alone may not be sensitive enough for thorough cleanliness assessment, it is often combined with additional analytical techniques like FTIR and GC-MS for more accurate results. 

Our team operates from Life Sciences hubs across the world, providing global access to our expert capabilities. Find your nearest Life Sciences hub on our Locations Page. 

Our specialized validation services support both single-use and reusable devices through comprehensive cleanliness testing. We evaluate cleaning methods against ISO 19227 standards, validate your cleaning processes, and assess cleaning agent residuals through TOC testing. It's important to note that validation approaches differ significantly between production cleaning and reprocessing instructions. Our expertise helps you maintain the highest standards of device cleanliness and safety throughout the product lifecycle. We also offer test failure investigation services to help troubleshoot any issues that may arise.