Endotoxin Essentials

Endotoxin Essentials
Andrew Taylor, Microbiology Supervisor

Pyrogens are a group of fever causing substances.  The most widely known pyrogen is bacterial endotoxins.  Bacterial endotoxins are:

  • Remnants of bacterial cells that can cause fever, diarrhea, or septic shock in patients  
  • Not removed during filter sterilization
  • Not removed during steam sterilization
  • Not detected by a sterility test

USP <797> requires a Bacterial Endotoxin Test (BET) for:

  • High Risk products prepared in groups greater than 25, except those for inhalation and ophthalmic administration
  • Multiple dose vials prepared for administration to multiple patients
  • Preparations exposed to longer than 12 hours at 2°C to 8°C before sterilization or longer than 6 hours at warmer than 8°C before sterilization

The Food and Drug Administration (FDA) requires a BET for all 503B outsourcing facility drug products reported to be non-pyrogenic.

Even if it is not mentioned specifically in the regulatory documents, it is important to check for the presence of endotoxins in raw materials, at various points in the compounding process, and in finished products before administering a drug to the patient.  

The limit for the maximum amount of endotoxin allowed to be present in drug substances or drug products can be found in USP monographs, or calculated using the route of administration, patient weight, and maximum bolus dose. Once the limit has been established, the primary test method used to determine the amount of bacterial endotoxins in drug substances and drug products is described in USP <85>.    

ARL Bio Pharma’s Bacterial Endotoxin Testing Process

ARL Bio Pharma follows the procedures provided in USP <85>.  The test is performed using depyrogenated glassware and supplies. The product to be tested is prepared using reagents specifically designed for BET. Each sample is tested in duplicate, using a standard curve, negative control, and positive control.  At the conclusion of the test, the amount of endotoxin is determined for each sample analyzed.  If the endotoxin concentration is found to be below the limit, and all controls were acceptable, the sample complies with USP <85> requirements. 

Reference Documents:

United States Pharmacopeia <797>
United States Pharmacopeia <85>

FDA Guidance for Industry: Pyrogen and Endotoxins Testing: Questions and Answers  https://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm314718.htm#_Toc315937925

FDA Guidance for Industry:  Current Good Manufacturing Practice – Interim Guidance for Human Drug Compounding Outsourcing Facilities Under Section 503B of the FD&C Act