An Alternative Microbiological Validation for an Online Water Bioburden Analyzer

Area of Science:

• Pharmaceutical Microbiology
• Analytical Chemistry
• Water Quality Monitoring

Background:

• The Mettler-Toledo 7000RMS is a bio-fluorescent particle counter (BFPC) for real-time bioburden monitoring of purified water (PW).
• Traditional methods like membrane filtration (MF) are time-consuming for microbial enumeration.

Purpose of the Study:

• To validate the Mettler-Toledo 7000RMS analyzer for monitoring bioburden in purified water.
• To assess the analyzer's performance against compendial testing methods.

Main Methods:

• Validation followed United States Pharmacopeia (USP) <1223> and European Pharmacopeia (EP) guidelines.
• The analyzer was challenged with 13 microorganisms and fluorescent beads.
• Results were compared to traditional membrane filtration (MF) and colony-forming unit (CFU) methods.

Main Results:

• The 7000RMS met all validation acceptance criteria for accuracy, specificity, precision, LOD, LOQ, linearity, and range.
• Performance was equivalent to the MF method according to USP <1223>.
• A characteristic lack of correlation to CFU counts was observed.

Conclusions:

• The 7000RMS analyzer is a viable alternative to traditional MF testing for purified water bioburden.
• The BFPC technology demonstrates superior capabilities for real-time monitoring compared to compendial methods.
• While equivalent to MF, direct correlation to CFU requires further investigation.