An Alternative Microbiological Validation for an Online Water Bioburden Analyzer.

Abstract

The Mettler-Toledo 7000RMS analyzer is a Bio-Fluorescent Particle Counter (BFPC) used to monitor real-time bioburden results from Purified Water (PW). Validation of the analyzer using 13 microorganisms and a low-intensity, fluorescent, polystyrene bead. During the execution of the validation, a laboratory water system that met Purified Water (PW) quality standards was connected to the 7000RMS, and a syringe pump was used to introduce various concentrations of microorganisms and fluorescent polystyrene beads to the analyzer. Samples were collected and tested via the traditional Membrane Filtration (MF) method and the Colony Forming Unit (CFU) plate count results were compared to the Auto-Fluorescent Unit (AFU) of the 7000RMS analyzer. The validation study was designed to follow the guidance in United States Pharmacopeia (USP) Chapter <1223 > (1), European Pharmacopeia (EP) Chapter 5.1.6 (2), PDA Technical Report 33 (3). Concepts and strategies were adapted from EP Chapter 2.6.12 Microbiological Examination of Non-sterile Products: Microbial Enumeration Tests, EP 10.2 (4), European Pharmacopeia Chapter 2.6.1 Sterility, EP 10.2 (5), USP Chapter <61> Microbiological Examination of Non-sterile Products: Microbial Enumeration Tests (6), USP Chapter <71> Sterility Tests (7), Japanese Pharmacopoeia (JP) General Information Chapter G8 Water: Quality Control of Water for Pharmaceutical Use (8). All pre-determined validation acceptance criteria for Accuracy, Specificity, Precision, Limit of Detection (LOD), Limit of Quantitation (LOQ), Linearity, and Range were met. Further, the 7000RMS demonstrated Performance Equivalence to the MF method per USP <1223> but characteristically lacked correlation to the CFU. This validation approach highlights the superior capabilities of the 7000RMS when compared against the traditional compendial MF testing method for PW.