Quantitative detection of microbial contaminants of drugs, by using the Milliflex® Quantum system

Introduction. It has been shown that the Milliflex® Quantum system (Merck, Germany) that combines a traditional method of membrane filtration and fluorescent staining of microcolonies can isolate and quantify microorganisms. Objective: to validate a procedure for the quantitative detection of microorganisms using the MiHiflex® Quantum system as an example. Material and methods. The study object was the Milliflex® Quantum system. For validation of the system, the investigators used 5 test strains as ready-to-use BioBall systems (Biomerieux, France); cassettes filled with the nutrient media trypticase soy agar and Sabouraud agar (Merck, Germany). Validation was performed in accordance with the requirements of the 14th edition of the State Pharmacopoeia of the Russian Federation. Results. During the study, the investigators assessed the following parameters: accuracy, precision, linearity, quantification limit, and working range. The time of detection of test microbial strains, by using this procedure, depended on the type of an isolated microorganism and was 12-24 hours. All microorganisms were quantitatively calculated with an acceptable level of accuracy, repeatability, intra-assay precision, and linearity. The system could isolate the minimum number of cells (5-10 CFU). Conclusion. The advantages of the validated procedure include the convenience of recording the results, especially in comparison with the visual counting of mold fungi, where the detection of individual colonies is difficult in some cases. This procedure can be applicable to the analysis of a large number of various filterable samples, including water, intermediate products, and finished medicinal products.

drugs, quantitative detection of microorganisms, validation