Microbiological monitoring during aseptic handling: Methods, limits and interpretation of results

Area of Science:

• Pharmaceutical Sciences
• Microbiology
• Healthcare Quality Assurance

Background:

• Aseptic handling is essential for preparing sterile pharmaceutical products using closed systems.
• Microbiological monitoring (MM) and media fills are standard practices for environmental and process control in sterile manufacturing.
• Evaluating MM methods in hospital pharmacy settings is vital for ensuring product safety and efficacy.

Purpose of the Study:

• To describe and evaluate the application of microbiological monitoring (MM) methods during aseptic handling in hospital pharmacies.
• To assess the effectiveness of different MM techniques, including glove prints and air sampling.
• To establish a reliable metric for assessing MM results and predicting process changes.

Main Methods:

• Application of various microbiological monitoring (MM) methods within laminar airflow or safety cabinets.
• Calculation of contamination recovery rate (CRR) based on colony forming units (cfu).
• Development and application of a rolling CRR for trend analysis using recent MM samples.

Main Results:

• Glove prints were identified as the most informative MM method, generally yielding the highest CRR.
• The added value of air sampling for MM in this context was found to be doubtful.
• A contamination recovery rate (CRR) below 10% was determined to be a realistic limit for aseptic handling in hospital pharmacies.

Conclusions:

• The use of CRR is advised for assessing MM results due to microbiological and statistical considerations.
• A rolling CRR, calculated from the last 100 samples, offers a balance between CRR reliability and timely process change detection.
• Glove prints are recommended as the primary MM method for aseptic handling in hospital pharmacies, aiming for a CRR below 10%.