Qualification of Biocleaning in Cleanrooms

Abstract
The production of sterile injectable solutions requires strict control of microbiological contamination to ensure the quality and safety of preparations. Following a quality audit in our unit, the lack of qualification of the cleaning and disinfection process (biocleaning) in Grade B cleanrooms (GBC) was identified as a major deviation. The aim of this work is to present the qualification approach for our biocleaning procedures.

Materials and Methods
Biocleaning in GBC is performed using wet mopping and wiping, alternating between a quaternary ammonium/diaminoalkylamine solution and a 1.5% hydrogen peroxide solution, followed by rinsing with 70% ethanol. A sterile polyester mop assigned to Grade B areas and an autoclaved mop handle are used. Qualification is based on the comparison of microbiological contamination levels before and after cleaning, at critical points identified through a risk analysis, across four cleanrooms (90 m²; N = 64 samples). Post-cleaning contamination levels must be significantly lower (in case of contaminations detected in pre-cleaning samples) and remain within Grade B specifications. Statistical analyses are conducted depending on the homogeneity of data variances: paired Student’s t-test when homogeneous, Wilcoxon paired test otherwise. A visual inspection is carried out to ensure the absence of residues.

Results and Discussion
Microbiological contamination levels were significantly reduced after biocleaning (p < 0.001). All 64 post-cleaning samples complied with Grade B requirements (< 5 CFU/plate; 55 mm agar). No product residues were observed during visual inspections.

Conclusion
These results confirm the effectiveness of the biocleaning protocol. The use of sterile products in alternation, combined with ethanol rinse, contributes to overall risk reduction in our operations. Thus, a prompt remediation of non-conformities strengthens the credibility of our unit with management and regulatory authorities.

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