Efficacy of four cleaning solutions for the decontamination of selected cytotoxic drugs on the different surfaces of an automated compounding system

The automated aseptic preparation of ready-to-administer antineoplastic drug solutions with robotic systems reduces the risk of occupational exposure. However, the surfaces in the preparation area of the robot are to be cleaned by wiping with an appropriate cleaning solution. The aim of the study was to evaluate the cleaning efficacy of four cleaning solutions on four surface materials installed in the APOTECAchemo robot. Predefined amounts of cisplatin (Cis), 5-fluorouracil (5-FU), and cyclophosphamide (CP) were intentionally spread on test plates made of stainless steel, aluminium, polyoxymethylene, and polycarbonate just as installed in the robotic system APOTECAchemo. After drying, the plates were cleaned with 0.2% ethanolic NaOH, 0.23% isopropanolic sodium dodecylsulfate (SDS-2P), 0.5% sodium hypochlorite (NaOCl), and 0.1% benzalkonium chloride (BZK) solutions following a standardized wiping protocol. Residual contamination was recovered with wipe tests, Pt was quantified by voltammetry, and 5-FU and CP was quantified by gas chromatography-tandem mass spectrometry (GC-MSMS). The mean residual contamination after cleaning and the cleaning efficacy (CE) rates were calculated and aggregated on different levels. The CE rates varied between 81.5% and 100% and lay in the majority of cases above 90%. The lowest CE rates were registered for Pt contamination. Especially on aluminium surfaces the residual contamination was high. The overall CE rates of the three different drugs and four different surface types amounted to 98.3% for NaOCl, 97.9% for SDS-2P, 96.9% for ethanolic NaOH, and 96.5% for BZK. The tested cleaning solutions proved to be higher than 90% in most cases, but none of them was able to eliminate 100% of the intentional surface contamination of three antineoplastic drugs on the test plates. The cleaning efficacy varied according to the different surface types and antineoplastic drug. Results could be used in the daily clinical practice to develop and implement effective cleaning procedures.