Detection of cyclophosphamide residues on community pharmacy counters: An exploratory survey

This is the authors' abstract. We don't add key points for this paper.

Objective This study aimed to evaluate cyclophosphamide contamination in community pharmacies, investigate patient-mediated transfer and indirect risks to the public, and examine the association between the use of hospital closed system transfer devices (CSTDs) and this contamination. Methods Wipe samples from patient counselling counters at 24 community pharmacies near 10 hospitals were analysed for cyclophosphamide contamination using liquid chromatography-mass spectrometry. A questionnaire survey was conducted to assess CSTD use and cleaning practices. Results Contamination was detected in 5/24 pharmacies (20.8%; median level: 0.7 ng/625 cm 2 ). The overall median across the 24 pharmacies was below the limit of quantification, which does not necessarily indicate absence of contamination. Moreover, four of the five pharmacies with contamination did not have cyclophosphamide in stock during the sampling period. Contamination was observed irrespective of hospital CSTD use or the pharmacy’s handling of cyclophosphamide. Conclusions Cyclophosphamide contamination detection on patient counselling counters in community pharmacies may be a result of patient-mediated transfer. However, alternative sources within pharmacies, such as inventory, packaging, and local handling, cannot be ruled out. Contamination was detected in settings with and without hospital CSTD use, indicating that CSTDs address handling-related contamination but do not mitigate patient-mediated pathways.