Background and importance Industries have been manufacturing prepackaged water for injection (WFI) and other aqueous solutes to enable simpler and practical hospital pharmacy compounding. In hospitals, the preparation of total parenteral nutrition (TPN) or other intravenous (IV) treatments like antibiotics are often administered for continuous treatment. Industrially prepackaged WFI are frequently employed to reconstitute or dilute parenteral preparations. This proves convenient due to their large volume variety availability in the market and stocking capabilities before being used in hospital compounding.

Aim and objectives However, prepackaged aqueous products could potentially leach plastic additives over time. These compounds could influence active substance stability through different physical–chemical interactions, which in turn could affect treatment efficacy. Furthermore, the patient, receiving continuous IV treatments, could get affected with potential endocrine disrupting (ED) compounds, leading to probable latent health effects.

Material and methods The Quality Control laboratory of the Pharmacy of the Lausanne University Hospital (Switzerland) has developed an analytical method using liquid chromatography coupled to a high-resolution mass spectrometer (LC-HRMS) for the analysis of plastic additives. An innovative setup, based on post-column infusion (PCI) using 2% ammonium hydroxide in methanol, was considered to boost the signal intensity of the analytes. This method enables the screening and identification of 30 known substances due to the use of retention time, exact mass (including isotopic pattern) and MS/MS spectra.

Results A comparison was made between prepackaged industrially purified WFI (IP-WFI) and a pharmaceutical-grade distilled water (PGD-WFI). A butylhydroxytoluene (BHT) derivative compound, 3-(3,5-di-tert-butyl-4-hydroxy-phenyl)propanoic acid, and bisphenol A were identified close to 2 ppm and 30 ppb, respectively, in IP-WFI compared to PGD-WFI. This suggests that IP-WFI, once purified and packaged, is stored in warehouses, which allows these additives to leach and concentrate over time. Conversely, PGD-WFI is carried out on site and is used directly for its intended purpose. In addition, both compounds possess ED phenol moieties, making them potential xenoestrogens.

Conclusion and relevance In conclusion, PGD-WFI possesses approximately five times less of these additives than IP-WFI. These plastic additives could lead to latent health issues in patients after continuous administration of parenteral treatments. Due to a lack of toxicology information for this BHT derivative, more studies are required for ED assessment.

Conflict of interest No conflict of interest