The study of extractable chemicals is used to evaluate whether a medical device contains harmful substances susceptible to migrate and contaminate the patients they are used in. The analysis of the biomaterial itself after extraction is often left aside. The aim of this study is to characterise and investigate whether any changes occur during the extraction process. Two biomaterials (thermoplastic polyurethane (TPU) and silicone from intravenous catheters) were studied after extraction, using acetone and hexane. To study the surface, we used scanning electron microscopy (morphological aspect), energy dispersive spectroscopy and X-ray photoelectron spectroscopy (atomic composition), infrared spectroscopy (molecular composition). Thermogravimetric analysis and differential scanning calorimetry were used for in-depth characterisation. It was found that the extreme surface consisted of the polymer and external contaminants or organic products that had migrated from the core to the surface. Analysis of TPU showed that acetone was a suitable swelling agent. No significant change in the material was observed after hexane maceration. For silicone, the situation was reversed. We concluded that the solvents used were well suited for an extractables study of these two materials, and gained understanding of the phenomena that could lead to leaching during their medical use.
Basle et al. (2026) studied this question.