Medical tubings in plasticized polyvinylchloride (PVC) are widely used for the infusion of medications but are known in some cases to cause content-container interactions (drug sorption and plasticizer release). The aim of this study was to assess interactions between drugs and five alternative materials to a reference plasticized PVC intravenous (IV) infusion tubing: three were PVC coextruded with polyethylene (PE), polyurethane (PU) or a thermoplastic elastomer (Styrene-EthyleneButadiene-Styrene (SEBS)) and two were SEBS or thermoplastic olefin (TPO) monolayer tubings. Diazepam and insulin were chosen as respective reference of absorption and adsorption while paracetamol acted as a negative control. The concentration of each drug was quantified with liquid chromatography to evaluate a potential loss after a static contact condition and simulated infusion at 1 mL/h and 10 mL/h dynamic condition by an electric syringe pump. A characterization of each material’s surface was performed by Fourier transform infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and by measurement of surface zeta potential. Plasticizer release was quantified by gas chromatography coupled with mass spectrometry (GC-MS). For all tubings except PVC/PU, no loss of paracetamol was observed in any condition. Diazepam sorption appeared to be less important with PVC/PE, PVC/SEBS, SEBS and TPO tubings than with PVC, but was more important when using PVC/PU tubings. PVC tubings induced the least loss of insulin amongst all the studied materials. Surface analysis by ATR-FTIR highlighted the presence of a plasticizer (that could be attributed to Tris (2-Ethylhexyl) Trimellitate (TOTM)) in the coextruded SEBS layer of PVC/SEBS, which could have influenced drug sorption, probably as a consequence of a migration from the PVC layer. Coextruded PVC/SEBS and PVC/PE presented the lowest zeta potential of all studied materials with respective values of −39 mV and −36 mV and were related to the highest sorption of insulin while PVC/PU with the highest zeta potential (about −9 mV) presented the highest absorption of diazepam. Coextruded layered materials appeared to have a lower plasticizer release than PVC alone. As a conclusion, PVC/PE and thermoplastic elastomers alone or coextruded with PVC could be interesting alternatives to PVC tubings with regards to sorption phenomena and plasticizer release.

Stability studies are essential to be able to assign an expiration date to medications. Color variation is one of the organoleptic characteristics of actives substances or medications which can indicate the presence of contaminations, impurities or degradations products. However there is no data available comparing the often used visual examination with spectrophotometric measurements during stability studies. The aim of this study was therefore to evaluate precisely how different the two methods are, by comparing the change of color of two drug formulations chosen as models, assessed by visual examination versus a spectrophotometric colorimetric analysis. Paracetamol and parenteral nutrition solutions were stored in stress conditions for up to 46 days, and were subjected to a visual examination using color reference solutions and to lightness and chromaticity measurement to determine their specific color by UV–Vis spectrophotometry. The color of paracetamol solutions changed faster when exposed to stress condition (light), as did the PNS when exposed to heat. In both cases, color variations were detected earlier and more precisely by UV–Vis spectrophotometry than by visual examination. Color measurement using an UV–Vis spectrophotometry should advantageously replace visual examination when assessing colors changes during drug stability studies.