Comparative study of sorption phenomena between syringes made of cyclic olefin copolymer or polypropylene and three medications.
1 Université Clermont Auvergne, CHU Clermont Ferrand, Clermont Auvergne INP, CNRS, ICCF,
F-63000 Clermont-Ferrand, France
2 SCHOTT Schweiz AG, St. Josefen-Strasse 20, 9001 St. Gallen, Switzerland
Syringes are widely used to store and administer drugs, and the contact time between drugs and syringes can vary from a few minutes to several weeks. The aim of this preliminary comparative study was to evaluate potential sorption phenomena occurring between drugs and syringes in polypropylene (PP) and a new material: Cyclic Olefin Copolymer (COC).
50 mL syringes made either of COC with an elastomer plunger lubricated by crosslinked silicone (Schott®), or of PP with an elastomer plunger lubricated by silicone oil (Pentaferte®) were used. Different parts were studied: assembled whole syringes and individual syringe parts (barrel and plunger). The devices were put in contact with the medications (paracetamol 1 mg/mL, diazepam 0.2 mg/mL and insulin 0.5 UI/mL) then stored in the dark at 25°C for up to 96h. Control groups without any device part were also included. At different times, a quantification of the active pharmaceutical ingredient was performed. Additionally, pH measurements were also carried out. All analyses were performed in triplicate.
For both syringes, paracetamol concentrations did not vary throughout the study, for none of the three contact groups (assembled syringes, barrel only, plunger only). Diazepam concentrations decreased when the solutions were in contact with the assembled PP syringes (loss of 34.9 ± 0.46%) after 96 hours of contact, but did not decrease during contact with the COC syringes. When in contact with the Pentaferte® plungers, a loss of 60.8 ± 0.64% was noticed, versus only a 10 ± 0.13 % loss for the Schott® plungers. Insulin concentrations in contact with assembled PP syringes decreased by 11.58 ± 1.35 %, and by 17.07 ± 3.04 % when in contact with the plunger alone. No significant loss of insulin was found with the COC syringes, or individually with the barrels or plungers. The pH increased for all solutions in contact with the Pentaferte® syringe parts, for example by 0.52 ± 0.19, 0.31 ± 0.07 and 0.51 ± 0.01 pH units for respectively paracetamol, diazepam and insulin solutions in contact with the assembled whole syringes. pH variations were even more pronounced for the solutions in contact with just the plunger. This phenomenon was not observed for the solutions in contact with elements of the Schott® syringes or in the control groups.
COC syringes induced less diazepam and insulin sorption than PP syringes. The plunger material seemed to be the main cause this interaction. The alkalinization of medications in contact with PP syringes parts could be caused by leachable compounds, and would need to be further studied.