Sorption of isosorbide dinitrate to central venous catheters.

As several studies demonstrated the sorption of isosorbide dinitrate (ISDN) to intravenous delivery systems, a study on the sorption of ISDN to several central venous catheters was performed. Fourteen different catheters were perfused during a 2 h period, under simulated infusion conditions, with ISDN (250 micrograms mL-1) in 0.9% (w/v) sodium chloride. The drug loss to a polyethylene and a silicone catheter was 0.2 and 6.1%, respectively. The sorption to a polyvinylchloride heparin-coated thermodilution catheter was 1-6.9% depending on the length of the catheter. The drug loss to polyurethane catheters of different composition varied between 3.8 and 28.9%. For polyurethane catheters composed of cycloaliphatic polyurethanes an inverse relation was shown between Shore A hardness and sorption.