Stability of drug additives in peritoneal dialysis solutions in a new container

To evaluate the stability of gentamicin, tobramycin, netilmycin, vancomycin, cefazolin, unfractionated heparin, and low molecular weight heparin when added to four different peritoneal dialysis (PD) solutions [Extraneal (Baxter Healthcare, Castlebar, Ireland); Physioneal, Nutrineal, and Dianeal (Baxter Healthcare, Grosotto, Italy)] in new, non-PVC Clear-Flex containers.

Gentamicin, tobramycin, netilmycin, vancomycin, cefazolin, unfractionated heparin, and low molecular weight heparin were injected into separate bags of PD solution. Samples were withdrawn at predefined sampling times and the concentration of each drug was analyzed using high-performance liquid chromatography (for gentamicin, tobramycin, vancomycin, and cefazolin), or bioassay (for netilmycin, gentamicin, and tobramycin in Nutrineal), or coagulation methods (heparins).

Netilmycin, vancomycin, cefazolin, and heparin in Physioneal, Nutrineal, Extraneal, and Dianeal were stable for at least 24 hours at 25 degrees C and for an additional 4 hours at 37 degrees C. Gentamicin in Nutrineal, Extraneal, and Dianeal was stable for at least 24 hours at 25 degrees C and for an additional 4 hours at 37 degrees C; gentamicin in Physioneal was stable for less than 24 hours at 25 degrees C. Tobramycin in Nutrineal and Extraneal was stable for at least 24 hours at 25 degrees C and for an additional 4 hours at 37 degrees C; tobramycin in Physioneal and Dianeal was stable for less than 24 hours at 25 degrees C.