Chemical and microbiological stability, anticoagulant efficacy and toxicity of 35 and 90 mM trisodium citrate solutions stored in plastic syringes.

Background: Trisodium citrate is an interesting alternative to heparin for the prevention of circuit clotting during extracorporeal procedures, but some protocols require non-commercially available citrate concentrations. Little published information is available about the stability of diluted citrate solutions.

Objectives: To evaluate the long-term stability, efficacy and toxicity of 35 mM and 90 mM trisodium citrate solutions prepared by diluting a commercially available sterile solution, stored in plastic syringes and used as an anticoagulant during citrate bag changes in the coupled plasma filtration adsorption (CPFA) technique in the COMPACT-2 clinical trial.

Methods: The chemical stability of trisodium citrate solutions was evaluated by high-performance liquid chromatography after 7, 14, 21 and 28 days of storage. Sterility tests were performed both immediately after preparation and after 28 days of storage.

Results: After 28 days of storage, the concentration of trisodium citrate had not changed in comparison with day 1, and both solutions passed the sterility test. A preliminary test indicated that a 35 mM solution is insufficient to ensure an effective anticoagulant action on an extracorporeal circuit, but the 90 mM solution was successfully used for 7 CPFA treatments in 2 patients, without clinical signs of toxicity.

Conclusions: Both the 35 mM and 90 mM solutions are chemically and microbiologically stable for 28 days when stored at room temperature in 50 mL syringes protected by light. The 90 mM solution is an effective and safe regional anticoagulant in the CPFA protocol.

Trial Registration Number: NCT01639664.