Study of Physicochemical Stability of Ziconotide in Medication Cassette Reservoir

Objective: To determine the physicochemical stability of ziconotide solutions for intrathecal administration in the Medication Cassette Reservoir (MCR).

Materials and methods: A stability indicating UPLC-DAD method was developed and validated according to the ICH guidelines. Two mixtures of ziconotide (0.40 μg/mL and 0.60 μg/mL) stored in MCR stored at 25 ± 2°C were evaluated for 14 days and compared to the initial observed concentrations.

Results: The physicochemical stability of the two solutions was demonstrated for two days thanks to relative concentrations, pH measurement, visual inspections, and turbidity assays. A degradation product was observed and increased during the study.

Conclusion: This study showed a very low physicochemical stability of diluted ziconotide stored at 25 ± 2°C in the MCR. The intrathecal administration of ziconotide does not seem appropriate with this device for outpatients.