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.