In vitro characterization of sunitinib eluting beads.

Purpose: To load embolization particles (DC-Beads, Biocompatibles, UK) with an anti-angiogenic agent (sunitinib) and to characterize the in vitro properties of the Beads-drug association.Materials: DC Beads of 100-300µm were loaded using a specially designed 10mg/ml sunitinib solution. Loading profile was studied by spectrophotometry of the supernatant solution at 430nm at different time points. Release experiment was performed using the USP method 4 (flow-through cell). Spectrophotometric determination at 430nm was used to measure drug concentration in the eluting solution.Results: We were able to load >98% of the drug in the DC-Beads in 2 hours. The maximum concentration was 20mg sunitinib/ml DC Beads. Loaded Beads gradually released 59% of the loaded drug in the eluting solution, by an ionic exchange mechanism,over 6 hours.Conclusions: DC Beads could be loaded with the multi tyrosine kinase inhibitor sunitinib using a specially designed solution. High drug payload can be achieved. The loaded DC Beads released the drug in an ionic eluting solution with an interesting release profile.