Rhodium and Palladium Metal Scavenging Application Note

This application note presents the findings of a study on the effectiveness of Carboxen® Synthetic Carbons in scavenging rhodium and palladium metals from active pharmaceutical ingredients (APIs). The study was motivated by the ICH-Q3D-R2 guidelines, which mandate a metal scavenging clean-up step for many APIs due to permissible elemental impurity levels. The research compared Carboxen® 564 and Carboxen® 1005 against a leading industry standard, Silica-Thiol, in terms of their ability to reduce metal concentrations. Experimental methods included varying solvents and temperatures to optimize scavenging conditions. Results indicated that Carboxen® 564 significantly reduced palladium levels, outperforming Silica-Thiol, while Carboxen® 1005 was effective for rhodium removal. The study also highlighted that both Carboxen® adsorbents demonstrated low affinity for APIs, resulting in high yields of the tested compounds, PF-06651600 and Valsartan. The findings suggest that Carboxen® materials can be advantageous for pharmaceutical applications requiring metal scavenging.