Patient safety has been the main factor and key driver that dictates high performance from metal scavenging products and processes. Johnson Matthey has four of its metal scavengers on file with the US Food and Drug Administration (FDA). Smopex has several benefits, such as carrying out metal recovery at high speed with high efficiency. Moreover, it maximises product purity and yield in fewer steps, according to the firm. "Removal of metal from solution is dependent upon the solution chemistry (metal species, ligands, pH, solvents, other metals, temperature), but with Smopex the reaction is usually fast," Mark Danks, technical specialist at Johnson Matthey Catalysts, told In-PharmaTechnologist.com. "Another benefit is that we can add more cross-linker during the manufacturing process, this increases the thermal stability of the product and enables it's use at up to 200 degrees Celsius - we typically recommend 120-130 degrees Celsius for standard products." API purification can be costly with regards to manufacturing an API but Johnson Matthey believes Smopex can minimise this cost. "Reducing precious metal losses from process waste streams and effluents, and recovering that metal value through precious metal refining, is key as this ensures that the catalyst cost contribution to the process is minimised. This idea of catalyst 'supply and refine' is a philosophy that Johnson Matthey follow - and Smopex can play a major part in that," said Danks. Smopex is made of a non-porous material with its functional groups located on the exterior of the fibre and can be used as a separate purification product. But as metal removal is seldom the only problem, Smopex is more often used as a complementary technology with other purification techniques. Moreover, the technology can be used in both batch and continuous processes, and if the chemistry is right then "anything in the periodic table can be scavenged", according to Johnson Matthey.