The Solvent Recovery and Distribution (SRD) area of Pfizer's Kalamazoo API site. Courtesy Pfizer Global Supply The researchers performed a case study on several API production waste streams in Kalamazoo, starting with the recovery of acetonitrile from the synthesis of selamectin (the active in the veterinary drug Revolution). Rowan designed a small-scale distillation, solvent-recovery system, and also evaluated it for recovery of isopropanol (used to manufacture nelfinavir, the active in Viracept) and toluene (used to make hydrocortisone). We spoke with Urbanski to get more feedback on this project and other solvent recovery efforts at Pfizer: PhM: What's particularly challenging about solvent recovery from small-volume waste streams? It's not just a matter of scaling down large-volume practices? F.U.: The bottom line is it depends on whether your existing plant was designed to handle smaller quantities of solvents in an efficient manner.